]> Git Repo - VerusCoin.git/commitdiff
Squashed 'src/snark/' content from commit 9ada3f8
authorJack Grigg <[email protected]>
Wed, 2 Aug 2017 10:17:25 +0000 (11:17 +0100)
committerJack Grigg <[email protected]>
Wed, 2 Aug 2017 10:17:25 +0000 (11:17 +0100)
git-subtree-dir: src/snark
git-subtree-split: 9ada3f84ab484c57b2247c2f41091fd6a0916573

123 files changed:
.gitignore [new file with mode: 0644]
AUTHORS [new file with mode: 0644]
LICENSE [new file with mode: 0644]
Makefile [new file with mode: 0644]
README.md [new file with mode: 0644]
doxygen.conf [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_g1.cpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_g1.hpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_g2.cpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_g2.hpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_init.cpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_init.hpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_pairing.cpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_pairing.hpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_pp.cpp [new file with mode: 0644]
src/algebra/curves/alt_bn128/alt_bn128_pp.hpp [new file with mode: 0644]
src/algebra/curves/curve_utils.hpp [new file with mode: 0644]
src/algebra/curves/curve_utils.tcc [new file with mode: 0644]
src/algebra/curves/public_params.hpp [new file with mode: 0644]
src/algebra/curves/tests/test_bilinearity.cpp [new file with mode: 0644]
src/algebra/curves/tests/test_groups.cpp [new file with mode: 0644]
src/algebra/evaluation_domain/domains/basic_radix2_domain.hpp [new file with mode: 0644]
src/algebra/evaluation_domain/domains/basic_radix2_domain.tcc [new file with mode: 0644]
src/algebra/evaluation_domain/domains/basic_radix2_domain_aux.hpp [new file with mode: 0644]
src/algebra/evaluation_domain/domains/basic_radix2_domain_aux.tcc [new file with mode: 0644]
src/algebra/evaluation_domain/evaluation_domain.hpp [new file with mode: 0644]
src/algebra/evaluation_domain/evaluation_domain.tcc [new file with mode: 0644]
src/algebra/exponentiation/exponentiation.hpp [new file with mode: 0644]
src/algebra/exponentiation/exponentiation.tcc [new file with mode: 0644]
src/algebra/fields/bigint.hpp [new file with mode: 0644]
src/algebra/fields/bigint.tcc [new file with mode: 0644]
src/algebra/fields/field_utils.hpp [new file with mode: 0644]
src/algebra/fields/field_utils.tcc [new file with mode: 0644]
src/algebra/fields/fp.hpp [new file with mode: 0644]
src/algebra/fields/fp.tcc [new file with mode: 0644]
src/algebra/fields/fp12_2over3over2.hpp [new file with mode: 0644]
src/algebra/fields/fp12_2over3over2.tcc [new file with mode: 0644]
src/algebra/fields/fp2.hpp [new file with mode: 0644]
src/algebra/fields/fp2.tcc [new file with mode: 0644]
src/algebra/fields/fp3.hpp [new file with mode: 0644]
src/algebra/fields/fp3.tcc [new file with mode: 0644]
src/algebra/fields/fp6_3over2.hpp [new file with mode: 0644]
src/algebra/fields/fp6_3over2.tcc [new file with mode: 0644]
src/algebra/fields/fp_aux.tcc [new file with mode: 0644]
src/algebra/fields/tests/test_bigint.cpp [new file with mode: 0644]
src/algebra/fields/tests/test_fields.cpp [new file with mode: 0644]
src/algebra/knowledge_commitment/knowledge_commitment.hpp [new file with mode: 0644]
src/algebra/knowledge_commitment/knowledge_commitment.tcc [new file with mode: 0644]
src/algebra/scalar_multiplication/kc_multiexp.hpp [new file with mode: 0644]
src/algebra/scalar_multiplication/kc_multiexp.tcc [new file with mode: 0644]
src/algebra/scalar_multiplication/multiexp.hpp [new file with mode: 0644]
src/algebra/scalar_multiplication/multiexp.tcc [new file with mode: 0644]
src/algebra/scalar_multiplication/wnaf.hpp [new file with mode: 0644]
src/algebra/scalar_multiplication/wnaf.tcc [new file with mode: 0644]
src/common/assert_except.hpp [new file with mode: 0644]
src/common/data_structures/accumulation_vector.hpp [new file with mode: 0644]
src/common/data_structures/accumulation_vector.tcc [new file with mode: 0644]
src/common/data_structures/merkle_tree.hpp [new file with mode: 0644]
src/common/data_structures/merkle_tree.tcc [new file with mode: 0644]
src/common/data_structures/sparse_vector.hpp [new file with mode: 0644]
src/common/data_structures/sparse_vector.tcc [new file with mode: 0644]
src/common/default_types/ec_pp.hpp [new file with mode: 0644]
src/common/default_types/r1cs_ppzksnark_pp.hpp [new file with mode: 0644]
src/common/profiling.cpp [new file with mode: 0644]
src/common/profiling.hpp [new file with mode: 0644]
src/common/serialization.hpp [new file with mode: 0644]
src/common/serialization.tcc [new file with mode: 0644]
src/common/template_utils.hpp [new file with mode: 0644]
src/common/utils.cpp [new file with mode: 0644]
src/common/utils.hpp [new file with mode: 0644]
src/common/utils.tcc [new file with mode: 0644]
src/gadgetlib1/constraint_profiling.cpp [new file with mode: 0644]
src/gadgetlib1/constraint_profiling.hpp [new file with mode: 0644]
src/gadgetlib1/examples/simple_example.hpp [new file with mode: 0644]
src/gadgetlib1/examples/simple_example.tcc [new file with mode: 0644]
src/gadgetlib1/gadget.hpp [new file with mode: 0644]
src/gadgetlib1/gadget.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/basic_gadgets.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/basic_gadgets.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/gadget_from_r1cs.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/gadget_from_r1cs.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/digest_selector_gadget.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/digest_selector_gadget.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/hash_io.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/hash_io.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/sha256_aux.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/sha256_aux.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/sha256_components.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/sha256_components.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/sha256_gadget.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/sha256_gadget.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/tests/generate_sha256_gadget_tests.py [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/tests/pypy_sha256.py [new file with mode: 0644]
src/gadgetlib1/gadgets/hashes/sha256/tests/test_sha256_gadget.cpp [new file with mode: 0644]
src/gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.hpp [new file with mode: 0644]
src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.tcc [new file with mode: 0644]
src/gadgetlib1/gadgets/merkle_tree/tests/test_merkle_tree_gadgets.cpp [new file with mode: 0644]
src/gadgetlib1/pb_variable.hpp [new file with mode: 0644]
src/gadgetlib1/pb_variable.tcc [new file with mode: 0644]
src/gadgetlib1/protoboard.hpp [new file with mode: 0644]
src/gadgetlib1/protoboard.tcc [new file with mode: 0644]
src/reductions/r1cs_to_qap/r1cs_to_qap.hpp [new file with mode: 0644]
src/reductions/r1cs_to_qap/r1cs_to_qap.tcc [new file with mode: 0644]
src/relations/arithmetic_programs/qap/qap.hpp [new file with mode: 0644]
src/relations/arithmetic_programs/qap/qap.tcc [new file with mode: 0644]
src/relations/arithmetic_programs/qap/tests/test_qap.cpp [new file with mode: 0644]
src/relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp [new file with mode: 0644]
src/relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.tcc [new file with mode: 0644]
src/relations/constraint_satisfaction_problems/r1cs/r1cs.hpp [new file with mode: 0644]
src/relations/constraint_satisfaction_problems/r1cs/r1cs.tcc [new file with mode: 0644]
src/relations/variable.hpp [new file with mode: 0644]
src/relations/variable.tcc [new file with mode: 0644]
src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.hpp [new file with mode: 0644]
src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.tcc [new file with mode: 0644]
src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark.cpp [new file with mode: 0644]
src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp [new file with mode: 0644]
src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc [new file with mode: 0644]
src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark_params.hpp [new file with mode: 0644]
src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/tests/test_r1cs_ppzksnark.cpp [new file with mode: 0644]

diff --git a/.gitignore b/.gitignore
new file mode 100644 (file)
index 0000000..f6fb450
--- /dev/null
@@ -0,0 +1,49 @@
+*.o
+*.a
+*.so
+*.d
+depinst/
+depsrc/
+README.html
+doxygen/
+src/gadgetlib2/examples/tutorial
+src/gadgetlib2/tests/gadgetlib2_test
+
+src/algebra/curves/tests/test_bilinearity
+src/algebra/curves/tests/test_groups
+src/algebra/fields/tests/test_fields
+src/common/routing_algorithms/profiling/profile_routing_algorithms
+src/common/routing_algorithms/tests/test_routing_algorithms
+src/gadgetlib1/gadgets/cpu_checkers/fooram/examples/test_fooram
+src/gadgetlib1/gadgets/hashes/knapsack/tests/test_knapsack_gadget
+src/gadgetlib1/gadgets/hashes/sha256/tests/test_sha256_gadget
+src/gadgetlib1/gadgets/merkle_tree/tests/test_merkle_tree_gadgets
+src/gadgetlib1/gadgets/routing/profiling/profile_routing_gadgets
+src/gadgetlib1/gadgets/set_commitment/tests/test_set_commitment_gadget
+src/gadgetlib1/gadgets/verifiers/tests/test_r1cs_ppzksnark_verifier_gadget
+src/reductions/ram_to_r1cs/examples/demo_arithmetization
+src/relations/arithmetic_programs/qap/tests/test_qap
+src/relations/arithmetic_programs/ssp/tests/test_ssp
+src/zk_proof_systems/pcd/r1cs_pcd/r1cs_mp_ppzkpcd/profiling/profile_r1cs_mp_ppzkpcd
+src/zk_proof_systems/pcd/r1cs_pcd/r1cs_mp_ppzkpcd/tests/test_r1cs_mp_ppzkpcd
+src/zk_proof_systems/pcd/r1cs_pcd/r1cs_sp_ppzkpcd/profiling/profile_r1cs_sp_ppzkpcd
+src/zk_proof_systems/pcd/r1cs_pcd/r1cs_sp_ppzkpcd/tests/test_r1cs_sp_ppzkpcd
+src/zk_proof_systems/ppzkadsnark/r1cs_ppzkadsnark/examples/demo_r1cs_ppzkadsnark
+src/zk_proof_systems/ppzksnark/bacs_ppzksnark/profiling/profile_bacs_ppzksnark
+src/zk_proof_systems/ppzksnark/bacs_ppzksnark/tests/test_bacs_ppzksnark
+src/zk_proof_systems/ppzksnark/r1cs_gg_ppzksnark/profiling/profile_r1cs_gg_ppzksnark
+src/zk_proof_systems/ppzksnark/r1cs_gg_ppzksnark/tests/test_r1cs_gg_ppzksnark
+src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark
+src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/tests/test_r1cs_ppzksnark
+src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark
+src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark_generator
+src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark_prover
+src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark_verifier
+src/zk_proof_systems/ppzksnark/ram_ppzksnark/profiling/profile_ram_ppzksnark
+src/zk_proof_systems/ppzksnark/ram_ppzksnark/tests/test_ram_ppzksnark
+src/zk_proof_systems/ppzksnark/tbcs_ppzksnark/profiling/profile_tbcs_ppzksnark
+src/zk_proof_systems/ppzksnark/tbcs_ppzksnark/tests/test_tbcs_ppzksnark
+src/zk_proof_systems/ppzksnark/uscs_ppzksnark/profiling/profile_uscs_ppzksnark
+src/zk_proof_systems/ppzksnark/uscs_ppzksnark/tests/test_uscs_ppzksnark
+src/zk_proof_systems/zksnark/ram_zksnark/profiling/profile_ram_zksnark
+src/zk_proof_systems/zksnark/ram_zksnark/tests/test_ram_zksnark
diff --git a/AUTHORS b/AUTHORS
new file mode 100644 (file)
index 0000000..1b2d7a2
--- /dev/null
+++ b/AUTHORS
@@ -0,0 +1,19 @@
+SCIPR Lab:
+    Eli Ben-Sasson
+    Alessandro Chiesa
+    Daniel Genkin
+    Shaul Kfir
+    Eran Tromer
+    Madars Virza
+
+External contributors:
+    Michael Backes
+    Manuel Barbosa
+    Dario Fiore
+    Jens Groth
+    Joshua A. Kroll
+    Shigeo MITSUNARI
+    Raphael Reischuk
+    Tadanori TERUYA
+    Sean Bowe
+    Daira Hopwood
diff --git a/LICENSE b/LICENSE
new file mode 100644 (file)
index 0000000..81cea11
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,24 @@
+The libsnark library is developed by SCIPR Lab (http://scipr-lab.org)
+and contributors.
+
+Copyright (c) 2012-2014 SCIPR Lab and contributors (see AUTHORS file).
+
+All files, with the exceptions below, are released under the MIT License:
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+  THE SOFTWARE.
diff --git a/Makefile b/Makefile
new file mode 100644 (file)
index 0000000..13e54da
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,277 @@
+#********************************************************************************
+# Makefile for the libsnark library.
+#********************************************************************************
+#* @author     This file is part of libsnark, developed by SCIPR Lab
+#*             and contributors (see AUTHORS).
+#* @copyright  MIT license (see LICENSE file)
+#*******************************************************************************/
+
+# To override these, use "make OPTFLAGS=..." etc.
+CURVE = BN128
+OPTFLAGS = -O2 -march=native -mtune=native
+FEATUREFLAGS = -DUSE_ASM -DMONTGOMERY_OUTPUT
+
+# Initialize this using "CXXFLAGS=... make". The makefile appends to that.
+CXXFLAGS += -std=c++11 -Wall -Wextra -Wno-unused-parameter -Wno-comment -Wfatal-errors $(OPTFLAGS) $(FEATUREFLAGS) -DCURVE_$(CURVE)
+
+DEPSRC = depsrc
+DEPINST = depinst
+
+CXXFLAGS += -I$(DEPINST)/include -Isrc
+LDFLAGS += -L$(DEPINST)/lib -Wl,-rpath,$(DEPINST)/lib
+LDLIBS += -lgmpxx -lgmp -lboost_program_options
+# OpenSSL and its dependencies (needed explicitly for static builds):
+LDLIBS += -lcrypto -ldl -lz
+# List of .a files to include within libsnark.a and libsnark.so:
+AR_LIBS =
+# List of library files to install:
+INSTALL_LIBS = $(LIB_FILE)
+# Sentinel file to check existence of this directory (since directories don't work as a Make dependency):
+DEPINST_EXISTS = $(DEPINST)/.exists
+
+
+COMPILE_GTEST :=
+ifneq ($(NO_GTEST),1)
+       GTESTDIR=/usr/src/gtest
+# Compile GTest from sourcecode if we can (e.g., Ubuntu). Otherwise use precompiled one (e.g., Fedora).
+# See https://code.google.com/p/googletest/wiki/FAQ#Why_is_it_not_recommended_to_install_a_pre-compiled_copy_of_Goog .
+       COMPILE_GTEST :=$(shell test -d $(GTESTDIR) && echo -n 1)
+       GTEST_LDLIBS += -lgtest -lpthread
+endif
+
+ifneq ($(NO_SUPERCOP),1)
+       SUPERCOP_LDLIBS += -lsupercop
+       INSTALL_LIBS += depinst/lib/libsupercop.a
+       # Would have been nicer to roll supercop into libsnark.a ("AR_LIBS += $(DEPINST)/lib/libsupercop.a"), but it doesn't support position-independent code (libsnark issue #20).
+endif
+
+LIB_SRCS = \
+       src/algebra/curves/alt_bn128/alt_bn128_g1.cpp \
+       src/algebra/curves/alt_bn128/alt_bn128_g2.cpp \
+       src/algebra/curves/alt_bn128/alt_bn128_init.cpp \
+       src/algebra/curves/alt_bn128/alt_bn128_pairing.cpp \
+       src/algebra/curves/alt_bn128/alt_bn128_pp.cpp \
+       src/common/profiling.cpp \
+       src/common/utils.cpp \
+       src/gadgetlib1/constraint_profiling.cpp \
+
+ifeq ($(CURVE),BN128)
+       LIB_SRCS += \
+               src/algebra/curves/bn128/bn128_g1.cpp \
+               src/algebra/curves/bn128/bn128_g2.cpp \
+               src/algebra/curves/bn128/bn128_gt.cpp \
+               src/algebra/curves/bn128/bn128_init.cpp \
+               src/algebra/curves/bn128/bn128_pairing.cpp \
+               src/algebra/curves/bn128/bn128_pp.cpp
+
+       CXXFLAGS += -DBN_SUPPORT_SNARK
+       AR_LIBS += $(DEPINST)/lib/libzm.a
+endif
+
+# FIXME: most of these are broken due to removed code.
+DISABLED_EXECUTABLES = \
+       src/algebra/curves/tests/test_bilinearity \
+       src/algebra/curves/tests/test_groups \
+       src/algebra/fields/tests/test_fields \
+       src/common/routing_algorithms/profiling/profile_routing_algorithms \
+       src/common/routing_algorithms/tests/test_routing_algorithms \
+       src/gadgetlib1/gadgets/cpu_checkers/fooram/examples/test_fooram \
+       src/gadgetlib1/gadgets/hashes/knapsack/tests/test_knapsack_gadget \
+       src/gadgetlib1/gadgets/hashes/sha256/tests/test_sha256_gadget \
+       src/gadgetlib1/gadgets/merkle_tree/tests/test_merkle_tree_gadgets \
+       src/gadgetlib1/gadgets/routing/profiling/profile_routing_gadgets \
+       src/gadgetlib1/gadgets/set_commitment/tests/test_set_commitment_gadget \
+       src/gadgetlib1/gadgets/verifiers/tests/test_r1cs_ppzksnark_verifier_gadget \
+       src/reductions/ram_to_r1cs/examples/demo_arithmetization \
+       src/relations/arithmetic_programs/qap/tests/test_qap \
+       src/relations/arithmetic_programs/ssp/tests/test_ssp \
+       src/zk_proof_systems/pcd/r1cs_pcd/r1cs_mp_ppzkpcd/profiling/profile_r1cs_mp_ppzkpcd \
+       src/zk_proof_systems/pcd/r1cs_pcd/r1cs_mp_ppzkpcd/tests/test_r1cs_mp_ppzkpcd \
+       src/zk_proof_systems/pcd/r1cs_pcd/r1cs_sp_ppzkpcd/profiling/profile_r1cs_sp_ppzkpcd \
+       src/zk_proof_systems/pcd/r1cs_pcd/r1cs_sp_ppzkpcd/tests/test_r1cs_sp_ppzkpcd \
+       src/zk_proof_systems/ppzksnark/bacs_ppzksnark/profiling/profile_bacs_ppzksnark \
+       src/zk_proof_systems/ppzksnark/bacs_ppzksnark/tests/test_bacs_ppzksnark \
+       src/zk_proof_systems/ppzksnark/r1cs_gg_ppzksnark/profiling/profile_r1cs_gg_ppzksnark \
+       src/zk_proof_systems/ppzksnark/r1cs_gg_ppzksnark/tests/test_r1cs_gg_ppzksnark \
+       src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark \
+       src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/tests/test_r1cs_ppzksnark \
+       src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark \
+       src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark_generator \
+       src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark_prover \
+       src/zk_proof_systems/ppzksnark/ram_ppzksnark/examples/demo_ram_ppzksnark_verifier \
+       src/zk_proof_systems/ppzksnark/ram_ppzksnark/profiling/profile_ram_ppzksnark \
+       src/zk_proof_systems/ppzksnark/ram_ppzksnark/tests/test_ram_ppzksnark \
+       src/zk_proof_systems/ppzksnark/tbcs_ppzksnark/profiling/profile_tbcs_ppzksnark \
+       src/zk_proof_systems/ppzksnark/tbcs_ppzksnark/tests/test_tbcs_ppzksnark \
+       src/zk_proof_systems/ppzksnark/uscs_ppzksnark/profiling/profile_uscs_ppzksnark \
+       src/zk_proof_systems/ppzksnark/uscs_ppzksnark/tests/test_uscs_ppzksnark \
+       src/zk_proof_systems/zksnark/ram_zksnark/profiling/profile_ram_zksnark \
+       src/zk_proof_systems/zksnark/ram_zksnark/tests/test_ram_zksnark
+
+EXECUTABLES = \
+       src/algebra/fields/tests/test_bigint
+
+EXECUTABLES_WITH_GTEST = \
+       src/gadgetlib2/examples/tutorial \
+       src/gadgetlib2/tests/gadgetlib2_test
+
+EXECUTABLES_WITH_SUPERCOP = \
+       src/zk_proof_systems/ppzkadsnark/r1cs_ppzkadsnark/examples/demo_r1cs_ppzkadsnark
+
+DOCS = README.html
+
+LIBSNARK_A = libsnark.a
+
+# For documentation of the following options, see README.md .
+
+ifeq ($(NO_PROCPS),1)
+       CXXFLAGS += -DNO_PROCPS
+else
+       LDLIBS += -lprocps
+endif
+
+ifeq ($(LOWMEM),1)
+       CXXFLAGS += -DLOWMEM
+endif
+
+ifeq ($(PROFILE_OP_COUNTS),1)
+       STATIC = 1
+       CXXFLAGS += -DPROFILE_OP_COUNTS
+endif
+
+ifeq ($(STATIC),1)
+       CXXFLAGS += -static -DSTATIC
+else
+       CXXFLAGS += -fPIC
+endif
+
+ifeq ($(MULTICORE),1)
+       CXXFLAGS += -DMULTICORE -fopenmp
+endif
+
+ifeq ($(CPPDEBUG),1)
+        CXXFLAGS += -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC
+        DEBUG = 1
+endif
+
+ifeq ($(DEBUG),1)
+        CXXFLAGS += -DDEBUG -ggdb3
+endif
+
+ifeq ($(PERFORMANCE),1)
+        OPTFLAGS = -O3 -march=native -mtune=native
+        CXXFLAGS += -DNDEBUG
+        # Enable link-time optimization:
+        CXXFLAGS += -flto -fuse-linker-plugin
+        LDFLAGS += -flto
+endif
+
+LIB_OBJS  =$(patsubst %.cpp,%.o,$(LIB_SRCS))
+EXEC_OBJS =$(patsubst %,%.o,$(EXECUTABLES) $(EXECUTABLES_WITH_GTEST) $(EXECUTABLES_WITH_SUPERCOP))
+
+all: \
+     $(if $(NO_GTEST),,$(EXECUTABLES_WITH_GTEST)) \
+     $(if $(NO_SUPERCOP),,$(EXECUTABLES_WITH_SUPERCOP)) \
+     $(EXECUTABLES) \
+     $(if $(NO_DOCS),,doc)
+
+doc: $(DOCS)
+
+$(DEPINST_EXISTS):
+       # Create placeholder directories for installed dependencies. Some make settings (including the default) require actually running ./prepare-depends.sh to populate this directory.
+       mkdir -p $(DEPINST)/lib $(DEPINST)/include
+       touch $@
+
+# In order to detect changes to #include dependencies. -MMD below generates a .d file for each .o file. Include the .d file.
+-include $(patsubst %.o,%.d, $(LIB_OBJS) $(EXEC_OBJS) )
+
+$(LIB_OBJS) $(EXEC_OBJS): %.o: %.cpp
+       $(CXX) -o $@   $< -c -MMD $(CXXFLAGS)
+
+LIBGTEST_A = $(DEPINST)/lib/libgtest.a
+
+$(LIBGTEST_A): $(GTESTDIR)/src/gtest-all.cc $(DEPINST_EXISTS)
+       $(CXX) -o $(DEPINST)/lib/gtest-all.o   -I $(GTESTDIR) -c -isystem $(GTESTDIR)/include $< $(CXXFLAGS)
+       $(AR) -rv $(LIBGTEST_A) $(DEPINST)/lib/gtest-all.o
+
+# libsnark.a will contains all of our relevant object files, and we also mash in the .a files of relevant dependencies built by ./prepare-depends.sh
+$(LIBSNARK_A): $(LIB_OBJS) $(AR_LIBS)
+       ( \
+         echo "create $(LIBSNARK_A)"; \
+         echo "addmod $(LIB_OBJS)"; \
+         if [ -n "$(AR_LIBS)" ]; then for AR_LIB in $(AR_LIBS); do echo addlib $$AR_LIB; done; fi; \
+         echo "save"; \
+         echo "end"; \
+       ) | $(AR) -M
+       $(AR) s $(LIBSNARK_A)
+
+libsnark.so: $(LIBSNARK_A) $(DEPINST_EXISTS)
+       $(CXX) -o $@   --shared -Wl,--whole-archive $(LIBSNARK_A) $(CXXFLAGS) $(LDFLAGS) -Wl,--no-whole-archive $(LDLIBS)
+
+src/gadgetlib2/tests/gadgetlib2_test: \
+       src/gadgetlib2/tests/adapters_UTEST.cpp \
+       src/gadgetlib2/tests/constraint_UTEST.cpp \
+       src/gadgetlib2/tests/gadget_UTEST.cpp \
+       src/gadgetlib2/tests/integration_UTEST.cpp \
+       src/gadgetlib2/tests/protoboard_UTEST.cpp \
+       src/gadgetlib2/tests/variable_UTEST.cpp
+
+$(EXECUTABLES): %: %.o $(LIBSNARK_A) $(DEPINST_EXISTS)
+       $(CXX) -o $@   [email protected] $(LIBSNARK_A) $(CXXFLAGS) $(LDFLAGS) $(LDLIBS)
+
+$(EXECUTABLES_WITH_GTEST): %: %.o $(LIBSNARK_A) $(if $(COMPILE_GTEST),$(LIBGTEST_A)) $(DEPINST_EXISTS)
+       $(CXX) -o $@   [email protected] $(LIBSNARK_A) $(CXXFLAGS) $(LDFLAGS) $(GTEST_LDLIBS) $(LDLIBS)
+
+$(EXECUTABLES_WITH_SUPERCOP): %: %.o $(LIBSNARK_A) $(DEPINST_EXISTS)
+       $(CXX) -o $@   [email protected] $(LIBSNARK_A) $(CXXFLAGS) $(LDFLAGS) $(SUPERCOP_LDLIBS) $(LDLIBS)
+
+
+ifeq ($(STATIC),1)
+LIB_FILE = $(LIBSNARK_A)
+else
+LIB_FILE = libsnark.so
+endif
+
+lib: $(LIB_FILE)
+
+$(DOCS): %.html: %.md
+       markdown_py -f $@ $^ -x toc -x extra --noisy
+#      TODO: Would be nice to enable "-x smartypants" but Ubuntu 12.04 doesn't support that.
+#      TODO: switch to redcarpet, to produce same output as GitHub's processing of README.md. But what about TOC?
+
+ifeq ($(PREFIX),)
+install:
+       $(error Please provide PREFIX. E.g. make install PREFIX=/usr)
+else
+HEADERS_SRC=$(shell find src -name '*.hpp' -o -name '*.tcc')
+HEADERS_DEST=$(patsubst src/%,$(PREFIX)/include/libsnark/%,$(HEADERS_SRC))
+
+$(HEADERS_DEST): $(PREFIX)/include/libsnark/%: src/%
+       mkdir -p $(shell dirname $@)
+       cp $< $@
+
+install: $(INSTALL_LIBS) $(HEADERS_DEST) $(DEPINST_EXISTS)
+       mkdir -p $(PREFIX)/lib
+       cp -v $(INSTALL_LIBS) $(PREFIX)/lib/
+       cp -rv $(DEPINST)/include $(PREFIX)
+endif
+
+doxy:
+       doxygen doxygen.conf
+
+# Clean generated files, except locally-compiled dependencies
+clean:
+       $(RM) \
+               $(LIB_OBJS) $(EXEC_OBJS) \
+               $(EXECUTABLES) $(EXECUTABLES_WITH_GTEST) $(EXECUTABLES_WITH_SUPERCOP) \
+               $(DOCS) \
+               ${patsubst %.o,%.d,${LIB_OBJS} ${EXEC_OBJS}} \
+               libsnark.so $(LIBSNARK_A) \
+       $(RM) -fr doxygen/ \
+       $(RM) $(LIBGTEST_A) $(DEPINST)/lib/gtest-all.o
+
+# Clean all, including locally-compiled dependencies
+clean-all: clean
+       $(RM) -fr $(DEPSRC) $(DEPINST)
+
+.PHONY: all clean clean-all doc doxy lib install
diff --git a/README.md b/README.md
new file mode 100644 (file)
index 0000000..d5aa340
--- /dev/null
+++ b/README.md
@@ -0,0 +1,628 @@
+libsnark: a C++ library for zkSNARK proofs
+================================================================================
+
+--------------------------------------------------------------------------------
+Authors
+--------------------------------------------------------------------------------
+
+The libsnark library is developed by the [SCIPR Lab] project and contributors
+and is released under the MIT License (see the [LICENSE] file).
+
+Copyright (c) 2012-2014 SCIPR Lab and contributors (see [AUTHORS] file).
+
+--------------------------------------------------------------------------------
+[TOC]
+
+<!---
+  NOTE: the file you are reading is in Markdown format, which is is fairly readable
+  directly, but can be converted into an HTML file with much nicer formatting.
+  To do so, run "make doc" (this requires the python-markdown package) and view
+  the resulting file README.html. Alternatively, view the latest HTML version at
+  https://github.com/scipr-lab/libsnark .
+-->
+
+--------------------------------------------------------------------------------
+Overview
+--------------------------------------------------------------------------------
+
+This library implements __zkSNARK__ schemes, which are a cryptographic method
+for proving/verifying, in zero knowledge, the integrity of computations.
+
+A computation can be expressed as an NP statement, in forms such as the following:
+
+- "The C program _foo_, when executed, returns exit code 0 if given the input _bar_ and some additional input _qux_."
+- "The Boolean circuit _foo_ is satisfiable by some input _qux_."
+- "The arithmetic circuit _foo_ accepts the partial assignment _bar_, when extended into some full assignment _qux_."
+- "The set of constraints _foo_ is satisfiable by the partial assignment _bar_, when extended into some full assignment _qux_."
+
+A prover who knows the witness for the NP statement (i.e., a satisfying input/assignment) can produce a short proof attesting to the truth of the NP statement. This proof can be verified by anyone, and offers the following properties.
+
+-   __Zero knowledge:__
+    the verifier learns nothing from the proof beside the truth of the statement (i.e., the value _qux_, in the above examples, remains secret).
+-   __Succinctness:__
+    the proof is short and easy to verify.
+-   __Non-interactivity:__
+    the proof is a string (i.e. it does not require back-and-forth interaction between the prover and the verifier).
+-   __Soundness:__
+    the proof is computationally sound (i.e., it is infeasible to fake a proof of a false NP statement). Such a proof system is also called an _argument_.
+-   __Proof of knowledge:__
+    the proof attests not just that the NP statement is true, but also that the
+    prover knows why (e.g., knows a valid _qux_).
+
+These properties are summarized by the _zkSNARK_ acronym, which stands for _Zero-Knowledge Succinct Non-interactive ARgument of Knowledge_ (though zkSNARKs are also knows as
+_succinct non-interactive computationally-sound zero-knowledge proofs of knowledge_).
+For formal definitions and theoretical discussions about these, see
+\[BCCT12], \[BCIOP13], and the references therein.
+
+The libsnark library currently provides a C++ implementation of:
+
+1.  General-purpose proof systems:
+    1.  A preprocessing zkSNARK for the NP-complete language "R1CS"
+        (_Rank-1 Constraint Systems_), which is a language that is similar to arithmetic
+        circuit satisfiability.
+    2. A preprocessing SNARK for a language of arithmetic circuits, "BACS"
+       (_Bilinear Arithmetic Circuit Satisfiability_). This simplifies the writing
+       of NP statements when the additional flexibility of R1CS is not needed.
+       Internally, it reduces to R1CS.
+    3. A preprocessing SNARK for the language "USCS"
+       (_Unitary-Square Constraint Systems_). This abstracts and implements the core
+       contribution of \[DFGK14]
+    4. A preprocessing SNARK for a language of Boolean circuits, "TBCS"
+       (_Two-input Boolean Circuit Satisfiability_). Internally, it reduces to USCS.
+       This is much more  efficient than going through R1CS.
+    5. ADSNARK, a preprocessing SNARKs for proving statements on authenticated
+       data, as described in \[BBFR15].
+    6. Proof-Carrying Data (PCD). This uses recursive composition of SNARKs, as
+       explained in \[BCCT13] and optimized in \[BCTV14b].
+2.  Gadget libraries (gadgetlib1 and gadgetlib2) for constructing R1CS
+    instances out of modular "gadget" classes.
+3.  Examples of applications that use the above proof systems to prove
+    statements about:
+    1. Several toy examples.
+    2. Execution of TinyRAM machine code, as explained in \[BCTV14a] and
+       \[BCGTV13]. (Such machine code can be obtained, e.g., by compiling from C.)
+       This is easily adapted to any other Random Access Machine that satisfies a
+       simple load-store interface.
+    3. A scalable for TinyRAM using Proof-Carrying Data, as explained in \[BCTV14b]
+    4. Zero-knowldge cluster MapReduce, as explained in \[CTV15].
+
+The zkSNARK construction implemented by libsnark follows, extends, and
+optimizes the approach described in \[BCTV14], itself an extension of
+\[BCGTV13], following the approach of \[BCIOP13] and \[GGPR13]. An alternative
+implementation of the basic approach is the _Pinocchio_ system of \[PGHR13].
+See these references for discussions of efficiency aspects that arise in
+practical use of such constructions, as well as security and trust
+considerations.
+
+This scheme is a _preprocessing zkSNARK_ (_ppzkSNARK_): before proofs can be
+created and verified, one needs to first decide on a size/circuit/system
+representing the NP statements to be proved, and run a _generator_ algorithm to
+create corresponding public parameters (a long proving key and a short
+verification key).
+
+Using the library involves the following high-level steps:
+
+1.  Express the statements to be proved as an R1CS (or any of the other
+    languages above, such as arithmetic circuits, Boolean circuits, or TinyRAM).
+    This is done by writing C++ code that constructs an R1CS, and linking this code
+    together with libsnark
+2.  Use libsnark's generator algorithm to create the public parameters for this
+    statement (once and for all).
+3.  Use libsnark's prover algorithm to create proofs of true statements about
+    the satisfiability of the R1CS.
+4.  Use libsnark's verifier algorithm to check proofs for alleged statements.
+
+
+--------------------------------------------------------------------------------
+The NP-complete language R1CS
+--------------------------------------------------------------------------------
+
+The ppzkSNARK supports proving/verifying membership in a specific NP-complete
+language: R1CS (*rank-1 constraint systems*). An instance of the language is
+specified by a set of equations over a prime field F, and each equation looks like:
+                   < A, (1,X) > * < B , (1,X) > = < C, (1,X) >
+where A,B,C are vectors over F, and X is a vector of variables.
+
+In particular, arithmetic (as well as boolean) circuits are easily reducible to
+this language by converting each gate into a rank-1 constraint. See \[BCGTV13]
+Appendix E (and "System of Rank 1 Quadratic Equations") for more details about this.
+
+
+--------------------------------------------------------------------------------
+Elliptic curve choices
+--------------------------------------------------------------------------------
+
+The ppzkSNARK can be instantiated with different parameter choices, depending on
+which elliptic curve is used. The libsnark library currently provides three
+options:
+
+* "edwards":
+   an instantiation based on an Edwards curve, providing 80 bits of security.
+
+* "bn128":
+   an instantiation based on a Barreto-Naehrig curve, providing 128
+   bits of security. The underlying curve implementation is
+   \[ate-pairing], which has incorporated our patch that changes the
+   BN curve to one suitable for SNARK applications.
+
+    *   This implementation uses dynamically-generated machine code for the curve
+        arithmetic. Some modern systems disallow execution of code on the heap, and
+        will thus block this implementation.
+
+        For example, on Fedora 20 at its default settings, you will get the error
+        `zmInit ERR:can't protect` when running this code. To solve this,
+        run `sudo setsebool -P allow_execheap 1` to allow execution,
+        or use `make CURVE=ALT_BN128` instead.
+
+* "alt_bn128":
+   an alternative to "bn128", somewhat slower but avoids dynamic code generation.
+
+Note that bn128 requires an x86-64 CPU while the other curve choices
+should be architecture-independent; see [portability](#portability).
+
+
+--------------------------------------------------------------------------------
+Gadget libraries
+--------------------------------------------------------------------------------
+
+The libsnark library currently provides two libraries for conveniently constructing
+R1CS instances out of reusable "gadgets". Both libraries provide a way to construct
+gadgets on other gadgets as well as additional explicit equations. In this way,
+complex R1CS instances can be built bottom up.
+
+### gadgetlib1
+
+This is a low-level library which expose all features of the preprocessing
+zkSNARK for R1CS. Its design is based on templates (as does the ppzkSNARK code)
+to efficiently support working on multiple elliptic curves simultaneously. This
+library is used for most of the constraint-building in libsnark, both internal
+(reductions and Proof-Carrying Data) and examples applications.
+
+### gadgetlib2
+
+This is an alternative library for constructing systems of polynomial equations
+and, in particular, also R1CS instances. It is better documented and easier to
+use than gadgetlib1, and its interface does not use templates. However, fewer
+useful gadgets are provided.
+
+
+--------------------------------------------------------------------------------
+Security
+--------------------------------------------------------------------------------
+
+The theoretical security of the underlying mathematical constructions, and the
+requisite assumptions, are analyzed in detailed in the aforementioned research
+papers.
+
+**
+This code is a research-quality proof of concept, and has not
+yet undergone extensive review or testing. It is thus not suitable,
+as is, for use in critical or production systems.
+**
+
+Known issues include the following:
+
+* The ppzkSNARK's generator and prover exhibit data-dependent running times
+  and memory usage. These form timing and cache-contention side channels,
+  which may be an issue in some applications.
+
+* Randomness is retrieved from /dev/urandom, but this should be
+  changed to a carefully considered (depending on system and threat
+  model) external, high-quality randomness source when creating
+  long-term proving/verification keys.
+
+
+--------------------------------------------------------------------------------
+Build instructions
+--------------------------------------------------------------------------------
+
+The libsnark library relies on the following:
+
+- C++ build environment
+- GMP for certain bit-integer arithmetic
+- libprocps for reporting memory usage
+- GTest for some of the unit tests
+
+So far we have tested these only on Linux, though we have been able to make the library work,
+with some features disabled (such as memory profiling or GTest tests), on Windows via Cygwin
+and on Mac OS X. (If you succeed in achieving more complete ports of the library, please
+let us know!) See also the notes on [portability](#portability) below.
+
+For example, on a fresh install of Ubuntu 14.04, install the following packages:
+
+    $ sudo apt-get install build-essential git libgmp3-dev libprocps3-dev libgtest-dev python-markdown libboost-all-dev libssl-dev
+
+Or, on Fedora 20:
+
+    $ sudo yum install gcc-c++ make git gmp-devel procps-ng-devel gtest-devel python-markdown
+
+Run the following, to fetch dependencies from their GitHub repos and compile them.
+(Not required if you set `CURVE` to other than the default `BN128` and also set `NO_SUPERCOP=1`.)
+
+    $ ./prepare-depends.sh
+
+Then, to compile the library, tests, profiling harness and documentation, run:
+
+    $ make
+
+To create just the HTML documentation, run
+
+    $ make doc
+
+and then view the resulting `README.html` (which contains the very text you are reading now).
+
+To create Doxygen documentation summarizing all files, classes and functions,
+with some (currently sparse) comments, install the `doxygen` and `graphviz` packages, then run
+
+    $ make doxy
+
+(this may take a few minutes). Then view the resulting [`doxygen/index.html`](doxygen/index.html).
+
+### Using libsnark as a library
+
+To develop an application that uses libsnark, you could add it within the libsnark directory tree and adjust the Makefile, but it is far better to build libsnark as a (shared or static) library. You can then write your code in a separate directory tree, and link it against libsnark.
+
+
+To build just the shared object library `libsnark.so`, run:
+
+    $ make lib
+
+To build just the static library `libsnark.a`, run:
+
+    $ make lib STATIC=1
+
+Note that static compilation requires static versions of all libraries it depends on.
+It may help to minize these dependencies by appending
+`CURVE=ALT_BN128 NO_PROCPS=1 NO_GTEST=1 NO_SUPERCOP=1`. On Fedora 21, the requisite 
+library RPM dependencies are then: 
+`boost-static glibc-static gmp-static libstdc++-static openssl-static zlib-static
+ boost-devel glibc-devel gmp-devel gmp-devel libstdc++-devel openssl-devel openssl-devel`.
+
+To build *and install* the libsnark library:
+
+    $ make install PREFIX=/install/path
+
+This will install `libsnark.so` into `/install/path/lib`; so your application should be linked using `-L/install/path/lib -lsnark`. It also installs the requisite headers into `/install/path/include`; so your application should be compiled using `-I/install/path/include`.
+
+In addition, unless you use `NO_SUPERCOP=1`, `libsupercop.a` will be installed and should be linked in using `-lsupercop`.
+
+
+### Building on Windows using Cygwin
+Install Cygwin using the graphical installer, including the `g++`, `libgmp`
+and `git` packages. Then disable the dependencies not easily supported under CygWin,
+using:
+
+    $ make NO_PROCPS=1 NO_GTEST=1 NO_DOCS=1
+
+
+### Building on Mac OS X
+
+On Mac OS X, install GMP from MacPorts (`port install gmp`). Then disable the
+dependencies not easily supported under CygWin, using:
+
+    $ make NO_PROCPS=1 NO_GTEST=1 NO_DOCS=1
+
+MacPorts does not write its libraries into standard system folders, so you
+might need to explicitly provide the paths to the header files and libraries by
+appending `CXXFLAGS=-I/opt/local/include LDFLAGS=-L/opt/local/lib` to the line
+above. Similarly, to pass the paths to ate-pairing you would run
+`INC_DIR=-I/opt/local/include LIB_DIR=-L/opt/local/lib ./prepare-depends.sh`
+instead of `./prepare-depends.sh` above.
+
+--------------------------------------------------------------------------------
+Tutorials
+--------------------------------------------------------------------------------
+
+libsnark includes a tutorial, and some usage examples, for the high-level API.
+
+* `src/gadgetlib1/examples1` contains a simple example for constructing a
+  constraint system using gadgetlib1.
+
+* `src/gadgetlib2/examples` contains a tutorial for using gadgetlib2 to express
+  NP statements as constraint systems. It introduces basic terminology, design
+  overview, and recommended programming style. It also shows how to invoke
+  ppzkSNARKs on such constraint systems. The main file, `tutorial.cpp`, builds
+  into a standalone executable.
+
+* `src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark.cpp`
+  constructs a simple constraint system and runs the ppzksnark. See below for how to
+   run it.
+
+
+--------------------------------------------------------------------------------
+Executing profiling example
+--------------------------------------------------------------------------------
+
+The command
+
+     $ src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark 1000 10 Fr
+
+exercises the ppzkSNARK (first generator, then prover, then verifier) on an
+R1CS instance with 1000 equations and an input consisting of 10 field elements.
+
+(If you get the error `zmInit ERR:can't protect`, see the discussion
+[above](#elliptic-curve-choices).)
+
+The command
+
+     $ src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark 1000 10 bytes
+
+does the same but now the input consists of 10 bytes.
+
+
+--------------------------------------------------------------------------------
+Build options
+--------------------------------------------------------------------------------
+
+The following flags change the behavior of the compiled code.
+
+*    `make FEATUREFLAGS='-Dname1 -Dname2 ...'`
+
+     Override the active conditional #define names (you can see the default at the top of the Makefile).
+     The next bullets list the most important conditionally-#defined features.
+     For example, `make FEATUREFLAGS='-DBINARY_OUTPUT'` enables binary output and disables the default
+     assembly optimizations and Montgomery-representation output.
+
+*    define `BINARY_OUTPUT`
+
+     In serialization, output raw binary data (instead of decimal, when not set).
+
+*   `make CURVE=choice` / define `CURVE_choice` (where `choice` is one of: 
+     ALT_BN128, BN128, EDWARDS, MNT4, MNT6)
+
+     Set the default curve to one of the above (see [elliptic curve choices](#elliptic-curve-choices)).
+
+*   `make DEBUG=1` / define `DEBUG`
+
+    Print additional information for debugging purposes.
+
+*   `make LOWMEM=1` / define `LOWMEM`
+
+    Limit the size of multi-exponentiation tables, for low-memory platforms.
+
+*   `make NO_DOCS=1`
+
+     Do not generate HTML documentation, e.g. on platforms where Markdown is not easily available.
+
+*   `make NO_PROCPS=1`
+
+     Do not link against libprocps. This disables memory profiling.
+
+*   `make NO_GTEST=1`
+
+     Do not link against GTest. The tutorial and test suite of gadgetlib2 tutorial won't be compiled.
+
+*   `make NO_SUPERCOP=1`
+
+     Do not link against SUPERCOP for optimized crypto. The ADSNARK executables will not be built.
+
+*   `make MULTICORE=1`
+
+     Enable parallelized execution of the ppzkSNARK generator and prover, using OpenMP.
+     This will utilize all cores on the CPU for heavyweight parallelizabe operations such as
+     FFT and multiexponentiation. The default is single-core.
+
+     To override the maximum number of cores used, set the environment variable `OMP_NUM_THREADS`
+     at runtime (not compile time), e.g., `OMP_NUM_THREADS=8 test_r1cs_sp_ppzkpc`. It defaults
+     to the autodetected number of cores, but on some devices, dynamic core management confused
+     OpenMP's autodetection, so setting `OMP_NUM_THREADS` is necessary for full utilization.
+
+*   define `NO_PT_COMPRESSION`
+
+    Do not use point compression.
+    This gives much faster serialization times, at the expense of ~2x larger
+    sizes for serialized keys and proofs.
+
+*   define `MONTGOMERY_OUTPUT` (on by default)
+
+    Serialize Fp elements as their Montgomery representations. If this
+    option is disabled then Fp elements are serialized as their
+    equivalence classes, which is slower but produces human-readable
+    output.
+
+*   `make PROFILE_OP_COUNTS=1` / define `PROFILE_OP_COUNTS`
+
+    Collect counts for field and curve operations inside static variables
+    of the corresponding algebraic objects. This option works for all
+    curves except bn128.
+
+*   define `USE_ASM` (on by default)
+
+    Use unrolled assembly routines for F[p] arithmetic and faster heap in
+    multi-exponentiation. (When not set, use GMP's `mpn_*` routines instead.)
+
+*   define `USE_MIXED_ADDITION`
+
+    Convert each element of the proving key and verification key to
+    affine coordinates. This allows using mixed addition formulas in
+    multiexponentiation and results in slightly faster prover and
+    verifier runtime at expense of increased proving time.
+
+*   `make PERFORMANCE=1`
+
+    Enables compiler optimizations such as link-time optimization, and disables debugging aids.
+    (On some distributions this causes a `plugin needed to handle lto object` link error and `undefined reference`s, which can be remedied by `AR=gcc-ar make ...`.)
+
+Not all combinations are tested together or supported by every part of the codebase.
+
+
+--------------------------------------------------------------------------------
+Portability
+--------------------------------------------------------------------------------
+
+libsnark is written in fairly standard C++11.
+
+However, having been developed on Linux on x86-64 CPUs, libsnark has some limitations
+with respect to portability. Specifically:
+
+1. libsnark's algebraic data structures assume little-endian byte order.
+
+2. Profiling routines use `clock_gettime` and `readproc` calls, which are Linux-specific.
+
+3. Random-number generation is done by reading from `/dev/urandom`, which is
+   specific to Unix-like systems.
+
+4. libsnark binary serialization routines (see `BINARY_OUTPUT` above) assume
+   a fixed machine word size (i.e. sizeof(mp_limb_t) for GMP's limb data type).
+   Objects serialized in binary on a 64-bit system cannot be de-serialized on
+   a 32-bit system, and vice versa.
+   (The decimal serialization routines have no such limitation.)
+
+5. libsnark requires a C++ compiler with good C++11 support. It has been
+   tested with g++ 4.7, g++ 4.8, and clang 3.4.
+
+6. On x86-64, we by default use highly optimized assembly implementations for some
+   operations (see `USE_ASM` above). On other architectures we fall back to a
+   portable C++ implementation, which is slower.
+
+Tested configurations include:
+
+* Debian jessie with g++ 4.7 on x86-64
+* Debian jessie with clang 3.4 on x86-64
+* Fedora 20/21 with g++ 4.8.2/4.9.2 on x86-64 and i686
+* Ubuntu 14.04 LTS with g++ 4.8 on x86-64
+* Ubuntu 14.04 LTS with g++ 4.8 on x86-32, for EDWARDS and ALT_BN128 curve choices
+* Debian wheezy with g++ 4.7 on ARM little endian (Debian armel port) inside QEMU, for EDWARDS and ALT_BN128 curve choices
+* Windows 7 with g++ 4.8.3 under Cygwin 1.7.30 on x86-64 with NO_PROCPS=1, NO_GTEST=1 and NO_DOCS=1, for EDWARDS and ALT_BN128 curve choices
+* Mac OS X 10.9.4 (Mavericks) with Apple LLVM version 5.1 (based on LLVM 3.4svn) on x86-64 with NO_PROCPS=1, NO_GTEST=1 and NO_DOCS=1
+
+
+--------------------------------------------------------------------------------
+Directory structure
+--------------------------------------------------------------------------------
+
+The directory structure of the libsnark library is as follows:
+
+* src/ --- main C++ source code, containing the following modules:
+    * algebra/ --- fields and elliptic curve groups
+    * common/ --- miscellaneous utilities
+    * gadgetlib1/ --- gadgetlib1, a library to construct R1CS instances
+        * gadgets/ --- basic gadgets for gadgetlib1
+    * gadgetlib2/ --- gadgetlib2, a library to construct R1CS instances
+    * qap/ --- quadratic arithmetic program
+        * domains/ --- support for fast interpolation/evaluation, by providing
+          FFTs and Lagrange-coefficient computations for various domains
+    * relations/ --- interfaces for expressing statement (relations between instances and witnesses) as various NP-complete languages
+        * constraint_satisfaction_problems/ --- R1CS and USCS languages
+        * circuit_satisfaction_problems/ ---  Boolean and arithmetic circuit satisfiability languages
+        * ram_computations/ --- RAM computation languages
+    * zk_proof_systems --- interfaces and implementations of the proof systems
+    * reductions --- reductions between languages (used internally, but contains many examples of building constraints)
+
+    Some of these module directories have the following subdirectories:
+
+    * ...
+        * examples/ --- example code and tutorials for this module
+        * tests/ --- unit tests for this module
+
+    In particular, the top-level API examples are at `src/r1cs_ppzksnark/examples/` and `src/gadgetlib2/examples/`.
+
+* depsrc/ --- created by `prepare_depends.sh` for retrieved sourcecode and local builds of external code
+  (currently: \[ate-pairing], and its dependency xbyak).
+
+* depinst/ --- created by `prepare_depends.sh` and `Makefile`
+  for local installation of locally-compiled dependencies.
+
+* doxygen/ --- created by `make doxy` and contains a Doxygen summary of all files, classes etc. in libsnark.
+
+
+--------------------------------------------------------------------------------
+Further considerations
+--------------------------------------------------------------------------------
+
+### Multiexponentiation window size
+
+The ppzkSNARK's generator has to solve a fixed-base multi-exponentiation
+problem.  We use a window-based method in which the optimal window size depends
+on the size of the multiexponentiation instance *and* the platform.
+
+On our benchmarking platform (a 3.40 GHz Intel Core i7-4770 CPU), we have
+computed for each curve optimal windows, provided as
+"fixed_base_exp_window_table" initialization sequences, for each curve; see
+`X_init.cpp` for X=edwards,bn128,alt_bn128.
+
+Performance on other platforms may not be optimal (but probably not be far off).
+Future releases of the libsnark library will include a tool that generates
+optimal window sizes.
+
+
+--------------------------------------------------------------------------------
+References
+--------------------------------------------------------------------------------
+
+\[BBFR15] [
+  _ADSNARK: nearly practical and privacy-preserving proofs on authenticated data_
+](https://eprint.iacr.org/2014/617),
+  Michael Backes, Manuel Barbosa, Dario Fiore, Raphael M. Reischuk,
+  IEEE Symposium on Security and Privacy (Oakland) 2015
+
+\[BCCT12] [
+  _From extractable collision resistance to succinct non-Interactive arguments of knowledge, and back again_
+](http://eprint.iacr.org/2011/443),
+  Nir Bitansky, Ran Canetti, Alessandro Chiesa, Eran Tromer,
+  Innovations in Computer Science (ITCS) 2012
+
+\[BCCT13] [
+  _Recursive composition and bootstrapping for SNARKs and proof-carrying data_
+](http://eprint.iacr.org/2012/095)
+  Nir Bitansky, Ran Canetti, Alessandro Chiesa, Eran Tromer,
+  Symposium on Theory of Computing (STOC) 13
+
+\[BCGTV13] [
+  _SNARKs for C: Verifying Program Executions Succinctly and in Zero Knowledge_
+](http://eprint.iacr.org/2013/507),
+  Eli Ben-Sasson, Alessandro Chiesa, Daniel Genkin, Eran Tromer, Madars Virza,
+  CRYPTO 2013
+
+\[BCIOP13] [
+  _Succinct Non-Interactive Arguments via Linear Interactive Proofs_
+](http://eprint.iacr.org/2012/718),
+  Nir Bitansky, Alessandro Chiesa, Yuval Ishai, Rafail Ostrovsky, Omer Paneth,
+  Theory of Cryptography Conference 2013
+
+\[BCTV14a] [
+  _Succinct Non-Interactive Zero Knowledge for a von Neumann Architecture_
+](http://eprint.iacr.org/2013/879),
+  Eli Ben-Sasson, Alessandro Chiesa, Eran Tromer, Madars Virza,
+  USENIX Security 2014
+
+\[BCTV14b] [
+  _Scalable succinct non-interactive arguments via cycles of elliptic curves_
+](https://eprint.iacr.org/2014/595),
+  Eli Ben-Sasson, Alessandro Chiesa, Eran Tromer, Madars Virza,
+  CRYPTO 2014
+
+\[CTV15] [
+  _Cluster computing in zero knowledge_
+](https://eprint.iacr.org/2015/377),
+  Alessandro Chiesa, Eran Tromer, Madars Virza,
+  Eurocrypt 2015
+
+\[DFGK14] [
+  Square span programs with applications to succinct NIZK arguments
+](https://eprint.iacr.org/2014/718),
+  George Danezis, Cedric Fournet, Jens Groth, Markulf Kohlweiss,
+  ASIACCS 2014
+
+\[GGPR13] [
+  _Quadratic span programs and succinct NIZKs without PCPs_
+](http://eprint.iacr.org/2012/215),
+  Rosario Gennaro, Craig Gentry, Bryan Parno, Mariana Raykova,
+  EUROCRYPT 2013
+
+\[ate-pairing] [
+  _High-Speed Software Implementation of the Optimal Ate Pairing over Barreto-Naehrig Curves_
+](https://github.com/herumi/ate-pairing),
+  MITSUNARI Shigeo, TERUYA Tadanori
+
+\[PGHR13] [
+  _Pinocchio: Nearly Practical Verifiable Computation_
+](http://eprint.iacr.org/2013/279),
+  Bryan Parno, Craig Gentry, Jon Howell, Mariana Raykova,
+  IEEE Symposium on Security and Privacy (Oakland) 2013
+
+[SCIPR Lab]: http://www.scipr-lab.org/ (Succinct Computational Integrity and Privacy Research Lab)
+
+[LICENSE]: LICENSE (LICENSE file in top directory of libsnark distribution)
+
+[AUTHORS]: AUTHORS (AUTHORS file in top directory of libsnark distribution)
diff --git a/doxygen.conf b/doxygen.conf
new file mode 100644 (file)
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--- /dev/null
@@ -0,0 +1,1807 @@
+# Doxyfile 1.8.2
+
+# This file describes the settings to be used by the documentation system
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diff --git a/src/algebra/curves/alt_bn128/alt_bn128_g1.cpp b/src/algebra/curves/alt_bn128/alt_bn128_g1.cpp
new file mode 100644 (file)
index 0000000..bf7f43d
--- /dev/null
@@ -0,0 +1,524 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "algebra/curves/alt_bn128/alt_bn128_g1.hpp"
+
+namespace libsnark {
+
+#ifdef PROFILE_OP_COUNTS
+long long alt_bn128_G1::add_cnt = 0;
+long long alt_bn128_G1::dbl_cnt = 0;
+#endif
+
+std::vector<size_t> alt_bn128_G1::wnaf_window_table;
+std::vector<size_t> alt_bn128_G1::fixed_base_exp_window_table;
+alt_bn128_G1 alt_bn128_G1::G1_zero;
+alt_bn128_G1 alt_bn128_G1::G1_one;
+
+alt_bn128_G1::alt_bn128_G1()
+{
+    this->X = G1_zero.X;
+    this->Y = G1_zero.Y;
+    this->Z = G1_zero.Z;
+}
+
+void alt_bn128_G1::print() const
+{
+    if (this->is_zero())
+    {
+        printf("O\n");
+    }
+    else
+    {
+        alt_bn128_G1 copy(*this);
+        copy.to_affine_coordinates();
+        gmp_printf("(%Nd , %Nd)\n",
+                   copy.X.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   copy.Y.as_bigint().data, alt_bn128_Fq::num_limbs);
+    }
+}
+
+void alt_bn128_G1::print_coordinates() const
+{
+    if (this->is_zero())
+    {
+        printf("O\n");
+    }
+    else
+    {
+        gmp_printf("(%Nd : %Nd : %Nd)\n",
+                   this->X.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   this->Y.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   this->Z.as_bigint().data, alt_bn128_Fq::num_limbs);
+    }
+}
+
+void alt_bn128_G1::to_affine_coordinates()
+{
+    if (this->is_zero())
+    {
+        this->X = alt_bn128_Fq::zero();
+        this->Y = alt_bn128_Fq::one();
+        this->Z = alt_bn128_Fq::zero();
+    }
+    else
+    {
+        alt_bn128_Fq Z_inv = Z.inverse();
+        alt_bn128_Fq Z2_inv = Z_inv.squared();
+        alt_bn128_Fq Z3_inv = Z2_inv * Z_inv;
+        this->X = this->X * Z2_inv;
+        this->Y = this->Y * Z3_inv;
+        this->Z = alt_bn128_Fq::one();
+    }
+}
+
+void alt_bn128_G1::to_special()
+{
+    this->to_affine_coordinates();
+}
+
+bool alt_bn128_G1::is_special() const
+{
+    return (this->is_zero() || this->Z == alt_bn128_Fq::one());
+}
+
+bool alt_bn128_G1::is_zero() const
+{
+    return (this->Z.is_zero());
+}
+
+bool alt_bn128_G1::operator==(const alt_bn128_G1 &other) const
+{
+    if (this->is_zero())
+    {
+        return other.is_zero();
+    }
+
+    if (other.is_zero())
+    {
+        return false;
+    }
+
+    /* now neither is O */
+
+    // using Jacobian coordinates so:
+    // (X1:Y1:Z1) = (X2:Y2:Z2)
+    // iff
+    // X1/Z1^2 == X2/Z2^2 and Y1/Z1^3 == Y2/Z2^3
+    // iff
+    // X1 * Z2^2 == X2 * Z1^2 and Y1 * Z2^3 == Y2 * Z1^3
+
+    alt_bn128_Fq Z1_squared = (this->Z).squared();
+    alt_bn128_Fq Z2_squared = (other.Z).squared();
+
+    if ((this->X * Z2_squared) != (other.X * Z1_squared))
+    {
+        return false;
+    }
+
+    alt_bn128_Fq Z1_cubed = (this->Z) * Z1_squared;
+    alt_bn128_Fq Z2_cubed = (other.Z) * Z2_squared;
+
+    if ((this->Y * Z2_cubed) != (other.Y * Z1_cubed))
+    {
+        return false;
+    }
+
+    return true;
+}
+
+bool alt_bn128_G1::operator!=(const alt_bn128_G1& other) const
+{
+    return !(operator==(other));
+}
+
+alt_bn128_G1 alt_bn128_G1::operator+(const alt_bn128_G1 &other) const
+{
+    // handle special cases having to do with O
+    if (this->is_zero())
+    {
+        return other;
+    }
+
+    if (other.is_zero())
+    {
+        return *this;
+    }
+
+    // no need to handle points of order 2,4
+    // (they cannot exist in a prime-order subgroup)
+
+    // check for doubling case
+
+    // using Jacobian coordinates so:
+    // (X1:Y1:Z1) = (X2:Y2:Z2)
+    // iff
+    // X1/Z1^2 == X2/Z2^2 and Y1/Z1^3 == Y2/Z2^3
+    // iff
+    // X1 * Z2^2 == X2 * Z1^2 and Y1 * Z2^3 == Y2 * Z1^3
+
+    alt_bn128_Fq Z1Z1 = (this->Z).squared();
+    alt_bn128_Fq Z2Z2 = (other.Z).squared();
+
+    alt_bn128_Fq U1 = this->X * Z2Z2;
+    alt_bn128_Fq U2 = other.X * Z1Z1;
+
+    alt_bn128_Fq Z1_cubed = (this->Z) * Z1Z1;
+    alt_bn128_Fq Z2_cubed = (other.Z) * Z2Z2;
+
+    alt_bn128_Fq S1 = (this->Y) * Z2_cubed;      // S1 = Y1 * Z2 * Z2Z2
+    alt_bn128_Fq S2 = (other.Y) * Z1_cubed;      // S2 = Y2 * Z1 * Z1Z1
+
+    if (U1 == U2 && S1 == S2)
+    {
+        // dbl case; nothing of above can be reused
+        return this->dbl();
+    }
+
+    // rest of add case
+    alt_bn128_Fq H = U2 - U1;                            // H = U2-U1
+    alt_bn128_Fq S2_minus_S1 = S2-S1;
+    alt_bn128_Fq I = (H+H).squared();                    // I = (2 * H)^2
+    alt_bn128_Fq J = H * I;                              // J = H * I
+    alt_bn128_Fq r = S2_minus_S1 + S2_minus_S1;          // r = 2 * (S2-S1)
+    alt_bn128_Fq V = U1 * I;                             // V = U1 * I
+    alt_bn128_Fq X3 = r.squared() - J - (V+V);           // X3 = r^2 - J - 2 * V
+    alt_bn128_Fq S1_J = S1 * J;
+    alt_bn128_Fq Y3 = r * (V-X3) - (S1_J+S1_J);          // Y3 = r * (V-X3)-2 S1 J
+    alt_bn128_Fq Z3 = ((this->Z+other.Z).squared()-Z1Z1-Z2Z2) * H; // Z3 = ((Z1+Z2)^2-Z1Z1-Z2Z2) * H
+
+    return alt_bn128_G1(X3, Y3, Z3);
+}
+
+alt_bn128_G1 alt_bn128_G1::operator-() const
+{
+    return alt_bn128_G1(this->X, -(this->Y), this->Z);
+}
+
+
+alt_bn128_G1 alt_bn128_G1::operator-(const alt_bn128_G1 &other) const
+{
+    return (*this) + (-other);
+}
+
+alt_bn128_G1 alt_bn128_G1::add(const alt_bn128_G1 &other) const
+{
+    // handle special cases having to do with O
+    if (this->is_zero())
+    {
+        return other;
+    }
+
+    if (other.is_zero())
+    {
+        return *this;
+    }
+
+    // no need to handle points of order 2,4
+    // (they cannot exist in a prime-order subgroup)
+
+    // handle double case
+    if (this->operator==(other))
+    {
+        return this->dbl();
+    }
+
+#ifdef PROFILE_OP_COUNTS
+    this->add_cnt++;
+#endif
+    // NOTE: does not handle O and pts of order 2,4
+    // http://www.hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-add-2007-bl
+
+    alt_bn128_Fq Z1Z1 = (this->Z).squared();             // Z1Z1 = Z1^2
+    alt_bn128_Fq Z2Z2 = (other.Z).squared();             // Z2Z2 = Z2^2
+    alt_bn128_Fq U1 = (this->X) * Z2Z2;                  // U1 = X1 * Z2Z2
+    alt_bn128_Fq U2 = (other.X) * Z1Z1;                  // U2 = X2 * Z1Z1
+    alt_bn128_Fq S1 = (this->Y) * (other.Z) * Z2Z2;      // S1 = Y1 * Z2 * Z2Z2
+    alt_bn128_Fq S2 = (other.Y) * (this->Z) * Z1Z1;      // S2 = Y2 * Z1 * Z1Z1
+    alt_bn128_Fq H = U2 - U1;                            // H = U2-U1
+    alt_bn128_Fq S2_minus_S1 = S2-S1;
+    alt_bn128_Fq I = (H+H).squared();                    // I = (2 * H)^2
+    alt_bn128_Fq J = H * I;                              // J = H * I
+    alt_bn128_Fq r = S2_minus_S1 + S2_minus_S1;          // r = 2 * (S2-S1)
+    alt_bn128_Fq V = U1 * I;                             // V = U1 * I
+    alt_bn128_Fq X3 = r.squared() - J - (V+V);           // X3 = r^2 - J - 2 * V
+    alt_bn128_Fq S1_J = S1 * J;
+    alt_bn128_Fq Y3 = r * (V-X3) - (S1_J+S1_J);          // Y3 = r * (V-X3)-2 S1 J
+    alt_bn128_Fq Z3 = ((this->Z+other.Z).squared()-Z1Z1-Z2Z2) * H; // Z3 = ((Z1+Z2)^2-Z1Z1-Z2Z2) * H
+
+    return alt_bn128_G1(X3, Y3, Z3);
+}
+
+alt_bn128_G1 alt_bn128_G1::mixed_add(const alt_bn128_G1 &other) const
+{
+#ifdef DEBUG
+    assert(other.is_special());
+#endif
+
+    // handle special cases having to do with O
+    if (this->is_zero())
+    {
+        return other;
+    }
+
+    if (other.is_zero())
+    {
+        return *this;
+    }
+
+    // no need to handle points of order 2,4
+    // (they cannot exist in a prime-order subgroup)
+
+    // check for doubling case
+
+    // using Jacobian coordinates so:
+    // (X1:Y1:Z1) = (X2:Y2:Z2)
+    // iff
+    // X1/Z1^2 == X2/Z2^2 and Y1/Z1^3 == Y2/Z2^3
+    // iff
+    // X1 * Z2^2 == X2 * Z1^2 and Y1 * Z2^3 == Y2 * Z1^3
+
+    // we know that Z2 = 1
+
+    const alt_bn128_Fq Z1Z1 = (this->Z).squared();
+
+    const alt_bn128_Fq &U1 = this->X;
+    const alt_bn128_Fq U2 = other.X * Z1Z1;
+
+    const alt_bn128_Fq Z1_cubed = (this->Z) * Z1Z1;
+
+    const alt_bn128_Fq &S1 = (this->Y);                // S1 = Y1 * Z2 * Z2Z2
+    const alt_bn128_Fq S2 = (other.Y) * Z1_cubed;      // S2 = Y2 * Z1 * Z1Z1
+
+    if (U1 == U2 && S1 == S2)
+    {
+        // dbl case; nothing of above can be reused
+        return this->dbl();
+    }
+
+#ifdef PROFILE_OP_COUNTS
+    this->add_cnt++;
+#endif
+
+    // NOTE: does not handle O and pts of order 2,4
+    // http://www.hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-madd-2007-bl
+    alt_bn128_Fq H = U2-(this->X);                         // H = U2-X1
+    alt_bn128_Fq HH = H.squared() ;                        // HH = H&2
+    alt_bn128_Fq I = HH+HH;                                // I = 4*HH
+    I = I + I;
+    alt_bn128_Fq J = H*I;                                  // J = H*I
+    alt_bn128_Fq r = S2-(this->Y);                         // r = 2*(S2-Y1)
+    r = r + r;
+    alt_bn128_Fq V = (this->X) * I ;                       // V = X1*I
+    alt_bn128_Fq X3 = r.squared()-J-V-V;                   // X3 = r^2-J-2*V
+    alt_bn128_Fq Y3 = (this->Y)*J;                         // Y3 = r*(V-X3)-2*Y1*J
+    Y3 = r*(V-X3) - Y3 - Y3;
+    alt_bn128_Fq Z3 = ((this->Z)+H).squared() - Z1Z1 - HH; // Z3 = (Z1+H)^2-Z1Z1-HH
+
+    return alt_bn128_G1(X3, Y3, Z3);
+}
+
+alt_bn128_G1 alt_bn128_G1::dbl() const
+{
+#ifdef PROFILE_OP_COUNTS
+    this->dbl_cnt++;
+#endif
+    // handle point at infinity
+    if (this->is_zero())
+    {
+        return (*this);
+    }
+
+    // no need to handle points of order 2,4
+    // (they cannot exist in a prime-order subgroup)
+
+    // NOTE: does not handle O and pts of order 2,4
+    // http://www.hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#doubling-dbl-2009-l
+
+    alt_bn128_Fq A = (this->X).squared();         // A = X1^2
+    alt_bn128_Fq B = (this->Y).squared();        // B = Y1^2
+    alt_bn128_Fq C = B.squared();                // C = B^2
+    alt_bn128_Fq D = (this->X + B).squared() - A - C;
+    D = D+D;                        // D = 2 * ((X1 + B)^2 - A - C)
+    alt_bn128_Fq E = A + A + A;                  // E = 3 * A
+    alt_bn128_Fq F = E.squared();                // F = E^2
+    alt_bn128_Fq X3 = F - (D+D);                 // X3 = F - 2 D
+    alt_bn128_Fq eightC = C+C;
+    eightC = eightC + eightC;
+    eightC = eightC + eightC;
+    alt_bn128_Fq Y3 = E * (D - X3) - eightC;     // Y3 = E * (D - X3) - 8 * C
+    alt_bn128_Fq Y1Z1 = (this->Y)*(this->Z);
+    alt_bn128_Fq Z3 = Y1Z1 + Y1Z1;               // Z3 = 2 * Y1 * Z1
+
+    return alt_bn128_G1(X3, Y3, Z3);
+}
+
+bool alt_bn128_G1::is_well_formed() const
+{
+    if (this->is_zero())
+    {
+        return true;
+    }
+    else
+    {
+        /*
+          y^2 = x^3 + b
+
+          We are using Jacobian coordinates, so equation we need to check is actually
+
+          (y/z^3)^2 = (x/z^2)^3 + b
+          y^2 / z^6 = x^3 / z^6 + b
+          y^2 = x^3 + b z^6
+        */
+        alt_bn128_Fq X2 = this->X.squared();
+        alt_bn128_Fq Y2 = this->Y.squared();
+        alt_bn128_Fq Z2 = this->Z.squared();
+
+        alt_bn128_Fq X3 = this->X * X2;
+        alt_bn128_Fq Z3 = this->Z * Z2;
+        alt_bn128_Fq Z6 = Z3.squared();
+
+        return (Y2 == X3 + alt_bn128_coeff_b * Z6);
+    }
+}
+
+alt_bn128_G1 alt_bn128_G1::zero()
+{
+    return G1_zero;
+}
+
+alt_bn128_G1 alt_bn128_G1::one()
+{
+    return G1_one;
+}
+
+alt_bn128_G1 alt_bn128_G1::random_element()
+{
+    return (scalar_field::random_element().as_bigint()) * G1_one;
+}
+
+std::ostream& operator<<(std::ostream &out, const alt_bn128_G1 &g)
+{
+    alt_bn128_G1 copy(g);
+    copy.to_affine_coordinates();
+
+    out << (copy.is_zero() ? 1 : 0) << OUTPUT_SEPARATOR;
+#ifdef NO_PT_COMPRESSION
+    out << copy.X << OUTPUT_SEPARATOR << copy.Y;
+#else
+    /* storing LSB of Y */
+    out << copy.X << OUTPUT_SEPARATOR << (copy.Y.as_bigint().data[0] & 1);
+#endif
+
+    return out;
+}
+
+std::istream& operator>>(std::istream &in, alt_bn128_G1 &g)
+{
+    char is_zero;
+    alt_bn128_Fq tX, tY;
+
+#ifdef NO_PT_COMPRESSION
+    in >> is_zero >> tX >> tY;
+    is_zero -= '0';
+#else
+    in.read((char*)&is_zero, 1); // this reads is_zero;
+    is_zero -= '0';
+    consume_OUTPUT_SEPARATOR(in);
+
+    unsigned char Y_lsb;
+    in >> tX;
+    consume_OUTPUT_SEPARATOR(in);
+    in.read((char*)&Y_lsb, 1);
+    Y_lsb -= '0';
+
+    // y = +/- sqrt(x^3 + b)
+    if (!is_zero)
+    {
+        alt_bn128_Fq tX2 = tX.squared();
+        alt_bn128_Fq tY2 = tX2*tX + alt_bn128_coeff_b;
+        tY = tY2.sqrt();
+
+        if ((tY.as_bigint().data[0] & 1) != Y_lsb)
+        {
+            tY = -tY;
+        }
+    }
+#endif
+    // using Jacobian coordinates
+    if (!is_zero)
+    {
+        g.X = tX;
+        g.Y = tY;
+        g.Z = alt_bn128_Fq::one();
+    }
+    else
+    {
+        g = alt_bn128_G1::zero();
+    }
+
+    return in;
+}
+
+std::ostream& operator<<(std::ostream& out, const std::vector<alt_bn128_G1> &v)
+{
+    out << v.size() << "\n";
+    for (const alt_bn128_G1& t : v)
+    {
+        out << t << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+std::istream& operator>>(std::istream& in, std::vector<alt_bn128_G1> &v)
+{
+    v.clear();
+
+    size_t s;
+    in >> s;
+    consume_newline(in);
+
+    v.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        alt_bn128_G1 g;
+        in >> g;
+        consume_OUTPUT_NEWLINE(in);
+        v.emplace_back(g);
+    }
+
+    return in;
+}
+
+template<>
+void batch_to_special_all_non_zeros<alt_bn128_G1>(std::vector<alt_bn128_G1> &vec)
+{
+    std::vector<alt_bn128_Fq> Z_vec;
+    Z_vec.reserve(vec.size());
+
+    for (auto &el: vec)
+    {
+        Z_vec.emplace_back(el.Z);
+    }
+    batch_invert<alt_bn128_Fq>(Z_vec);
+
+    const alt_bn128_Fq one = alt_bn128_Fq::one();
+
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        alt_bn128_Fq Z2 = Z_vec[i].squared();
+        alt_bn128_Fq Z3 = Z_vec[i] * Z2;
+
+        vec[i].X = vec[i].X * Z2;
+        vec[i].Y = vec[i].Y * Z3;
+        vec[i].Z = one;
+    }
+}
+
+} // libsnark
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_g1.hpp b/src/algebra/curves/alt_bn128/alt_bn128_g1.hpp
new file mode 100644 (file)
index 0000000..da11a2e
--- /dev/null
@@ -0,0 +1,95 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef ALT_BN128_G1_HPP_
+#define ALT_BN128_G1_HPP_
+#include <vector>
+#include "algebra/curves/alt_bn128/alt_bn128_init.hpp"
+#include "algebra/curves/curve_utils.hpp"
+
+namespace libsnark {
+
+class alt_bn128_G1;
+std::ostream& operator<<(std::ostream &, const alt_bn128_G1&);
+std::istream& operator>>(std::istream &, alt_bn128_G1&);
+
+class alt_bn128_G1 {
+public:
+#ifdef PROFILE_OP_COUNTS
+    static long long add_cnt;
+    static long long dbl_cnt;
+#endif
+    static std::vector<size_t> wnaf_window_table;
+    static std::vector<size_t> fixed_base_exp_window_table;
+    static alt_bn128_G1 G1_zero;
+    static alt_bn128_G1 G1_one;
+
+    typedef alt_bn128_Fq base_field;
+    typedef alt_bn128_Fr scalar_field;
+
+    alt_bn128_Fq X, Y, Z;
+
+    // using Jacobian coordinates
+    alt_bn128_G1();
+    alt_bn128_G1(const alt_bn128_Fq& X, const alt_bn128_Fq& Y, const alt_bn128_Fq& Z) : X(X), Y(Y), Z(Z) {};
+
+    void print() const;
+    void print_coordinates() const;
+
+    void to_affine_coordinates();
+    void to_special();
+    bool is_special() const;
+
+    bool is_zero() const;
+
+    bool operator==(const alt_bn128_G1 &other) const;
+    bool operator!=(const alt_bn128_G1 &other) const;
+
+    alt_bn128_G1 operator+(const alt_bn128_G1 &other) const;
+    alt_bn128_G1 operator-() const;
+    alt_bn128_G1 operator-(const alt_bn128_G1 &other) const;
+
+    alt_bn128_G1 add(const alt_bn128_G1 &other) const;
+    alt_bn128_G1 mixed_add(const alt_bn128_G1 &other) const;
+    alt_bn128_G1 dbl() const;
+
+    bool is_well_formed() const;
+
+    static alt_bn128_G1 zero();
+    static alt_bn128_G1 one();
+    static alt_bn128_G1 random_element();
+
+    static size_t size_in_bits() { return base_field::size_in_bits() + 1; }
+    static bigint<base_field::num_limbs> base_field_char() { return base_field::field_char(); }
+    static bigint<scalar_field::num_limbs> order() { return scalar_field::field_char(); }
+
+    friend std::ostream& operator<<(std::ostream &out, const alt_bn128_G1 &g);
+    friend std::istream& operator>>(std::istream &in, alt_bn128_G1 &g);
+};
+
+template<mp_size_t m>
+alt_bn128_G1 operator*(const bigint<m> &lhs, const alt_bn128_G1 &rhs)
+{
+    return scalar_mul<alt_bn128_G1, m>(rhs, lhs);
+}
+
+template<mp_size_t m, const bigint<m>& modulus_p>
+alt_bn128_G1 operator*(const Fp_model<m,modulus_p> &lhs, const alt_bn128_G1 &rhs)
+{
+    return scalar_mul<alt_bn128_G1, m>(rhs, lhs.as_bigint());
+}
+
+std::ostream& operator<<(std::ostream& out, const std::vector<alt_bn128_G1> &v);
+std::istream& operator>>(std::istream& in, std::vector<alt_bn128_G1> &v);
+
+template<typename T>
+void batch_to_special_all_non_zeros(std::vector<T> &vec);
+template<>
+void batch_to_special_all_non_zeros<alt_bn128_G1>(std::vector<alt_bn128_G1> &vec);
+
+} // libsnark
+#endif // ALT_BN128_G1_HPP_
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_g2.cpp b/src/algebra/curves/alt_bn128/alt_bn128_g2.cpp
new file mode 100644 (file)
index 0000000..c4152e4
--- /dev/null
@@ -0,0 +1,505 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "algebra/curves/alt_bn128/alt_bn128_g2.hpp"
+
+namespace libsnark {
+
+#ifdef PROFILE_OP_COUNTS
+long long alt_bn128_G2::add_cnt = 0;
+long long alt_bn128_G2::dbl_cnt = 0;
+#endif
+
+std::vector<size_t> alt_bn128_G2::wnaf_window_table;
+std::vector<size_t> alt_bn128_G2::fixed_base_exp_window_table;
+alt_bn128_G2 alt_bn128_G2::G2_zero;
+alt_bn128_G2 alt_bn128_G2::G2_one;
+
+alt_bn128_G2::alt_bn128_G2()
+{
+    this->X = G2_zero.X;
+    this->Y = G2_zero.Y;
+    this->Z = G2_zero.Z;
+}
+
+alt_bn128_Fq2 alt_bn128_G2::mul_by_b(const alt_bn128_Fq2 &elt)
+{
+    return alt_bn128_Fq2(alt_bn128_twist_mul_by_b_c0 * elt.c0, alt_bn128_twist_mul_by_b_c1 * elt.c1);
+}
+
+void alt_bn128_G2::print() const
+{
+    if (this->is_zero())
+    {
+        printf("O\n");
+    }
+    else
+    {
+        alt_bn128_G2 copy(*this);
+        copy.to_affine_coordinates();
+        gmp_printf("(%Nd*z + %Nd , %Nd*z + %Nd)\n",
+                   copy.X.c1.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   copy.X.c0.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   copy.Y.c1.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   copy.Y.c0.as_bigint().data, alt_bn128_Fq::num_limbs);
+    }
+}
+
+void alt_bn128_G2::print_coordinates() const
+{
+    if (this->is_zero())
+    {
+        printf("O\n");
+    }
+    else
+    {
+        gmp_printf("(%Nd*z + %Nd : %Nd*z + %Nd : %Nd*z + %Nd)\n",
+                   this->X.c1.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   this->X.c0.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   this->Y.c1.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   this->Y.c0.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   this->Z.c1.as_bigint().data, alt_bn128_Fq::num_limbs,
+                   this->Z.c0.as_bigint().data, alt_bn128_Fq::num_limbs);
+    }
+}
+
+void alt_bn128_G2::to_affine_coordinates()
+{
+    if (this->is_zero())
+    {
+        this->X = alt_bn128_Fq2::zero();
+        this->Y = alt_bn128_Fq2::one();
+        this->Z = alt_bn128_Fq2::zero();
+    }
+    else
+    {
+        alt_bn128_Fq2 Z_inv = Z.inverse();
+        alt_bn128_Fq2 Z2_inv = Z_inv.squared();
+        alt_bn128_Fq2 Z3_inv = Z2_inv * Z_inv;
+        this->X = this->X * Z2_inv;
+        this->Y = this->Y * Z3_inv;
+        this->Z = alt_bn128_Fq2::one();
+    }
+}
+
+void alt_bn128_G2::to_special()
+{
+    this->to_affine_coordinates();
+}
+
+bool alt_bn128_G2::is_special() const
+{
+    return (this->is_zero() || this->Z == alt_bn128_Fq2::one());
+}
+
+bool alt_bn128_G2::is_zero() const
+{
+    return (this->Z.is_zero());
+}
+
+bool alt_bn128_G2::operator==(const alt_bn128_G2 &other) const
+{
+    if (this->is_zero())
+    {
+        return other.is_zero();
+    }
+
+    if (other.is_zero())
+    {
+        return false;
+    }
+
+    /* now neither is O */
+
+    // using Jacobian coordinates so:
+    // (X1:Y1:Z1) = (X2:Y2:Z2)
+    // iff
+    // X1/Z1^2 == X2/Z2^2 and Y1/Z1^3 == Y2/Z2^3
+    // iff
+    // X1 * Z2^2 == X2 * Z1^2 and Y1 * Z2^3 == Y2 * Z1^3
+
+    alt_bn128_Fq2 Z1_squared = (this->Z).squared();
+    alt_bn128_Fq2 Z2_squared = (other.Z).squared();
+
+    if ((this->X * Z2_squared) != (other.X * Z1_squared))
+    {
+        return false;
+    }
+
+    alt_bn128_Fq2 Z1_cubed = (this->Z) * Z1_squared;
+    alt_bn128_Fq2 Z2_cubed = (other.Z) * Z2_squared;
+
+    if ((this->Y * Z2_cubed) != (other.Y * Z1_cubed))
+    {
+        return false;
+    }
+
+    return true;
+}
+
+bool alt_bn128_G2::operator!=(const alt_bn128_G2& other) const
+{
+    return !(operator==(other));
+}
+
+alt_bn128_G2 alt_bn128_G2::operator+(const alt_bn128_G2 &other) const
+{
+    // handle special cases having to do with O
+    if (this->is_zero())
+    {
+        return other;
+    }
+
+    if (other.is_zero())
+    {
+        return *this;
+    }
+
+    // no need to handle points of order 2,4
+    // (they cannot exist in a prime-order subgroup)
+
+    // check for doubling case
+
+    // using Jacobian coordinates so:
+    // (X1:Y1:Z1) = (X2:Y2:Z2)
+    // iff
+    // X1/Z1^2 == X2/Z2^2 and Y1/Z1^3 == Y2/Z2^3
+    // iff
+    // X1 * Z2^2 == X2 * Z1^2 and Y1 * Z2^3 == Y2 * Z1^3
+
+    alt_bn128_Fq2 Z1Z1 = (this->Z).squared();
+    alt_bn128_Fq2 Z2Z2 = (other.Z).squared();
+
+    alt_bn128_Fq2 U1 = this->X * Z2Z2;
+    alt_bn128_Fq2 U2 = other.X * Z1Z1;
+
+    alt_bn128_Fq2 Z1_cubed = (this->Z) * Z1Z1;
+    alt_bn128_Fq2 Z2_cubed = (other.Z) * Z2Z2;
+
+    alt_bn128_Fq2 S1 = (this->Y) * Z2_cubed;      // S1 = Y1 * Z2 * Z2Z2
+    alt_bn128_Fq2 S2 = (other.Y) * Z1_cubed;      // S2 = Y2 * Z1 * Z1Z1
+
+    if (U1 == U2 && S1 == S2)
+    {
+        // dbl case; nothing of above can be reused
+        return this->dbl();
+    }
+
+    // rest of add case
+    alt_bn128_Fq2 H = U2 - U1;                            // H = U2-U1
+    alt_bn128_Fq2 S2_minus_S1 = S2-S1;
+    alt_bn128_Fq2 I = (H+H).squared();                    // I = (2 * H)^2
+    alt_bn128_Fq2 J = H * I;                              // J = H * I
+    alt_bn128_Fq2 r = S2_minus_S1 + S2_minus_S1;          // r = 2 * (S2-S1)
+    alt_bn128_Fq2 V = U1 * I;                             // V = U1 * I
+    alt_bn128_Fq2 X3 = r.squared() - J - (V+V);           // X3 = r^2 - J - 2 * V
+    alt_bn128_Fq2 S1_J = S1 * J;
+    alt_bn128_Fq2 Y3 = r * (V-X3) - (S1_J+S1_J);          // Y3 = r * (V-X3)-2 S1 J
+    alt_bn128_Fq2 Z3 = ((this->Z+other.Z).squared()-Z1Z1-Z2Z2) * H; // Z3 = ((Z1+Z2)^2-Z1Z1-Z2Z2) * H
+
+    return alt_bn128_G2(X3, Y3, Z3);
+}
+
+alt_bn128_G2 alt_bn128_G2::operator-() const
+{
+    return alt_bn128_G2(this->X, -(this->Y), this->Z);
+}
+
+
+alt_bn128_G2 alt_bn128_G2::operator-(const alt_bn128_G2 &other) const
+{
+    return (*this) + (-other);
+}
+
+alt_bn128_G2 alt_bn128_G2::add(const alt_bn128_G2 &other) const
+{
+    // handle special cases having to do with O
+    if (this->is_zero())
+    {
+        return other;
+    }
+
+    if (other.is_zero())
+    {
+        return *this;
+    }
+
+    // no need to handle points of order 2,4
+    // (they cannot exist in a prime-order subgroup)
+
+    // handle double case
+    if (this->operator==(other))
+    {
+        return this->dbl();
+    }
+
+#ifdef PROFILE_OP_COUNTS
+    this->add_cnt++;
+#endif
+    // NOTE: does not handle O and pts of order 2,4
+    // http://www.hyperelliptic.org/EFD/g1p/auto-shortw-projective.html#addition-add-1998-cmo-2
+
+    alt_bn128_Fq2 Z1Z1 = (this->Z).squared();             // Z1Z1 = Z1^2
+    alt_bn128_Fq2 Z2Z2 = (other.Z).squared();             // Z2Z2 = Z2^2
+    alt_bn128_Fq2 U1 = (this->X) * Z2Z2;                  // U1 = X1 * Z2Z2
+    alt_bn128_Fq2 U2 = (other.X) * Z1Z1;                  // U2 = X2 * Z1Z1
+    alt_bn128_Fq2 S1 = (this->Y) * (other.Z) * Z2Z2;      // S1 = Y1 * Z2 * Z2Z2
+    alt_bn128_Fq2 S2 = (other.Y) * (this->Z) * Z1Z1;      // S2 = Y2 * Z1 * Z1Z1
+    alt_bn128_Fq2 H = U2 - U1;                            // H = U2-U1
+    alt_bn128_Fq2 S2_minus_S1 = S2-S1;
+    alt_bn128_Fq2 I = (H+H).squared();                    // I = (2 * H)^2
+    alt_bn128_Fq2 J = H * I;                              // J = H * I
+    alt_bn128_Fq2 r = S2_minus_S1 + S2_minus_S1;          // r = 2 * (S2-S1)
+    alt_bn128_Fq2 V = U1 * I;                             // V = U1 * I
+    alt_bn128_Fq2 X3 = r.squared() - J - (V+V);           // X3 = r^2 - J - 2 * V
+    alt_bn128_Fq2 S1_J = S1 * J;
+    alt_bn128_Fq2 Y3 = r * (V-X3) - (S1_J+S1_J);          // Y3 = r * (V-X3)-2 S1 J
+    alt_bn128_Fq2 Z3 = ((this->Z+other.Z).squared()-Z1Z1-Z2Z2) * H; // Z3 = ((Z1+Z2)^2-Z1Z1-Z2Z2) * H
+
+    return alt_bn128_G2(X3, Y3, Z3);
+}
+
+alt_bn128_G2 alt_bn128_G2::mixed_add(const alt_bn128_G2 &other) const
+{
+#ifdef DEBUG
+    assert(other.is_special());
+#endif
+
+    // handle special cases having to do with O
+    if (this->is_zero())
+    {
+        return other;
+    }
+
+    if (other.is_zero())
+    {
+        return *this;
+    }
+
+    // no need to handle points of order 2,4
+    // (they cannot exist in a prime-order subgroup)
+
+    // check for doubling case
+
+    // using Jacobian coordinates so:
+    // (X1:Y1:Z1) = (X2:Y2:Z2)
+    // iff
+    // X1/Z1^2 == X2/Z2^2 and Y1/Z1^3 == Y2/Z2^3
+    // iff
+    // X1 * Z2^2 == X2 * Z1^2 and Y1 * Z2^3 == Y2 * Z1^3
+
+    // we know that Z2 = 1
+
+    const alt_bn128_Fq2 Z1Z1 = (this->Z).squared();
+
+    const alt_bn128_Fq2 &U1 = this->X;
+    const alt_bn128_Fq2 U2 = other.X * Z1Z1;
+
+    const alt_bn128_Fq2 Z1_cubed = (this->Z) * Z1Z1;
+
+    const alt_bn128_Fq2 &S1 = (this->Y);                // S1 = Y1 * Z2 * Z2Z2
+    const alt_bn128_Fq2 S2 = (other.Y) * Z1_cubed;      // S2 = Y2 * Z1 * Z1Z1
+
+    if (U1 == U2 && S1 == S2)
+    {
+        // dbl case; nothing of above can be reused
+        return this->dbl();
+    }
+
+#ifdef PROFILE_OP_COUNTS
+    this->add_cnt++;
+#endif
+
+    // NOTE: does not handle O and pts of order 2,4
+    // http://www.hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-madd-2007-bl
+    alt_bn128_Fq2 H = U2-(this->X);                         // H = U2-X1
+    alt_bn128_Fq2 HH = H.squared() ;                        // HH = H&2
+    alt_bn128_Fq2 I = HH+HH;                                // I = 4*HH
+    I = I + I;
+    alt_bn128_Fq2 J = H*I;                                  // J = H*I
+    alt_bn128_Fq2 r = S2-(this->Y);                         // r = 2*(S2-Y1)
+    r = r + r;
+    alt_bn128_Fq2 V = (this->X) * I ;                       // V = X1*I
+    alt_bn128_Fq2 X3 = r.squared()-J-V-V;                   // X3 = r^2-J-2*V
+    alt_bn128_Fq2 Y3 = (this->Y)*J;                         // Y3 = r*(V-X3)-2*Y1*J
+    Y3 = r*(V-X3) - Y3 - Y3;
+    alt_bn128_Fq2 Z3 = ((this->Z)+H).squared() - Z1Z1 - HH; // Z3 = (Z1+H)^2-Z1Z1-HH
+
+    return alt_bn128_G2(X3, Y3, Z3);
+}
+
+alt_bn128_G2 alt_bn128_G2::dbl() const
+{
+#ifdef PROFILE_OP_COUNTS
+    this->dbl_cnt++;
+#endif
+    // handle point at infinity
+    if (this->is_zero())
+    {
+        return (*this);
+    }
+
+    // NOTE: does not handle O and pts of order 2,4
+    // http://www.hyperelliptic.org/EFD/g1p/auto-shortw-projective.html#doubling-dbl-2007-bl
+
+    alt_bn128_Fq2 A = (this->X).squared();         // A = X1^2
+    alt_bn128_Fq2 B = (this->Y).squared();        // B = Y1^2
+    alt_bn128_Fq2 C = B.squared();                // C = B^2
+    alt_bn128_Fq2 D = (this->X + B).squared() - A - C;
+    D = D+D;                        // D = 2 * ((X1 + B)^2 - A - C)
+    alt_bn128_Fq2 E = A + A + A;                  // E = 3 * A
+    alt_bn128_Fq2 F = E.squared();                // F = E^2
+    alt_bn128_Fq2 X3 = F - (D+D);                 // X3 = F - 2 D
+    alt_bn128_Fq2 eightC = C+C;
+    eightC = eightC + eightC;
+    eightC = eightC + eightC;
+    alt_bn128_Fq2 Y3 = E * (D - X3) - eightC;     // Y3 = E * (D - X3) - 8 * C
+    alt_bn128_Fq2 Y1Z1 = (this->Y)*(this->Z);
+    alt_bn128_Fq2 Z3 = Y1Z1 + Y1Z1;               // Z3 = 2 * Y1 * Z1
+
+    return alt_bn128_G2(X3, Y3, Z3);
+}
+
+alt_bn128_G2 alt_bn128_G2::mul_by_q() const
+{
+    return alt_bn128_G2(alt_bn128_twist_mul_by_q_X * (this->X).Frobenius_map(1),
+                      alt_bn128_twist_mul_by_q_Y * (this->Y).Frobenius_map(1),
+                      (this->Z).Frobenius_map(1));
+}
+
+bool alt_bn128_G2::is_well_formed() const
+{
+    if (this->is_zero())
+    {
+        return true;
+    }
+    else
+    {
+        /*
+          y^2 = x^3 + b
+
+          We are using Jacobian coordinates, so equation we need to check is actually
+
+          (y/z^3)^2 = (x/z^2)^3 + b
+          y^2 / z^6 = x^3 / z^6 + b
+          y^2 = x^3 + b z^6
+        */
+        alt_bn128_Fq2 X2 = this->X.squared();
+        alt_bn128_Fq2 Y2 = this->Y.squared();
+        alt_bn128_Fq2 Z2 = this->Z.squared();
+
+        alt_bn128_Fq2 X3 = this->X * X2;
+        alt_bn128_Fq2 Z3 = this->Z * Z2;
+        alt_bn128_Fq2 Z6 = Z3.squared();
+
+        return (Y2 == X3 + alt_bn128_twist_coeff_b * Z6);
+    }
+}
+
+alt_bn128_G2 alt_bn128_G2::zero()
+{
+    return G2_zero;
+}
+
+alt_bn128_G2 alt_bn128_G2::one()
+{
+    return G2_one;
+}
+
+alt_bn128_G2 alt_bn128_G2::random_element()
+{
+    return (alt_bn128_Fr::random_element().as_bigint()) * G2_one;
+}
+
+std::ostream& operator<<(std::ostream &out, const alt_bn128_G2 &g)
+{
+    alt_bn128_G2 copy(g);
+    copy.to_affine_coordinates();
+    out << (copy.is_zero() ? 1 : 0) << OUTPUT_SEPARATOR;
+#ifdef NO_PT_COMPRESSION
+    out << copy.X << OUTPUT_SEPARATOR << copy.Y;
+#else
+    /* storing LSB of Y */
+    out << copy.X << OUTPUT_SEPARATOR << (copy.Y.c0.as_bigint().data[0] & 1);
+#endif
+
+    return out;
+}
+
+std::istream& operator>>(std::istream &in, alt_bn128_G2 &g)
+{
+    char is_zero;
+    alt_bn128_Fq2 tX, tY;
+
+#ifdef NO_PT_COMPRESSION
+    in >> is_zero >> tX >> tY;
+    is_zero -= '0';
+#else
+    in.read((char*)&is_zero, 1); // this reads is_zero;
+    is_zero -= '0';
+    consume_OUTPUT_SEPARATOR(in);
+
+    unsigned char Y_lsb;
+    in >> tX;
+    consume_OUTPUT_SEPARATOR(in);
+    in.read((char*)&Y_lsb, 1);
+    Y_lsb -= '0';
+
+    // y = +/- sqrt(x^3 + b)
+    if (!is_zero)
+    {
+        alt_bn128_Fq2 tX2 = tX.squared();
+        alt_bn128_Fq2 tY2 = tX2 * tX + alt_bn128_twist_coeff_b;
+        tY = tY2.sqrt();
+
+        if ((tY.c0.as_bigint().data[0] & 1) != Y_lsb)
+        {
+            tY = -tY;
+        }
+    }
+#endif
+    // using projective coordinates
+    if (!is_zero)
+    {
+        g.X = tX;
+        g.Y = tY;
+        g.Z = alt_bn128_Fq2::one();
+    }
+    else
+    {
+        g = alt_bn128_G2::zero();
+    }
+
+    return in;
+}
+
+template<>
+void batch_to_special_all_non_zeros<alt_bn128_G2>(std::vector<alt_bn128_G2> &vec)
+{
+    std::vector<alt_bn128_Fq2> Z_vec;
+    Z_vec.reserve(vec.size());
+
+    for (auto &el: vec)
+    {
+        Z_vec.emplace_back(el.Z);
+    }
+    batch_invert<alt_bn128_Fq2>(Z_vec);
+
+    const alt_bn128_Fq2 one = alt_bn128_Fq2::one();
+
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        alt_bn128_Fq2 Z2 = Z_vec[i].squared();
+        alt_bn128_Fq2 Z3 = Z_vec[i] * Z2;
+
+        vec[i].X = vec[i].X * Z2;
+        vec[i].Y = vec[i].Y * Z3;
+        vec[i].Z = one;
+    }
+}
+
+} // libsnark
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_g2.hpp b/src/algebra/curves/alt_bn128/alt_bn128_g2.hpp
new file mode 100644 (file)
index 0000000..a996a2d
--- /dev/null
@@ -0,0 +1,96 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef ALT_BN128_G2_HPP_
+#define ALT_BN128_G2_HPP_
+#include <vector>
+#include "algebra/curves/alt_bn128/alt_bn128_init.hpp"
+#include "algebra/curves/curve_utils.hpp"
+
+namespace libsnark {
+
+class alt_bn128_G2;
+std::ostream& operator<<(std::ostream &, const alt_bn128_G2&);
+std::istream& operator>>(std::istream &, alt_bn128_G2&);
+
+class alt_bn128_G2 {
+public:
+#ifdef PROFILE_OP_COUNTS
+    static long long add_cnt;
+    static long long dbl_cnt;
+#endif
+    static std::vector<size_t> wnaf_window_table;
+    static std::vector<size_t> fixed_base_exp_window_table;
+    static alt_bn128_G2 G2_zero;
+    static alt_bn128_G2 G2_one;
+
+    typedef alt_bn128_Fq base_field;
+    typedef alt_bn128_Fq2 twist_field;
+    typedef alt_bn128_Fr scalar_field;
+
+    alt_bn128_Fq2 X, Y, Z;
+
+    // using Jacobian coordinates
+    alt_bn128_G2();
+    alt_bn128_G2(const alt_bn128_Fq2& X, const alt_bn128_Fq2& Y, const alt_bn128_Fq2& Z) : X(X), Y(Y), Z(Z) {};
+
+    static alt_bn128_Fq2 mul_by_b(const alt_bn128_Fq2 &elt);
+
+    void print() const;
+    void print_coordinates() const;
+
+    void to_affine_coordinates();
+    void to_special();
+    bool is_special() const;
+
+    bool is_zero() const;
+
+    bool operator==(const alt_bn128_G2 &other) const;
+    bool operator!=(const alt_bn128_G2 &other) const;
+
+    alt_bn128_G2 operator+(const alt_bn128_G2 &other) const;
+    alt_bn128_G2 operator-() const;
+    alt_bn128_G2 operator-(const alt_bn128_G2 &other) const;
+
+    alt_bn128_G2 add(const alt_bn128_G2 &other) const;
+    alt_bn128_G2 mixed_add(const alt_bn128_G2 &other) const;
+    alt_bn128_G2 dbl() const;
+    alt_bn128_G2 mul_by_q() const;
+
+    bool is_well_formed() const;
+
+    static alt_bn128_G2 zero();
+    static alt_bn128_G2 one();
+    static alt_bn128_G2 random_element();
+
+    static size_t size_in_bits() { return twist_field::size_in_bits() + 1; }
+    static bigint<base_field::num_limbs> base_field_char() { return base_field::field_char(); }
+    static bigint<scalar_field::num_limbs> order() { return scalar_field::field_char(); }
+
+    friend std::ostream& operator<<(std::ostream &out, const alt_bn128_G2 &g);
+    friend std::istream& operator>>(std::istream &in, alt_bn128_G2 &g);
+};
+
+template<mp_size_t m>
+alt_bn128_G2 operator*(const bigint<m> &lhs, const alt_bn128_G2 &rhs)
+{
+    return scalar_mul<alt_bn128_G2, m>(rhs, lhs);
+}
+
+template<mp_size_t m, const bigint<m>& modulus_p>
+alt_bn128_G2 operator*(const Fp_model<m,modulus_p> &lhs, const alt_bn128_G2 &rhs)
+{
+    return scalar_mul<alt_bn128_G2, m>(rhs, lhs.as_bigint());
+}
+
+template<typename T>
+void batch_to_special_all_non_zeros(std::vector<T> &vec);
+template<>
+void batch_to_special_all_non_zeros<alt_bn128_G2>(std::vector<alt_bn128_G2> &vec);
+
+} // libsnark
+#endif // ALT_BN128_G2_HPP_
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_init.cpp b/src/algebra/curves/alt_bn128/alt_bn128_init.cpp
new file mode 100644 (file)
index 0000000..7c23773
--- /dev/null
@@ -0,0 +1,273 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "algebra/curves/alt_bn128/alt_bn128_init.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_g1.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_g2.hpp"
+
+namespace libsnark {
+
+bigint<alt_bn128_r_limbs> alt_bn128_modulus_r;
+bigint<alt_bn128_q_limbs> alt_bn128_modulus_q;
+
+alt_bn128_Fq alt_bn128_coeff_b;
+alt_bn128_Fq2 alt_bn128_twist;
+alt_bn128_Fq2 alt_bn128_twist_coeff_b;
+alt_bn128_Fq alt_bn128_twist_mul_by_b_c0;
+alt_bn128_Fq alt_bn128_twist_mul_by_b_c1;
+alt_bn128_Fq2 alt_bn128_twist_mul_by_q_X;
+alt_bn128_Fq2 alt_bn128_twist_mul_by_q_Y;
+
+bigint<alt_bn128_q_limbs> alt_bn128_ate_loop_count;
+bool alt_bn128_ate_is_loop_count_neg;
+bigint<12*alt_bn128_q_limbs> alt_bn128_final_exponent;
+bigint<alt_bn128_q_limbs> alt_bn128_final_exponent_z;
+bool alt_bn128_final_exponent_is_z_neg;
+
+void init_alt_bn128_params()
+{
+    typedef bigint<alt_bn128_r_limbs> bigint_r;
+    typedef bigint<alt_bn128_q_limbs> bigint_q;
+
+    assert(sizeof(mp_limb_t) == 8 || sizeof(mp_limb_t) == 4); // Montgomery assumes this
+
+    /* parameters for scalar field Fr */
+
+    alt_bn128_modulus_r = bigint_r("21888242871839275222246405745257275088548364400416034343698204186575808495617");
+    assert(alt_bn128_Fr::modulus_is_valid());
+    if (sizeof(mp_limb_t) == 8)
+    {
+        alt_bn128_Fr::Rsquared = bigint_r("944936681149208446651664254269745548490766851729442924617792859073125903783");
+        alt_bn128_Fr::Rcubed = bigint_r("5866548545943845227489894872040244720403868105578784105281690076696998248512");
+        alt_bn128_Fr::inv = 0xc2e1f593efffffff;
+    }
+    if (sizeof(mp_limb_t) == 4)
+    {
+        alt_bn128_Fr::Rsquared = bigint_r("944936681149208446651664254269745548490766851729442924617792859073125903783");
+        alt_bn128_Fr::Rcubed = bigint_r("5866548545943845227489894872040244720403868105578784105281690076696998248512");
+        alt_bn128_Fr::inv = 0xefffffff;
+    }
+    alt_bn128_Fr::num_bits = 254;
+    alt_bn128_Fr::euler = bigint_r("10944121435919637611123202872628637544274182200208017171849102093287904247808");
+    alt_bn128_Fr::s = 28;
+    alt_bn128_Fr::t = bigint_r("81540058820840996586704275553141814055101440848469862132140264610111");
+    alt_bn128_Fr::t_minus_1_over_2 = bigint_r("40770029410420498293352137776570907027550720424234931066070132305055");
+    alt_bn128_Fr::multiplicative_generator = alt_bn128_Fr("5");
+    alt_bn128_Fr::root_of_unity = alt_bn128_Fr("19103219067921713944291392827692070036145651957329286315305642004821462161904");
+    alt_bn128_Fr::nqr = alt_bn128_Fr("5");
+    alt_bn128_Fr::nqr_to_t = alt_bn128_Fr("19103219067921713944291392827692070036145651957329286315305642004821462161904");
+
+    /* parameters for base field Fq */
+
+    alt_bn128_modulus_q = bigint_q("21888242871839275222246405745257275088696311157297823662689037894645226208583");
+    assert(alt_bn128_Fq::modulus_is_valid());
+    if (sizeof(mp_limb_t) == 8)
+    {
+        alt_bn128_Fq::Rsquared = bigint_q("3096616502983703923843567936837374451735540968419076528771170197431451843209");
+        alt_bn128_Fq::Rcubed = bigint_q("14921786541159648185948152738563080959093619838510245177710943249661917737183");
+        alt_bn128_Fq::inv = 0x87d20782e4866389;
+    }
+    if (sizeof(mp_limb_t) == 4)
+    {
+        alt_bn128_Fq::Rsquared = bigint_q("3096616502983703923843567936837374451735540968419076528771170197431451843209");
+        alt_bn128_Fq::Rcubed = bigint_q("14921786541159648185948152738563080959093619838510245177710943249661917737183");
+        alt_bn128_Fq::inv = 0xe4866389;
+    }
+    alt_bn128_Fq::num_bits = 254;
+    alt_bn128_Fq::euler = bigint_q("10944121435919637611123202872628637544348155578648911831344518947322613104291");
+    alt_bn128_Fq::s = 1;
+    alt_bn128_Fq::t = bigint_q("10944121435919637611123202872628637544348155578648911831344518947322613104291");
+    alt_bn128_Fq::t_minus_1_over_2 = bigint_q("5472060717959818805561601436314318772174077789324455915672259473661306552145");
+    alt_bn128_Fq::multiplicative_generator = alt_bn128_Fq("3");
+    alt_bn128_Fq::root_of_unity = alt_bn128_Fq("21888242871839275222246405745257275088696311157297823662689037894645226208582");
+    alt_bn128_Fq::nqr = alt_bn128_Fq("3");
+    alt_bn128_Fq::nqr_to_t = alt_bn128_Fq("21888242871839275222246405745257275088696311157297823662689037894645226208582");
+
+    /* parameters for twist field Fq2 */
+    alt_bn128_Fq2::euler = bigint<2*alt_bn128_q_limbs>("239547588008311421220994022608339370399626158265550411218223901127035046843189118723920525909718935985594116157406550130918127817069793474323196511433944");
+    alt_bn128_Fq2::s = 4;
+    alt_bn128_Fq2::t = bigint<2*alt_bn128_q_limbs>("29943448501038927652624252826042421299953269783193801402277987640879380855398639840490065738714866998199264519675818766364765977133724184290399563929243");
+    alt_bn128_Fq2::t_minus_1_over_2 = bigint<2*alt_bn128_q_limbs>("14971724250519463826312126413021210649976634891596900701138993820439690427699319920245032869357433499099632259837909383182382988566862092145199781964621");
+    alt_bn128_Fq2::non_residue = alt_bn128_Fq("21888242871839275222246405745257275088696311157297823662689037894645226208582");
+    alt_bn128_Fq2::nqr = alt_bn128_Fq2(alt_bn128_Fq("2"),alt_bn128_Fq("1"));
+    alt_bn128_Fq2::nqr_to_t = alt_bn128_Fq2(alt_bn128_Fq("5033503716262624267312492558379982687175200734934877598599011485707452665730"),alt_bn128_Fq("314498342015008975724433667930697407966947188435857772134235984660852259084"));
+    alt_bn128_Fq2::Frobenius_coeffs_c1[0] = alt_bn128_Fq("1");
+    alt_bn128_Fq2::Frobenius_coeffs_c1[1] = alt_bn128_Fq("21888242871839275222246405745257275088696311157297823662689037894645226208582");
+
+    /* parameters for Fq6 */
+    alt_bn128_Fq6::non_residue = alt_bn128_Fq2(alt_bn128_Fq("9"),alt_bn128_Fq("1"));
+    alt_bn128_Fq6::Frobenius_coeffs_c1[0] = alt_bn128_Fq2(alt_bn128_Fq("1"),alt_bn128_Fq("0"));
+    alt_bn128_Fq6::Frobenius_coeffs_c1[1] = alt_bn128_Fq2(alt_bn128_Fq("21575463638280843010398324269430826099269044274347216827212613867836435027261"),alt_bn128_Fq("10307601595873709700152284273816112264069230130616436755625194854815875713954"));
+    alt_bn128_Fq6::Frobenius_coeffs_c1[2] = alt_bn128_Fq2(alt_bn128_Fq("21888242871839275220042445260109153167277707414472061641714758635765020556616"),alt_bn128_Fq("0"));
+    alt_bn128_Fq6::Frobenius_coeffs_c1[3] = alt_bn128_Fq2(alt_bn128_Fq("3772000881919853776433695186713858239009073593817195771773381919316419345261"),alt_bn128_Fq("2236595495967245188281701248203181795121068902605861227855261137820944008926"));
+    alt_bn128_Fq6::Frobenius_coeffs_c1[4] = alt_bn128_Fq2(alt_bn128_Fq("2203960485148121921418603742825762020974279258880205651966"),alt_bn128_Fq("0"));
+    alt_bn128_Fq6::Frobenius_coeffs_c1[5] = alt_bn128_Fq2(alt_bn128_Fq("18429021223477853657660792034369865839114504446431234726392080002137598044644"),alt_bn128_Fq("9344045779998320333812420223237981029506012124075525679208581902008406485703"));
+    alt_bn128_Fq6::Frobenius_coeffs_c2[0] = alt_bn128_Fq2(alt_bn128_Fq("1"),alt_bn128_Fq("0"));
+    alt_bn128_Fq6::Frobenius_coeffs_c2[1] = alt_bn128_Fq2(alt_bn128_Fq("2581911344467009335267311115468803099551665605076196740867805258568234346338"),alt_bn128_Fq("19937756971775647987995932169929341994314640652964949448313374472400716661030"));
+    alt_bn128_Fq6::Frobenius_coeffs_c2[2] = alt_bn128_Fq2(alt_bn128_Fq("2203960485148121921418603742825762020974279258880205651966"),alt_bn128_Fq("0"));
+    alt_bn128_Fq6::Frobenius_coeffs_c2[3] = alt_bn128_Fq2(alt_bn128_Fq("5324479202449903542726783395506214481928257762400643279780343368557297135718"),alt_bn128_Fq("16208900380737693084919495127334387981393726419856888799917914180988844123039"));
+    alt_bn128_Fq6::Frobenius_coeffs_c2[4] = alt_bn128_Fq2(alt_bn128_Fq("21888242871839275220042445260109153167277707414472061641714758635765020556616"),alt_bn128_Fq("0"));
+    alt_bn128_Fq6::Frobenius_coeffs_c2[5] = alt_bn128_Fq2(alt_bn128_Fq("13981852324922362344252311234282257507216387789820983642040889267519694726527"),alt_bn128_Fq("7629828391165209371577384193250820201684255241773809077146787135900891633097"));
+
+    /* parameters for Fq12 */
+
+    alt_bn128_Fq12::non_residue = alt_bn128_Fq2(alt_bn128_Fq("9"),alt_bn128_Fq("1"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[0]  = alt_bn128_Fq2(alt_bn128_Fq("1"),alt_bn128_Fq("0"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[1]  = alt_bn128_Fq2(alt_bn128_Fq("8376118865763821496583973867626364092589906065868298776909617916018768340080"),alt_bn128_Fq("16469823323077808223889137241176536799009286646108169935659301613961712198316"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[2]  = alt_bn128_Fq2(alt_bn128_Fq("21888242871839275220042445260109153167277707414472061641714758635765020556617"),alt_bn128_Fq("0"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[3]  = alt_bn128_Fq2(alt_bn128_Fq("11697423496358154304825782922584725312912383441159505038794027105778954184319"),alt_bn128_Fq("303847389135065887422783454877609941456349188919719272345083954437860409601"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[4]  = alt_bn128_Fq2(alt_bn128_Fq("21888242871839275220042445260109153167277707414472061641714758635765020556616"),alt_bn128_Fq("0"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[5]  = alt_bn128_Fq2(alt_bn128_Fq("3321304630594332808241809054958361220322477375291206261884409189760185844239"),alt_bn128_Fq("5722266937896532885780051958958348231143373700109372999374820235121374419868"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[6]  = alt_bn128_Fq2(alt_bn128_Fq("21888242871839275222246405745257275088696311157297823662689037894645226208582"),alt_bn128_Fq("0"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[7]  = alt_bn128_Fq2(alt_bn128_Fq("13512124006075453725662431877630910996106405091429524885779419978626457868503"),alt_bn128_Fq("5418419548761466998357268504080738289687024511189653727029736280683514010267"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[8]  = alt_bn128_Fq2(alt_bn128_Fq("2203960485148121921418603742825762020974279258880205651966"),alt_bn128_Fq("0"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[9]  = alt_bn128_Fq2(alt_bn128_Fq("10190819375481120917420622822672549775783927716138318623895010788866272024264"),alt_bn128_Fq("21584395482704209334823622290379665147239961968378104390343953940207365798982"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[10] = alt_bn128_Fq2(alt_bn128_Fq("2203960485148121921418603742825762020974279258880205651967"),alt_bn128_Fq("0"));
+    alt_bn128_Fq12::Frobenius_coeffs_c1[11] = alt_bn128_Fq2(alt_bn128_Fq("18566938241244942414004596690298913868373833782006617400804628704885040364344"),alt_bn128_Fq("16165975933942742336466353786298926857552937457188450663314217659523851788715"));
+
+    /* choice of short Weierstrass curve and its twist */
+
+    alt_bn128_coeff_b = alt_bn128_Fq("3");
+    alt_bn128_twist = alt_bn128_Fq2(alt_bn128_Fq("9"), alt_bn128_Fq("1"));
+    alt_bn128_twist_coeff_b = alt_bn128_coeff_b * alt_bn128_twist.inverse();
+    alt_bn128_twist_mul_by_b_c0 = alt_bn128_coeff_b * alt_bn128_Fq2::non_residue;
+    alt_bn128_twist_mul_by_b_c1 = alt_bn128_coeff_b * alt_bn128_Fq2::non_residue;
+    alt_bn128_twist_mul_by_q_X = alt_bn128_Fq2(alt_bn128_Fq("21575463638280843010398324269430826099269044274347216827212613867836435027261"),
+                                           alt_bn128_Fq("10307601595873709700152284273816112264069230130616436755625194854815875713954"));
+    alt_bn128_twist_mul_by_q_Y = alt_bn128_Fq2(alt_bn128_Fq("2821565182194536844548159561693502659359617185244120367078079554186484126554"),
+                                           alt_bn128_Fq("3505843767911556378687030309984248845540243509899259641013678093033130930403"));
+
+    /* choice of group G1 */
+    alt_bn128_G1::G1_zero = alt_bn128_G1(alt_bn128_Fq::zero(),
+                                     alt_bn128_Fq::one(),
+                                     alt_bn128_Fq::zero());
+    alt_bn128_G1::G1_one = alt_bn128_G1(alt_bn128_Fq("1"),
+                                    alt_bn128_Fq("2"),
+                                    alt_bn128_Fq::one());
+    alt_bn128_G1::wnaf_window_table.push_back(11);
+    alt_bn128_G1::wnaf_window_table.push_back(24);
+    alt_bn128_G1::wnaf_window_table.push_back(60);
+    alt_bn128_G1::wnaf_window_table.push_back(127);
+
+    alt_bn128_G1::fixed_base_exp_window_table.resize(0);
+    // window 1 is unbeaten in [-inf, 4.99]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(1);
+    // window 2 is unbeaten in [4.99, 10.99]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(5);
+    // window 3 is unbeaten in [10.99, 32.29]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(11);
+    // window 4 is unbeaten in [32.29, 55.23]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(32);
+    // window 5 is unbeaten in [55.23, 162.03]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(55);
+    // window 6 is unbeaten in [162.03, 360.15]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(162);
+    // window 7 is unbeaten in [360.15, 815.44]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(360);
+    // window 8 is unbeaten in [815.44, 2373.07]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(815);
+    // window 9 is unbeaten in [2373.07, 6977.75]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(2373);
+    // window 10 is unbeaten in [6977.75, 7122.23]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(6978);
+    // window 11 is unbeaten in [7122.23, 57818.46]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(7122);
+    // window 12 is never the best
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(0);
+    // window 13 is unbeaten in [57818.46, 169679.14]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(57818);
+    // window 14 is never the best
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(0);
+    // window 15 is unbeaten in [169679.14, 439758.91]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(169679);
+    // window 16 is unbeaten in [439758.91, 936073.41]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(439759);
+    // window 17 is unbeaten in [936073.41, 4666554.74]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(936073);
+    // window 18 is never the best
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(0);
+    // window 19 is unbeaten in [4666554.74, 7580404.42]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(4666555);
+    // window 20 is unbeaten in [7580404.42, 34552892.20]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(7580404);
+    // window 21 is never the best
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(0);
+    // window 22 is unbeaten in [34552892.20, inf]
+    alt_bn128_G1::fixed_base_exp_window_table.push_back(34552892);
+
+    /* choice of group G2 */
+
+    alt_bn128_G2::G2_zero = alt_bn128_G2(alt_bn128_Fq2::zero(),
+                                     alt_bn128_Fq2::one(),
+                                     alt_bn128_Fq2::zero());
+
+    alt_bn128_G2::G2_one = alt_bn128_G2(alt_bn128_Fq2(alt_bn128_Fq("10857046999023057135944570762232829481370756359578518086990519993285655852781"),
+                                                alt_bn128_Fq("11559732032986387107991004021392285783925812861821192530917403151452391805634")),
+                                    alt_bn128_Fq2(alt_bn128_Fq("8495653923123431417604973247489272438418190587263600148770280649306958101930"),
+                                                alt_bn128_Fq("4082367875863433681332203403145435568316851327593401208105741076214120093531")),
+                                    alt_bn128_Fq2::one());
+    alt_bn128_G2::wnaf_window_table.push_back(5);
+    alt_bn128_G2::wnaf_window_table.push_back(15);
+    alt_bn128_G2::wnaf_window_table.push_back(39);
+    alt_bn128_G2::wnaf_window_table.push_back(109);
+
+    alt_bn128_G2::fixed_base_exp_window_table.resize(0);
+    // window 1 is unbeaten in [-inf, 5.10]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(1);
+    // window 2 is unbeaten in [5.10, 10.43]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(5);
+    // window 3 is unbeaten in [10.43, 25.28]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(10);
+    // window 4 is unbeaten in [25.28, 59.00]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(25);
+    // window 5 is unbeaten in [59.00, 154.03]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(59);
+    // window 6 is unbeaten in [154.03, 334.25]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(154);
+    // window 7 is unbeaten in [334.25, 742.58]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(334);
+    // window 8 is unbeaten in [742.58, 2034.40]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(743);
+    // window 9 is unbeaten in [2034.40, 4987.56]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(2034);
+    // window 10 is unbeaten in [4987.56, 8888.27]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(4988);
+    // window 11 is unbeaten in [8888.27, 26271.13]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(8888);
+    // window 12 is unbeaten in [26271.13, 39768.20]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(26271);
+    // window 13 is unbeaten in [39768.20, 106275.75]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(39768);
+    // window 14 is unbeaten in [106275.75, 141703.40]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(106276);
+    // window 15 is unbeaten in [141703.40, 462422.97]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(141703);
+    // window 16 is unbeaten in [462422.97, 926871.84]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(462423);
+    // window 17 is unbeaten in [926871.84, 4873049.17]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(926872);
+    // window 18 is never the best
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(0);
+    // window 19 is unbeaten in [4873049.17, 5706707.88]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(4873049);
+    // window 20 is unbeaten in [5706707.88, 31673814.95]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(5706708);
+    // window 21 is never the best
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(0);
+    // window 22 is unbeaten in [31673814.95, inf]
+    alt_bn128_G2::fixed_base_exp_window_table.push_back(31673815);
+
+    /* pairing parameters */
+
+    alt_bn128_ate_loop_count = bigint_q("29793968203157093288");
+    alt_bn128_ate_is_loop_count_neg = false;
+    alt_bn128_final_exponent = bigint<12*alt_bn128_q_limbs>("552484233613224096312617126783173147097382103762957654188882734314196910839907541213974502761540629817009608548654680343627701153829446747810907373256841551006201639677726139946029199968412598804882391702273019083653272047566316584365559776493027495458238373902875937659943504873220554161550525926302303331747463515644711876653177129578303191095900909191624817826566688241804408081892785725967931714097716709526092261278071952560171111444072049229123565057483750161460024353346284167282452756217662335528813519139808291170539072125381230815729071544861602750936964829313608137325426383735122175229541155376346436093930287402089517426973178917569713384748081827255472576937471496195752727188261435633271238710131736096299798168852925540549342330775279877006784354801422249722573783561685179618816480037695005515426162362431072245638324744480");
+    alt_bn128_final_exponent_z = bigint_q("4965661367192848881");
+    alt_bn128_final_exponent_is_z_neg = false;
+
+}
+} // libsnark
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_init.hpp b/src/algebra/curves/alt_bn128/alt_bn128_init.hpp
new file mode 100644 (file)
index 0000000..c3bea76
--- /dev/null
@@ -0,0 +1,57 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef ALT_BN128_INIT_HPP_
+#define ALT_BN128_INIT_HPP_
+#include "algebra/curves/public_params.hpp"
+#include "algebra/fields/fp.hpp"
+#include "algebra/fields/fp2.hpp"
+#include "algebra/fields/fp6_3over2.hpp"
+#include "algebra/fields/fp12_2over3over2.hpp"
+
+namespace libsnark {
+
+const mp_size_t alt_bn128_r_bitcount = 254;
+const mp_size_t alt_bn128_q_bitcount = 254;
+
+const mp_size_t alt_bn128_r_limbs = (alt_bn128_r_bitcount+GMP_NUMB_BITS-1)/GMP_NUMB_BITS;
+const mp_size_t alt_bn128_q_limbs = (alt_bn128_q_bitcount+GMP_NUMB_BITS-1)/GMP_NUMB_BITS;
+
+extern bigint<alt_bn128_r_limbs> alt_bn128_modulus_r;
+extern bigint<alt_bn128_q_limbs> alt_bn128_modulus_q;
+
+typedef Fp_model<alt_bn128_r_limbs, alt_bn128_modulus_r> alt_bn128_Fr;
+typedef Fp_model<alt_bn128_q_limbs, alt_bn128_modulus_q> alt_bn128_Fq;
+typedef Fp2_model<alt_bn128_q_limbs, alt_bn128_modulus_q> alt_bn128_Fq2;
+typedef Fp6_3over2_model<alt_bn128_q_limbs, alt_bn128_modulus_q> alt_bn128_Fq6;
+typedef Fp12_2over3over2_model<alt_bn128_q_limbs, alt_bn128_modulus_q> alt_bn128_Fq12;
+typedef alt_bn128_Fq12 alt_bn128_GT;
+
+// parameters for Barreto--Naehrig curve E/Fq : y^2 = x^3 + b
+extern alt_bn128_Fq alt_bn128_coeff_b;
+// parameters for twisted Barreto--Naehrig curve E'/Fq2 : y^2 = x^3 + b/xi
+extern alt_bn128_Fq2 alt_bn128_twist;
+extern alt_bn128_Fq2 alt_bn128_twist_coeff_b;
+extern alt_bn128_Fq alt_bn128_twist_mul_by_b_c0;
+extern alt_bn128_Fq alt_bn128_twist_mul_by_b_c1;
+extern alt_bn128_Fq2 alt_bn128_twist_mul_by_q_X;
+extern alt_bn128_Fq2 alt_bn128_twist_mul_by_q_Y;
+
+// parameters for pairing
+extern bigint<alt_bn128_q_limbs> alt_bn128_ate_loop_count;
+extern bool alt_bn128_ate_is_loop_count_neg;
+extern bigint<12*alt_bn128_q_limbs> alt_bn128_final_exponent;
+extern bigint<alt_bn128_q_limbs> alt_bn128_final_exponent_z;
+extern bool alt_bn128_final_exponent_is_z_neg;
+
+void init_alt_bn128_params();
+
+class alt_bn128_G1;
+class alt_bn128_G2;
+
+} // libsnark
+#endif // ALT_BN128_INIT_HPP_
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_pairing.cpp b/src/algebra/curves/alt_bn128/alt_bn128_pairing.cpp
new file mode 100644 (file)
index 0000000..db556c5
--- /dev/null
@@ -0,0 +1,547 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "algebra/curves/alt_bn128/alt_bn128_pairing.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_init.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_g1.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_g2.hpp"
+#include <cassert>
+#include "common/profiling.hpp"
+#include "common/assert_except.hpp"
+
+namespace libsnark {
+
+bool alt_bn128_ate_G1_precomp::operator==(const alt_bn128_ate_G1_precomp &other) const
+{
+    return (this->PX == other.PX &&
+            this->PY == other.PY);
+}
+
+std::ostream& operator<<(std::ostream &out, const alt_bn128_ate_G1_precomp &prec_P)
+{
+    out << prec_P.PX << OUTPUT_SEPARATOR << prec_P.PY;
+
+    return out;
+}
+
+std::istream& operator>>(std::istream &in, alt_bn128_ate_G1_precomp &prec_P)
+{
+    in >> prec_P.PX;
+    consume_OUTPUT_SEPARATOR(in);
+    in >> prec_P.PY;
+
+    return in;
+}
+
+bool  alt_bn128_ate_ell_coeffs::operator==(const alt_bn128_ate_ell_coeffs &other) const
+{
+    return (this->ell_0 == other.ell_0 &&
+            this->ell_VW == other.ell_VW &&
+            this->ell_VV == other.ell_VV);
+}
+
+std::ostream& operator<<(std::ostream &out, const alt_bn128_ate_ell_coeffs &c)
+{
+    out << c.ell_0 << OUTPUT_SEPARATOR << c.ell_VW << OUTPUT_SEPARATOR << c.ell_VV;
+    return out;
+}
+
+std::istream& operator>>(std::istream &in, alt_bn128_ate_ell_coeffs &c)
+{
+    in >> c.ell_0;
+    consume_OUTPUT_SEPARATOR(in);
+    in >> c.ell_VW;
+    consume_OUTPUT_SEPARATOR(in);
+    in >> c.ell_VV;
+
+    return in;
+}
+
+bool alt_bn128_ate_G2_precomp::operator==(const alt_bn128_ate_G2_precomp &other) const
+{
+    return (this->QX == other.QX &&
+            this->QY == other.QY &&
+            this->coeffs == other.coeffs);
+}
+
+std::ostream& operator<<(std::ostream& out, const alt_bn128_ate_G2_precomp &prec_Q)
+{
+    out << prec_Q.QX << OUTPUT_SEPARATOR << prec_Q.QY << "\n";
+    out << prec_Q.coeffs.size() << "\n";
+    for (const alt_bn128_ate_ell_coeffs &c : prec_Q.coeffs)
+    {
+        out << c << OUTPUT_NEWLINE;
+    }
+    return out;
+}
+
+std::istream& operator>>(std::istream& in, alt_bn128_ate_G2_precomp &prec_Q)
+{
+    in >> prec_Q.QX;
+    consume_OUTPUT_SEPARATOR(in);
+    in >> prec_Q.QY;
+    consume_newline(in);
+
+    prec_Q.coeffs.clear();
+    size_t s;
+    in >> s;
+
+    consume_newline(in);
+
+    prec_Q.coeffs.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        alt_bn128_ate_ell_coeffs c;
+        in >> c;
+        consume_OUTPUT_NEWLINE(in);
+        prec_Q.coeffs.emplace_back(c);
+    }
+
+    return in;
+}
+
+/* final exponentiations */
+
+alt_bn128_Fq12 alt_bn128_final_exponentiation_first_chunk(const alt_bn128_Fq12 &elt)
+{
+    enter_block("Call to alt_bn128_final_exponentiation_first_chunk");
+
+    /*
+      Computes result = elt^((q^6-1)*(q^2+1)).
+      Follows, e.g., Beuchat et al page 9, by computing result as follows:
+         elt^((q^6-1)*(q^2+1)) = (conj(elt) * elt^(-1))^(q^2+1)
+      More precisely:
+      A = conj(elt)
+      B = elt.inverse()
+      C = A * B
+      D = C.Frobenius_map(2)
+      result = D * C
+    */
+
+    const alt_bn128_Fq12 A = alt_bn128_Fq12(elt.c0,-elt.c1);
+    const alt_bn128_Fq12 B = elt.inverse();
+    const alt_bn128_Fq12 C = A * B;
+    const alt_bn128_Fq12 D = C.Frobenius_map(2);
+    const alt_bn128_Fq12 result = D * C;
+
+    leave_block("Call to alt_bn128_final_exponentiation_first_chunk");
+
+    return result;
+}
+
+alt_bn128_Fq12 alt_bn128_exp_by_neg_z(const alt_bn128_Fq12 &elt)
+{
+    enter_block("Call to alt_bn128_exp_by_neg_z");
+
+    alt_bn128_Fq12 result = elt.cyclotomic_exp(alt_bn128_final_exponent_z);
+    if (!alt_bn128_final_exponent_is_z_neg)
+    {
+        result = result.unitary_inverse();
+    }
+
+    leave_block("Call to alt_bn128_exp_by_neg_z");
+
+    return result;
+}
+
+alt_bn128_Fq12 alt_bn128_final_exponentiation_last_chunk(const alt_bn128_Fq12 &elt)
+{
+    enter_block("Call to alt_bn128_final_exponentiation_last_chunk");
+
+    /*
+      Follows Laura Fuentes-Castaneda et al. "Faster hashing to G2"
+      by computing:
+
+      result = elt^(q^3 * (12*z^3 + 6z^2 + 4z - 1) +
+                    q^2 * (12*z^3 + 6z^2 + 6z) +
+                    q   * (12*z^3 + 6z^2 + 4z) +
+                    1   * (12*z^3 + 12z^2 + 6z + 1))
+      which equals
+
+      result = elt^( 2z * ( 6z^2 + 3z + 1 ) * (q^4 - q^2 + 1)/r ).
+
+      Using the following addition chain:
+
+      A = exp_by_neg_z(elt)  // = elt^(-z)
+      B = A^2                // = elt^(-2*z)
+      C = B^2                // = elt^(-4*z)
+      D = C * B              // = elt^(-6*z)
+      E = exp_by_neg_z(D)    // = elt^(6*z^2)
+      F = E^2                // = elt^(12*z^2)
+      G = epx_by_neg_z(F)    // = elt^(-12*z^3)
+      H = conj(D)            // = elt^(6*z)
+      I = conj(G)            // = elt^(12*z^3)
+      J = I * E              // = elt^(12*z^3 + 6*z^2)
+      K = J * H              // = elt^(12*z^3 + 6*z^2 + 6*z)
+      L = K * B              // = elt^(12*z^3 + 6*z^2 + 4*z)
+      M = K * E              // = elt^(12*z^3 + 12*z^2 + 6*z)
+      N = M * elt            // = elt^(12*z^3 + 12*z^2 + 6*z + 1)
+      O = L.Frobenius_map(1) // = elt^(q*(12*z^3 + 6*z^2 + 4*z))
+      P = O * N              // = elt^(q*(12*z^3 + 6*z^2 + 4*z) * (12*z^3 + 12*z^2 + 6*z + 1))
+      Q = K.Frobenius_map(2) // = elt^(q^2 * (12*z^3 + 6*z^2 + 6*z))
+      R = Q * P              // = elt^(q^2 * (12*z^3 + 6*z^2 + 6*z) + q*(12*z^3 + 6*z^2 + 4*z) * (12*z^3 + 12*z^2 + 6*z + 1))
+      S = conj(elt)          // = elt^(-1)
+      T = S * L              // = elt^(12*z^3 + 6*z^2 + 4*z - 1)
+      U = T.Frobenius_map(3) // = elt^(q^3(12*z^3 + 6*z^2 + 4*z - 1))
+      V = U * R              // = elt^(q^3(12*z^3 + 6*z^2 + 4*z - 1) + q^2 * (12*z^3 + 6*z^2 + 6*z) + q*(12*z^3 + 6*z^2 + 4*z) * (12*z^3 + 12*z^2 + 6*z + 1))
+      result = V
+
+    */
+
+    const alt_bn128_Fq12 A = alt_bn128_exp_by_neg_z(elt);
+    const alt_bn128_Fq12 B = A.cyclotomic_squared();
+    const alt_bn128_Fq12 C = B.cyclotomic_squared();
+    const alt_bn128_Fq12 D = C * B;
+    const alt_bn128_Fq12 E = alt_bn128_exp_by_neg_z(D);
+    const alt_bn128_Fq12 F = E.cyclotomic_squared();
+    const alt_bn128_Fq12 G = alt_bn128_exp_by_neg_z(F);
+    const alt_bn128_Fq12 H = D.unitary_inverse();
+    const alt_bn128_Fq12 I = G.unitary_inverse();
+    const alt_bn128_Fq12 J = I * E;
+    const alt_bn128_Fq12 K = J * H;
+    const alt_bn128_Fq12 L = K * B;
+    const alt_bn128_Fq12 M = K * E;
+    const alt_bn128_Fq12 N = M * elt;
+    const alt_bn128_Fq12 O = L.Frobenius_map(1);
+    const alt_bn128_Fq12 P = O * N;
+    const alt_bn128_Fq12 Q = K.Frobenius_map(2);
+    const alt_bn128_Fq12 R = Q * P;
+    const alt_bn128_Fq12 S = elt.unitary_inverse();
+    const alt_bn128_Fq12 T = S * L;
+    const alt_bn128_Fq12 U = T.Frobenius_map(3);
+    const alt_bn128_Fq12 V = U * R;
+
+    const alt_bn128_Fq12 result = V;
+
+    leave_block("Call to alt_bn128_final_exponentiation_last_chunk");
+
+    return result;
+}
+
+alt_bn128_GT alt_bn128_final_exponentiation(const alt_bn128_Fq12 &elt)
+{
+    enter_block("Call to alt_bn128_final_exponentiation");
+    /* OLD naive version:
+        alt_bn128_GT result = elt^alt_bn128_final_exponent;
+    */
+    alt_bn128_Fq12 A = alt_bn128_final_exponentiation_first_chunk(elt);
+    alt_bn128_GT result = alt_bn128_final_exponentiation_last_chunk(A);
+
+    leave_block("Call to alt_bn128_final_exponentiation");
+    return result;
+}
+
+/* ate pairing */
+
+void doubling_step_for_flipped_miller_loop(const alt_bn128_Fq two_inv,
+                                           alt_bn128_G2 &current,
+                                           alt_bn128_ate_ell_coeffs &c)
+{
+    const alt_bn128_Fq2 X = current.X, Y = current.Y, Z = current.Z;
+
+    const alt_bn128_Fq2 A = two_inv * (X * Y);                     // A = X1 * Y1 / 2
+    const alt_bn128_Fq2 B = Y.squared();                           // B = Y1^2
+    const alt_bn128_Fq2 C = Z.squared();                           // C = Z1^2
+    const alt_bn128_Fq2 D = C+C+C;                                 // D = 3 * C
+    const alt_bn128_Fq2 E = alt_bn128_twist_coeff_b * D;             // E = twist_b * D
+    const alt_bn128_Fq2 F = E+E+E;                                 // F = 3 * E
+    const alt_bn128_Fq2 G = two_inv * (B+F);                       // G = (B+F)/2
+    const alt_bn128_Fq2 H = (Y+Z).squared() - (B+C);               // H = (Y1+Z1)^2-(B+C)
+    const alt_bn128_Fq2 I = E-B;                                   // I = E-B
+    const alt_bn128_Fq2 J = X.squared();                           // J = X1^2
+    const alt_bn128_Fq2 E_squared = E.squared();                   // E_squared = E^2
+
+    current.X = A * (B-F);                                       // X3 = A * (B-F)
+    current.Y = G.squared() - (E_squared+E_squared+E_squared);   // Y3 = G^2 - 3*E^2
+    current.Z = B * H;                                           // Z3 = B * H
+    c.ell_0 = alt_bn128_twist * I;                                 // ell_0 = xi * I
+    c.ell_VW = -H;                                               // ell_VW = - H (later: * yP)
+    c.ell_VV = J+J+J;                                            // ell_VV = 3*J (later: * xP)
+}
+
+void mixed_addition_step_for_flipped_miller_loop(const alt_bn128_G2 base,
+                                                 alt_bn128_G2 &current,
+                                                 alt_bn128_ate_ell_coeffs &c)
+{
+    const alt_bn128_Fq2 X1 = current.X, Y1 = current.Y, Z1 = current.Z;
+    const alt_bn128_Fq2 &x2 = base.X, &y2 = base.Y;
+
+    const alt_bn128_Fq2 D = X1 - x2 * Z1;          // D = X1 - X2*Z1
+    const alt_bn128_Fq2 E = Y1 - y2 * Z1;          // E = Y1 - Y2*Z1
+    const alt_bn128_Fq2 F = D.squared();           // F = D^2
+    const alt_bn128_Fq2 G = E.squared();           // G = E^2
+    const alt_bn128_Fq2 H = D*F;                   // H = D*F
+    const alt_bn128_Fq2 I = X1 * F;                // I = X1 * F
+    const alt_bn128_Fq2 J = H + Z1*G - (I+I);      // J = H + Z1*G - (I+I)
+
+    current.X = D * J;                           // X3 = D*J
+    current.Y = E * (I-J)-(H * Y1);              // Y3 = E*(I-J)-(H*Y1)
+    current.Z = Z1 * H;                          // Z3 = Z1*H
+    c.ell_0 = alt_bn128_twist * (E * x2 - D * y2); // ell_0 = xi * (E * X2 - D * Y2)
+    c.ell_VV = - E;                              // ell_VV = - E (later: * xP)
+    c.ell_VW = D;                                // ell_VW = D (later: * yP    )
+}
+
+alt_bn128_ate_G1_precomp alt_bn128_ate_precompute_G1(const alt_bn128_G1& P)
+{
+    enter_block("Call to alt_bn128_ate_precompute_G1");
+
+    alt_bn128_G1 Pcopy = P;
+    Pcopy.to_affine_coordinates();
+
+    alt_bn128_ate_G1_precomp result;
+    result.PX = Pcopy.X;
+    result.PY = Pcopy.Y;
+
+    leave_block("Call to alt_bn128_ate_precompute_G1");
+    return result;
+}
+
+alt_bn128_ate_G2_precomp alt_bn128_ate_precompute_G2(const alt_bn128_G2& Q)
+{
+    enter_block("Call to alt_bn128_ate_precompute_G2");
+
+    alt_bn128_G2 Qcopy(Q);
+    Qcopy.to_affine_coordinates();
+
+    alt_bn128_Fq two_inv = (alt_bn128_Fq("2").inverse()); // could add to global params if needed
+
+    alt_bn128_ate_G2_precomp result;
+    result.QX = Qcopy.X;
+    result.QY = Qcopy.Y;
+
+    alt_bn128_G2 R;
+    R.X = Qcopy.X;
+    R.Y = Qcopy.Y;
+    R.Z = alt_bn128_Fq2::one();
+
+    const bigint<alt_bn128_Fr::num_limbs> &loop_count = alt_bn128_ate_loop_count;
+    bool found_one = false;
+    alt_bn128_ate_ell_coeffs c;
+
+    for (long i = loop_count.max_bits(); i >= 0; --i)
+    {
+        const bool bit = loop_count.test_bit(i);
+        if (!found_one)
+        {
+            /* this skips the MSB itself */
+            found_one |= bit;
+            continue;
+        }
+
+        doubling_step_for_flipped_miller_loop(two_inv, R, c);
+        result.coeffs.push_back(c);
+
+        if (bit)
+        {
+            mixed_addition_step_for_flipped_miller_loop(Qcopy, R, c);
+            result.coeffs.push_back(c);
+        }
+    }
+
+    alt_bn128_G2 Q1 = Qcopy.mul_by_q();
+    assert_except(Q1.Z == alt_bn128_Fq2::one());
+    alt_bn128_G2 Q2 = Q1.mul_by_q();
+    assert_except(Q2.Z == alt_bn128_Fq2::one());
+
+    if (alt_bn128_ate_is_loop_count_neg)
+    {
+        R.Y = - R.Y;
+    }
+    Q2.Y = - Q2.Y;
+
+    mixed_addition_step_for_flipped_miller_loop(Q1, R, c);
+    result.coeffs.push_back(c);
+
+    mixed_addition_step_for_flipped_miller_loop(Q2, R, c);
+    result.coeffs.push_back(c);
+
+    leave_block("Call to alt_bn128_ate_precompute_G2");
+    return result;
+}
+
+alt_bn128_Fq12 alt_bn128_ate_miller_loop(const alt_bn128_ate_G1_precomp &prec_P,
+                                     const alt_bn128_ate_G2_precomp &prec_Q)
+{
+    enter_block("Call to alt_bn128_ate_miller_loop");
+
+    alt_bn128_Fq12 f = alt_bn128_Fq12::one();
+
+    bool found_one = false;
+    size_t idx = 0;
+
+    const bigint<alt_bn128_Fr::num_limbs> &loop_count = alt_bn128_ate_loop_count;
+    alt_bn128_ate_ell_coeffs c;
+
+    for (long i = loop_count.max_bits(); i >= 0; --i)
+    {
+        const bool bit = loop_count.test_bit(i);
+        if (!found_one)
+        {
+            /* this skips the MSB itself */
+            found_one |= bit;
+            continue;
+        }
+
+        /* code below gets executed for all bits (EXCEPT the MSB itself) of
+           alt_bn128_param_p (skipping leading zeros) in MSB to LSB
+           order */
+
+        c = prec_Q.coeffs[idx++];
+        f = f.squared();
+        f = f.mul_by_024(c.ell_0, prec_P.PY * c.ell_VW, prec_P.PX * c.ell_VV);
+
+        if (bit)
+        {
+            c = prec_Q.coeffs[idx++];
+            f = f.mul_by_024(c.ell_0, prec_P.PY * c.ell_VW, prec_P.PX * c.ell_VV);
+        }
+
+    }
+
+    if (alt_bn128_ate_is_loop_count_neg)
+    {
+       f = f.inverse();
+    }
+
+    c = prec_Q.coeffs[idx++];
+    f = f.mul_by_024(c.ell_0,prec_P.PY * c.ell_VW,prec_P.PX * c.ell_VV);
+
+    c = prec_Q.coeffs[idx++];
+    f = f.mul_by_024(c.ell_0,prec_P.PY * c.ell_VW,prec_P.PX * c.ell_VV);
+
+    leave_block("Call to alt_bn128_ate_miller_loop");
+    return f;
+}
+
+alt_bn128_Fq12 alt_bn128_ate_double_miller_loop(const alt_bn128_ate_G1_precomp &prec_P1,
+                                     const alt_bn128_ate_G2_precomp &prec_Q1,
+                                     const alt_bn128_ate_G1_precomp &prec_P2,
+                                     const alt_bn128_ate_G2_precomp &prec_Q2)
+{
+    enter_block("Call to alt_bn128_ate_double_miller_loop");
+
+    alt_bn128_Fq12 f = alt_bn128_Fq12::one();
+
+    bool found_one = false;
+    size_t idx = 0;
+
+    const bigint<alt_bn128_Fr::num_limbs> &loop_count = alt_bn128_ate_loop_count;
+    for (long i = loop_count.max_bits(); i >= 0; --i)
+    {
+        const bool bit = loop_count.test_bit(i);
+        if (!found_one)
+        {
+            /* this skips the MSB itself */
+            found_one |= bit;
+            continue;
+        }
+
+        /* code below gets executed for all bits (EXCEPT the MSB itself) of
+           alt_bn128_param_p (skipping leading zeros) in MSB to LSB
+           order */
+
+        alt_bn128_ate_ell_coeffs c1 = prec_Q1.coeffs[idx];
+        alt_bn128_ate_ell_coeffs c2 = prec_Q2.coeffs[idx];
+        ++idx;
+
+        f = f.squared();
+
+        f = f.mul_by_024(c1.ell_0, prec_P1.PY * c1.ell_VW, prec_P1.PX * c1.ell_VV);
+        f = f.mul_by_024(c2.ell_0, prec_P2.PY * c2.ell_VW, prec_P2.PX * c2.ell_VV);
+
+        if (bit)
+        {
+            alt_bn128_ate_ell_coeffs c1 = prec_Q1.coeffs[idx];
+            alt_bn128_ate_ell_coeffs c2 = prec_Q2.coeffs[idx];
+            ++idx;
+
+            f = f.mul_by_024(c1.ell_0, prec_P1.PY * c1.ell_VW, prec_P1.PX * c1.ell_VV);
+            f = f.mul_by_024(c2.ell_0, prec_P2.PY * c2.ell_VW, prec_P2.PX * c2.ell_VV);
+        }
+    }
+
+    if (alt_bn128_ate_is_loop_count_neg)
+    {
+       f = f.inverse();
+    }
+
+    alt_bn128_ate_ell_coeffs c1 = prec_Q1.coeffs[idx];
+    alt_bn128_ate_ell_coeffs c2 = prec_Q2.coeffs[idx];
+    ++idx;
+    f = f.mul_by_024(c1.ell_0, prec_P1.PY * c1.ell_VW, prec_P1.PX * c1.ell_VV);
+    f = f.mul_by_024(c2.ell_0, prec_P2.PY * c2.ell_VW, prec_P2.PX * c2.ell_VV);
+
+    c1 = prec_Q1.coeffs[idx];
+    c2 = prec_Q2.coeffs[idx];
+    ++idx;
+    f = f.mul_by_024(c1.ell_0, prec_P1.PY * c1.ell_VW, prec_P1.PX * c1.ell_VV);
+    f = f.mul_by_024(c2.ell_0, prec_P2.PY * c2.ell_VW, prec_P2.PX * c2.ell_VV);
+
+    leave_block("Call to alt_bn128_ate_double_miller_loop");
+
+    return f;
+}
+
+alt_bn128_Fq12 alt_bn128_ate_pairing(const alt_bn128_G1& P, const alt_bn128_G2 &Q)
+{
+    enter_block("Call to alt_bn128_ate_pairing");
+    alt_bn128_ate_G1_precomp prec_P = alt_bn128_ate_precompute_G1(P);
+    alt_bn128_ate_G2_precomp prec_Q = alt_bn128_ate_precompute_G2(Q);
+    alt_bn128_Fq12 result = alt_bn128_ate_miller_loop(prec_P, prec_Q);
+    leave_block("Call to alt_bn128_ate_pairing");
+    return result;
+}
+
+alt_bn128_GT alt_bn128_ate_reduced_pairing(const alt_bn128_G1 &P, const alt_bn128_G2 &Q)
+{
+    enter_block("Call to alt_bn128_ate_reduced_pairing");
+    const alt_bn128_Fq12 f = alt_bn128_ate_pairing(P, Q);
+    const alt_bn128_GT result = alt_bn128_final_exponentiation(f);
+    leave_block("Call to alt_bn128_ate_reduced_pairing");
+    return result;
+}
+
+/* choice of pairing */
+
+alt_bn128_G1_precomp alt_bn128_precompute_G1(const alt_bn128_G1& P)
+{
+    return alt_bn128_ate_precompute_G1(P);
+}
+
+alt_bn128_G2_precomp alt_bn128_precompute_G2(const alt_bn128_G2& Q)
+{
+    return alt_bn128_ate_precompute_G2(Q);
+}
+
+alt_bn128_Fq12 alt_bn128_miller_loop(const alt_bn128_G1_precomp &prec_P,
+                          const alt_bn128_G2_precomp &prec_Q)
+{
+    return alt_bn128_ate_miller_loop(prec_P, prec_Q);
+}
+
+alt_bn128_Fq12 alt_bn128_double_miller_loop(const alt_bn128_G1_precomp &prec_P1,
+                                 const alt_bn128_G2_precomp &prec_Q1,
+                                 const alt_bn128_G1_precomp &prec_P2,
+                                 const alt_bn128_G2_precomp &prec_Q2)
+{
+    return alt_bn128_ate_double_miller_loop(prec_P1, prec_Q1, prec_P2, prec_Q2);
+}
+
+alt_bn128_Fq12 alt_bn128_pairing(const alt_bn128_G1& P,
+                      const alt_bn128_G2 &Q)
+{
+    return alt_bn128_ate_pairing(P, Q);
+}
+
+alt_bn128_GT alt_bn128_reduced_pairing(const alt_bn128_G1 &P,
+                             const alt_bn128_G2 &Q)
+{
+    return alt_bn128_ate_reduced_pairing(P, Q);
+}
+} // libsnark
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_pairing.hpp b/src/algebra/curves/alt_bn128/alt_bn128_pairing.hpp
new file mode 100644 (file)
index 0000000..15d3254
--- /dev/null
@@ -0,0 +1,92 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef ALT_BN128_PAIRING_HPP_
+#define ALT_BN128_PAIRING_HPP_
+#include <vector>
+#include "algebra/curves/alt_bn128/alt_bn128_init.hpp"
+
+namespace libsnark {
+
+/* final exponentiation */
+
+alt_bn128_GT alt_bn128_final_exponentiation(const alt_bn128_Fq12 &elt);
+
+/* ate pairing */
+
+struct alt_bn128_ate_G1_precomp {
+    alt_bn128_Fq PX;
+    alt_bn128_Fq PY;
+
+    bool operator==(const alt_bn128_ate_G1_precomp &other) const;
+    friend std::ostream& operator<<(std::ostream &out, const alt_bn128_ate_G1_precomp &prec_P);
+    friend std::istream& operator>>(std::istream &in, alt_bn128_ate_G1_precomp &prec_P);
+};
+
+struct alt_bn128_ate_ell_coeffs {
+    alt_bn128_Fq2 ell_0;
+    alt_bn128_Fq2 ell_VW;
+    alt_bn128_Fq2 ell_VV;
+
+    bool operator==(const alt_bn128_ate_ell_coeffs &other) const;
+    friend std::ostream& operator<<(std::ostream &out, const alt_bn128_ate_ell_coeffs &dc);
+    friend std::istream& operator>>(std::istream &in, alt_bn128_ate_ell_coeffs &dc);
+};
+
+struct alt_bn128_ate_G2_precomp {
+    alt_bn128_Fq2 QX;
+    alt_bn128_Fq2 QY;
+    std::vector<alt_bn128_ate_ell_coeffs> coeffs;
+
+    bool operator==(const alt_bn128_ate_G2_precomp &other) const;
+    friend std::ostream& operator<<(std::ostream &out, const alt_bn128_ate_G2_precomp &prec_Q);
+    friend std::istream& operator>>(std::istream &in, alt_bn128_ate_G2_precomp &prec_Q);
+};
+
+alt_bn128_ate_G1_precomp alt_bn128_ate_precompute_G1(const alt_bn128_G1& P);
+alt_bn128_ate_G2_precomp alt_bn128_ate_precompute_G2(const alt_bn128_G2& Q);
+
+alt_bn128_Fq12 alt_bn128_ate_miller_loop(const alt_bn128_ate_G1_precomp &prec_P,
+                              const alt_bn128_ate_G2_precomp &prec_Q);
+alt_bn128_Fq12 alt_bn128_ate_double_miller_loop(const alt_bn128_ate_G1_precomp &prec_P1,
+                                     const alt_bn128_ate_G2_precomp &prec_Q1,
+                                     const alt_bn128_ate_G1_precomp &prec_P2,
+                                     const alt_bn128_ate_G2_precomp &prec_Q2);
+
+alt_bn128_Fq12 alt_bn128_ate_pairing(const alt_bn128_G1& P,
+                          const alt_bn128_G2 &Q);
+alt_bn128_GT alt_bn128_ate_reduced_pairing(const alt_bn128_G1 &P,
+                                 const alt_bn128_G2 &Q);
+
+/* choice of pairing */
+
+typedef alt_bn128_ate_G1_precomp alt_bn128_G1_precomp;
+typedef alt_bn128_ate_G2_precomp alt_bn128_G2_precomp;
+
+alt_bn128_G1_precomp alt_bn128_precompute_G1(const alt_bn128_G1& P);
+
+alt_bn128_G2_precomp alt_bn128_precompute_G2(const alt_bn128_G2& Q);
+
+alt_bn128_Fq12 alt_bn128_miller_loop(const alt_bn128_G1_precomp &prec_P,
+                          const alt_bn128_G2_precomp &prec_Q);
+
+alt_bn128_Fq12 alt_bn128_double_miller_loop(const alt_bn128_G1_precomp &prec_P1,
+                                 const alt_bn128_G2_precomp &prec_Q1,
+                                 const alt_bn128_G1_precomp &prec_P2,
+                                 const alt_bn128_G2_precomp &prec_Q2);
+
+alt_bn128_Fq12 alt_bn128_pairing(const alt_bn128_G1& P,
+                      const alt_bn128_G2 &Q);
+
+alt_bn128_GT alt_bn128_reduced_pairing(const alt_bn128_G1 &P,
+                             const alt_bn128_G2 &Q);
+
+alt_bn128_GT alt_bn128_affine_reduced_pairing(const alt_bn128_G1 &P,
+                                    const alt_bn128_G2 &Q);
+
+} // libsnark
+#endif // ALT_BN128_PAIRING_HPP_
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_pp.cpp b/src/algebra/curves/alt_bn128/alt_bn128_pp.cpp
new file mode 100644 (file)
index 0000000..25ea924
--- /dev/null
@@ -0,0 +1,58 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "algebra/curves/alt_bn128/alt_bn128_pp.hpp"
+
+namespace libsnark {
+
+void alt_bn128_pp::init_public_params()
+{
+    init_alt_bn128_params();
+}
+
+alt_bn128_GT alt_bn128_pp::final_exponentiation(const alt_bn128_Fq12 &elt)
+{
+    return alt_bn128_final_exponentiation(elt);
+}
+
+alt_bn128_G1_precomp alt_bn128_pp::precompute_G1(const alt_bn128_G1 &P)
+{
+    return alt_bn128_precompute_G1(P);
+}
+
+alt_bn128_G2_precomp alt_bn128_pp::precompute_G2(const alt_bn128_G2 &Q)
+{
+    return alt_bn128_precompute_G2(Q);
+}
+
+alt_bn128_Fq12 alt_bn128_pp::miller_loop(const alt_bn128_G1_precomp &prec_P,
+                                         const alt_bn128_G2_precomp &prec_Q)
+{
+    return alt_bn128_miller_loop(prec_P, prec_Q);
+}
+
+alt_bn128_Fq12 alt_bn128_pp::double_miller_loop(const alt_bn128_G1_precomp &prec_P1,
+                                                const alt_bn128_G2_precomp &prec_Q1,
+                                                const alt_bn128_G1_precomp &prec_P2,
+                                                const alt_bn128_G2_precomp &prec_Q2)
+{
+    return alt_bn128_double_miller_loop(prec_P1, prec_Q1, prec_P2, prec_Q2);
+}
+
+alt_bn128_Fq12 alt_bn128_pp::pairing(const alt_bn128_G1 &P,
+                                     const alt_bn128_G2 &Q)
+{
+    return alt_bn128_pairing(P, Q);
+}
+
+alt_bn128_Fq12 alt_bn128_pp::reduced_pairing(const alt_bn128_G1 &P,
+                                             const alt_bn128_G2 &Q)
+{
+    return alt_bn128_reduced_pairing(P, Q);
+}
+
+} // libsnark
diff --git a/src/algebra/curves/alt_bn128/alt_bn128_pp.hpp b/src/algebra/curves/alt_bn128/alt_bn128_pp.hpp
new file mode 100644 (file)
index 0000000..ec8059d
--- /dev/null
@@ -0,0 +1,50 @@
+/** @file
+*****************************************************************************
+* @author     This file is part of libsnark, developed by SCIPR Lab
+*             and contributors (see AUTHORS).
+* @copyright  MIT license (see LICENSE file)
+*****************************************************************************/
+
+#ifndef ALT_BN128_PP_HPP_
+#define ALT_BN128_PP_HPP_
+#include "algebra/curves/public_params.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_init.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_g1.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_g2.hpp"
+#include "algebra/curves/alt_bn128/alt_bn128_pairing.hpp"
+
+namespace libsnark {
+
+class alt_bn128_pp {
+public:
+    typedef alt_bn128_Fr Fp_type;
+    typedef alt_bn128_G1 G1_type;
+    typedef alt_bn128_G2 G2_type;
+    typedef alt_bn128_G1_precomp G1_precomp_type;
+    typedef alt_bn128_G2_precomp G2_precomp_type;
+    typedef alt_bn128_Fq Fq_type;
+    typedef alt_bn128_Fq2 Fqe_type;
+    typedef alt_bn128_Fq12 Fqk_type;
+    typedef alt_bn128_GT GT_type;
+
+    static const bool has_affine_pairing = false;
+
+    static void init_public_params();
+    static alt_bn128_GT final_exponentiation(const alt_bn128_Fq12 &elt);
+    static alt_bn128_G1_precomp precompute_G1(const alt_bn128_G1 &P);
+    static alt_bn128_G2_precomp precompute_G2(const alt_bn128_G2 &Q);
+    static alt_bn128_Fq12 miller_loop(const alt_bn128_G1_precomp &prec_P,
+                                      const alt_bn128_G2_precomp &prec_Q);
+    static alt_bn128_Fq12 double_miller_loop(const alt_bn128_G1_precomp &prec_P1,
+                                             const alt_bn128_G2_precomp &prec_Q1,
+                                             const alt_bn128_G1_precomp &prec_P2,
+                                             const alt_bn128_G2_precomp &prec_Q2);
+    static alt_bn128_Fq12 pairing(const alt_bn128_G1 &P,
+                                  const alt_bn128_G2 &Q);
+    static alt_bn128_Fq12 reduced_pairing(const alt_bn128_G1 &P,
+                                          const alt_bn128_G2 &Q);
+};
+
+} // libsnark
+
+#endif // ALT_BN128_PP_HPP_
diff --git a/src/algebra/curves/curve_utils.hpp b/src/algebra/curves/curve_utils.hpp
new file mode 100644 (file)
index 0000000..33a8e1e
--- /dev/null
@@ -0,0 +1,22 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef CURVE_UTILS_HPP_
+#define CURVE_UTILS_HPP_
+#include <cstdint>
+
+#include "algebra/fields/bigint.hpp"
+
+namespace libsnark {
+
+template<typename GroupT, mp_size_t m>
+GroupT scalar_mul(const GroupT &base, const bigint<m> &scalar);
+
+} // libsnark
+#include "algebra/curves/curve_utils.tcc"
+
+#endif // CURVE_UTILS_HPP_
diff --git a/src/algebra/curves/curve_utils.tcc b/src/algebra/curves/curve_utils.tcc
new file mode 100644 (file)
index 0000000..251d75d
--- /dev/null
@@ -0,0 +1,37 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef CURVE_UTILS_TCC_
+#define CURVE_UTILS_TCC_
+
+namespace libsnark {
+
+template<typename GroupT, mp_size_t m>
+GroupT scalar_mul(const GroupT &base, const bigint<m> &scalar)
+{
+    GroupT result = GroupT::zero();
+
+    bool found_one = false;
+    for (long i = scalar.max_bits() - 1; i >= 0; --i)
+    {
+        if (found_one)
+        {
+            result = result.dbl();
+        }
+
+        if (scalar.test_bit(i))
+        {
+            found_one = true;
+            result = result + base;
+        }
+    }
+
+    return result;
+}
+
+} // libsnark
+#endif // CURVE_UTILS_TCC_
diff --git a/src/algebra/curves/public_params.hpp b/src/algebra/curves/public_params.hpp
new file mode 100644 (file)
index 0000000..07e0475
--- /dev/null
@@ -0,0 +1,103 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef PUBLIC_PARAMS_HPP_
+#define PUBLIC_PARAMS_HPP_
+#include <vector>
+
+namespace libsnark {
+
+/*
+  for every curve the user should define corresponding
+  public_params with the following typedefs:
+
+  Fp_type
+  G1_type
+  G2_type
+  G1_precomp_type
+  G2_precomp_type
+  affine_ate_G1_precomp_type
+  affine_ate_G2_precomp_type
+  Fq_type
+  Fqe_type
+  Fqk_type
+  GT_type
+
+  one should also define the following static methods:
+
+  void init_public_params();
+
+  GT<EC_ppT> final_exponentiation(const Fqk<EC_ppT> &elt);
+
+  G1_precomp<EC_ppT> precompute_G1(const G1<EC_ppT> &P);
+  G2_precomp<EC_ppT> precompute_G2(const G2<EC_ppT> &Q);
+
+  Fqk<EC_ppT> miller_loop(const G1_precomp<EC_ppT> &prec_P,
+                          const G2_precomp<EC_ppT> &prec_Q);
+
+  affine_ate_G1_precomp<EC_ppT> affine_ate_precompute_G1(const G1<EC_ppT> &P);
+  affine_ate_G2_precomp<EC_ppT> affine_ate_precompute_G2(const G2<EC_ppT> &Q);
+
+
+  Fqk<EC_ppT> affine_ate_miller_loop(const affine_ate_G1_precomp<EC_ppT> &prec_P,
+                                     const affine_ate_G2_precomp<EC_ppT> &prec_Q);
+  Fqk<EC_ppT> affine_ate_e_over_e_miller_loop(const affine_ate_G1_precomp<EC_ppT> &prec_P1,
+                                              const affine_ate_G2_precomp<EC_ppT> &prec_Q1,
+                                              const affine_ate_G1_precomp<EC_ppT> &prec_P2,
+                                              const affine_ate_G2_precomp<EC_ppT> &prec_Q2);
+  Fqk<EC_ppT> affine_ate_e_times_e_over_e_miller_loop(const affine_ate_G1_precomp<EC_ppT> &prec_P1,
+                                                      const affine_ate_G2_precomp<EC_ppT> &prec_Q1,
+                                                      const affine_ate_G1_precomp<EC_ppT> &prec_P2,
+                                                      const affine_ate_G2_precomp<EC_ppT> &prec_Q2,
+                                                      const affine_ate_G1_precomp<EC_ppT> &prec_P3,
+                                                      const affine_ate_G2_precomp<EC_ppT> &prec_Q3);
+  Fqk<EC_ppT> double_miller_loop(const G1_precomp<EC_ppT> &prec_P1,
+                                 const G2_precomp<EC_ppT> &prec_Q1,
+                                 const G1_precomp<EC_ppT> &prec_P2,
+                                 const G2_precomp<EC_ppT> &prec_Q2);
+
+  Fqk<EC_ppT> pairing(const G1<EC_ppT> &P,
+                      const G2<EC_ppT> &Q);
+  GT<EC_ppT> reduced_pairing(const G1<EC_ppT> &P,
+                             const G2<EC_ppT> &Q);
+  GT<EC_ppT> affine_reduced_pairing(const G1<EC_ppT> &P,
+                                    const G2<EC_ppT> &Q);
+*/
+
+template<typename EC_ppT>
+using Fr = typename EC_ppT::Fp_type;
+template<typename EC_ppT>
+using G1 = typename EC_ppT::G1_type;
+template<typename EC_ppT>
+using G2 = typename EC_ppT::G2_type;
+template<typename EC_ppT>
+using G1_precomp = typename EC_ppT::G1_precomp_type;
+template<typename EC_ppT>
+using G2_precomp = typename EC_ppT::G2_precomp_type;
+template<typename EC_ppT>
+using affine_ate_G1_precomp = typename EC_ppT::affine_ate_G1_precomp_type;
+template<typename EC_ppT>
+using affine_ate_G2_precomp = typename EC_ppT::affine_ate_G2_precomp_type;
+template<typename EC_ppT>
+using Fq = typename EC_ppT::Fq_type;
+template<typename EC_ppT>
+using Fqe = typename EC_ppT::Fqe_type;
+template<typename EC_ppT>
+using Fqk = typename EC_ppT::Fqk_type;
+template<typename EC_ppT>
+using GT = typename EC_ppT::GT_type;
+
+template<typename EC_ppT>
+using Fr_vector = std::vector<Fr<EC_ppT> >;
+template<typename EC_ppT>
+using G1_vector = std::vector<G1<EC_ppT> >;
+template<typename EC_ppT>
+using G2_vector = std::vector<G2<EC_ppT> >;
+
+} // libsnark
+
+#endif // PUBLIC_PARAMS_HPP_
diff --git a/src/algebra/curves/tests/test_bilinearity.cpp b/src/algebra/curves/tests/test_bilinearity.cpp
new file mode 100644 (file)
index 0000000..2957452
--- /dev/null
@@ -0,0 +1,136 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#include "common/profiling.hpp"
+#include "algebra/curves/edwards/edwards_pp.hpp"
+#ifdef CURVE_BN128
+#include "algebra/curves/bn128/bn128_pp.hpp"
+#endif
+#include "algebra/curves/alt_bn128/alt_bn128_pp.hpp"
+#include "algebra/curves/mnt/mnt4/mnt4_pp.hpp"
+#include "algebra/curves/mnt/mnt6/mnt6_pp.hpp"
+
+using namespace libsnark;
+
+template<typename ppT>
+void pairing_test()
+{
+    GT<ppT> GT_one = GT<ppT>::one();
+
+    printf("Running bilinearity tests:\n");
+    G1<ppT> P = (Fr<ppT>::random_element()) * G1<ppT>::one();
+    //G1<ppT> P = Fr<ppT>("2") * G1<ppT>::one();
+    G2<ppT> Q = (Fr<ppT>::random_element()) * G2<ppT>::one();
+    //G2<ppT> Q = Fr<ppT>("3") * G2<ppT>::one();
+
+    printf("P:\n");
+    P.print();
+    P.print_coordinates();
+    printf("Q:\n");
+    Q.print();
+    Q.print_coordinates();
+    printf("\n\n");
+
+    Fr<ppT> s = Fr<ppT>::random_element();
+    //Fr<ppT> s = Fr<ppT>("2");
+    G1<ppT> sP = s * P;
+    G2<ppT> sQ = s * Q;
+
+    printf("Pairing bilinearity tests (three must match):\n");
+    GT<ppT> ans1 = ppT::reduced_pairing(sP, Q);
+    GT<ppT> ans2 = ppT::reduced_pairing(P, sQ);
+    GT<ppT> ans3 = ppT::reduced_pairing(P, Q)^s;
+    ans1.print();
+    ans2.print();
+    ans3.print();
+    assert(ans1 == ans2);
+    assert(ans2 == ans3);
+
+    assert(ans1 != GT_one);
+    assert((ans1^Fr<ppT>::field_char()) == GT_one);
+    printf("\n\n");
+}
+
+template<typename ppT>
+void double_miller_loop_test()
+{
+    const G1<ppT> P1 = (Fr<ppT>::random_element()) * G1<ppT>::one();
+    const G1<ppT> P2 = (Fr<ppT>::random_element()) * G1<ppT>::one();
+    const G2<ppT> Q1 = (Fr<ppT>::random_element()) * G2<ppT>::one();
+    const G2<ppT> Q2 = (Fr<ppT>::random_element()) * G2<ppT>::one();
+
+    const G1_precomp<ppT> prec_P1 = ppT::precompute_G1(P1);
+    const G1_precomp<ppT> prec_P2 = ppT::precompute_G1(P2);
+    const G2_precomp<ppT> prec_Q1 = ppT::precompute_G2(Q1);
+    const G2_precomp<ppT> prec_Q2 = ppT::precompute_G2(Q2);
+
+    const Fqk<ppT> ans_1 = ppT::miller_loop(prec_P1, prec_Q1);
+    const Fqk<ppT> ans_2 = ppT::miller_loop(prec_P2, prec_Q2);
+    const Fqk<ppT> ans_12 = ppT::double_miller_loop(prec_P1, prec_Q1, prec_P2, prec_Q2);
+    assert(ans_1 * ans_2 == ans_12);
+}
+
+template<typename ppT>
+void affine_pairing_test()
+{
+    GT<ppT> GT_one = GT<ppT>::one();
+
+    printf("Running bilinearity tests:\n");
+    G1<ppT> P = (Fr<ppT>::random_element()) * G1<ppT>::one();
+    G2<ppT> Q = (Fr<ppT>::random_element()) * G2<ppT>::one();
+
+    printf("P:\n");
+    P.print();
+    printf("Q:\n");
+    Q.print();
+    printf("\n\n");
+
+    Fr<ppT> s = Fr<ppT>::random_element();
+    G1<ppT> sP = s * P;
+    G2<ppT> sQ = s * Q;
+
+    printf("Pairing bilinearity tests (three must match):\n");
+    GT<ppT> ans1 = ppT::affine_reduced_pairing(sP, Q);
+    GT<ppT> ans2 = ppT::affine_reduced_pairing(P, sQ);
+    GT<ppT> ans3 = ppT::affine_reduced_pairing(P, Q)^s;
+    ans1.print();
+    ans2.print();
+    ans3.print();
+    assert(ans1 == ans2);
+    assert(ans2 == ans3);
+
+    assert(ans1 != GT_one);
+    assert((ans1^Fr<ppT>::field_char()) == GT_one);
+    printf("\n\n");
+}
+
+int main(void)
+{
+    start_profiling();
+    edwards_pp::init_public_params();
+    pairing_test<edwards_pp>();
+    double_miller_loop_test<edwards_pp>();
+
+    mnt6_pp::init_public_params();
+    pairing_test<mnt6_pp>();
+    double_miller_loop_test<mnt6_pp>();
+    affine_pairing_test<mnt6_pp>();
+
+    mnt4_pp::init_public_params();
+    pairing_test<mnt4_pp>();
+    double_miller_loop_test<mnt4_pp>();
+    affine_pairing_test<mnt4_pp>();
+
+    alt_bn128_pp::init_public_params();
+    pairing_test<alt_bn128_pp>();
+    double_miller_loop_test<alt_bn128_pp>();
+
+#ifdef CURVE_BN128       // BN128 has fancy dependencies so it may be disabled
+    bn128_pp::init_public_params();
+    pairing_test<bn128_pp>();
+    double_miller_loop_test<bn128_pp>();
+#endif
+}
diff --git a/src/algebra/curves/tests/test_groups.cpp b/src/algebra/curves/tests/test_groups.cpp
new file mode 100644 (file)
index 0000000..725e490
--- /dev/null
@@ -0,0 +1,175 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#include "common/profiling.hpp"
+#include "algebra/curves/edwards/edwards_pp.hpp"
+#include "algebra/curves/mnt/mnt4/mnt4_pp.hpp"
+#include "algebra/curves/mnt/mnt6/mnt6_pp.hpp"
+#ifdef CURVE_BN128
+#include "algebra/curves/bn128/bn128_pp.hpp"
+#endif
+#include "algebra/curves/alt_bn128/alt_bn128_pp.hpp"
+#include <sstream>
+
+using namespace libsnark;
+
+template<typename GroupT>
+void test_mixed_add()
+{
+    GroupT base, el, result;
+
+    base = GroupT::zero();
+    el = GroupT::zero();
+    el.to_special();
+    result = base.mixed_add(el);
+    assert(result == base + el);
+
+    base = GroupT::zero();
+    el = GroupT::random_element();
+    el.to_special();
+    result = base.mixed_add(el);
+    assert(result == base + el);
+
+    base = GroupT::random_element();
+    el = GroupT::zero();
+    el.to_special();
+    result = base.mixed_add(el);
+    assert(result == base + el);
+
+    base = GroupT::random_element();
+    el = GroupT::random_element();
+    el.to_special();
+    result = base.mixed_add(el);
+    assert(result == base + el);
+
+    base = GroupT::random_element();
+    el = base;
+    el.to_special();
+    result = base.mixed_add(el);
+    assert(result == base.dbl());
+}
+
+template<typename GroupT>
+void test_group()
+{
+    bigint<1> rand1 = bigint<1>("76749407");
+    bigint<1> rand2 = bigint<1>("44410867");
+    bigint<1> randsum = bigint<1>("121160274");
+
+    GroupT zero = GroupT::zero();
+    assert(zero == zero);
+    GroupT one = GroupT::one();
+    assert(one == one);
+    GroupT two = bigint<1>(2l) * GroupT::one();
+    assert(two == two);
+    GroupT five = bigint<1>(5l) * GroupT::one();
+
+    GroupT three = bigint<1>(3l) * GroupT::one();
+    GroupT four = bigint<1>(4l) * GroupT::one();
+
+    assert(two+five == three+four);
+
+    GroupT a = GroupT::random_element();
+    GroupT b = GroupT::random_element();
+
+    assert(one != zero);
+    assert(a != zero);
+    assert(a != one);
+
+    assert(b != zero);
+    assert(b != one);
+
+    assert(a.dbl() == a + a);
+    assert(b.dbl() == b + b);
+    assert(one.add(two) == three);
+    assert(two.add(one) == three);
+    assert(a + b == b + a);
+    assert(a - a == zero);
+    assert(a - b == a + (-b));
+    assert(a - b == (-b) + a);
+
+    // handle special cases
+    assert(zero + (-a) == -a);
+    assert(zero - a == -a);
+    assert(a - zero == a);
+    assert(a + zero == a);
+    assert(zero + a == a);
+
+    assert((a + b).dbl() == (a + b) + (b + a));
+    assert(bigint<1>("2") * (a + b) == (a + b) + (b + a));
+
+    assert((rand1 * a) + (rand2 * a) == (randsum * a));
+
+    assert(GroupT::order() * a == zero);
+    assert(GroupT::order() * one == zero);
+    assert((GroupT::order() * a) - a != zero);
+    assert((GroupT::order() * one) - one != zero);
+
+    test_mixed_add<GroupT>();
+}
+
+template<typename GroupT>
+void test_mul_by_q()
+{
+    GroupT a = GroupT::random_element();
+    assert((GroupT::base_field_char()*a) == a.mul_by_q());
+}
+
+template<typename GroupT>
+void test_output()
+{
+    GroupT g = GroupT::zero();
+
+    for (size_t i = 0; i < 1000; ++i)
+    {
+        std::stringstream ss;
+        ss << g;
+        GroupT gg;
+        ss >> gg;
+        assert(g == gg);
+        /* use a random point in next iteration */
+        g = GroupT::random_element();
+    }
+}
+
+int main(void)
+{
+    edwards_pp::init_public_params();
+    test_group<G1<edwards_pp> >();
+    test_output<G1<edwards_pp> >();
+    test_group<G2<edwards_pp> >();
+    test_output<G2<edwards_pp> >();
+    test_mul_by_q<G2<edwards_pp> >();
+
+    mnt4_pp::init_public_params();
+    test_group<G1<mnt4_pp> >();
+    test_output<G1<mnt4_pp> >();
+    test_group<G2<mnt4_pp> >();
+    test_output<G2<mnt4_pp> >();
+    test_mul_by_q<G2<mnt4_pp> >();
+
+    mnt6_pp::init_public_params();
+    test_group<G1<mnt6_pp> >();
+    test_output<G1<mnt6_pp> >();
+    test_group<G2<mnt6_pp> >();
+    test_output<G2<mnt6_pp> >();
+    test_mul_by_q<G2<mnt6_pp> >();
+
+    alt_bn128_pp::init_public_params();
+    test_group<G1<alt_bn128_pp> >();
+    test_output<G1<alt_bn128_pp> >();
+    test_group<G2<alt_bn128_pp> >();
+    test_output<G2<alt_bn128_pp> >();
+    test_mul_by_q<G2<alt_bn128_pp> >();
+
+#ifdef CURVE_BN128       // BN128 has fancy dependencies so it may be disabled
+    bn128_pp::init_public_params();
+    test_group<G1<bn128_pp> >();
+    test_output<G1<bn128_pp> >();
+    test_group<G2<bn128_pp> >();
+    test_output<G2<bn128_pp> >();
+#endif
+}
diff --git a/src/algebra/evaluation_domain/domains/basic_radix2_domain.hpp b/src/algebra/evaluation_domain/domains/basic_radix2_domain.hpp
new file mode 100644 (file)
index 0000000..3e127a0
--- /dev/null
@@ -0,0 +1,45 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for the "basic radix-2" evaluation domain.
+
+ Roughly, the domain has size m = 2^k and consists of the m-th roots of unity.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BASIC_RADIX2_DOMAIN_HPP_
+#define BASIC_RADIX2_DOMAIN_HPP_
+
+#include "algebra/evaluation_domain/evaluation_domain.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+class basic_radix2_domain : public evaluation_domain<FieldT> {
+public:
+
+    FieldT omega;
+
+    basic_radix2_domain(const size_t m);
+
+    void FFT(std::vector<FieldT> &a);
+    void iFFT(std::vector<FieldT> &a);
+    void cosetFFT(std::vector<FieldT> &a, const FieldT &g);
+    void icosetFFT(std::vector<FieldT> &a, const FieldT &g);
+    std::vector<FieldT> lagrange_coeffs(const FieldT &t);
+    FieldT get_element(const size_t idx);
+    FieldT compute_Z(const FieldT &t);
+    void add_poly_Z(const FieldT &coeff, std::vector<FieldT> &H);
+    void divide_by_Z_on_coset(std::vector<FieldT> &P);
+
+};
+
+} // libsnark
+
+#include "algebra/evaluation_domain/domains/basic_radix2_domain.tcc"
+
+#endif // BASIC_RADIX2_DOMAIN_HPP_
diff --git a/src/algebra/evaluation_domain/domains/basic_radix2_domain.tcc b/src/algebra/evaluation_domain/domains/basic_radix2_domain.tcc
new file mode 100644 (file)
index 0000000..d315e83
--- /dev/null
@@ -0,0 +1,112 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for the "basic radix-2" evaluation domain.
+
+ See basic_radix2_domain.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BASIC_RADIX2_DOMAIN_TCC_
+#define BASIC_RADIX2_DOMAIN_TCC_
+
+#include "algebra/evaluation_domain/domains/basic_radix2_domain_aux.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+basic_radix2_domain<FieldT>::basic_radix2_domain(const size_t m) : evaluation_domain<FieldT>(m)
+{
+    assert(m > 1);
+    const size_t logm = log2(m);
+    assert(logm <= (FieldT::s));
+
+    omega = get_root_of_unity<FieldT>(m);
+}
+
+template<typename FieldT>
+void basic_radix2_domain<FieldT>::FFT(std::vector<FieldT> &a)
+{
+    enter_block("Execute FFT");
+    assert(a.size() == this->m);
+    _basic_radix2_FFT(a, omega);
+    leave_block("Execute FFT");
+}
+
+template<typename FieldT>
+void basic_radix2_domain<FieldT>::iFFT(std::vector<FieldT> &a)
+{
+    enter_block("Execute inverse FFT");
+    assert(a.size() == this->m);
+    _basic_radix2_FFT(a, omega.inverse());
+
+    const FieldT sconst = FieldT(a.size()).inverse();
+    for (size_t i = 0; i < a.size(); ++i)
+    {
+        a[i] *= sconst;
+    }
+    leave_block("Execute inverse FFT");
+}
+
+template<typename FieldT>
+void basic_radix2_domain<FieldT>::cosetFFT(std::vector<FieldT> &a, const FieldT &g)
+{
+    enter_block("Execute coset FFT");
+    _multiply_by_coset(a, g);
+    FFT(a);
+    leave_block("Execute coset FFT");
+}
+
+template<typename FieldT>
+void basic_radix2_domain<FieldT>::icosetFFT(std::vector<FieldT> &a, const FieldT &g)
+{
+    enter_block("Execute inverse coset IFFT");
+    iFFT(a);
+    _multiply_by_coset(a, g.inverse());
+    leave_block("Execute inverse coset IFFT");
+}
+
+template<typename FieldT>
+std::vector<FieldT> basic_radix2_domain<FieldT>::lagrange_coeffs(const FieldT &t)
+{
+    return _basic_radix2_lagrange_coeffs(this->m, t);
+}
+
+template<typename FieldT>
+FieldT basic_radix2_domain<FieldT>::get_element(const size_t idx)
+{
+    return omega^idx;
+}
+
+template<typename FieldT>
+FieldT basic_radix2_domain<FieldT>::compute_Z(const FieldT &t)
+{
+    return (t^this->m) - FieldT::one();
+}
+
+template<typename FieldT>
+void basic_radix2_domain<FieldT>::add_poly_Z(const FieldT &coeff, std::vector<FieldT> &H)
+{
+    assert(H.size() == this->m+1);
+    H[this->m] += coeff;
+    H[0] -= coeff;
+}
+
+template<typename FieldT>
+void basic_radix2_domain<FieldT>::divide_by_Z_on_coset(std::vector<FieldT> &P)
+{
+    const FieldT coset = FieldT::multiplicative_generator;
+    const FieldT Z_inverse_at_coset = this->compute_Z(coset).inverse();
+    for (size_t i = 0; i < this->m; ++i)
+    {
+        P[i] *= Z_inverse_at_coset;
+    }
+}
+
+} // libsnark
+
+#endif // BASIC_RADIX2_DOMAIN_TCC_
diff --git a/src/algebra/evaluation_domain/domains/basic_radix2_domain_aux.hpp b/src/algebra/evaluation_domain/domains/basic_radix2_domain_aux.hpp
new file mode 100644 (file)
index 0000000..c42ab2f
--- /dev/null
@@ -0,0 +1,48 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for auxiliary functions for the "basic radix-2" evaluation domain.
+
+ These functions compute the radix-2 FFT (in single- or multi-thread mode) and,
+ also compute Lagrange coefficients.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BASIC_RADIX2_DOMAIN_AUX_HPP_
+#define BASIC_RADIX2_DOMAIN_AUX_HPP_
+
+namespace libsnark {
+
+/**
+ * Compute the radix-2 FFT of the vector a over the set S={omega^{0},...,omega^{m-1}}.
+ */
+template<typename FieldT>
+void _basic_radix2_FFT(std::vector<FieldT> &a, const FieldT &omega);
+
+/**
+ * A multi-thread version of _basic_radix2_FFT.
+ */
+template<typename FieldT>
+void _parallel_basic_radix2_FFT(std::vector<FieldT> &a, const FieldT &omega);
+
+/**
+ * Translate the vector a to a coset defined by g.
+ */
+template<typename FieldT>
+void _multiply_by_coset(std::vector<FieldT> &a, const FieldT &g);
+
+/**
+ * Compute the m Lagrange coefficients, relative to the set S={omega^{0},...,omega^{m-1}}, at the field element t.
+ */
+template<typename FieldT>
+std::vector<FieldT> _basic_radix2_lagrange_coeffs(const size_t m, const FieldT &t);
+
+} // libsnark
+
+#include "algebra/evaluation_domain/domains/basic_radix2_domain_aux.tcc"
+
+#endif // BASIC_RADIX2_DOMAIN_AUX_HPP_
diff --git a/src/algebra/evaluation_domain/domains/basic_radix2_domain_aux.tcc b/src/algebra/evaluation_domain/domains/basic_radix2_domain_aux.tcc
new file mode 100644 (file)
index 0000000..138b82d
--- /dev/null
@@ -0,0 +1,242 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for auxiliary functions for the "basic radix-2" evaluation domain.
+
+ See basic_radix2_domain_aux.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BASIC_RADIX2_DOMAIN_AUX_TCC_
+#define BASIC_RADIX2_DOMAIN_AUX_TCC_
+
+#include <cassert>
+#ifdef MULTICORE
+#include <omp.h>
+#endif
+#include "algebra/fields/field_utils.hpp"
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+#ifdef MULTICORE
+#define _basic_radix2_FFT _basic_parallel_radix2_FFT
+#else
+#define _basic_radix2_FFT _basic_serial_radix2_FFT
+#endif
+
+/*
+ Below we make use of pseudocode from [CLRS 2n Ed, pp. 864].
+ Also, note that it's the caller's responsibility to multiply by 1/N.
+ */
+template<typename FieldT>
+void _basic_serial_radix2_FFT(std::vector<FieldT> &a, const FieldT &omega)
+{
+    const size_t n = a.size(), logn = log2(n);
+    assert(n == (1u << logn));
+
+    /* swapping in place (from Storer's book) */
+    for (size_t k = 0; k < n; ++k)
+    {
+        const size_t rk = bitreverse(k, logn);
+        if (k < rk)
+            std::swap(a[k], a[rk]);
+    }
+
+    size_t m = 1; // invariant: m = 2^{s-1}
+    for (size_t s = 1; s <= logn; ++s)
+    {
+        // w_m is 2^s-th root of unity now
+        const FieldT w_m = omega^(n/(2*m));
+
+        asm volatile ("/* pre-inner */");
+        for (size_t k = 0; k < n; k += 2*m)
+        {
+            FieldT w = FieldT::one();
+            for (size_t j = 0; j < m; ++j)
+            {
+                const FieldT t = w * a[k+j+m];
+                a[k+j+m] = a[k+j] - t;
+                a[k+j] += t;
+                w *= w_m;
+            }
+        }
+        asm volatile ("/* post-inner */");
+        m *= 2;
+    }
+}
+
+template<typename FieldT>
+void _basic_parallel_radix2_FFT_inner(std::vector<FieldT> &a, const FieldT &omega, const size_t log_cpus)
+{
+    const size_t num_cpus = 1ul<<log_cpus;
+
+    const size_t m = a.size();
+    const size_t log_m = log2(m);
+    assert(m == 1ul<<log_m);
+
+    if (log_m < log_cpus)
+    {
+        _basic_serial_radix2_FFT(a, omega);
+        return;
+    }
+
+    enter_block("Shuffle inputs");
+    std::vector<std::vector<FieldT> > tmp(num_cpus);
+    for (size_t j = 0; j < num_cpus; ++j)
+    {
+        tmp[j].resize(1ul<<(log_m-log_cpus), FieldT::zero());
+    }
+
+#ifdef MULTICORE
+    #pragma omp parallel for
+#endif
+    for (size_t j = 0; j < num_cpus; ++j)
+    {
+        const FieldT omega_j = omega^j;
+        const FieldT omega_step = omega^(j<<(log_m - log_cpus));
+
+        FieldT elt = FieldT::one();
+        for (size_t i = 0; i < 1ul<<(log_m - log_cpus); ++i)
+        {
+            for (size_t s = 0; s < num_cpus; ++s)
+            {
+                // invariant: elt is omega^(j*idx)
+                const size_t idx = (i + (s<<(log_m - log_cpus))) % (1u << log_m);
+                tmp[j][i] += a[idx] * elt;
+                elt *= omega_step;
+            }
+            elt *= omega_j;
+        }
+    }
+    leave_block("Shuffle inputs");
+
+    enter_block("Execute sub-FFTs");
+    const FieldT omega_num_cpus = omega^num_cpus;
+
+#ifdef MULTICORE
+    #pragma omp parallel for
+#endif
+    for (size_t j = 0; j < num_cpus; ++j)
+    {
+        _basic_serial_radix2_FFT(tmp[j], omega_num_cpus);
+    }
+    leave_block("Execute sub-FFTs");
+
+    enter_block("Re-shuffle outputs");
+
+#ifdef MULTICORE
+    #pragma omp parallel for
+#endif
+    for (size_t i = 0; i < num_cpus; ++i)
+    {
+        for (size_t j = 0; j < 1ul<<(log_m - log_cpus); ++j)
+        {
+            // now: i = idx >> (log_m - log_cpus) and j = idx % (1u << (log_m - log_cpus)), for idx = ((i<<(log_m-log_cpus))+j) % (1u << log_m)
+            a[(j<<log_cpus) + i] = tmp[i][j];
+        }
+    }
+    leave_block("Re-shuffle outputs");
+}
+
+template<typename FieldT>
+void _basic_parallel_radix2_FFT(std::vector<FieldT> &a, const FieldT &omega)
+{
+#ifdef MULTICORE
+    const size_t num_cpus = omp_get_max_threads();
+#else
+    const size_t num_cpus = 1;
+#endif
+    const size_t log_cpus = ((num_cpus & (num_cpus - 1)) == 0 ? log2(num_cpus) : log2(num_cpus) - 1);
+
+#ifdef DEBUG
+    print_indent(); printf("* Invoking parallel FFT on 2^%zu CPUs (omp_get_max_threads = %zu)\n", log_cpus, num_cpus);
+#endif
+
+    if (log_cpus == 0)
+    {
+        _basic_serial_radix2_FFT(a, omega);
+    }
+    else
+    {
+        _basic_parallel_radix2_FFT_inner(a, omega, log_cpus);
+    }
+}
+
+template<typename FieldT>
+void _multiply_by_coset(std::vector<FieldT> &a, const FieldT &g)
+{
+    //enter_block("Multiply by coset");
+    FieldT u = g;
+    for (size_t i = 1; i < a.size(); ++i)
+    {
+        a[i] *= u;
+        u *= g;
+    }
+    //leave_block("Multiply by coset");
+}
+
+template<typename FieldT>
+std::vector<FieldT> _basic_radix2_lagrange_coeffs(const size_t m, const FieldT &t)
+{
+    if (m == 1)
+    {
+        return std::vector<FieldT>(1, FieldT::one());
+    }
+
+    assert(m == (1u << log2(m)));
+
+    const FieldT omega = get_root_of_unity<FieldT>(m);
+
+    std::vector<FieldT> u(m, FieldT::zero());
+
+    /*
+     If t equals one of the roots of unity in S={omega^{0},...,omega^{m-1}}
+     then output 1 at the right place, and 0 elsewhere
+     */
+
+    if ((t^m) == (FieldT::one()))
+    {
+        FieldT omega_i = FieldT::one();
+        for (size_t i = 0; i < m; ++i)
+        {
+            if (omega_i == t) // i.e., t equals omega^i
+            {
+                u[i] = FieldT::one();
+                return u;
+            }
+
+            omega_i *= omega;
+        }
+    }
+
+    /*
+     Otherwise, if t does not equal any of the roots of unity in S,
+     then compute each L_{i,S}(t) as Z_{S}(t) * v_i / (t-\omega^i)
+     where:
+     - Z_{S}(t) = \prod_{j} (t-\omega^j) = (t^m-1), and
+     - v_{i} = 1 / \prod_{j \neq i} (\omega^i-\omega^j).
+     Below we use the fact that v_{0} = 1/m and v_{i+1} = \omega * v_{i}.
+     */
+
+    const FieldT Z = (t^m)-FieldT::one();
+    FieldT l = Z * FieldT(m).inverse();
+    FieldT r = FieldT::one();
+    for (size_t i = 0; i < m; ++i)
+    {
+        u[i] = l * (t - r).inverse();
+        l *= omega;
+        r *= omega;
+    }
+
+    return u;
+}
+
+} // libsnark
+
+#endif // BASIC_RADIX2_DOMAIN_AUX_TCC_
diff --git a/src/algebra/evaluation_domain/evaluation_domain.hpp b/src/algebra/evaluation_domain/evaluation_domain.hpp
new file mode 100644 (file)
index 0000000..358db97
--- /dev/null
@@ -0,0 +1,125 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for evaluation domains.
+
+ Roughly, given a desired size m for the domain, the constructor selects
+ a choice of domain S with size ~m that has been selected so to optimize
+ - computations of Lagrange polynomials, and
+ - FFT/iFFT computations.
+ An evaluation domain also provides other other functions, e.g., accessing
+ individual elements in S or evaluating its vanishing polynomial.
+
+ The descriptions below make use of the definition of a *Lagrange polynomial*,
+ which we recall. Given a field F, a subset S=(a_i)_i of F, and an index idx
+ in {0,...,|S-1|}, the idx-th Lagrange polynomial (wrt to subset S) is defined to be
+ \f[   L_{idx,S}(z) := prod_{k \neq idx} (z - a_k) / prod_{k \neq idx} (a_{idx} - a_k)   \f]
+ Note that, by construction:
+ \f[   \forall j \neq idx: L_{idx,S}(a_{idx}) = 1  \text{ and }  L_{idx,S}(a_j) = 0   \f]
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef EVALUATION_DOMAIN_HPP_
+#define EVALUATION_DOMAIN_HPP_
+
+#include <memory>
+
+namespace libsnark {
+
+/**
+ * An evaluation domain.
+ */
+template<typename FieldT>
+class evaluation_domain {
+public:
+
+    const size_t m;
+
+    /**
+     * Construct an evaluation domain S of size m, if possible.
+     *
+     * (See the function get_evaluation_domain below.)
+     */
+    evaluation_domain(const size_t m) : m(m) {};
+
+    /**
+     * Get the idx-th element in S.
+     */
+    virtual FieldT get_element(const size_t idx) = 0;
+
+    /**
+     * Compute the FFT, over the domain S, of the vector a.
+     */
+    virtual void FFT(std::vector<FieldT> &a) = 0;
+
+    /**
+     * Compute the inverse FFT, over the domain S, of the vector a.
+     */
+    virtual void iFFT(std::vector<FieldT> &a) = 0;
+
+    /**
+     * Compute the FFT, over the domain g*S, of the vector a.
+     */
+    virtual void cosetFFT(std::vector<FieldT> &a, const FieldT &g) = 0;
+
+    /**
+     * Compute the inverse FFT, over the domain g*S, of the vector a.
+     */
+    virtual void icosetFFT(std::vector<FieldT> &a, const FieldT &g) = 0;
+
+    /**
+     * Evaluate all Lagrange polynomials.
+     *
+     * The inputs are:
+     * - an integer m
+     * - an element t
+     * The output is a vector (b_{0},...,b_{m-1})
+     * where b_{i} is the evaluation of L_{i,S}(z) at z = t.
+     */
+    virtual std::vector<FieldT> lagrange_coeffs(const FieldT &t) = 0;
+
+    /**
+     * Evaluate the vanishing polynomial of S at the field element t.
+     */
+    virtual FieldT compute_Z(const FieldT &t) = 0;
+
+    /**
+     * Add the coefficients of the vanishing polynomial of S to the coefficients of the polynomial H.
+     */
+    virtual void add_poly_Z(const FieldT &coeff, std::vector<FieldT> &H) = 0;
+
+    /**
+     * Multiply by the evaluation, on a coset of S, of the inverse of the vanishing polynomial of S.
+     */
+    virtual void divide_by_Z_on_coset(std::vector<FieldT> &P) = 0;
+};
+
+/**
+ * Return an evaluation domain object in which the domain S has size |S| >= min_size.
+ * The function chooses from different supported domains, depending on min_size.
+ */
+template<typename FieldT>
+std::shared_ptr<evaluation_domain<FieldT> > get_evaluation_domain(const size_t min_size);
+
+/**
+ * Naive evaluation of a *single* Lagrange polynomial, used for testing purposes.
+ *
+ * The inputs are:
+ * - an integer m
+ * - a domain S = (a_{0},...,a_{m-1}) of size m
+ * - a field element element t
+ * - an index idx in {0,...,m-1}
+ * The output is the polynomial L_{idx,S}(z) evaluated at z = t.
+ */
+template<typename FieldT>
+FieldT lagrange_eval(const size_t m, const std::vector<FieldT> &domain, const FieldT &t, const size_t idx);
+
+} // libsnark
+
+#include "algebra/evaluation_domain/evaluation_domain.tcc"
+
+#endif // EVALUATION_DOMAIN_HPP_
diff --git a/src/algebra/evaluation_domain/evaluation_domain.tcc b/src/algebra/evaluation_domain/evaluation_domain.tcc
new file mode 100644 (file)
index 0000000..8e3ea7a
--- /dev/null
@@ -0,0 +1,117 @@
+/** @file
+ *****************************************************************************
+
+ Imeplementation of interfaces for evaluation domains.
+
+ See evaluation_domain.hpp .
+
+ We currently implement, and select among, three types of domains:
+ - "basic radix-2": the domain has size m = 2^k and consists of the m-th roots of unity
+ - "extended radix-2": the domain has size m = 2^{k+1} and consists of "the m-th roots of unity" union "a coset"
+ - "step radix-2": the domain has size m = 2^k + 2^r and consists of "the 2^k-th roots of unity" union "a coset of 2^r-th roots of unity"
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef EVALUATION_DOMAIN_TCC_
+#define EVALUATION_DOMAIN_TCC_
+
+#include <cassert>
+#include "algebra/fields/field_utils.hpp"
+#include "algebra/evaluation_domain/domains/basic_radix2_domain.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+std::shared_ptr<evaluation_domain<FieldT> > get_evaluation_domain(const size_t min_size)
+{
+    assert(min_size > 1);
+    const size_t log_min_size = log2(min_size);
+    assert(log_min_size <= (FieldT::s+1));
+
+    std::shared_ptr<evaluation_domain<FieldT> > result;
+    if (min_size == (1u << log_min_size))
+    {
+        if (log_min_size == FieldT::s+1)
+        {
+            if (!inhibit_profiling_info)
+            {
+                print_indent(); printf("* Selected domain: extended_radix2\n");
+            }
+            assert(0);
+        }
+        else
+        {
+            if (!inhibit_profiling_info)
+            {
+                print_indent(); printf("* Selected domain: basic_radix2\n");
+            }
+            result.reset(new basic_radix2_domain<FieldT>(min_size));
+        }
+    }
+    else
+    {
+        const size_t big = 1ul<<(log2(min_size)-1);
+        const size_t small = min_size - big;
+        const size_t rounded_small = (1ul<<log2(small));
+        if (big == rounded_small)
+        {
+            if (log2(big + rounded_small) < FieldT::s+1)
+            {
+                if (!inhibit_profiling_info)
+                {
+                    print_indent(); printf("* Selected domain: basic_radix2\n");
+                }
+                result.reset(new basic_radix2_domain<FieldT>(big + rounded_small));
+            }
+            else
+            {
+                if (!inhibit_profiling_info)
+                {
+                    print_indent(); printf("* Selected domain: extended_radix2\n");
+                }
+                assert(0);
+            }
+        }
+        else
+        {
+            if (!inhibit_profiling_info)
+            {
+                print_indent(); printf("* Selected domain: step_radix2\n");
+            }
+            assert(0);
+        }
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+FieldT lagrange_eval(const size_t m, const std::vector<FieldT> &domain, const FieldT &t, const size_t idx)
+{
+    assert(m == domain.size());
+    assert(idx < m);
+
+    FieldT num = FieldT::one();
+    FieldT denom = FieldT::one();
+
+    for (size_t k = 0; k < m; ++k)
+    {
+        if (k == idx)
+        {
+            continue;
+        }
+
+        num *= t - domain[k];
+        denom *= domain[idx] - domain[k];
+    }
+
+    return num * denom.inverse();
+}
+
+} // libsnark
+
+#endif // EVALUATION_DOMAIN_TCC_
diff --git a/src/algebra/exponentiation/exponentiation.hpp b/src/algebra/exponentiation/exponentiation.hpp
new file mode 100644 (file)
index 0000000..a8a2c92
--- /dev/null
@@ -0,0 +1,31 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for (square-and-multiply) exponentiation.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef EXPONENTIATION_HPP_
+#define EXPONENTIATION_HPP_
+
+#include <cstdint>
+
+#include "algebra/fields/bigint.hpp"
+
+namespace libsnark {
+
+template<typename FieldT, mp_size_t m>
+FieldT power(const FieldT &base, const bigint<m> &exponent);
+
+template<typename FieldT>
+FieldT power(const FieldT &base, const unsigned long exponent);
+
+} // libsnark
+
+#include "algebra/exponentiation/exponentiation.tcc"
+
+#endif // EXPONENTIATION_HPP_
diff --git a/src/algebra/exponentiation/exponentiation.tcc b/src/algebra/exponentiation/exponentiation.tcc
new file mode 100644 (file)
index 0000000..dd557eb
--- /dev/null
@@ -0,0 +1,53 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for (square-and-multiply) exponentiation.
+
+ See exponentiation.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef EXPONENTIATION_TCC_
+#define EXPONENTIATION_TCC_
+
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+template<typename FieldT, mp_size_t m>
+FieldT power(const FieldT &base, const bigint<m> &exponent)
+{
+    FieldT result = FieldT::one();
+
+    bool found_one = false;
+
+    for (long i = exponent.max_bits() - 1; i >= 0; --i)
+    {
+        if (found_one)
+        {
+            result = result * result;
+        }
+
+        if (exponent.test_bit(i))
+        {
+            found_one = true;
+            result = result * base;
+        }
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+FieldT power(const FieldT &base, const unsigned long exponent)
+{
+    return power<FieldT>(base, bigint<1>(exponent));
+}
+
+} // libsnark
+
+#endif // EXPONENTIATION_TCC_
diff --git a/src/algebra/fields/bigint.hpp b/src/algebra/fields/bigint.hpp
new file mode 100644 (file)
index 0000000..ff00dd5
--- /dev/null
@@ -0,0 +1,70 @@
+/** @file
+ *****************************************************************************
+ Declaration of bigint wrapper class around GMP's MPZ long integers.
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BIGINT_HPP_
+#define BIGINT_HPP_
+#include <cstddef>
+#include <iostream>
+#include <gmp.h>
+#include "common/serialization.hpp"
+
+namespace libsnark {
+
+template<mp_size_t n> class bigint;
+template<mp_size_t n> std::ostream& operator<<(std::ostream &, const bigint<n>&);
+template<mp_size_t n> std::istream& operator>>(std::istream &, bigint<n>&);
+
+/**
+ * Wrapper class around GMP's MPZ long integers. It supports arithmetic operations,
+ * serialization and randomization. Serialization is fragile, see common/serialization.hpp.
+ */
+
+template<mp_size_t n>
+class bigint {
+public:
+    static const mp_size_t N = n;
+
+    mp_limb_t data[n] = {0};
+
+    bigint() = default;
+    bigint(const unsigned long x); /// Initalize from a small integer
+    bigint(const char* s); /// Initialize from a string containing an integer in decimal notation
+    bigint(const mpz_t r); /// Initialize from MPZ element
+
+    void print() const;
+    void print_hex() const;
+    bool operator==(const bigint<n>& other) const;
+    bool operator!=(const bigint<n>& other) const;
+    void clear();
+    bool is_zero() const;
+    size_t max_bits() const { return n * GMP_NUMB_BITS; }
+    size_t num_bits() const;
+
+    unsigned long as_ulong() const; /* return the last limb of the integer */
+    void to_mpz(mpz_t r) const;
+    bool test_bit(const std::size_t bitno) const;
+
+    template<mp_size_t m> inline void operator+=(const bigint<m>& other);
+    template<mp_size_t m> inline bigint<n+m> operator*(const bigint<m>& other) const;
+    template<mp_size_t d> static inline void div_qr(bigint<n-d+1>& quotient, bigint<d>& remainder,
+                                                    const bigint<n>& dividend, const bigint<d>& divisor);
+    template<mp_size_t m> inline bigint<m> shorten(const bigint<m>& q, const char *msg) const;
+
+    inline void limit(const bigint<n>& q, const char *msg) const;
+    bool operator>(const bigint<n>& other) const;
+
+    bigint& randomize();
+
+    friend std::ostream& operator<< <n>(std::ostream &out, const bigint<n> &b);
+    friend std::istream& operator>> <n>(std::istream &in, bigint<n> &b);
+};
+
+} // libsnark
+#include "algebra/fields/bigint.tcc"
+#endif
diff --git a/src/algebra/fields/bigint.tcc b/src/algebra/fields/bigint.tcc
new file mode 100644 (file)
index 0000000..f81addf
--- /dev/null
@@ -0,0 +1,278 @@
+/** @file
+ *****************************************************************************
+ Implementation of bigint wrapper class around GMP's MPZ long integers.
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BIGINT_TCC_
+#define BIGINT_TCC_
+#include <cassert>
+#include <climits>
+#include <cstring>
+#include "sodium.h"
+
+namespace libsnark {
+
+template<mp_size_t n>
+bigint<n>::bigint(const unsigned long x) /// Initalize from a small integer
+{
+    static_assert(ULONG_MAX <= GMP_NUMB_MAX, "unsigned long does not fit in a GMP limb");
+    this->data[0] = x;
+}
+
+template<mp_size_t n>
+bigint<n>::bigint(const char* s) /// Initialize from a string containing an integer in decimal notation
+{
+    size_t l = strlen(s);
+    unsigned char* s_copy = new unsigned char[l];
+
+    for (size_t i = 0; i < l; ++i)
+    {
+        assert(s[i] >= '0' && s[i] <= '9');
+        s_copy[i] = s[i] - '0';
+    }
+
+    mp_size_t limbs_written = mpn_set_str(this->data, s_copy, l, 10);
+    assert(limbs_written <= n);
+
+    delete[] s_copy;
+}
+
+template<mp_size_t n>
+bigint<n>::bigint(const mpz_t r) /// Initialize from MPZ element
+{
+    mpz_t k;
+    mpz_init_set(k, r);
+
+    for (size_t i = 0; i < n; ++i)
+    {
+        data[i] = mpz_get_ui(k);
+        mpz_fdiv_q_2exp(k, k, GMP_NUMB_BITS);
+    }
+
+    assert(mpz_sgn(k) == 0);
+    mpz_clear(k);
+}
+
+template<mp_size_t n>
+void bigint<n>::print() const
+{
+    gmp_printf("%Nd\n", this->data, n);
+}
+
+template<mp_size_t n>
+void bigint<n>::print_hex() const
+{
+    gmp_printf("%Nx\n", this->data, n);
+}
+
+template<mp_size_t n>
+bool bigint<n>::operator==(const bigint<n>& other) const
+{
+    return (mpn_cmp(this->data, other.data, n) == 0);
+}
+
+template<mp_size_t n>
+bool bigint<n>::operator!=(const bigint<n>& other) const
+{
+    return !(operator==(other));
+}
+
+template<mp_size_t n>
+void bigint<n>::clear()
+{
+    mpn_zero(this->data, n);
+}
+
+template<mp_size_t n>
+bool bigint<n>::is_zero() const
+{
+    for (mp_size_t i = 0; i < n; ++i)
+    {
+        if (this->data[i])
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+template<mp_size_t n>
+size_t bigint<n>::num_bits() const
+{
+/*
+    for (long i = max_bits(); i >= 0; --i)
+    {
+        if (this->test_bit(i))
+        {
+            return i+1;
+        }
+    }
+
+    return 0;
+*/
+    for (long i = n-1; i >= 0; --i)
+    {
+        mp_limb_t x = this->data[i];
+        if (x == 0)
+        {
+            continue;
+        }
+        else
+        {
+            return ((i+1) * GMP_NUMB_BITS) - __builtin_clzl(x);
+        }
+    }
+    return 0;
+}
+
+template<mp_size_t n>
+unsigned long bigint<n>::as_ulong() const
+{
+    return this->data[0];
+}
+
+template<mp_size_t n>
+void bigint<n>::to_mpz(mpz_t r) const
+{
+    mpz_set_ui(r, 0);
+
+    for (int i = n-1; i >= 0; --i)
+    {
+        mpz_mul_2exp(r, r, GMP_NUMB_BITS);
+        mpz_add_ui(r, r, this->data[i]);
+    }
+}
+
+template<mp_size_t n>
+bool bigint<n>::test_bit(const std::size_t bitno) const
+{
+    if (bitno >= n * GMP_NUMB_BITS)
+    {
+        return false;
+    }
+    else
+    {
+        const std::size_t part = bitno/GMP_NUMB_BITS;
+        const std::size_t bit = bitno - (GMP_NUMB_BITS*part);
+        const mp_limb_t one = 1;
+        return (this->data[part] & (one<<bit));
+    }
+}
+
+
+template<mp_size_t n> template<mp_size_t m>
+inline void bigint<n>::operator+=(const bigint<m>& other)
+{
+    static_assert(n >= m, "first arg must not be smaller than second arg for bigint in-place add");
+    mpn_add(data, data, n, other.data, m);
+}
+
+template<mp_size_t n> template<mp_size_t m>
+inline bigint<n+m> bigint<n>::operator*(const bigint<m>& other) const
+{
+    static_assert(n >= m, "first arg must not be smaller than second arg for bigint mul");
+    bigint<n+m> res;
+    mpn_mul(res.data, data, n, other.data, m);
+    return res;
+}
+
+template<mp_size_t n> template<mp_size_t d>
+inline void bigint<n>::div_qr(bigint<n-d+1>& quotient, bigint<d>& remainder,
+                              const bigint<n>& dividend, const bigint<d>& divisor)
+{
+    static_assert(n >= d, "dividend must not be smaller than divisor for bigint::div_qr");
+    assert(divisor.data[d-1] != 0);
+    mpn_tdiv_qr(quotient.data, remainder.data, 0, dividend.data, n, divisor.data, d);
+}
+
+// Return a copy shortened to m limbs provided it is less than limit, throwing std::domain_error if not in range.
+template<mp_size_t n> template<mp_size_t m>
+inline bigint<m> bigint<n>::shorten(const bigint<m>& q, const char *msg) const
+{
+    static_assert(m <= n, "number of limbs must not increase for bigint::shorten");
+    for (mp_size_t i = m; i < n; i++) { // high-order limbs
+        if (data[i] != 0) {
+            throw std::domain_error(msg);
+        }
+    }
+    bigint<m> res;
+    mpn_copyi(res.data, data, n);
+    res.limit(q, msg);
+    return res;
+}
+
+template<mp_size_t n>
+inline void bigint<n>::limit(const bigint<n>& q, const char *msg) const
+{
+    if (!(q > *this)) {
+        throw std::domain_error(msg);
+    }
+}
+
+template<mp_size_t n>
+inline bool bigint<n>::operator>(const bigint<n>& other) const
+{
+    return mpn_cmp(this->data, other.data, n) > 0;
+}
+
+template<mp_size_t n>
+bigint<n>& bigint<n>::randomize()
+{
+    assert(GMP_NUMB_BITS == sizeof(mp_limb_t) * 8);
+
+    randombytes_buf(this->data, sizeof(mp_limb_t) * n);
+
+    return (*this);
+}
+
+
+template<mp_size_t n>
+std::ostream& operator<<(std::ostream &out, const bigint<n> &b)
+{
+#ifdef BINARY_OUTPUT
+    out.write((char*)b.data, sizeof(b.data[0]) * n);
+#else
+    mpz_t t;
+    mpz_init(t);
+    b.to_mpz(t);
+
+    out << t;
+
+    mpz_clear(t);
+#endif
+    return out;
+}
+
+template<mp_size_t n>
+std::istream& operator>>(std::istream &in, bigint<n> &b)
+{
+#ifdef BINARY_OUTPUT
+    in.read((char*)b.data, sizeof(b.data[0]) * n);
+#else
+    std::string s;
+    in >> s;
+
+    size_t l = s.size();
+    unsigned char* s_copy = new unsigned char[l];
+
+    for (size_t i = 0; i < l; ++i)
+    {
+        assert(s[i] >= '0' && s[i] <= '9');
+        s_copy[i] = s[i] - '0';
+    }
+
+    mp_size_t limbs_written = mpn_set_str(b.data, s_copy, l, 10);
+    assert(limbs_written <= n);
+
+    delete[] s_copy;
+#endif
+    return in;
+}
+
+} // libsnark
+#endif // BIGINT_TCC_
diff --git a/src/algebra/fields/field_utils.hpp b/src/algebra/fields/field_utils.hpp
new file mode 100644 (file)
index 0000000..a07ecfe
--- /dev/null
@@ -0,0 +1,51 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FIELD_UTILS_HPP_
+#define FIELD_UTILS_HPP_
+#include <cstdint>
+
+#include "common/utils.hpp"
+#include "algebra/fields/bigint.hpp"
+
+namespace libsnark {
+
+// returns root of unity of order n (for n a power of 2), if one exists
+template<typename FieldT>
+FieldT get_root_of_unity(const size_t n);
+
+template<typename FieldT>
+std::vector<FieldT> pack_int_vector_into_field_element_vector(const std::vector<size_t> &v, const size_t w);
+
+template<typename FieldT>
+std::vector<FieldT> pack_bit_vector_into_field_element_vector(const bit_vector &v, const size_t chunk_bits);
+
+template<typename FieldT>
+std::vector<FieldT> pack_bit_vector_into_field_element_vector(const bit_vector &v);
+
+template<typename FieldT>
+std::vector<FieldT> convert_bit_vector_to_field_element_vector(const bit_vector &v);
+
+template<typename FieldT>
+bit_vector convert_field_element_vector_to_bit_vector(const std::vector<FieldT> &v);
+
+template<typename FieldT>
+bit_vector convert_field_element_to_bit_vector(const FieldT &el);
+
+template<typename FieldT>
+bit_vector convert_field_element_to_bit_vector(const FieldT &el, const size_t bitcount);
+
+template<typename FieldT>
+FieldT convert_bit_vector_to_field_element(const bit_vector &v);
+
+template<typename FieldT>
+void batch_invert(std::vector<FieldT> &vec);
+
+} // libsnark
+#include "algebra/fields/field_utils.tcc"
+
+#endif // FIELD_UTILS_HPP_
diff --git a/src/algebra/fields/field_utils.tcc b/src/algebra/fields/field_utils.tcc
new file mode 100644 (file)
index 0000000..13197b2
--- /dev/null
@@ -0,0 +1,183 @@
+/** @file
+ *****************************************************************************
+ Implementation of misc. math and serialization utility functions
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FIELD_UTILS_TCC_
+#define FIELD_UTILS_TCC_
+
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+FieldT coset_shift()
+{
+    return FieldT::multiplicative_generator.squared();
+}
+
+template<typename FieldT>
+FieldT get_root_of_unity(const size_t n)
+{
+    const size_t logn = log2(n);
+    assert(n == (1u << logn));
+    assert(logn <= FieldT::s);
+
+    FieldT omega = FieldT::root_of_unity;
+    for (size_t i = FieldT::s; i > logn; --i)
+    {
+        omega *= omega;
+    }
+
+    return omega;
+}
+
+template<typename FieldT>
+std::vector<FieldT> pack_int_vector_into_field_element_vector(const std::vector<size_t> &v, const size_t w)
+{
+    const size_t chunk_bits = FieldT::capacity();
+    const size_t repacked_size = div_ceil(v.size() * w, chunk_bits);
+    std::vector<FieldT> result(repacked_size);
+
+    for (size_t i = 0; i < repacked_size; ++i)
+    {
+        bigint<FieldT::num_limbs> b;
+        for (size_t j = 0; j < chunk_bits; ++j)
+        {
+            const size_t word_index = (i * chunk_bits + j) / w;
+            const size_t pos_in_word = (i * chunk_bits + j) % w;
+            const size_t word_or_0 = (word_index < v.size() ? v[word_index] : 0);
+            const size_t bit = (word_or_0 >> pos_in_word) & 1;
+
+            b.data[j / GMP_NUMB_BITS] |= bit << (j % GMP_NUMB_BITS);
+        }
+        result[i] = FieldT(b);
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+std::vector<FieldT> pack_bit_vector_into_field_element_vector(const bit_vector &v, const size_t chunk_bits)
+{
+    assert(chunk_bits <= FieldT::capacity());
+
+    const size_t repacked_size = div_ceil(v.size(), chunk_bits);
+    std::vector<FieldT> result(repacked_size);
+
+    for (size_t i = 0; i < repacked_size; ++i)
+    {
+        bigint<FieldT::num_limbs> b;
+        for (size_t j = 0; j < chunk_bits; ++j)
+        {
+            b.data[j / GMP_NUMB_BITS] |= ((i * chunk_bits + j) < v.size() && v[i * chunk_bits + j] ? 1ll : 0ll) << (j % GMP_NUMB_BITS);
+        }
+        result[i] = FieldT(b);
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+std::vector<FieldT> pack_bit_vector_into_field_element_vector(const bit_vector &v)
+{
+    return pack_bit_vector_into_field_element_vector<FieldT>(v, FieldT::capacity());
+}
+
+template<typename FieldT>
+std::vector<FieldT> convert_bit_vector_to_field_element_vector(const bit_vector &v)
+{
+    std::vector<FieldT> result;
+    result.reserve(v.size());
+
+    for (const bool b : v)
+    {
+        result.emplace_back(b ? FieldT::one() : FieldT::zero());
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+bit_vector convert_field_element_vector_to_bit_vector(const std::vector<FieldT> &v)
+{
+    bit_vector result;
+
+    for (const FieldT &el : v)
+    {
+        const bit_vector el_bits = convert_field_element_to_bit_vector<FieldT>(el);
+        result.insert(result.end(), el_bits.begin(), el_bits.end());
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+bit_vector convert_field_element_to_bit_vector(const FieldT &el)
+{
+    bit_vector result;
+
+    bigint<FieldT::num_limbs> b = el.as_bigint();
+    for (size_t i = 0; i < FieldT::size_in_bits(); ++i)
+    {
+        result.push_back(b.test_bit(i));
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+bit_vector convert_field_element_to_bit_vector(const FieldT &el, const size_t bitcount)
+{
+    bit_vector result = convert_field_element_to_bit_vector(el);
+    result.resize(bitcount);
+
+    return result;
+}
+
+template<typename FieldT>
+FieldT convert_bit_vector_to_field_element(const bit_vector &v)
+{
+    assert(v.size() <= FieldT::size_in_bits());
+
+    FieldT res = FieldT::zero();
+    FieldT c = FieldT::one();
+    for (bool b : v)
+    {
+        res += b ? c : FieldT::zero();
+        c += c;
+    }
+    return res;
+}
+
+template<typename FieldT>
+void batch_invert(std::vector<FieldT> &vec)
+{
+    std::vector<FieldT> prod;
+    prod.reserve(vec.size());
+
+    FieldT acc = FieldT::one();
+
+    for (auto el : vec)
+    {
+        assert(!el.is_zero());
+        prod.emplace_back(acc);
+        acc = acc * el;
+    }
+
+    FieldT acc_inverse = acc.inverse();
+
+    for (long i = vec.size()-1; i >= 0; --i)
+    {
+        const FieldT old_el = vec[i];
+        vec[i] = acc_inverse * prod[i];
+        acc_inverse = acc_inverse * old_el;
+    }
+}
+
+} // libsnark
+#endif // FIELD_UTILS_TCC_
diff --git a/src/algebra/fields/fp.hpp b/src/algebra/fields/fp.hpp
new file mode 100644 (file)
index 0000000..a498683
--- /dev/null
@@ -0,0 +1,182 @@
+/** @file
+ *****************************************************************************
+ Declaration of arithmetic in the finite field F[p], for prime p of fixed length.
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP_HPP_
+#define FP_HPP_
+
+#include "algebra/fields/bigint.hpp"
+#include "algebra/exponentiation/exponentiation.hpp"
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp_model;
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &, const Fp_model<n, modulus>&);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &, Fp_model<n, modulus> &);
+
+/**
+ * Arithmetic in the finite field F[p], for prime p of fixed length.
+ *
+ * This class implements Fp-arithmetic, for a large prime p, using a fixed number
+ * of words. It is optimized for tight memory consumption, so the modulus p is
+ * passed as a template parameter, to avoid per-element overheads.
+ *
+ * The implementation is mostly a wrapper around GMP's MPN (constant-size integers).
+ * But for the integer sizes of interest for libsnark (3 to 5 limbs of 64 bits each),
+ * we implement performance-critical routines, like addition and multiplication,
+ * using hand-optimzied assembly code.
+*/
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp_model {
+public:
+    bigint<n> mont_repr;
+public:
+    static const mp_size_t num_limbs = n;
+    static const constexpr bigint<n>& mod = modulus;
+#ifdef PROFILE_OP_COUNTS
+    static long long add_cnt;
+    static long long sub_cnt;
+    static long long mul_cnt;
+    static long long sqr_cnt;
+    static long long inv_cnt;
+#endif
+    static size_t num_bits;
+    static bigint<n> euler; // (modulus-1)/2
+    static size_t s; // modulus = 2^s * t + 1
+    static bigint<n> t; // with t odd
+    static bigint<n> t_minus_1_over_2; // (t-1)/2
+    static Fp_model<n, modulus> nqr; // a quadratic nonresidue
+    static Fp_model<n, modulus> nqr_to_t; // nqr^t
+    static Fp_model<n, modulus> multiplicative_generator; // generator of Fp^*
+    static Fp_model<n, modulus> root_of_unity; // generator^((modulus-1)/2^s)
+    static mp_limb_t inv; // modulus^(-1) mod W, where W = 2^(word size)
+    static bigint<n> Rsquared; // R^2, where R = W^k, where k = ??
+    static bigint<n> Rcubed;   // R^3
+
+    static bool modulus_is_valid() { return modulus.data[n-1] != 0; } // mpn inverse assumes that highest limb is non-zero
+
+    Fp_model() {};
+    Fp_model(const bigint<n> &b);
+    Fp_model(const long x, const bool is_unsigned=false);
+
+    void set_ulong(const unsigned long x);
+
+    void mul_reduce(const bigint<n> &other);
+
+    void clear();
+
+    /* Return the standard (not Montgomery) representation of the
+       Field element's requivalence class. I.e. Fp(2).as_bigint()
+        would return bigint(2) */
+    bigint<n> as_bigint() const;
+    /* Return the last limb of the standard representation of the
+       field element. E.g. on 64-bit architectures Fp(123).as_ulong()
+       and Fp(2^64+123).as_ulong() would both return 123. */
+    unsigned long as_ulong() const;
+
+    bool operator==(const Fp_model& other) const;
+    bool operator!=(const Fp_model& other) const;
+    bool is_zero() const;
+
+    void print() const;
+
+    Fp_model& operator+=(const Fp_model& other);
+    Fp_model& operator-=(const Fp_model& other);
+    Fp_model& operator*=(const Fp_model& other);
+    Fp_model& operator^=(const unsigned long pow);
+
+    template<mp_size_t m>
+    Fp_model& operator^=(const bigint<m> &pow);
+
+    Fp_model operator+(const Fp_model& other) const;
+    Fp_model operator-(const Fp_model& other) const;
+    Fp_model operator*(const Fp_model& other) const;
+    Fp_model operator-() const;
+    Fp_model squared() const;
+    Fp_model& invert();
+    Fp_model inverse() const;
+    Fp_model sqrt() const; // HAS TO BE A SQUARE (else does not terminate)
+
+    Fp_model operator^(const unsigned long pow) const;
+    template<mp_size_t m>
+    Fp_model operator^(const bigint<m> &pow) const;
+
+    static size_t size_in_bits() { return num_bits; }
+    static size_t capacity() { return num_bits - 1; }
+    static bigint<n> field_char() { return modulus; }
+
+    static Fp_model<n, modulus> zero();
+    static Fp_model<n, modulus> one();
+    static Fp_model<n, modulus> random_element();
+
+    friend std::ostream& operator<< <n,modulus>(std::ostream &out, const Fp_model<n, modulus> &p);
+    friend std::istream& operator>> <n,modulus>(std::istream &in, Fp_model<n, modulus> &p);
+};
+
+#ifdef PROFILE_OP_COUNTS
+template<mp_size_t n, const bigint<n>& modulus>
+long long Fp_model<n, modulus>::add_cnt = 0;
+
+template<mp_size_t n, const bigint<n>& modulus>
+long long Fp_model<n, modulus>::sub_cnt = 0;
+
+template<mp_size_t n, const bigint<n>& modulus>
+long long Fp_model<n, modulus>::mul_cnt = 0;
+
+template<mp_size_t n, const bigint<n>& modulus>
+long long Fp_model<n, modulus>::sqr_cnt = 0;
+
+template<mp_size_t n, const bigint<n>& modulus>
+long long Fp_model<n, modulus>::inv_cnt = 0;
+#endif
+
+template<mp_size_t n, const bigint<n>& modulus>
+size_t Fp_model<n, modulus>::num_bits;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<n> Fp_model<n, modulus>::euler;
+
+template<mp_size_t n, const bigint<n>& modulus>
+size_t Fp_model<n, modulus>::s;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<n> Fp_model<n, modulus>::t;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<n> Fp_model<n, modulus>::t_minus_1_over_2;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp_model<n, modulus>::nqr;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp_model<n, modulus>::nqr_to_t;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp_model<n, modulus>::multiplicative_generator;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp_model<n, modulus>::root_of_unity;
+
+template<mp_size_t n, const bigint<n>& modulus>
+mp_limb_t Fp_model<n, modulus>::inv;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<n> Fp_model<n, modulus>::Rsquared;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<n> Fp_model<n, modulus>::Rcubed;
+
+} // libsnark
+#include "algebra/fields/fp.tcc"
+
+#endif // FP_HPP_
diff --git a/src/algebra/fields/fp.tcc b/src/algebra/fields/fp.tcc
new file mode 100644 (file)
index 0000000..566e993
--- /dev/null
@@ -0,0 +1,790 @@
+/** @file
+ *****************************************************************************
+ Implementation of arithmetic in the finite field F[p], for prime p of fixed length.
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP_TCC_
+#define FP_TCC_
+#include <cassert>
+#include <cstdlib>
+#include <cmath>
+
+#include "algebra/fields/fp_aux.tcc"
+#include "algebra/fields/field_utils.hpp"
+#include "common/assert_except.hpp"
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+void Fp_model<n,modulus>::mul_reduce(const bigint<n> &other)
+{
+    /* stupid pre-processor tricks; beware */
+#if defined(__x86_64__) && defined(USE_ASM)
+    if (n == 3)
+    { // Use asm-optimized Comba multiplication and reduction
+        mp_limb_t res[2*n];
+        mp_limb_t c0, c1, c2;
+        COMBA_3_BY_3_MUL(c0, c1, c2, res, this->mont_repr.data, other.data);
+
+        mp_limb_t k;
+        mp_limb_t tmp1, tmp2, tmp3;
+        REDUCE_6_LIMB_PRODUCT(k, tmp1, tmp2, tmp3, inv, res, modulus.data);
+
+        /* subtract t > mod */
+        __asm__
+            ("/* check for overflow */        \n\t"
+             MONT_CMP(16)
+             MONT_CMP(8)
+             MONT_CMP(0)
+
+             "/* subtract mod if overflow */  \n\t"
+             "subtract%=:                     \n\t"
+             MONT_FIRSTSUB
+             MONT_NEXTSUB(8)
+             MONT_NEXTSUB(16)
+             "done%=:                         \n\t"
+             :
+             : [tmp] "r" (res+n), [M] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+        mpn_copyi(this->mont_repr.data, res+n, n);
+    }
+    else if (n == 4)
+    { // use asm-optimized "CIOS method"
+
+        mp_limb_t tmp[n+1];
+        mp_limb_t T0=0, T1=1, cy=2, u=3; // TODO: fix this
+
+        __asm__ (MONT_PRECOMPUTE
+                 MONT_FIRSTITER(1)
+                 MONT_FIRSTITER(2)
+                 MONT_FIRSTITER(3)
+                 MONT_FINALIZE(3)
+                 MONT_ITERFIRST(1)
+                 MONT_ITERITER(1, 1)
+                 MONT_ITERITER(1, 2)
+                 MONT_ITERITER(1, 3)
+                 MONT_FINALIZE(3)
+                 MONT_ITERFIRST(2)
+                 MONT_ITERITER(2, 1)
+                 MONT_ITERITER(2, 2)
+                 MONT_ITERITER(2, 3)
+                 MONT_FINALIZE(3)
+                 MONT_ITERFIRST(3)
+                 MONT_ITERITER(3, 1)
+                 MONT_ITERITER(3, 2)
+                 MONT_ITERITER(3, 3)
+                 MONT_FINALIZE(3)
+                 "/* check for overflow */        \n\t"
+                 MONT_CMP(24)
+                 MONT_CMP(16)
+                 MONT_CMP(8)
+                 MONT_CMP(0)
+
+                 "/* subtract mod if overflow */  \n\t"
+                 "subtract%=:                     \n\t"
+                 MONT_FIRSTSUB
+                 MONT_NEXTSUB(8)
+                 MONT_NEXTSUB(16)
+                 MONT_NEXTSUB(24)
+                 "done%=:                         \n\t"
+                 :
+                 : [tmp] "r" (tmp), [A] "r" (this->mont_repr.data), [B] "r" (other.data), [inv] "r" (inv), [M] "r" (modulus.data),
+                   [T0] "r" (T0), [T1] "r" (T1), [cy] "r" (cy), [u] "r" (u)
+                 : "cc", "memory", "%rax", "%rdx"
+        );
+        mpn_copyi(this->mont_repr.data, tmp, n);
+    }
+    else if (n == 5)
+    { // use asm-optimized "CIOS method"
+
+        mp_limb_t tmp[n+1];
+        mp_limb_t T0=0, T1=1, cy=2, u=3; // TODO: fix this
+
+        __asm__ (MONT_PRECOMPUTE
+                 MONT_FIRSTITER(1)
+                 MONT_FIRSTITER(2)
+                 MONT_FIRSTITER(3)
+                 MONT_FIRSTITER(4)
+                 MONT_FINALIZE(4)
+                 MONT_ITERFIRST(1)
+                 MONT_ITERITER(1, 1)
+                 MONT_ITERITER(1, 2)
+                 MONT_ITERITER(1, 3)
+                 MONT_ITERITER(1, 4)
+                 MONT_FINALIZE(4)
+                 MONT_ITERFIRST(2)
+                 MONT_ITERITER(2, 1)
+                 MONT_ITERITER(2, 2)
+                 MONT_ITERITER(2, 3)
+                 MONT_ITERITER(2, 4)
+                 MONT_FINALIZE(4)
+                 MONT_ITERFIRST(3)
+                 MONT_ITERITER(3, 1)
+                 MONT_ITERITER(3, 2)
+                 MONT_ITERITER(3, 3)
+                 MONT_ITERITER(3, 4)
+                 MONT_FINALIZE(4)
+                 MONT_ITERFIRST(4)
+                 MONT_ITERITER(4, 1)
+                 MONT_ITERITER(4, 2)
+                 MONT_ITERITER(4, 3)
+                 MONT_ITERITER(4, 4)
+                 MONT_FINALIZE(4)
+                 "/* check for overflow */        \n\t"
+                 MONT_CMP(32)
+                 MONT_CMP(24)
+                 MONT_CMP(16)
+                 MONT_CMP(8)
+                 MONT_CMP(0)
+
+                 "/* subtract mod if overflow */  \n\t"
+                 "subtract%=:                     \n\t"
+                 MONT_FIRSTSUB
+                 MONT_NEXTSUB(8)
+                 MONT_NEXTSUB(16)
+                 MONT_NEXTSUB(24)
+                 MONT_NEXTSUB(32)
+                 "done%=:                         \n\t"
+                 :
+                 : [tmp] "r" (tmp), [A] "r" (this->mont_repr.data), [B] "r" (other.data), [inv] "r" (inv), [M] "r" (modulus.data),
+                   [T0] "r" (T0), [T1] "r" (T1), [cy] "r" (cy), [u] "r" (u)
+                 : "cc", "memory", "%rax", "%rdx"
+        );
+        mpn_copyi(this->mont_repr.data, tmp, n);
+    }
+    else
+#endif
+    {
+        mp_limb_t res[2*n];
+        mpn_mul_n(res, this->mont_repr.data, other.data, n);
+
+        /*
+          The Montgomery reduction here is based on Algorithm 14.32 in
+          Handbook of Applied Cryptography
+          <http://cacr.uwaterloo.ca/hac/about/chap14.pdf>.
+         */
+        for (size_t i = 0; i < n; ++i)
+        {
+            mp_limb_t k = inv * res[i];
+            /* calculate res = res + k * mod * b^i */
+            mp_limb_t carryout = mpn_addmul_1(res+i, modulus.data, n, k);
+            carryout = mpn_add_1(res+n+i, res+n+i, n-i, carryout);
+            assert(carryout == 0);
+        }
+
+        if (mpn_cmp(res+n, modulus.data, n) >= 0)
+        {
+            const mp_limb_t borrow = mpn_sub(res+n, res+n, n, modulus.data, n);
+            assert(borrow == 0);
+        }
+
+        mpn_copyi(this->mont_repr.data, res+n, n);
+    }
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus>::Fp_model(const bigint<n> &b)
+{
+    mpn_copyi(this->mont_repr.data, Rsquared.data, n);
+    mul_reduce(b);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus>::Fp_model(const long x, const bool is_unsigned)
+{
+    if (is_unsigned || x >= 0)
+    {
+        this->mont_repr.data[0] = x;
+    }
+    else
+    {
+        const mp_limb_t borrow = mpn_sub_1(this->mont_repr.data, modulus.data, n, -x);
+        assert(borrow == 0);
+    }
+
+    mul_reduce(Rsquared);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+void Fp_model<n,modulus>::set_ulong(const unsigned long x)
+{
+    this->mont_repr.clear();
+    this->mont_repr.data[0] = x;
+    mul_reduce(Rsquared);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+void Fp_model<n,modulus>::clear()
+{
+    this->mont_repr.clear();
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<n> Fp_model<n,modulus>::as_bigint() const
+{
+    bigint<n> one;
+    one.clear();
+    one.data[0] = 1;
+
+    Fp_model<n, modulus> res(*this);
+    res.mul_reduce(one);
+
+    return (res.mont_repr);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+unsigned long Fp_model<n,modulus>::as_ulong() const
+{
+    return this->as_bigint().as_ulong();
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp_model<n,modulus>::operator==(const Fp_model& other) const
+{
+    return (this->mont_repr == other.mont_repr);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp_model<n,modulus>::operator!=(const Fp_model& other) const
+{
+    return (this->mont_repr != other.mont_repr);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp_model<n,modulus>::is_zero() const
+{
+    return (this->mont_repr.is_zero()); // zero maps to zero
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+void Fp_model<n,modulus>::print() const
+{
+    Fp_model<n,modulus> tmp;
+    tmp.mont_repr.data[0] = 1;
+    tmp.mul_reduce(this->mont_repr);
+
+    tmp.mont_repr.print();
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::zero()
+{
+    Fp_model<n,modulus> res;
+    res.mont_repr.clear();
+    return res;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::one()
+{
+    Fp_model<n,modulus> res;
+    res.mont_repr.data[0] = 1;
+    res.mul_reduce(Rsquared);
+    return res;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus>& Fp_model<n,modulus>::operator+=(const Fp_model<n,modulus>& other)
+{
+#ifdef PROFILE_OP_COUNTS
+    this->add_cnt++;
+#endif
+#if defined(__x86_64__) && defined(USE_ASM)
+    if (n == 3)
+    {
+        __asm__
+            ("/* perform bignum addition */   \n\t"
+             ADD_FIRSTADD
+             ADD_NEXTADD(8)
+             ADD_NEXTADD(16)
+             "/* if overflow: subtract     */ \n\t"
+             "/* (tricky point: if A and B are in the range we do not need to do anything special for the possible carry flag) */ \n\t"
+             "jc      subtract%=              \n\t"
+
+             "/* check for overflow */        \n\t"
+             ADD_CMP(16)
+             ADD_CMP(8)
+             ADD_CMP(0)
+
+             "/* subtract mod if overflow */  \n\t"
+             "subtract%=:                     \n\t"
+             ADD_FIRSTSUB
+             ADD_NEXTSUB(8)
+             ADD_NEXTSUB(16)
+             "done%=:                         \n\t"
+             :
+             : [A] "r" (this->mont_repr.data), [B] "r" (other.mont_repr.data), [mod] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+    }
+    else if (n == 4)
+    {
+        __asm__
+            ("/* perform bignum addition */   \n\t"
+             ADD_FIRSTADD
+             ADD_NEXTADD(8)
+             ADD_NEXTADD(16)
+             ADD_NEXTADD(24)
+             "/* if overflow: subtract     */ \n\t"
+             "/* (tricky point: if A and B are in the range we do not need to do anything special for the possible carry flag) */ \n\t"
+             "jc      subtract%=              \n\t"
+
+             "/* check for overflow */        \n\t"
+             ADD_CMP(24)
+             ADD_CMP(16)
+             ADD_CMP(8)
+             ADD_CMP(0)
+
+             "/* subtract mod if overflow */  \n\t"
+             "subtract%=:                     \n\t"
+             ADD_FIRSTSUB
+             ADD_NEXTSUB(8)
+             ADD_NEXTSUB(16)
+             ADD_NEXTSUB(24)
+             "done%=:                         \n\t"
+             :
+             : [A] "r" (this->mont_repr.data), [B] "r" (other.mont_repr.data), [mod] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+    }
+    else if (n == 5)
+    {
+        __asm__
+            ("/* perform bignum addition */   \n\t"
+             ADD_FIRSTADD
+             ADD_NEXTADD(8)
+             ADD_NEXTADD(16)
+             ADD_NEXTADD(24)
+             ADD_NEXTADD(32)
+             "/* if overflow: subtract     */ \n\t"
+             "/* (tricky point: if A and B are in the range we do not need to do anything special for the possible carry flag) */ \n\t"
+             "jc      subtract%=              \n\t"
+
+             "/* check for overflow */        \n\t"
+             ADD_CMP(32)
+             ADD_CMP(24)
+             ADD_CMP(16)
+             ADD_CMP(8)
+             ADD_CMP(0)
+
+             "/* subtract mod if overflow */  \n\t"
+             "subtract%=:                     \n\t"
+             ADD_FIRSTSUB
+             ADD_NEXTSUB(8)
+             ADD_NEXTSUB(16)
+             ADD_NEXTSUB(24)
+             ADD_NEXTSUB(32)
+             "done%=:                         \n\t"
+             :
+             : [A] "r" (this->mont_repr.data), [B] "r" (other.mont_repr.data), [mod] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+    }
+    else
+#endif
+    {
+        mp_limb_t scratch[n+1];
+        const mp_limb_t carry = mpn_add_n(scratch, this->mont_repr.data, other.mont_repr.data, n);
+        scratch[n] = carry;
+
+        if (carry || mpn_cmp(scratch, modulus.data, n) >= 0)
+        {
+            const mp_limb_t borrow = mpn_sub(scratch, scratch, n+1, modulus.data, n);
+            assert(borrow == 0);
+        }
+
+        mpn_copyi(this->mont_repr.data, scratch, n);
+    }
+
+    return *this;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus>& Fp_model<n,modulus>::operator-=(const Fp_model<n,modulus>& other)
+{
+#ifdef PROFILE_OP_COUNTS
+    this->sub_cnt++;
+#endif
+#if defined(__x86_64__) && defined(USE_ASM)
+    if (n == 3)
+    {
+        __asm__
+            (SUB_FIRSTSUB
+             SUB_NEXTSUB(8)
+             SUB_NEXTSUB(16)
+
+             "jnc     done%=\n\t"
+
+             SUB_FIRSTADD
+             SUB_NEXTADD(8)
+             SUB_NEXTADD(16)
+
+             "done%=:\n\t"
+             :
+             : [A] "r" (this->mont_repr.data), [B] "r" (other.mont_repr.data), [mod] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+    }
+    else if (n == 4)
+    {
+        __asm__
+            (SUB_FIRSTSUB
+             SUB_NEXTSUB(8)
+             SUB_NEXTSUB(16)
+             SUB_NEXTSUB(24)
+
+             "jnc     done%=\n\t"
+
+             SUB_FIRSTADD
+             SUB_NEXTADD(8)
+             SUB_NEXTADD(16)
+             SUB_NEXTADD(24)
+
+             "done%=:\n\t"
+             :
+             : [A] "r" (this->mont_repr.data), [B] "r" (other.mont_repr.data), [mod] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+    }
+    else if (n == 5)
+    {
+        __asm__
+            (SUB_FIRSTSUB
+             SUB_NEXTSUB(8)
+             SUB_NEXTSUB(16)
+             SUB_NEXTSUB(24)
+             SUB_NEXTSUB(32)
+
+             "jnc     done%=\n\t"
+
+             SUB_FIRSTADD
+             SUB_NEXTADD(8)
+             SUB_NEXTADD(16)
+             SUB_NEXTADD(24)
+             SUB_NEXTADD(32)
+
+             "done%=:\n\t"
+             :
+             : [A] "r" (this->mont_repr.data), [B] "r" (other.mont_repr.data), [mod] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+    }
+    else
+#endif
+    {
+        mp_limb_t scratch[n+1];
+        if (mpn_cmp(this->mont_repr.data, other.mont_repr.data, n) < 0)
+        {
+            const mp_limb_t carry = mpn_add_n(scratch, this->mont_repr.data, modulus.data, n);
+            scratch[n] = carry;
+        }
+        else
+        {
+            mpn_copyi(scratch, this->mont_repr.data, n);
+            scratch[n] = 0;
+        }
+
+        const mp_limb_t borrow = mpn_sub(scratch, scratch, n+1, other.mont_repr.data, n);
+        assert(borrow == 0);
+
+        mpn_copyi(this->mont_repr.data, scratch, n);
+    }
+    return *this;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus>& Fp_model<n,modulus>::operator*=(const Fp_model<n,modulus>& other)
+{
+#ifdef PROFILE_OP_COUNTS
+    this->mul_cnt++;
+#endif
+
+    mul_reduce(other.mont_repr);
+    return *this;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus>& Fp_model<n,modulus>::operator^=(const unsigned long pow)
+{
+    (*this) = power<Fp_model<n, modulus> >(*this, pow);
+    return (*this);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+template<mp_size_t m>
+Fp_model<n,modulus>& Fp_model<n,modulus>::operator^=(const bigint<m> &pow)
+{
+    (*this) = power<Fp_model<n, modulus>, m>(*this, pow);
+    return (*this);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::operator+(const Fp_model<n,modulus>& other) const
+{
+    Fp_model<n, modulus> r(*this);
+    return (r += other);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::operator-(const Fp_model<n,modulus>& other) const
+{
+    Fp_model<n, modulus> r(*this);
+    return (r -= other);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::operator*(const Fp_model<n,modulus>& other) const
+{
+    Fp_model<n, modulus> r(*this);
+    return (r *= other);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::operator^(const unsigned long pow) const
+{
+    Fp_model<n, modulus> r(*this);
+    return (r ^= pow);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+template<mp_size_t m>
+Fp_model<n,modulus> Fp_model<n,modulus>::operator^(const bigint<m> &pow) const
+{
+    Fp_model<n, modulus> r(*this);
+    return (r ^= pow);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::operator-() const
+{
+#ifdef PROFILE_OP_COUNTS
+    this->sub_cnt++;
+#endif
+
+    if (this->is_zero())
+    {
+        return (*this);
+    }
+    else
+    {
+        Fp_model<n, modulus> r;
+        mpn_sub_n(r.mont_repr.data, modulus.data, this->mont_repr.data, n);
+        return r;
+    }
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::squared() const
+{
+#ifdef PROFILE_OP_COUNTS
+    this->sqr_cnt++;
+    this->mul_cnt--; // zero out the upcoming mul
+#endif
+    /* stupid pre-processor tricks; beware */
+#if defined(__x86_64__) && defined(USE_ASM)
+    if (n == 3)
+    { // use asm-optimized Comba squaring
+        mp_limb_t res[2*n];
+        mp_limb_t c0, c1, c2;
+        COMBA_3_BY_3_SQR(c0, c1, c2, res, this->mont_repr.data);
+
+        mp_limb_t k;
+        mp_limb_t tmp1, tmp2, tmp3;
+        REDUCE_6_LIMB_PRODUCT(k, tmp1, tmp2, tmp3, inv, res, modulus.data);
+
+        /* subtract t > mod */
+        __asm__ volatile
+            ("/* check for overflow */        \n\t"
+             MONT_CMP(16)
+             MONT_CMP(8)
+             MONT_CMP(0)
+
+             "/* subtract mod if overflow */  \n\t"
+             "subtract%=:                     \n\t"
+             MONT_FIRSTSUB
+             MONT_NEXTSUB(8)
+             MONT_NEXTSUB(16)
+             "done%=:                         \n\t"
+             :
+             : [tmp] "r" (res+n), [M] "r" (modulus.data)
+             : "cc", "memory", "%rax");
+
+        Fp_model<n, modulus> r;
+        mpn_copyi(r.mont_repr.data, res+n, n);
+        return r;
+    }
+    else
+#endif
+    {
+        Fp_model<n, modulus> r(*this);
+        return (r *= r);
+    }
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus>& Fp_model<n,modulus>::invert()
+{
+#ifdef PROFILE_OP_COUNTS
+    this->inv_cnt++;
+#endif
+
+    assert(!this->is_zero());
+
+    bigint<n> g; /* gp should have room for vn = n limbs */
+
+    mp_limb_t s[n+1]; /* sp should have room for vn+1 limbs */
+    mp_size_t sn;
+
+    bigint<n> v = modulus; // both source operands are destroyed by mpn_gcdext
+
+    /* computes gcd(u, v) = g = u*s + v*t, so s*u will be 1 (mod v) */
+    const mp_size_t gn = mpn_gcdext(g.data, s, &sn, this->mont_repr.data, n, v.data, n);
+    assert(gn == 1 && g.data[0] == 1); /* inverse exists */
+
+    mp_limb_t q; /* division result fits into q, as sn <= n+1 */
+    /* sn < 0 indicates negative sn; will fix up later */
+
+    if (std::abs(sn) >= n)
+    {
+        /* if sn could require modulus reduction, do it here */
+        mpn_tdiv_qr(&q, this->mont_repr.data, 0, s, std::abs(sn), modulus.data, n);
+    }
+    else
+    {
+        /* otherwise just copy it over */
+        mpn_zero(this->mont_repr.data, n);
+        mpn_copyi(this->mont_repr.data, s, std::abs(sn));
+    }
+
+    /* fix up the negative sn */
+    if (sn < 0)
+    {
+        const mp_limb_t borrow = mpn_sub_n(this->mont_repr.data, modulus.data, this->mont_repr.data, n);
+        assert(borrow == 0);
+    }
+
+    mul_reduce(Rcubed);
+    return *this;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::inverse() const
+{
+    Fp_model<n, modulus> r(*this);
+    return (r.invert());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp_model<n,modulus>::random_element() /// returns random element of Fp_model
+{
+    /* note that as Montgomery representation is a bijection then
+       selecting a random element of {xR} is the same as selecting a
+       random element of {x} */
+    Fp_model<n, modulus> r;
+    do
+    {
+        r.mont_repr.randomize();
+
+        /* clear all bits higher than MSB of modulus */
+        size_t bitno = GMP_NUMB_BITS * n - 1;
+        while (modulus.test_bit(bitno) == false)
+        {
+            const std::size_t part = bitno/GMP_NUMB_BITS;
+            const std::size_t bit = bitno - (GMP_NUMB_BITS*part);
+
+            r.mont_repr.data[part] &= ~(1ul<<bit);
+
+            bitno--;
+        }
+    }
+   /* if r.data is still >= modulus -- repeat (rejection sampling) */
+    while (mpn_cmp(r.mont_repr.data, modulus.data, n) >= 0);
+
+    return r;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n,modulus> Fp_model<n,modulus>::sqrt() const
+{
+    if (is_zero()) {
+        return *this;
+    }
+
+    Fp_model<n,modulus> one = Fp_model<n,modulus>::one();
+
+    size_t v = Fp_model<n,modulus>::s;
+    Fp_model<n,modulus> z = Fp_model<n,modulus>::nqr_to_t;
+    Fp_model<n,modulus> w = (*this)^Fp_model<n,modulus>::t_minus_1_over_2;
+    Fp_model<n,modulus> x = (*this) * w;
+    Fp_model<n,modulus> b = x * w; // b = (*this)^t
+
+
+    // check if square with euler's criterion
+    Fp_model<n,modulus> check = b;
+    for (size_t i = 0; i < v-1; ++i)
+    {
+        check = check.squared();
+    }
+    if (check != one)
+    {
+        assert_except(0);
+    }
+
+
+    // compute square root with Tonelli--Shanks
+    // (does not terminate if not a square!)
+
+    while (b != one)
+    {
+        size_t m = 0;
+        Fp_model<n,modulus> b2m = b;
+        while (b2m != one)
+        {
+            /* invariant: b2m = b^(2^m) after entering this loop */
+            b2m = b2m.squared();
+            m += 1;
+        }
+
+        int j = v-m-1;
+        w = z;
+        while (j > 0)
+        {
+            w = w.squared();
+            --j;
+        } // w = z^2^(v-m-1)
+
+        z = w.squared();
+        b = b * z;
+        x = x * w;
+        v = m;
+    }
+
+    return x;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &out, const Fp_model<n, modulus> &p)
+{
+#ifndef MONTGOMERY_OUTPUT
+    Fp_model<n,modulus> tmp;
+    tmp.mont_repr.data[0] = 1;
+    tmp.mul_reduce(p.mont_repr);
+    out << tmp.mont_repr;
+#else
+    out << p.mont_repr;
+#endif
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &in, Fp_model<n, modulus> &p)
+{
+#ifndef MONTGOMERY_OUTPUT
+    in >> p.mont_repr;
+    p.mul_reduce(Fp_model<n, modulus>::Rsquared);
+#else
+    in >> p.mont_repr;
+#endif
+    return in;
+}
+
+} // libsnark
+#endif // FP_TCC_
diff --git a/src/algebra/fields/fp12_2over3over2.hpp b/src/algebra/fields/fp12_2over3over2.hpp
new file mode 100644 (file)
index 0000000..1de9d88
--- /dev/null
@@ -0,0 +1,116 @@
+/** @file
+ *****************************************************************************
+ Declaration of arithmetic in the finite field F[((p^2)^3)^2].
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP12_2OVER3OVER2_HPP_
+#define FP12_2OVER3OVER2_HPP_
+#include "algebra/fields/fp.hpp"
+#include "algebra/fields/fp2.hpp"
+#include "algebra/fields/fp6_3over2.hpp"
+#include <vector>
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp12_2over3over2_model;
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &, const Fp12_2over3over2_model<n, modulus> &);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &, Fp12_2over3over2_model<n, modulus> &);
+
+/**
+ * Arithmetic in the finite field F[((p^2)^3)^2].
+ *
+ * Let p := modulus. This interface provides arithmetic for the extension field
+ * Fp12 = Fp6[W]/(W^2-V) where Fp6 = Fp2[V]/(V^3-non_residue) and non_residue is in Fp2
+ *
+ * ASSUMPTION: p = 1 (mod 6)
+ */
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp12_2over3over2_model {
+public:
+    typedef Fp_model<n, modulus> my_Fp;
+    typedef Fp2_model<n, modulus> my_Fp2;
+    typedef Fp6_3over2_model<n, modulus> my_Fp6;
+
+    static Fp2_model<n, modulus> non_residue;
+    static Fp2_model<n, modulus> Frobenius_coeffs_c1[12]; // non_residue^((modulus^i-1)/6) for i=0,...,11
+
+    my_Fp6 c0, c1;
+    Fp12_2over3over2_model() {};
+    Fp12_2over3over2_model(const my_Fp6& c0, const my_Fp6& c1) : c0(c0), c1(c1) {};
+
+    void clear() { c0.clear(); c1.clear(); }
+    void print() const { printf("c0/c1:\n"); c0.print(); c1.print(); }
+
+    static Fp12_2over3over2_model<n, modulus> zero();
+    static Fp12_2over3over2_model<n, modulus> one();
+    static Fp12_2over3over2_model<n, modulus> random_element();
+
+    bool is_zero() const { return c0.is_zero() && c1.is_zero(); }
+    bool operator==(const Fp12_2over3over2_model &other) const;
+    bool operator!=(const Fp12_2over3over2_model &other) const;
+
+    Fp12_2over3over2_model operator+(const Fp12_2over3over2_model &other) const;
+    Fp12_2over3over2_model operator-(const Fp12_2over3over2_model &other) const;
+    Fp12_2over3over2_model operator*(const Fp12_2over3over2_model &other) const;
+    Fp12_2over3over2_model operator-() const;
+    Fp12_2over3over2_model squared() const; // default is squared_complex
+    Fp12_2over3over2_model squared_karatsuba() const;
+    Fp12_2over3over2_model squared_complex() const;
+    Fp12_2over3over2_model inverse() const;
+    Fp12_2over3over2_model Frobenius_map(unsigned long power) const;
+    Fp12_2over3over2_model unitary_inverse() const;
+    Fp12_2over3over2_model cyclotomic_squared() const;
+
+    Fp12_2over3over2_model mul_by_024(const my_Fp2 &ell_0, const my_Fp2 &ell_VW, const my_Fp2 &ell_VV) const;
+
+    static my_Fp6 mul_by_non_residue(const my_Fp6 &elt);
+
+    template<mp_size_t m>
+    Fp12_2over3over2_model cyclotomic_exp(const bigint<m> &exponent) const;
+
+    static bigint<n> base_field_char() { return modulus; }
+    static size_t extension_degree() { return 12; }
+
+    friend std::ostream& operator<< <n, modulus>(std::ostream &out, const Fp12_2over3over2_model<n, modulus> &el);
+    friend std::istream& operator>> <n, modulus>(std::istream &in, Fp12_2over3over2_model<n, modulus> &el);
+};
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp12_2over3over2_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp12_2over3over2_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp12_2over3over2_model<n, modulus> &rhs);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n, modulus> operator*(const Fp2_model<n, modulus> &lhs, const Fp12_2over3over2_model<n, modulus> &rhs);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n, modulus> operator*(const Fp6_3over2_model<n, modulus> &lhs, const Fp12_2over3over2_model<n, modulus> &rhs);
+
+template<mp_size_t n, const bigint<n>& modulus, mp_size_t m>
+Fp12_2over3over2_model<n, modulus> operator^(const Fp12_2over3over2_model<n, modulus> &self, const bigint<m> &exponent);
+
+template<mp_size_t n, const bigint<n>& modulus, mp_size_t m, const bigint<m>& exp_modulus>
+Fp12_2over3over2_model<n, modulus> operator^(const Fp12_2over3over2_model<n, modulus> &self, const Fp_model<m, exp_modulus> &exponent);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp12_2over3over2_model<n, modulus>::non_residue;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp12_2over3over2_model<n, modulus>::Frobenius_coeffs_c1[12];
+
+} // libsnark
+#include "algebra/fields/fp12_2over3over2.tcc"
+#endif // FP12_2OVER3OVER2_HPP_
diff --git a/src/algebra/fields/fp12_2over3over2.tcc b/src/algebra/fields/fp12_2over3over2.tcc
new file mode 100644 (file)
index 0000000..2fbc0b6
--- /dev/null
@@ -0,0 +1,412 @@
+/** @file
+ *****************************************************************************
+ Implementation of arithmetic in the finite field F[((p^2)^3)^2].
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP12_2OVER3OVER2_TCC_
+#define FP12_2OVER3OVER2_TCC_
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n, modulus> Fp12_2over3over2_model<n,modulus>::mul_by_non_residue(const Fp6_3over2_model<n, modulus> &elt)
+{
+    return Fp6_3over2_model<n, modulus>(non_residue * elt.c2, elt.c0, elt.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::zero()
+{
+    return Fp12_2over3over2_model<n, modulus>(my_Fp6::zero(), my_Fp6::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::one()
+{
+    return Fp12_2over3over2_model<n, modulus>(my_Fp6::one(), my_Fp6::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::random_element()
+{
+    Fp12_2over3over2_model<n, modulus> r;
+    r.c0 = my_Fp6::random_element();
+    r.c1 = my_Fp6::random_element();
+
+    return r;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp12_2over3over2_model<n,modulus>::operator==(const Fp12_2over3over2_model<n,modulus> &other) const
+{
+    return (this->c0 == other.c0 && this->c1 == other.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp12_2over3over2_model<n,modulus>::operator!=(const Fp12_2over3over2_model<n,modulus> &other) const
+{
+    return !(operator==(other));
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::operator+(const Fp12_2over3over2_model<n,modulus> &other) const
+{
+    return Fp12_2over3over2_model<n,modulus>(this->c0 + other.c0,
+                                             this->c1 + other.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::operator-(const Fp12_2over3over2_model<n,modulus> &other) const
+{
+    return Fp12_2over3over2_model<n,modulus>(this->c0 - other.c0,
+                                             this->c1 - other.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp12_2over3over2_model<n, modulus> &rhs)
+{
+    return Fp12_2over3over2_model<n,modulus>(lhs*rhs.c0,
+                                             lhs*rhs.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n, modulus> operator*(const Fp2_model<n, modulus> &lhs, const Fp12_2over3over2_model<n, modulus> &rhs)
+{
+    return Fp12_2over3over2_model<n,modulus>(lhs*rhs.c0,
+                                             lhs*rhs.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n, modulus> operator*(const Fp6_3over2_model<n, modulus> &lhs, const Fp12_2over3over2_model<n, modulus> &rhs)
+{
+    return Fp12_2over3over2_model<n,modulus>(lhs*rhs.c0,
+                                             lhs*rhs.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::operator*(const Fp12_2over3over2_model<n,modulus> &other) const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 3 (Karatsuba) */
+
+    const my_Fp6 &A = other.c0, &B = other.c1,
+        &a = this->c0, &b = this->c1;
+    const my_Fp6 aA = a * A;
+    const my_Fp6 bB = b * B;
+
+    return Fp12_2over3over2_model<n,modulus>(aA + Fp12_2over3over2_model<n, modulus>::mul_by_non_residue(bB),
+                                             (a + b)*(A+B) - aA - bB);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::operator-() const
+{
+    return Fp12_2over3over2_model<n,modulus>(-this->c0,
+                                             -this->c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::squared() const
+{
+    return squared_complex();
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::squared_karatsuba() const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 3 (Karatsuba squaring) */
+
+    const my_Fp6 &a = this->c0, &b = this->c1;
+    const my_Fp6 asq = a.squared();
+    const my_Fp6 bsq = b.squared();
+
+    return Fp12_2over3over2_model<n,modulus>(asq + Fp12_2over3over2_model<n, modulus>::mul_by_non_residue(bsq),
+                                             (a + b).squared() - asq - bsq);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::squared_complex() const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 3 (Complex squaring) */
+
+    const my_Fp6 &a = this->c0, &b = this->c1;
+    const my_Fp6 ab = a * b;
+
+    return Fp12_2over3over2_model<n,modulus>((a + b) * (a + Fp12_2over3over2_model<n, modulus>::mul_by_non_residue(b)) - ab - Fp12_2over3over2_model<n, modulus>::mul_by_non_residue(ab),
+                                             ab + ab);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::inverse() const
+{
+    /* From "High-Speed Software Implementation of the Optimal Ate Pairing over Barreto-Naehrig Curves"; Algorithm 8 */
+
+    const my_Fp6 &a = this->c0, &b = this->c1;
+    const my_Fp6 t0 = a.squared();
+    const my_Fp6 t1 = b.squared();
+    const my_Fp6 t2 = t0 - Fp12_2over3over2_model<n, modulus>::mul_by_non_residue(t1);
+    const my_Fp6 t3 = t2.inverse();
+    const my_Fp6 c0 = a * t3;
+    const my_Fp6 c1 = - (b * t3);
+
+    return Fp12_2over3over2_model<n,modulus>(c0, c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::Frobenius_map(unsigned long power) const
+{
+    return Fp12_2over3over2_model<n,modulus>(c0.Frobenius_map(power),
+                                             Frobenius_coeffs_c1[power % 12] * c1.Frobenius_map(power));
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::unitary_inverse() const
+{
+    return Fp12_2over3over2_model<n,modulus>(this->c0,
+                                             -this->c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::cyclotomic_squared() const
+{
+    /* OLD: naive implementation
+       return (*this).squared();
+    */
+    my_Fp2 z0 = this->c0.c0;
+    my_Fp2 z4 = this->c0.c1;
+    my_Fp2 z3 = this->c0.c2;
+    my_Fp2 z2 = this->c1.c0;
+    my_Fp2 z1 = this->c1.c1;
+    my_Fp2 z5 = this->c1.c2;
+
+    my_Fp2 t0, t1, t2, t3, t4, t5, tmp;
+
+    // t0 + t1*y = (z0 + z1*y)^2 = a^2
+    tmp = z0 * z1;
+    t0 = (z0 + z1) * (z0 + my_Fp6::non_residue * z1) - tmp - my_Fp6::non_residue * tmp;
+    t1 = tmp + tmp;
+    // t2 + t3*y = (z2 + z3*y)^2 = b^2
+    tmp = z2 * z3;
+    t2 = (z2 + z3) * (z2 + my_Fp6::non_residue * z3) - tmp - my_Fp6::non_residue * tmp;
+    t3 = tmp + tmp;
+    // t4 + t5*y = (z4 + z5*y)^2 = c^2
+    tmp = z4 * z5;
+    t4 = (z4 + z5) * (z4 + my_Fp6::non_residue * z5) - tmp - my_Fp6::non_residue * tmp;
+    t5 = tmp + tmp;
+
+    // for A
+
+    // z0 = 3 * t0 - 2 * z0
+    z0 = t0 - z0;
+    z0 = z0 + z0;
+    z0 = z0 + t0;
+    // z1 = 3 * t1 + 2 * z1
+    z1 = t1 + z1;
+    z1 = z1 + z1;
+    z1 = z1 + t1;
+
+    // for B
+
+    // z2 = 3 * (xi * t5) + 2 * z2
+    tmp = my_Fp6::non_residue * t5;
+    z2 = tmp + z2;
+    z2 = z2 + z2;
+    z2 = z2 + tmp;
+
+    // z3 = 3 * t4 - 2 * z3
+    z3 = t4 - z3;
+    z3 = z3 + z3;
+    z3 = z3 + t4;
+
+    // for C
+
+    // z4 = 3 * t2 - 2 * z4
+    z4 = t2 - z4;
+    z4 = z4 + z4;
+    z4 = z4 + t2;
+
+    // z5 = 3 * t3 + 2 * z5
+    z5 = t3 + z5;
+    z5 = z5 + z5;
+    z5 = z5 + t3;
+
+    return Fp12_2over3over2_model<n,modulus>(my_Fp6(z0,z4,z3),my_Fp6(z2,z1,z5));
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp12_2over3over2_model<n,modulus> Fp12_2over3over2_model<n,modulus>::mul_by_024(const Fp2_model<n, modulus> &ell_0,
+                                                                                const Fp2_model<n, modulus> &ell_VW,
+                                                                                const Fp2_model<n, modulus> &ell_VV) const
+{
+    /* OLD: naive implementation
+       Fp12_2over3over2_model<n,modulus> a(my_Fp6(ell_0, my_Fp2::zero(), ell_VV),
+       my_Fp6(my_Fp2::zero(), ell_VW, my_Fp2::zero()));
+
+       return (*this) * a;
+    */
+    my_Fp2 z0 = this->c0.c0;
+    my_Fp2 z1 = this->c0.c1;
+    my_Fp2 z2 = this->c0.c2;
+    my_Fp2 z3 = this->c1.c0;
+    my_Fp2 z4 = this->c1.c1;
+    my_Fp2 z5 = this->c1.c2;
+
+    my_Fp2 x0 = ell_0;
+    my_Fp2 x2 = ell_VV;
+    my_Fp2 x4 = ell_VW;
+
+    my_Fp2 t0, t1, t2, s0, T3, T4, D0, D2, D4, S1;
+
+    D0 = z0 * x0;
+    D2 = z2 * x2;
+    D4 = z4 * x4;
+    t2 = z0 + z4;
+    t1 = z0 + z2;
+    s0 = z1 + z3 + z5;
+
+    // For z.a_.a_ = z0.
+    S1 = z1 * x2;
+    T3 = S1 + D4;
+    T4 = my_Fp6::non_residue * T3 + D0;
+    z0 = T4;
+
+    // For z.a_.b_ = z1
+    T3 = z5 * x4;
+    S1 = S1 + T3;
+    T3 = T3 + D2;
+    T4 = my_Fp6::non_residue * T3;
+    T3 = z1 * x0;
+    S1 = S1 + T3;
+    T4 = T4 + T3;
+    z1 = T4;
+
+    // For z.a_.c_ = z2
+    t0 = x0 + x2;
+    T3 = t1 * t0 - D0 - D2;
+    T4 = z3 * x4;
+    S1 = S1 + T4;
+    T3 = T3 + T4;
+
+    // For z.b_.a_ = z3 (z3 needs z2)
+    t0 = z2 + z4;
+    z2 = T3;
+    t1 = x2 + x4;
+    T3 = t0 * t1 - D2 - D4;
+    T4 = my_Fp6::non_residue * T3;
+    T3 = z3 * x0;
+    S1 = S1 + T3;
+    T4 = T4 + T3;
+    z3 = T4;
+
+    // For z.b_.b_ = z4
+    T3 = z5 * x2;
+    S1 = S1 + T3;
+    T4 = my_Fp6::non_residue * T3;
+    t0 = x0 + x4;
+    T3 = t2 * t0 - D0 - D4;
+    T4 = T4 + T3;
+    z4 = T4;
+
+    // For z.b_.c_ = z5.
+    t0 = x0 + x2 + x4;
+    T3 = s0 * t0 - S1;
+    z5 = T3;
+
+    return Fp12_2over3over2_model<n,modulus>(my_Fp6(z0,z1,z2),my_Fp6(z3,z4,z5));
+
+}
+
+template<mp_size_t n, const bigint<n>& modulus, mp_size_t m>
+Fp12_2over3over2_model<n, modulus> operator^(const Fp12_2over3over2_model<n, modulus> &self, const bigint<m> &exponent)
+{
+    return power<Fp12_2over3over2_model<n, modulus> >(self, exponent);
+}
+
+template<mp_size_t n, const bigint<n>& modulus, mp_size_t m, const bigint<m>& exp_modulus>
+Fp12_2over3over2_model<n, modulus> operator^(const Fp12_2over3over2_model<n, modulus> &self, const Fp_model<m, exp_modulus> &exponent)
+{
+    return self^(exponent.as_bigint());
+}
+
+
+template<mp_size_t n, const bigint<n>& modulus>
+template<mp_size_t m>
+Fp12_2over3over2_model<n, modulus> Fp12_2over3over2_model<n,modulus>::cyclotomic_exp(const bigint<m> &exponent) const
+{
+    Fp12_2over3over2_model<n,modulus> res = Fp12_2over3over2_model<n,modulus>::one();
+
+    bool found_one = false;
+    for (long i = m-1; i >= 0; --i)
+    {
+        for (long j = GMP_NUMB_BITS - 1; j >= 0; --j)
+        {
+            if (found_one)
+            {
+                res = res.cyclotomic_squared();
+            }
+
+            if (exponent.data[i] & (1ul<<j))
+            {
+                found_one = true;
+                res = res * (*this);
+            }
+        }
+    }
+
+    return res;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &out, const Fp12_2over3over2_model<n, modulus> &el)
+{
+    out << el.c0 << OUTPUT_SEPARATOR << el.c1;
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &in, Fp12_2over3over2_model<n, modulus> &el)
+{
+    in >> el.c0 >> el.c1;
+    return in;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp12_2over3over2_model<n, modulus> > &v)
+{
+    out << v.size() << "\n";
+    for (const Fp12_2over3over2_model<n, modulus>& t : v)
+    {
+        out << t << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp12_2over3over2_model<n, modulus> > &v)
+{
+    v.clear();
+
+    size_t s;
+    in >> s;
+
+    char b;
+    in.read(&b, 1);
+
+    v.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        Fp12_2over3over2_model<n, modulus> el;
+        in >> el;
+        v.emplace_back(el);
+    }
+
+    return in;
+}
+
+} // libsnark
+#endif // FP12_2OVER3OVER2_TCC_
diff --git a/src/algebra/fields/fp2.hpp b/src/algebra/fields/fp2.hpp
new file mode 100644 (file)
index 0000000..f077269
--- /dev/null
@@ -0,0 +1,120 @@
+/** @file
+ *****************************************************************************
+ Implementation of arithmetic in the finite field F[p^2].
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP2_HPP_
+#define FP2_HPP_
+#include "algebra/fields/fp.hpp"
+#include <vector>
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp2_model;
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &, const Fp2_model<n, modulus> &);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &, Fp2_model<n, modulus> &);
+
+/**
+ * Arithmetic in the field F[p^3].
+ *
+ * Let p := modulus. This interface provides arithmetic for the extension field
+ * Fp2 = Fp[U]/(U^2-non_residue), where non_residue is in Fp.
+ *
+ * ASSUMPTION: p = 1 (mod 6)
+ */
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp2_model {
+public:
+    typedef Fp_model<n, modulus> my_Fp;
+
+    static bigint<2*n> euler; // (modulus^2-1)/2
+    static size_t s;       // modulus^2 = 2^s * t + 1
+    static bigint<2*n> t;  // with t odd
+    static bigint<2*n> t_minus_1_over_2; // (t-1)/2
+    static my_Fp non_residue; // X^4-non_residue irreducible over Fp; used for constructing Fp2 = Fp[X] / (X^2 - non_residue)
+    static Fp2_model<n, modulus> nqr; // a quadratic nonresidue in Fp2
+    static Fp2_model<n, modulus> nqr_to_t; // nqr^t
+    static my_Fp Frobenius_coeffs_c1[2]; // non_residue^((modulus^i-1)/2) for i=0,1
+
+    my_Fp c0, c1;
+    Fp2_model() {};
+    Fp2_model(const my_Fp& c0, const my_Fp& c1) : c0(c0), c1(c1) {};
+
+    void clear() { c0.clear(); c1.clear(); }
+    void print() const { printf("c0/c1:\n"); c0.print(); c1.print(); }
+
+    static Fp2_model<n, modulus> zero();
+    static Fp2_model<n, modulus> one();
+    static Fp2_model<n, modulus> random_element();
+
+    bool is_zero() const { return c0.is_zero() && c1.is_zero(); }
+    bool operator==(const Fp2_model &other) const;
+    bool operator!=(const Fp2_model &other) const;
+
+    Fp2_model operator+(const Fp2_model &other) const;
+    Fp2_model operator-(const Fp2_model &other) const;
+    Fp2_model operator*(const Fp2_model &other) const;
+    Fp2_model operator-() const;
+    Fp2_model squared() const; // default is squared_complex
+    Fp2_model inverse() const;
+    Fp2_model Frobenius_map(unsigned long power) const;
+    Fp2_model sqrt() const; // HAS TO BE A SQUARE (else does not terminate)
+    Fp2_model squared_karatsuba() const;
+    Fp2_model squared_complex() const;
+
+    template<mp_size_t m>
+    Fp2_model operator^(const bigint<m> &other) const;
+
+    static size_t size_in_bits() { return 2*my_Fp::size_in_bits(); }
+    static bigint<n> base_field_char() { return modulus; }
+
+    friend std::ostream& operator<< <n, modulus>(std::ostream &out, const Fp2_model<n, modulus> &el);
+    friend std::istream& operator>> <n, modulus>(std::istream &in, Fp2_model<n, modulus> &el);
+};
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp2_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp2_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp2_model<n, modulus> &rhs);
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<2*n> Fp2_model<n, modulus>::euler;
+
+template<mp_size_t n, const bigint<n>& modulus>
+size_t Fp2_model<n, modulus>::s;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<2*n> Fp2_model<n, modulus>::t;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<2*n> Fp2_model<n, modulus>::t_minus_1_over_2;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp2_model<n, modulus>::non_residue;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp2_model<n, modulus>::nqr;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp2_model<n, modulus>::nqr_to_t;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp2_model<n, modulus>::Frobenius_coeffs_c1[2];
+
+} // libsnark
+#include "algebra/fields/fp2.tcc"
+
+#endif // FP2_HPP_
diff --git a/src/algebra/fields/fp2.tcc b/src/algebra/fields/fp2.tcc
new file mode 100644 (file)
index 0000000..1632a04
--- /dev/null
@@ -0,0 +1,261 @@
+/** @file
+ *****************************************************************************
+ Implementation of arithmetic in the finite field F[p^2].
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP2_TCC_
+#define FP2_TCC_
+
+#include "algebra/fields/field_utils.hpp"
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::zero()
+{
+    return Fp2_model<n, modulus>(my_Fp::zero(), my_Fp::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::one()
+{
+    return Fp2_model<n, modulus>(my_Fp::one(), my_Fp::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::random_element()
+{
+    Fp2_model<n, modulus> r;
+    r.c0 = my_Fp::random_element();
+    r.c1 = my_Fp::random_element();
+
+    return r;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp2_model<n,modulus>::operator==(const Fp2_model<n,modulus> &other) const
+{
+    return (this->c0 == other.c0 && this->c1 == other.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp2_model<n,modulus>::operator!=(const Fp2_model<n,modulus> &other) const
+{
+    return !(operator==(other));
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::operator+(const Fp2_model<n,modulus> &other) const
+{
+    return Fp2_model<n,modulus>(this->c0 + other.c0,
+                                this->c1 + other.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::operator-(const Fp2_model<n,modulus> &other) const
+{
+    return Fp2_model<n,modulus>(this->c0 - other.c0,
+                                this->c1 - other.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp2_model<n, modulus> &rhs)
+{
+    return Fp2_model<n,modulus>(lhs*rhs.c0,
+                                lhs*rhs.c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::operator*(const Fp2_model<n,modulus> &other) const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 3 (Karatsuba) */
+    const my_Fp
+        &A = other.c0, &B = other.c1,
+        &a = this->c0, &b = this->c1;
+    const my_Fp aA = a * A;
+    const my_Fp bB = b * B;
+
+    return Fp2_model<n,modulus>(aA + non_residue * bB,
+                                (a + b)*(A+B) - aA - bB);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::operator-() const
+{
+    return Fp2_model<n,modulus>(-this->c0,
+                                -this->c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::squared() const
+{
+    return squared_complex();
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::squared_karatsuba() const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 3 (Karatsuba squaring) */
+    const my_Fp &a = this->c0, &b = this->c1;
+    const my_Fp asq = a.squared();
+    const my_Fp bsq = b.squared();
+
+    return Fp2_model<n,modulus>(asq + non_residue * bsq,
+                                (a + b).squared() - asq - bsq);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::squared_complex() const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 3 (Complex squaring) */
+    const my_Fp &a = this->c0, &b = this->c1;
+    const my_Fp ab = a * b;
+
+    return Fp2_model<n,modulus>((a + b) * (a + non_residue * b) - ab - non_residue * ab,
+                                ab + ab);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::inverse() const
+{
+    const my_Fp &a = this->c0, &b = this->c1;
+
+    /* From "High-Speed Software Implementation of the Optimal Ate Pairing over Barreto-Naehrig Curves"; Algorithm 8 */
+    const my_Fp t0 = a.squared();
+    const my_Fp t1 = b.squared();
+    const my_Fp t2 = t0 - non_residue * t1;
+    const my_Fp t3 = t2.inverse();
+    const my_Fp c0 = a * t3;
+    const my_Fp c1 = - (b * t3);
+
+    return Fp2_model<n,modulus>(c0, c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::Frobenius_map(unsigned long power) const
+{
+    return Fp2_model<n,modulus>(c0,
+                                Frobenius_coeffs_c1[power % 2] * c1);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::sqrt() const
+{
+    if (is_zero()) {
+        return *this;
+    }
+
+    Fp2_model<n,modulus> one = Fp2_model<n,modulus>::one();
+
+    size_t v = Fp2_model<n,modulus>::s;
+    Fp2_model<n,modulus> z = Fp2_model<n,modulus>::nqr_to_t;
+    Fp2_model<n,modulus> w = (*this)^Fp2_model<n,modulus>::t_minus_1_over_2;
+    Fp2_model<n,modulus> x = (*this) * w;
+    Fp2_model<n,modulus> b = x * w; // b = (*this)^t
+
+
+    // check if square with euler's criterion
+    Fp2_model<n,modulus> check = b;
+    for (size_t i = 0; i < v-1; ++i)
+    {
+        check = check.squared();
+    }
+    if (check != one)
+    {
+        assert_except(0);
+    }
+
+
+    // compute square root with Tonelli--Shanks
+    // (does not terminate if not a square!)
+
+    while (b != one)
+    {
+        size_t m = 0;
+        Fp2_model<n,modulus> b2m = b;
+        while (b2m != one)
+        {
+            /* invariant: b2m = b^(2^m) after entering this loop */
+            b2m = b2m.squared();
+            m += 1;
+        }
+
+        int j = v-m-1;
+        w = z;
+        while (j > 0)
+        {
+            w = w.squared();
+            --j;
+        } // w = z^2^(v-m-1)
+
+        z = w.squared();
+        b = b * z;
+        x = x * w;
+        v = m;
+    }
+
+    return x;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+template<mp_size_t m>
+Fp2_model<n,modulus> Fp2_model<n,modulus>::operator^(const bigint<m> &pow) const
+{
+    return power<Fp2_model<n, modulus>, m>(*this, pow);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &out, const Fp2_model<n, modulus> &el)
+{
+    out << el.c0 << OUTPUT_SEPARATOR << el.c1;
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &in, Fp2_model<n, modulus> &el)
+{
+    in >> el.c0 >> el.c1;
+    return in;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp2_model<n, modulus> > &v)
+{
+    out << v.size() << "\n";
+    for (const Fp2_model<n, modulus>& t : v)
+    {
+        out << t << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp2_model<n, modulus> > &v)
+{
+    v.clear();
+
+    size_t s;
+    in >> s;
+
+    char b;
+    in.read(&b, 1);
+
+    v.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        Fp2_model<n, modulus> el;
+        in >> el;
+        v.emplace_back(el);
+    }
+
+    return in;
+}
+
+} // libsnark
+#endif // FP2_TCC_
diff --git a/src/algebra/fields/fp3.hpp b/src/algebra/fields/fp3.hpp
new file mode 100644 (file)
index 0000000..53b178a
--- /dev/null
@@ -0,0 +1,122 @@
+/** @file
+ *****************************************************************************
+ Declaration of arithmetic in the finite  field F[p^3].
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP3_HPP_
+#define FP3_HPP_
+#include "algebra/fields/fp.hpp"
+#include <vector>
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp3_model;
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &, const Fp3_model<n, modulus> &);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &, Fp3_model<n, modulus> &);
+
+/**
+ * Arithmetic in the field F[p^3].
+ *
+ * Let p := modulus. This interface provides arithmetic for the extension field
+ * Fp3 = Fp[U]/(U^3-non_residue), where non_residue is in Fp.
+ *
+ * ASSUMPTION: p = 1 (mod 6)
+ */
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp3_model {
+public:
+    typedef Fp_model<n, modulus> my_Fp;
+
+    static bigint<3*n> euler; // (modulus^3-1)/2
+    static size_t s;       // modulus^3 = 2^s * t + 1
+    static bigint<3*n> t;  // with t odd
+    static bigint<3*n> t_minus_1_over_2; // (t-1)/2
+    static my_Fp non_residue; // X^6-non_residue irreducible over Fp; used for constructing Fp3 = Fp[X] / (X^3 - non_residue)
+    static Fp3_model<n, modulus> nqr; // a quadratic nonresidue in Fp3
+    static Fp3_model<n, modulus> nqr_to_t; // nqr^t
+    static my_Fp Frobenius_coeffs_c1[3]; // non_residue^((modulus^i-1)/3)   for i=0,1,2
+    static my_Fp Frobenius_coeffs_c2[3]; // non_residue^((2*modulus^i-2)/3) for i=0,1,2
+
+    my_Fp c0, c1, c2;
+    Fp3_model() {};
+    Fp3_model(const my_Fp& c0, const my_Fp& c1, const my_Fp& c2) : c0(c0), c1(c1), c2(c2) {};
+
+    void clear() { c0.clear(); c1.clear(); c2.clear(); }
+    void print() const { printf("c0/c1/c2:\n"); c0.print(); c1.print(); c2.print(); }
+
+    static Fp3_model<n, modulus> zero();
+    static Fp3_model<n, modulus> one();
+    static Fp3_model<n, modulus> random_element();
+
+    bool is_zero() const { return c0.is_zero() && c1.is_zero() && c2.is_zero(); }
+    bool operator==(const Fp3_model &other) const;
+    bool operator!=(const Fp3_model &other) const;
+
+    Fp3_model operator+(const Fp3_model &other) const;
+    Fp3_model operator-(const Fp3_model &other) const;
+    Fp3_model operator*(const Fp3_model &other) const;
+    Fp3_model operator-() const;
+    Fp3_model squared() const;
+    Fp3_model inverse() const;
+    Fp3_model Frobenius_map(unsigned long power) const;
+    Fp3_model sqrt() const; // HAS TO BE A SQUARE (else does not terminate)
+
+    template<mp_size_t m>
+    Fp3_model operator^(const bigint<m> &other) const;
+
+    static size_t size_in_bits() { return 3*my_Fp::size_in_bits(); }
+    static bigint<n> base_field_char() { return modulus; }
+
+    friend std::ostream& operator<< <n, modulus>(std::ostream &out, const Fp3_model<n, modulus> &el);
+    friend std::istream& operator>> <n, modulus>(std::istream &in, Fp3_model<n, modulus> &el);
+};
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp3_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp3_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp3_model<n, modulus> &rhs);
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<3*n> Fp3_model<n, modulus>::euler;
+
+template<mp_size_t n, const bigint<n>& modulus>
+size_t Fp3_model<n, modulus>::s;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<3*n> Fp3_model<n, modulus>::t;
+
+template<mp_size_t n, const bigint<n>& modulus>
+bigint<3*n> Fp3_model<n, modulus>::t_minus_1_over_2;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp3_model<n, modulus>::non_residue;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n, modulus> Fp3_model<n, modulus>::nqr;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n, modulus> Fp3_model<n, modulus>::nqr_to_t;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp3_model<n, modulus>::Frobenius_coeffs_c1[3];
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp_model<n, modulus> Fp3_model<n, modulus>::Frobenius_coeffs_c2[3];
+
+} // libsnark
+#include "algebra/fields/fp3.tcc"
+
+#endif // FP3_HPP_
diff --git a/src/algebra/fields/fp3.tcc b/src/algebra/fields/fp3.tcc
new file mode 100644 (file)
index 0000000..590a2a9
--- /dev/null
@@ -0,0 +1,259 @@
+/** @file
+ *****************************************************************************
+ Implementation of arithmetic in the finite field F[p^3].
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP3_TCC_
+#define FP3_TCC_
+
+#include "algebra/fields/field_utils.hpp"
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::zero()
+{
+    return Fp3_model<n, modulus>(my_Fp::zero(), my_Fp::zero(), my_Fp::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::one()
+{
+    return Fp3_model<n, modulus>(my_Fp::one(), my_Fp::zero(), my_Fp::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::random_element()
+{
+    Fp3_model<n, modulus> r;
+    r.c0 = my_Fp::random_element();
+    r.c1 = my_Fp::random_element();
+    r.c2 = my_Fp::random_element();
+
+    return r;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp3_model<n,modulus>::operator==(const Fp3_model<n,modulus> &other) const
+{
+    return (this->c0 == other.c0 && this->c1 == other.c1 && this->c2 == other.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp3_model<n,modulus>::operator!=(const Fp3_model<n,modulus> &other) const
+{
+    return !(operator==(other));
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::operator+(const Fp3_model<n,modulus> &other) const
+{
+    return Fp3_model<n,modulus>(this->c0 + other.c0,
+                                this->c1 + other.c1,
+                                this->c2 + other.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::operator-(const Fp3_model<n,modulus> &other) const
+{
+    return Fp3_model<n,modulus>(this->c0 - other.c0,
+                                this->c1 - other.c1,
+                                this->c2 - other.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp3_model<n, modulus> &rhs)
+{
+    return Fp3_model<n,modulus>(lhs*rhs.c0,
+                                lhs*rhs.c1,
+                                lhs*rhs.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::operator*(const Fp3_model<n,modulus> &other) const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 4 (Karatsuba) */
+    const my_Fp
+        &A = other.c0, &B = other.c1, &C = other.c2,
+        &a = this->c0, &b = this->c1, &c = this->c2;
+    const my_Fp aA = a*A;
+    const my_Fp bB = b*B;
+    const my_Fp cC = c*C;
+
+    return Fp3_model<n,modulus>(aA + non_residue*((b+c)*(B+C)-bB-cC),
+                                (a+b)*(A+B)-aA-bB+non_residue*cC,
+                                (a+c)*(A+C)-aA+bB-cC);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::operator-() const
+{
+    return Fp3_model<n,modulus>(-this->c0,
+                                -this->c1,
+                                -this->c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::squared() const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 4 (CH-SQR2) */
+    const my_Fp
+        &a = this->c0, &b = this->c1, &c = this->c2;
+    const my_Fp s0 = a.squared();
+    const my_Fp ab = a*b;
+    const my_Fp s1 = ab + ab;
+    const my_Fp s2 = (a - b + c).squared();
+    const my_Fp bc = b*c;
+    const my_Fp s3 = bc + bc;
+    const my_Fp s4 = c.squared();
+
+    return Fp3_model<n,modulus>(s0 + non_residue * s3,
+                                s1 + non_residue * s4,
+                                s1 + s2 + s3 - s0 - s4);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::inverse() const
+{
+    const my_Fp
+        &a = this->c0, &b = this->c1, &c = this->c2;
+
+    /* From "High-Speed Software Implementation of the Optimal Ate Pairing over Barreto-Naehrig Curves"; Algorithm 17 */
+    const my_Fp t0 = a.squared();
+    const my_Fp t1 = b.squared();
+    const my_Fp t2 = c.squared();
+    const my_Fp t3 = a*b;
+    const my_Fp t4 = a*c;
+    const my_Fp t5 = b*c;
+    const my_Fp c0 = t0 - non_residue * t5;
+    const my_Fp c1 = non_residue * t2 - t3;
+    const my_Fp c2 = t1 - t4; // typo in paper referenced above. should be "-" as per Scott, but is "*"
+    const my_Fp t6 = (a * c0 + non_residue * (c * c1 + b * c2)).inverse();
+    return Fp3_model<n,modulus>(t6 * c0, t6 * c1, t6 * c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::Frobenius_map(unsigned long power) const
+{
+    return Fp3_model<n,modulus>(c0,
+                                Frobenius_coeffs_c1[power % 3] * c1,
+                                Frobenius_coeffs_c2[power % 3] * c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::sqrt() const
+{
+    Fp3_model<n,modulus> one = Fp3_model<n,modulus>::one();
+
+    size_t v = Fp3_model<n,modulus>::s;
+    Fp3_model<n,modulus> z = Fp3_model<n,modulus>::nqr_to_t;
+    Fp3_model<n,modulus> w = (*this)^Fp3_model<n,modulus>::t_minus_1_over_2;
+    Fp3_model<n,modulus> x = (*this) * w;
+    Fp3_model<n,modulus> b = x * w; // b = (*this)^t
+
+#if DEBUG
+    // check if square with euler's criterion
+    Fp3_model<n,modulus> check = b;
+    for (size_t i = 0; i < v-1; ++i)
+    {
+        check = check.squared();
+    }
+    if (check != one)
+    {
+        assert(0);
+    }
+#endif
+
+    // compute square root with Tonelli--Shanks
+    // (does not terminate if not a square!)
+
+    while (b != one)
+    {
+        size_t m = 0;
+        Fp3_model<n,modulus> b2m = b;
+        while (b2m != one)
+        {
+            /* invariant: b2m = b^(2^m) after entering this loop */
+            b2m = b2m.squared();
+            m += 1;
+        }
+
+        int j = v-m-1;
+        w = z;
+        while (j > 0)
+        {
+            w = w.squared();
+            --j;
+        } // w = z^2^(v-m-1)
+
+        z = w.squared();
+        b = b * z;
+        x = x * w;
+        v = m;
+    }
+
+    return x;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+template<mp_size_t m>
+Fp3_model<n,modulus> Fp3_model<n,modulus>::operator^(const bigint<m> &pow) const
+{
+    return power<Fp3_model<n, modulus> >(*this, pow);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &out, const Fp3_model<n, modulus> &el)
+{
+    out << el.c0 << OUTPUT_SEPARATOR << el.c1 << OUTPUT_SEPARATOR << el.c2;
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &in, Fp3_model<n, modulus> &el)
+{
+    in >> el.c0 >> el.c1 >> el.c2;
+    return in;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp3_model<n, modulus> > &v)
+{
+    out << v.size() << "\n";
+    for (const Fp3_model<n, modulus>& t : v)
+    {
+        out << t << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp3_model<n, modulus> > &v)
+{
+    v.clear();
+
+    size_t s;
+    in >> s;
+
+    char b;
+    in.read(&b, 1);
+
+    v.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        Fp3_model<n, modulus> el;
+        in >> el;
+        v.emplace_back(el);
+    }
+
+    return in;
+}
+
+} // libsnark
+#endif // FP3_TCC_
diff --git a/src/algebra/fields/fp6_3over2.hpp b/src/algebra/fields/fp6_3over2.hpp
new file mode 100644 (file)
index 0000000..335d61c
--- /dev/null
@@ -0,0 +1,104 @@
+/** @file
+ *****************************************************************************
+ Declaration of arithmetic in the finite field F[(p^2)^3]
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP6_3OVER2_HPP_
+#define FP6_3OVER2_HPP_
+#include "algebra/fields/fp.hpp"
+#include "algebra/fields/fp2.hpp"
+#include <vector>
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp6_3over2_model;
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &, const Fp6_3over2_model<n, modulus> &);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &, Fp6_3over2_model<n, modulus> &);
+
+/**
+ * Arithmetic in the finite field F[(p^2)^3].
+ *
+ * Let p := modulus. This interface provides arithmetic for the extension field
+ *  Fp6 = Fp2[V]/(V^3-non_residue) where non_residue is in Fp.
+ *
+ * ASSUMPTION: p = 1 (mod 6)
+ */
+template<mp_size_t n, const bigint<n>& modulus>
+class Fp6_3over2_model {
+public:
+    typedef Fp_model<n, modulus> my_Fp;
+    typedef Fp2_model<n, modulus> my_Fp2;
+
+    static my_Fp2 non_residue;
+    static my_Fp2 Frobenius_coeffs_c1[6]; // non_residue^((modulus^i-1)/3)   for i=0,1,2,3,4,5
+    static my_Fp2 Frobenius_coeffs_c2[6]; // non_residue^((2*modulus^i-2)/3) for i=0,1,2,3,4,5
+
+    my_Fp2 c0, c1, c2;
+    Fp6_3over2_model() {};
+    Fp6_3over2_model(const my_Fp2& c0, const my_Fp2& c1, const my_Fp2& c2) : c0(c0), c1(c1), c2(c2) {};
+
+    void clear() { c0.clear(); c1.clear(); c2.clear(); }
+    void print() const { printf("c0/c1/c2:\n"); c0.print(); c1.print(); c2.print(); }
+
+    static Fp6_3over2_model<n, modulus> zero();
+    static Fp6_3over2_model<n, modulus> one();
+    static Fp6_3over2_model<n, modulus> random_element();
+
+    bool is_zero() const { return c0.is_zero() && c1.is_zero() && c2.is_zero(); }
+    bool operator==(const Fp6_3over2_model &other) const;
+    bool operator!=(const Fp6_3over2_model &other) const;
+
+    Fp6_3over2_model operator+(const Fp6_3over2_model &other) const;
+    Fp6_3over2_model operator-(const Fp6_3over2_model &other) const;
+    Fp6_3over2_model operator*(const Fp6_3over2_model &other) const;
+    Fp6_3over2_model operator-() const;
+    Fp6_3over2_model squared() const;
+    Fp6_3over2_model inverse() const;
+    Fp6_3over2_model Frobenius_map(unsigned long power) const;
+
+    static my_Fp2 mul_by_non_residue(const my_Fp2 &elt);
+
+    template<mp_size_t m>
+    Fp6_3over2_model operator^(const bigint<m> &other) const;
+
+    static bigint<n> base_field_char() { return modulus; }
+    static size_t extension_degree() { return 6; }
+
+    friend std::ostream& operator<< <n, modulus>(std::ostream &out, const Fp6_3over2_model<n, modulus> &el);
+    friend std::istream& operator>> <n, modulus>(std::istream &in, Fp6_3over2_model<n, modulus> &el);
+};
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp6_3over2_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp6_3over2_model<n, modulus> > &v);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp6_3over2_model<n, modulus> &rhs);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n, modulus> operator*(const Fp2_model<n, modulus> &lhs, const Fp6_3over2_model<n, modulus> &rhs);
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp6_3over2_model<n, modulus>::non_residue;
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp6_3over2_model<n, modulus>::Frobenius_coeffs_c1[6];
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp6_3over2_model<n, modulus>::Frobenius_coeffs_c2[6];
+
+} // libsnark
+#include "algebra/fields/fp6_3over2.tcc"
+
+#endif // FP6_3OVER2_HPP_
diff --git a/src/algebra/fields/fp6_3over2.tcc b/src/algebra/fields/fp6_3over2.tcc
new file mode 100644 (file)
index 0000000..f4fffde
--- /dev/null
@@ -0,0 +1,216 @@
+/** @file
+ *****************************************************************************
+ Implementation of arithmetic in the finite field F[(p^2)^3].
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP6_3OVER2_TCC_
+#define FP6_3OVER2_TCC_
+#include "algebra/fields/field_utils.hpp"
+
+namespace libsnark {
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp2_model<n, modulus> Fp6_3over2_model<n,modulus>::mul_by_non_residue(const Fp2_model<n, modulus> &elt)
+{
+    return Fp2_model<n, modulus>(non_residue * elt);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::zero()
+{
+    return Fp6_3over2_model<n, modulus>(my_Fp2::zero(), my_Fp2::zero(), my_Fp2::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::one()
+{
+    return Fp6_3over2_model<n, modulus>(my_Fp2::one(), my_Fp2::zero(), my_Fp2::zero());
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::random_element()
+{
+    Fp6_3over2_model<n, modulus> r;
+    r.c0 = my_Fp2::random_element();
+    r.c1 = my_Fp2::random_element();
+    r.c2 = my_Fp2::random_element();
+
+    return r;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp6_3over2_model<n,modulus>::operator==(const Fp6_3over2_model<n,modulus> &other) const
+{
+    return (this->c0 == other.c0 && this->c1 == other.c1 && this->c2 == other.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+bool Fp6_3over2_model<n,modulus>::operator!=(const Fp6_3over2_model<n,modulus> &other) const
+{
+    return !(operator==(other));
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::operator+(const Fp6_3over2_model<n,modulus> &other) const
+{
+    return Fp6_3over2_model<n,modulus>(this->c0 + other.c0,
+                                       this->c1 + other.c1,
+                                       this->c2 + other.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::operator-(const Fp6_3over2_model<n,modulus> &other) const
+{
+    return Fp6_3over2_model<n,modulus>(this->c0 - other.c0,
+                                       this->c1 - other.c1,
+                                       this->c2 - other.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n, modulus> operator*(const Fp_model<n, modulus> &lhs, const Fp6_3over2_model<n, modulus> &rhs)
+{
+    return Fp6_3over2_model<n,modulus>(lhs*rhs.c0,
+                                       lhs*rhs.c1,
+                                       lhs*rhs.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n, modulus> operator*(const Fp2_model<n, modulus> &lhs, const Fp6_3over2_model<n, modulus> &rhs)
+{
+    return Fp6_3over2_model<n,modulus>(lhs*rhs.c0,
+                                       lhs*rhs.c1,
+                                       lhs*rhs.c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::operator*(const Fp6_3over2_model<n,modulus> &other) const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 4 (Karatsuba) */
+
+    const my_Fp2 &A = other.c0, &B = other.c1, &C = other.c2,
+                 &a = this->c0, &b = this->c1, &c = this->c2;
+    const my_Fp2 aA = a*A;
+    const my_Fp2 bB = b*B;
+    const my_Fp2 cC = c*C;
+
+    return Fp6_3over2_model<n,modulus>(aA + Fp6_3over2_model<n,modulus>::mul_by_non_residue((b+c)*(B+C)-bB-cC),
+                                       (a+b)*(A+B)-aA-bB+Fp6_3over2_model<n,modulus>::mul_by_non_residue(cC),
+                                       (a+c)*(A+C)-aA+bB-cC);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::operator-() const
+{
+    return Fp6_3over2_model<n,modulus>(-this->c0,
+                                       -this->c1,
+                                       -this->c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::squared() const
+{
+    /* Devegili OhEig Scott Dahab --- Multiplication and Squaring on Pairing-Friendly Fields.pdf; Section 4 (CH-SQR2) */
+
+    const my_Fp2 &a = this->c0, &b = this->c1, &c = this->c2;
+    const my_Fp2 s0 = a.squared();
+    const my_Fp2 ab = a*b;
+    const my_Fp2 s1 = ab + ab;
+    const my_Fp2 s2 = (a - b + c).squared();
+    const my_Fp2 bc = b*c;
+    const my_Fp2 s3 = bc + bc;
+    const my_Fp2 s4 = c.squared();
+
+    return Fp6_3over2_model<n,modulus>(s0 + Fp6_3over2_model<n,modulus>::mul_by_non_residue(s3),
+                                       s1 + Fp6_3over2_model<n,modulus>::mul_by_non_residue(s4),
+                                       s1 + s2 + s3 - s0 - s4);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::inverse() const
+{
+    /* From "High-Speed Software Implementation of the Optimal Ate Pairing over Barreto-Naehrig Curves"; Algorithm 17 */
+
+    const my_Fp2 &a = this->c0, &b = this->c1, &c = this->c2;
+    const my_Fp2 t0 = a.squared();
+    const my_Fp2 t1 = b.squared();
+    const my_Fp2 t2 = c.squared();
+    const my_Fp2 t3 = a*b;
+    const my_Fp2 t4 = a*c;
+    const my_Fp2 t5 = b*c;
+    const my_Fp2 c0 = t0 - Fp6_3over2_model<n,modulus>::mul_by_non_residue(t5);
+    const my_Fp2 c1 = Fp6_3over2_model<n,modulus>::mul_by_non_residue(t2) - t3;
+    const my_Fp2 c2 = t1 - t4; // typo in paper referenced above. should be "-" as per Scott, but is "*"
+    const my_Fp2 t6 = (a * c0 + Fp6_3over2_model<n,modulus>::mul_by_non_residue((c * c1 + b * c2))).inverse();
+    return Fp6_3over2_model<n,modulus>(t6 * c0, t6 * c1, t6 * c2);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::Frobenius_map(unsigned long power) const
+{
+    return Fp6_3over2_model<n,modulus>(c0.Frobenius_map(power),
+                                       Frobenius_coeffs_c1[power % 6] * c1.Frobenius_map(power),
+                                       Frobenius_coeffs_c2[power % 6] * c2.Frobenius_map(power));
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+template<mp_size_t m>
+Fp6_3over2_model<n,modulus> Fp6_3over2_model<n,modulus>::operator^(const bigint<m> &pow) const
+{
+    return power<Fp6_3over2_model<n, modulus>, m>(*this, pow);
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream &out, const Fp6_3over2_model<n, modulus> &el)
+{
+    out << el.c0 << OUTPUT_SEPARATOR << el.c1 << OUTPUT_SEPARATOR << el.c2;
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream &in, Fp6_3over2_model<n, modulus> &el)
+{
+    in >> el.c0 >> el.c1 >> el.c2;
+    return in;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::ostream& operator<<(std::ostream& out, const std::vector<Fp6_3over2_model<n, modulus> > &v)
+{
+    out << v.size() << "\n";
+    for (const Fp6_3over2_model<n, modulus>& t : v)
+    {
+        out << t << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+template<mp_size_t n, const bigint<n>& modulus>
+std::istream& operator>>(std::istream& in, std::vector<Fp6_3over2_model<n, modulus> > &v)
+{
+    v.clear();
+
+    size_t s;
+    in >> s;
+
+    char b;
+    in.read(&b, 1);
+
+    v.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        Fp6_3over2_model<n, modulus> el;
+        in >> el;
+        v.emplace_back(el);
+    }
+
+    return in;
+}
+
+} // libsnark
+#endif // FP6_3_OVER_2_TCC_
diff --git a/src/algebra/fields/fp_aux.tcc b/src/algebra/fields/fp_aux.tcc
new file mode 100644 (file)
index 0000000..7f8a3ea
--- /dev/null
@@ -0,0 +1,389 @@
+/** @file
+ *****************************************************************************
+ Assembly code snippets for F[p] finite field arithmetic, used by fp.tcc .
+ Specific to x86-64, and used only if USE_ASM is defined.
+ On other architectures or without USE_ASM, fp.tcc uses a portable
+ C++ implementation instead.
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef FP_AUX_TCC_
+#define FP_AUX_TCC_
+
+namespace libsnark {
+
+#define STR_HELPER(x) #x
+#define STR(x) STR_HELPER(x)
+
+/* addq is faster than adcq, even if preceded by clc */
+#define ADD_FIRSTADD                            \
+    "movq    (%[B]), %%rax           \n\t"      \
+    "addq    %%rax, (%[A])           \n\t"
+
+#define ADD_NEXTADD(ofs)                                \
+    "movq    " STR(ofs) "(%[B]), %%rax          \n\t"   \
+    "adcq    %%rax, " STR(ofs) "(%[A])          \n\t"
+
+#define ADD_CMP(ofs)                                  \
+    "movq    " STR(ofs) "(%[mod]), %%rax   \n\t"      \
+    "cmpq    %%rax, " STR(ofs) "(%[A])     \n\t"      \
+    "jb      done%=              \n\t"                \
+    "ja      subtract%=          \n\t"
+
+#define ADD_FIRSTSUB                            \
+    "movq    (%[mod]), %%rax     \n\t"          \
+    "subq    %%rax, (%[A])       \n\t"
+
+#define ADD_FIRSTSUB                            \
+    "movq    (%[mod]), %%rax     \n\t"          \
+    "subq    %%rax, (%[A])       \n\t"
+
+#define ADD_NEXTSUB(ofs)                                \
+    "movq    " STR(ofs) "(%[mod]), %%rax    \n\t"       \
+    "sbbq    %%rax, " STR(ofs) "(%[A])      \n\t"
+
+#define SUB_FIRSTSUB                            \
+    "movq    (%[B]), %%rax\n\t"                 \
+    "subq    %%rax, (%[A])\n\t"
+
+#define SUB_NEXTSUB(ofs)                        \
+    "movq    " STR(ofs) "(%[B]), %%rax\n\t"     \
+    "sbbq    %%rax, " STR(ofs) "(%[A])\n\t"
+
+#define SUB_FIRSTADD                            \
+    "movq    (%[mod]), %%rax\n\t"               \
+    "addq    %%rax, (%[A])\n\t"
+
+#define SUB_NEXTADD(ofs)                        \
+    "movq    " STR(ofs) "(%[mod]), %%rax\n\t"   \
+    "adcq    %%rax, " STR(ofs) "(%[A])\n\t"
+
+#define MONT_CMP(ofs)                                 \
+    "movq    " STR(ofs) "(%[M]), %%rax   \n\t"        \
+    "cmpq    %%rax, " STR(ofs) "(%[tmp])   \n\t"      \
+    "jb      done%=              \n\t"                \
+    "ja      subtract%=          \n\t"
+
+#define MONT_FIRSTSUB                           \
+    "movq    (%[M]), %%rax     \n\t"            \
+    "subq    %%rax, (%[tmp])     \n\t"
+
+#define MONT_NEXTSUB(ofs)                               \
+    "movq    " STR(ofs) "(%[M]), %%rax    \n\t"         \
+    "sbbq    %%rax, " STR(ofs) "(%[tmp])   \n\t"
+
+/*
+  The x86-64 Montgomery multiplication here is similar
+  to Algorithm 2 (CIOS method) in http://eprint.iacr.org/2012/140.pdf
+  and the PowerPC pseudocode of gmp-ecm library (c) Paul Zimmermann and Alexander Kruppa
+  (see comments on top of powerpc64/mulredc.m4).
+*/
+
+#define MONT_PRECOMPUTE                                                 \
+    "xorq    %[cy], %[cy]            \n\t"                              \
+    "movq    0(%[A]), %%rax          \n\t"                              \
+    "mulq    0(%[B])                 \n\t"                              \
+    "movq    %%rax, %[T0]            \n\t"                              \
+    "movq    %%rdx, %[T1]            # T1:T0 <- A[0] * B[0] \n\t"       \
+    "mulq    %[inv]                  \n\t"                              \
+    "movq    %%rax, %[u]             # u <- T0 * inv \n\t"              \
+    "mulq    0(%[M])                 \n\t"                              \
+    "addq    %[T0], %%rax            \n\t"                              \
+    "adcq    %%rdx, %[T1]            \n\t"                              \
+    "adcq    $0, %[cy]               # cy:T1 <- (M[0]*u + T1 * b + T0) / b\n\t"
+
+#define MONT_FIRSTITER(j)                                               \
+    "xorq    %[T0], %[T0]            \n\t"                              \
+    "movq    0(%[A]), %%rax          \n\t"                              \
+    "mulq    " STR((j*8)) "(%[B])                 \n\t"                 \
+    "addq    %[T1], %%rax            \n\t"                              \
+    "movq    %%rax, " STR(((j-1)*8)) "(%[tmp])        \n\t"             \
+    "adcq    $0, %%rdx               \n\t"                              \
+    "movq    %%rdx, %[T1]            # now T1:tmp[j-1] <-- X[0] * Y[j] + T1\n\t" \
+    "movq    " STR((j*8)) "(%[M]), %%rax          \n\t"                 \
+    "mulq    %[u]                    \n\t"                              \
+    "addq    %%rax, " STR(((j-1)*8)) "(%[tmp])        \n\t"             \
+    "adcq    %[cy], %%rdx            \n\t"                              \
+    "adcq    $0, %[T0]               \n\t"                              \
+    "xorq    %[cy], %[cy]            \n\t"                              \
+    "addq    %%rdx, %[T1]            \n\t"                              \
+    "adcq    %[T0], %[cy]            # cy:T1:tmp[j-1] <---- (X[0] * Y[j] + T1) + (M[j] * u + cy * b) \n\t"
+
+#define MONT_ITERFIRST(i)                            \
+    "xorq    %[cy], %[cy]            \n\t"              \
+    "movq    " STR((i*8)) "(%[A]), %%rax          \n\t" \
+    "mulq    0(%[B])                 \n\t"              \
+    "addq    0(%[tmp]), %%rax        \n\t"              \
+    "adcq    8(%[tmp]), %%rdx        \n\t"              \
+    "adcq    $0, %[cy]               \n\t"              \
+    "movq    %%rax, %[T0]            \n\t"                              \
+    "movq    %%rdx, %[T1]            # cy:T1:T0 <- A[i] * B[0] + tmp[1] * b + tmp[0]\n\t" \
+    "mulq    %[inv]                  \n\t"                              \
+    "movq    %%rax, %[u]             # u <- T0 * inv\n\t"               \
+    "mulq    0(%[M])                 \n\t"                              \
+    "addq    %[T0], %%rax            \n\t"                              \
+    "adcq    %%rdx, %[T1]            \n\t"                              \
+    "adcq    $0, %[cy]               # cy:T1 <- (M[0]*u + cy * b * b + T1 * b + T0) / b\n\t"
+
+#define MONT_ITERITER(i, j)                                             \
+    "xorq    %[T0], %[T0]            \n\t"                              \
+    "movq    " STR((i*8)) "(%[A]), %%rax          \n\t"                 \
+    "mulq    " STR((j*8)) "(%[B])                 \n\t"                 \
+    "addq    %[T1], %%rax            \n\t"                              \
+    "movq    %%rax, " STR(((j-1)*8)) "(%[tmp])        \n\t"                              \
+    "adcq    $0, %%rdx               \n\t"                              \
+    "movq    %%rdx, %[T1]            # now T1:tmp[j-1] <-- X[i] * Y[j] + T1 \n\t" \
+    "movq    " STR((j*8)) "(%[M]), %%rax          \n\t"                 \
+    "mulq    %[u]                    \n\t"                              \
+    "addq    %%rax, " STR(((j-1)*8)) "(%[tmp])        \n\t"             \
+    "adcq    %[cy], %%rdx            \n\t"                              \
+    "adcq    $0, %[T0]               \n\t"                              \
+    "xorq    %[cy], %[cy]            \n\t"                              \
+    "addq    %%rdx, %[T1]            \n\t"                              \
+    "adcq    %[T0], %[cy]            # cy:T1:tmp[j-1] <-- (X[i] * Y[j] + T1) + M[j] * u + cy * b \n\t" \
+    "addq    " STR(((j+1)*8)) "(%[tmp]), %[T1]       \n\t" \
+    "adcq    $0, %[cy]               # cy:T1:tmp[j-1] <-- (X[i] * Y[j] + T1) + M[j] * u + (tmp[j+1] + cy) * b \n\t"
+
+#define MONT_FINALIZE(j)                  \
+    "movq    %[T1], " STR((j*8)) "(%[tmp])       \n\t"          \
+    "movq    %[cy], " STR(((j+1)*8)) "(%[tmp])       \n\t"
+
+/*
+  Comba multiplication and squaring routines are based on the
+  public-domain tomsfastmath library by Tom St Denis
+  <http://www.libtom.org/>
+  <https://github.com/libtom/tomsfastmath/blob/master/src/sqr/fp_sqr_comba.c
+  <https://github.com/libtom/tomsfastmath/blob/master/src/mul/fp_mul_comba.c>
+
+  Compared to the above, we save 5-20% of cycles by using careful register
+  renaming to implement Comba forward operation.
+ */
+
+#define COMBA_3_BY_3_MUL(c0_, c1_, c2_, res_, A_, B_)    \
+    asm volatile (                              \
+        "movq  0(%[A]), %%rax             \n\t" \
+        "mulq  0(%[B])                    \n\t" \
+        "movq  %%rax, 0(%[res])           \n\t" \
+        "movq  %%rdx, %[c0]               \n\t" \
+                                                \
+        "xorq  %[c1], %[c1]               \n\t" \
+        "movq  0(%[A]), %%rax             \n\t" \
+        "mulq  8(%[B])                    \n\t" \
+        "addq  %%rax, %[c0]               \n\t" \
+        "adcq  %%rdx, %[c1]               \n\t" \
+                                                \
+        "xorq  %[c2], %[c2]               \n\t" \
+        "movq  8(%[A]), %%rax             \n\t" \
+        "mulq  0(%[B])                    \n\t" \
+        "addq  %%rax, %[c0]               \n\t" \
+        "movq  %[c0], 8(%[res])           \n\t" \
+        "adcq  %%rdx, %[c1]               \n\t" \
+        "adcq  $0, %[c2]                  \n\t" \
+                                                \
+        "// register renaming (c1, c2, c0)\n\t" \
+        "xorq  %[c0], %[c0]               \n\t" \
+        "movq  0(%[A]), %%rax             \n\t" \
+        "mulq  16(%[B])                   \n\t" \
+        "addq  %%rax, %[c1]               \n\t" \
+        "adcq  %%rdx, %[c2]               \n\t" \
+        "adcq  $0, %[c0]                  \n\t" \
+                                                \
+        "movq  8(%[A]), %%rax             \n\t" \
+        "mulq  8(%[B])                    \n\t" \
+        "addq  %%rax, %[c1]               \n\t" \
+        "adcq  %%rdx, %[c2]               \n\t" \
+        "adcq  $0, %[c0]                  \n\t" \
+                                                \
+        "movq  16(%[A]), %%rax            \n\t" \
+        "mulq  0(%[B])                    \n\t" \
+        "addq  %%rax, %[c1]               \n\t" \
+        "movq  %[c1], 16(%[res])          \n\t" \
+        "adcq  %%rdx, %[c2]               \n\t" \
+        "adcq  $0, %[c0]                  \n\t" \
+                                                \
+        "// register renaming (c2, c0, c1)\n\t" \
+        "xorq  %[c1], %[c1]               \n\t" \
+        "movq  8(%[A]), %%rax             \n\t" \
+        "mulq  16(%[B])                   \n\t" \
+        "addq  %%rax, %[c2]               \n\t" \
+        "adcq  %%rdx, %[c0]               \n\t" \
+        "adcq  $0, %[c1]                  \n\t" \
+                                                \
+        "movq  16(%[A]), %%rax            \n\t" \
+        "mulq  8(%[B])                    \n\t" \
+        "addq  %%rax, %[c2]               \n\t" \
+        "movq  %[c2], 24(%[res])          \n\t" \
+        "adcq  %%rdx, %[c0]               \n\t" \
+        "adcq  $0, %[c1]                  \n\t" \
+                                                \
+        "// register renaming (c0, c1, c2)\n\t" \
+        "xorq  %[c2], %[c2]               \n\t" \
+        "movq  16(%[A]), %%rax            \n\t" \
+        "mulq  16(%[B])                   \n\t" \
+        "addq  %%rax, %[c0]               \n\t" \
+        "movq  %[c0], 32(%[res])          \n\t" \
+        "adcq  %%rdx, %[c1]               \n\t" \
+        "movq  %[c1], 40(%[res])          \n\t" \
+        : [c0] "=&r" (c0_), [c1] "=&r" (c1_), [c2] "=&r" (c2_) \
+        : [res] "r" (res_), [A] "r" (A_), [B] "r" (B_)     \
+        : "%rax", "%rdx", "cc", "memory")
+
+#define COMBA_3_BY_3_SQR(c0_, c1_, c2_, res_, A_)    \
+    asm volatile (                              \
+        "xorq  %[c1], %[c1]               \n\t" \
+        "xorq  %[c2], %[c2]               \n\t" \
+        "movq  0(%[A]), %%rax             \n\t" \
+        "mulq  %%rax                      \n\t" \
+        "movq  %%rax, 0(%[res])           \n\t" \
+        "movq  %%rdx, %[c0]               \n\t" \
+                                                \
+        "movq  0(%[A]), %%rax             \n\t" \
+        "mulq  8(%[A])                    \n\t" \
+        "addq  %%rax, %[c0]               \n\t" \
+        "adcq  %%rdx, %[c1]               \n\t" \
+        "addq  %%rax, %[c0]               \n\t" \
+        "movq  %[c0], 8(%[res])           \n\t" \
+        "adcq  %%rdx, %[c1]               \n\t" \
+        "adcq  $0, %[c2]                  \n\t" \
+                                                \
+        "// register renaming (c1, c2, c0)\n\t" \
+        "movq  0(%[A]), %%rax             \n\t" \
+        "xorq  %[c0], %[c0]               \n\t" \
+        "mulq  16(%[A])                   \n\t" \
+        "addq  %%rax, %[c1]               \n\t" \
+        "adcq  %%rdx, %[c2]               \n\t" \
+        "adcq  $0, %[c0]                  \n\t" \
+        "addq  %%rax, %[c1]               \n\t" \
+        "adcq  %%rdx, %[c2]               \n\t" \
+        "adcq  $0, %[c0]                  \n\t" \
+                                                \
+        "movq  8(%[A]), %%rax             \n\t" \
+        "mulq  %%rax                      \n\t" \
+        "addq  %%rax, %[c1]               \n\t" \
+        "movq  %[c1], 16(%[res])          \n\t" \
+        "adcq  %%rdx, %[c2]               \n\t" \
+        "adcq  $0, %[c0]                  \n\t" \
+                                                \
+        "// register renaming (c2, c0, c1)\n\t" \
+        "movq  8(%[A]), %%rax             \n\t" \
+        "xorq  %[c1], %[c1]               \n\t" \
+        "mulq  16(%[A])                   \n\t" \
+        "addq  %%rax, %[c2]               \n\t" \
+        "adcq  %%rdx, %[c0]               \n\t" \
+        "adcq  $0, %[c1]                  \n\t" \
+        "addq  %%rax, %[c2]               \n\t" \
+        "movq  %[c2], 24(%[res])          \n\t" \
+        "adcq  %%rdx, %[c0]               \n\t" \
+        "adcq  $0, %[c1]                  \n\t" \
+                                                \
+        "// register renaming (c0, c1, c2)\n\t" \
+        "movq  16(%[A]), %%rax            \n\t" \
+        "mulq  %%rax                      \n\t" \
+        "addq  %%rax, %[c0]               \n\t" \
+        "movq  %[c0], 32(%[res])          \n\t" \
+        "adcq  %%rdx, %[c1]               \n\t" \
+        "movq  %[c1], 40(%[res])          \n\t" \
+                                                \
+        : [c0] "=&r" (c0_), [c1] "=&r" (c1_), [c2] "=&r" (c2_) \
+        : [res] "r" (res_), [A] "r" (A_) \
+        : "%rax", "%rdx", "cc", "memory")
+
+/*
+  The Montgomery reduction here is based on Algorithm 14.32 in
+  Handbook of Applied Cryptography
+  <http://cacr.uwaterloo.ca/hac/about/chap14.pdf>.
+ */
+#define REDUCE_6_LIMB_PRODUCT(k_, tmp1_, tmp2_, tmp3_, inv_, res_, mod_) \
+    __asm__ volatile                               \
+        ("///////////////////////////////////\n\t" \
+         "movq   0(%[res]), %%rax            \n\t" \
+         "mulq   %[modprime]                 \n\t" \
+         "movq   %%rax, %[k]                 \n\t" \
+                                                   \
+         "movq   (%[mod]), %%rax             \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "movq   %%rax, %[tmp1]              \n\t" \
+         "movq   %%rdx, %[tmp2]              \n\t" \
+                                                   \
+         "xorq   %[tmp3], %[tmp3]            \n\t" \
+         "movq   8(%[mod]), %%rax            \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "addq   %[tmp1], 0(%[res])          \n\t" \
+         "adcq   %%rax, %[tmp2]              \n\t" \
+         "adcq   %%rdx, %[tmp3]              \n\t" \
+                                                   \
+         "xorq   %[tmp1], %[tmp1]            \n\t" \
+         "movq   16(%[mod]), %%rax           \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "addq   %[tmp2], 8(%[res])          \n\t" \
+         "adcq   %%rax, %[tmp3]              \n\t" \
+         "adcq   %%rdx, %[tmp1]              \n\t" \
+                                                   \
+         "addq   %[tmp3], 16(%[res])         \n\t" \
+         "adcq   %[tmp1], 24(%[res])         \n\t" \
+         "adcq   $0, 32(%[res])              \n\t" \
+         "adcq   $0, 40(%[res])              \n\t" \
+                                                   \
+         "///////////////////////////////////\n\t" \
+         "movq   8(%[res]), %%rax            \n\t" \
+         "mulq   %[modprime]                 \n\t" \
+         "movq   %%rax, %[k]                 \n\t" \
+                                                   \
+         "movq   (%[mod]), %%rax             \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "movq   %%rax, %[tmp1]              \n\t" \
+         "movq   %%rdx, %[tmp2]              \n\t" \
+                                                   \
+         "xorq   %[tmp3], %[tmp3]            \n\t" \
+         "movq   8(%[mod]), %%rax            \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "addq   %[tmp1], 8(%[res])          \n\t" \
+         "adcq   %%rax, %[tmp2]              \n\t" \
+         "adcq   %%rdx, %[tmp3]              \n\t" \
+                                                   \
+         "xorq   %[tmp1], %[tmp1]            \n\t" \
+         "movq   16(%[mod]), %%rax           \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "addq   %[tmp2], 16(%[res])         \n\t" \
+         "adcq   %%rax, %[tmp3]              \n\t" \
+         "adcq   %%rdx, %[tmp1]              \n\t" \
+                                                   \
+         "addq   %[tmp3], 24(%[res])         \n\t" \
+         "adcq   %[tmp1], 32(%[res])         \n\t" \
+         "adcq   $0, 40(%[res])              \n\t" \
+                                                   \
+         "///////////////////////////////////\n\t" \
+         "movq   16(%[res]), %%rax           \n\t" \
+         "mulq   %[modprime]                 \n\t" \
+         "movq   %%rax, %[k]                 \n\t" \
+                                                   \
+         "movq   (%[mod]), %%rax             \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "movq   %%rax, %[tmp1]              \n\t" \
+         "movq   %%rdx, %[tmp2]              \n\t" \
+                                                   \
+         "xorq   %[tmp3], %[tmp3]            \n\t" \
+         "movq   8(%[mod]), %%rax            \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "addq   %[tmp1], 16(%[res])         \n\t" \
+         "adcq   %%rax, %[tmp2]              \n\t" \
+         "adcq   %%rdx, %[tmp3]              \n\t" \
+                                                   \
+         "xorq   %[tmp1], %[tmp1]            \n\t" \
+         "movq   16(%[mod]), %%rax           \n\t" \
+         "mulq   %[k]                        \n\t" \
+         "addq   %[tmp2], 24(%[res])         \n\t" \
+         "adcq   %%rax, %[tmp3]              \n\t" \
+         "adcq   %%rdx, %[tmp1]              \n\t" \
+                                                   \
+         "addq   %[tmp3], 32(%[res])         \n\t" \
+         "adcq   %[tmp1], 40(%[res])         \n\t" \
+         : [k] "=&r" (k_), [tmp1] "=&r" (tmp1_), [tmp2] "=&r" (tmp2_), [tmp3] "=&r" (tmp3_) \
+         : [modprime] "r" (inv_), [res] "r" (res_), [mod] "r" (mod_) \
+         : "%rax", "%rdx", "cc", "memory")
+
+} // libsnark
+#endif // FP_AUX_TCC_
diff --git a/src/algebra/fields/tests/test_bigint.cpp b/src/algebra/fields/tests/test_bigint.cpp
new file mode 100644 (file)
index 0000000..b66aae0
--- /dev/null
@@ -0,0 +1,107 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "algebra/fields/bigint.hpp"
+
+using namespace libsnark;
+
+void test_bigint()
+{
+    static_assert(ULONG_MAX == 0xFFFFFFFFFFFFFFFFul, "unsigned long not 64-bit");
+    static_assert(GMP_NUMB_BITS == 64, "GMP limb not 64-bit");
+
+    const char *b1_decimal = "76749407";
+    const char *b2_decimal = "435020359732196472065729437602";
+    const char *b3_decimal = "33387554642372758038536799358397002014";
+    const char *b2_binary = "0000000000000000000000000000010101111101101000000110100001011010"
+                            "1101101010001001000001101000101000100110011001110001111110100010";
+
+    bigint<1> b0 = bigint<1>(0ul);
+    bigint<1> b1 = bigint<1>(b1_decimal);
+    bigint<2> b2 = bigint<2>(b2_decimal);
+
+    assert(b0.as_ulong() == 0ul);
+    assert(b0.is_zero());
+    assert(b1.as_ulong() == 76749407ul);
+    assert(!(b1.is_zero()));
+    assert(b2.as_ulong() == 15747124762497195938ul);
+    assert(!(b2.is_zero()));
+    assert(b0 != b1);
+    assert(!(b0 == b1));
+
+    assert(b2.max_bits() == 128);
+    assert(b2.num_bits() == 99);
+    for (size_t i = 0; i < 128; i++) {
+        assert(b2.test_bit(i) == (b2_binary[127-i] == '1'));
+    }
+
+    bigint<3> b3 = b2 * b1;
+
+    assert(b3 == bigint<3>(b3_decimal));
+    assert(!(b3.is_zero()));
+
+    bigint<3> b3a { b3 };
+    assert(b3a == bigint<3>(b3_decimal));
+    assert(b3a == b3);
+    assert(!(b3a.is_zero()));
+
+    mpz_t m3;
+    mpz_init(m3);
+    b3.to_mpz(m3);
+    bigint<3> b3b { m3 };
+    assert(b3b == b3);
+
+    bigint<2> quotient;
+    bigint<2> remainder;
+    bigint<3>::div_qr(quotient, remainder, b3, b2);
+    assert(quotient.num_bits() < GMP_NUMB_BITS);
+    assert(quotient.as_ulong() == b1.as_ulong());
+    bigint<1> b1inc = bigint<1>("76749408");
+    bigint<1> b1a = quotient.shorten(b1inc, "test");
+    assert(b1a == b1);
+    assert(remainder.is_zero());
+    remainder.limit(b2, "test");
+
+    try {
+        (void)(quotient.shorten(b1, "test"));
+        assert(false);
+    } catch (std::domain_error) {}
+    try {
+        remainder.limit(remainder, "test");
+        assert(false);
+    } catch (std::domain_error) {}
+
+    bigint<1> br = bigint<1>("42");
+    b3 += br;
+    assert(b3 != b3a);
+    assert(b3 > b3a);
+    assert(!(b3a > b3));
+
+    bigint<3>::div_qr(quotient, remainder, b3, b2);
+    assert(quotient.num_bits() < GMP_NUMB_BITS);
+    assert(quotient.as_ulong() == b1.as_ulong());
+    assert(remainder.num_bits() < GMP_NUMB_BITS);
+    assert(remainder.as_ulong() == 42);
+
+    b3a.clear();
+    assert(b3a.is_zero());
+    assert(b3a.num_bits() == 0);
+    assert(!(b3.is_zero()));
+
+    bigint<4> bx = bigint<4>().randomize();
+    bigint<4> by = bigint<4>().randomize();
+    assert(!(bx == by));
+
+    // TODO: test serialization
+}
+
+int main(void)
+{
+    test_bigint();
+    return 0;
+}
+
diff --git a/src/algebra/fields/tests/test_fields.cpp b/src/algebra/fields/tests/test_fields.cpp
new file mode 100644 (file)
index 0000000..a05f601
--- /dev/null
@@ -0,0 +1,245 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#include "common/profiling.hpp"
+#include "algebra/curves/edwards/edwards_pp.hpp"
+#include "algebra/curves/mnt/mnt4/mnt4_pp.hpp"
+#include "algebra/curves/mnt/mnt6/mnt6_pp.hpp"
+#ifdef CURVE_BN128
+#include "algebra/curves/bn128/bn128_pp.hpp"
+#endif
+#include "algebra/curves/alt_bn128/alt_bn128_pp.hpp"
+#include "algebra/fields/fp6_3over2.hpp"
+#include "algebra/fields/fp12_2over3over2.hpp"
+
+using namespace libsnark;
+
+template<typename FieldT>
+void test_field()
+{
+    bigint<1> rand1 = bigint<1>("76749407");
+    bigint<1> rand2 = bigint<1>("44410867");
+    bigint<1> randsum = bigint<1>("121160274");
+
+    FieldT zero = FieldT::zero();
+    FieldT one = FieldT::one();
+    FieldT a = FieldT::random_element();
+    FieldT a_ser;
+    a_ser = reserialize<FieldT>(a);
+    assert(a_ser == a);
+
+    FieldT b = FieldT::random_element();
+    FieldT c = FieldT::random_element();
+    FieldT d = FieldT::random_element();
+
+    assert(a != zero);
+    assert(a != one);
+
+    assert(a * a == a.squared());
+    assert((a + b).squared() == a.squared() + a*b + b*a + b.squared());
+    assert((a + b)*(c + d) == a*c + a*d + b*c + b*d);
+    assert(a - b == a + (-b));
+    assert(a - b == (-b) + a);
+
+    assert((a ^ rand1) * (a ^ rand2) == (a^randsum));
+
+    assert(a * a.inverse() == one);
+    assert((a + b) * c.inverse() == a * c.inverse() + (b.inverse() * c).inverse());
+
+}
+
+template<typename FieldT>
+void test_sqrt()
+{
+    for (size_t i = 0; i < 100; ++i)
+    {
+        FieldT a = FieldT::random_element();
+        FieldT asq = a.squared();
+        assert(asq.sqrt() == a || asq.sqrt() == -a);
+    }
+}
+
+template<typename FieldT>
+void test_two_squarings()
+{
+    FieldT a = FieldT::random_element();
+    assert(a.squared() == a * a);
+    assert(a.squared() == a.squared_complex());
+    assert(a.squared() == a.squared_karatsuba());
+}
+
+template<typename FieldT>
+void test_Frobenius()
+{
+    FieldT a = FieldT::random_element();
+    assert(a.Frobenius_map(0) == a);
+    FieldT a_q = a ^ FieldT::base_field_char();
+    for (size_t power = 1; power < 10; ++power)
+    {
+        const FieldT a_qi = a.Frobenius_map(power);
+        assert(a_qi == a_q);
+
+        a_q = a_q ^ FieldT::base_field_char();
+    }
+}
+
+template<typename FieldT>
+void test_unitary_inverse()
+{
+    assert(FieldT::extension_degree() % 2 == 0);
+    FieldT a = FieldT::random_element();
+    FieldT aqcubed_minus1 = a.Frobenius_map(FieldT::extension_degree()/2) * a.inverse();
+    assert(aqcubed_minus1.inverse() == aqcubed_minus1.unitary_inverse());
+}
+
+template<typename FieldT>
+void test_cyclotomic_squaring();
+
+template<>
+void test_cyclotomic_squaring<Fqk<edwards_pp> >()
+{
+    typedef Fqk<edwards_pp> FieldT;
+    assert(FieldT::extension_degree() % 2 == 0);
+    FieldT a = FieldT::random_element();
+    FieldT a_unitary = a.Frobenius_map(FieldT::extension_degree()/2) * a.inverse();
+    // beta = a^((q^(k/2)-1)*(q+1))
+    FieldT beta = a_unitary.Frobenius_map(1) * a_unitary;
+    assert(beta.cyclotomic_squared() == beta.squared());
+}
+
+template<>
+void test_cyclotomic_squaring<Fqk<mnt4_pp> >()
+{
+    typedef Fqk<mnt4_pp> FieldT;
+    assert(FieldT::extension_degree() % 2 == 0);
+    FieldT a = FieldT::random_element();
+    FieldT a_unitary = a.Frobenius_map(FieldT::extension_degree()/2) * a.inverse();
+    // beta = a^(q^(k/2)-1)
+    FieldT beta = a_unitary;
+    assert(beta.cyclotomic_squared() == beta.squared());
+}
+
+template<>
+void test_cyclotomic_squaring<Fqk<mnt6_pp> >()
+{
+    typedef Fqk<mnt6_pp> FieldT;
+    assert(FieldT::extension_degree() % 2 == 0);
+    FieldT a = FieldT::random_element();
+    FieldT a_unitary = a.Frobenius_map(FieldT::extension_degree()/2) * a.inverse();
+    // beta = a^((q^(k/2)-1)*(q+1))
+    FieldT beta = a_unitary.Frobenius_map(1) * a_unitary;
+    assert(beta.cyclotomic_squared() == beta.squared());
+}
+
+template<typename ppT>
+void test_all_fields()
+{
+    test_field<Fr<ppT> >();
+    test_field<Fq<ppT> >();
+    test_field<Fqe<ppT> >();
+    test_field<Fqk<ppT> >();
+
+    test_sqrt<Fr<ppT> >();
+    test_sqrt<Fq<ppT> >();
+    test_sqrt<Fqe<ppT> >();
+
+    test_Frobenius<Fqe<ppT> >();
+    test_Frobenius<Fqk<ppT> >();
+
+    test_unitary_inverse<Fqk<ppT> >();
+}
+
+template<typename Fp4T>
+void test_Fp4_tom_cook()
+{
+    typedef typename Fp4T::my_Fp FieldT;
+    for (size_t i = 0; i < 100; ++i)
+    {
+        const Fp4T a = Fp4T::random_element();
+        const Fp4T b = Fp4T::random_element();
+        const Fp4T correct_res = a * b;
+
+        Fp4T res;
+
+        const FieldT
+            &a0 = a.c0.c0,
+            &a1 = a.c1.c0,
+            &a2 = a.c0.c1,
+            &a3 = a.c1.c1;
+
+        const FieldT
+            &b0 = b.c0.c0,
+            &b1 = b.c1.c0,
+            &b2 = b.c0.c1,
+            &b3 = b.c1.c1;
+
+        FieldT
+            &c0 = res.c0.c0,
+            &c1 = res.c1.c0,
+            &c2 = res.c0.c1,
+            &c3 = res.c1.c1;
+
+        const FieldT v0 = a0 * b0;
+        const FieldT v1 = (a0 + a1 + a2 + a3) * (b0 + b1 + b2 + b3);
+        const FieldT v2 = (a0 - a1 + a2 - a3) * (b0 - b1 + b2 - b3);
+        const FieldT v3 = (a0 + FieldT(2)*a1 + FieldT(4)*a2 + FieldT(8)*a3) * (b0 + FieldT(2)*b1 + FieldT(4)*b2 + FieldT(8)*b3);
+        const FieldT v4 = (a0 - FieldT(2)*a1 + FieldT(4)*a2 - FieldT(8)*a3) * (b0 - FieldT(2)*b1 + FieldT(4)*b2 - FieldT(8)*b3);
+        const FieldT v5 = (a0 + FieldT(3)*a1 + FieldT(9)*a2 + FieldT(27)*a3) * (b0 + FieldT(3)*b1 + FieldT(9)*b2 + FieldT(27)*b3);
+        const FieldT v6 = a3 * b3;
+
+        const FieldT beta = Fp4T::non_residue;
+
+        c0 = v0 + beta*(FieldT(4).inverse()*v0 - FieldT(6).inverse()*(v1 + v2) + FieldT(24).inverse() * (v3 + v4) - FieldT(5) * v6);
+        c1 = - FieldT(3).inverse()*v0 + v1 - FieldT(2).inverse()*v2 - FieldT(4).inverse()*v3 + FieldT(20).inverse() * v4 + FieldT(30).inverse() * v5 - FieldT(12) * v6 + beta * ( - FieldT(12).inverse() * (v0 - v1) + FieldT(24).inverse()*(v2 - v3) - FieldT(120).inverse() * (v4 - v5) - FieldT(3) * v6);
+        c2 = - (FieldT(5)*(FieldT(4).inverse()))* v0 + (FieldT(2)*(FieldT(3).inverse()))*(v1 + v2) - FieldT(24).inverse()*(v3 + v4) + FieldT(4)*v6 + beta*v6;
+        c3 = FieldT(12).inverse() * (FieldT(5)*v0 - FieldT(7)*v1) - FieldT(24).inverse()*(v2 - FieldT(7)*v3 + v4 + v5) + FieldT(15)*v6;
+
+        assert(res == correct_res);
+
+        // {v0, v3, v4, v5}
+        const FieldT u = (FieldT::one() - beta).inverse();
+        assert(v0 == u * c0 + beta * u * c2 - beta * u * FieldT(2).inverse() * v1 - beta * u * FieldT(2).inverse() * v2 + beta * v6);
+        assert(v3 == - FieldT(15) * u * c0 - FieldT(30) * u * c1 - FieldT(3) * (FieldT(4) + beta) * u * c2 - FieldT(6) * (FieldT(4) + beta) * u * c3 + (FieldT(24) - FieldT(3) * beta * FieldT(2).inverse()) * u * v1 + (-FieldT(8) + beta * FieldT(2).inverse()) * u * v2
+               - FieldT(3) * (-FieldT(16) + beta) * v6);
+        assert(v4 == - FieldT(15) * u * c0 + FieldT(30) * u * c1 - FieldT(3) * (FieldT(4) + beta) * u * c2 + FieldT(6) * (FieldT(4) + beta) * u * c3 + (FieldT(24) - FieldT(3) * beta * FieldT(2).inverse()) * u * v2 + (-FieldT(8) + beta * FieldT(2).inverse()) * u * v1
+               - FieldT(3) * (-FieldT(16) + beta) * v6);
+        assert(v5 == - FieldT(80) * u * c0 - FieldT(240) * u * c1 - FieldT(8) * (FieldT(9) + beta) * u * c2 - FieldT(24) * (FieldT(9) + beta) * u * c3 - FieldT(2) * (-FieldT(81) + beta) * u * v1 + (-FieldT(81) + beta) * u * v2
+               - FieldT(8) * (-FieldT(81) + beta) * v6);
+
+        // c0 + beta c2 - (beta v1)/2 - (beta v2)/ 2 - (-1 + beta) beta v6,
+        // -15 c0 - 30 c1 - 3 (4 + beta) c2 - 6 (4 + beta) c3 + (24 - (3 beta)/2) v1 + (-8 + beta/2) v2 + 3 (-16 + beta) (-1 + beta) v6,
+        // -15 c0 + 30 c1 - 3 (4 + beta) c2 + 6 (4 + beta) c3 + (-8 + beta/2) v1 + (24 - (3 beta)/2) v2 + 3 (-16 + beta) (-1 + beta) v6,
+        // -80 c0 - 240 c1 - 8 (9 + beta) c2 - 24 (9 + beta) c3 - 2 (-81 + beta) v1 + (-81 + beta) v2 + 8 (-81 + beta) (-1 + beta) v6
+    }
+}
+
+int main(void)
+{
+    edwards_pp::init_public_params();
+    test_all_fields<edwards_pp>();
+    test_cyclotomic_squaring<Fqk<edwards_pp> >();
+
+    mnt4_pp::init_public_params();
+    test_all_fields<mnt4_pp>();
+    test_Fp4_tom_cook<mnt4_Fq4>();
+    test_two_squarings<Fqe<mnt4_pp> >();
+    test_cyclotomic_squaring<Fqk<mnt4_pp> >();
+
+    mnt6_pp::init_public_params();
+    test_all_fields<mnt6_pp>();
+    test_cyclotomic_squaring<Fqk<mnt6_pp> >();
+
+    alt_bn128_pp::init_public_params();
+    test_field<alt_bn128_Fq6>();
+    test_Frobenius<alt_bn128_Fq6>();
+    test_all_fields<alt_bn128_pp>();
+
+#ifdef CURVE_BN128       // BN128 has fancy dependencies so it may be disabled
+    bn128_pp::init_public_params();
+    test_field<Fr<bn128_pp> >();
+    test_field<Fq<bn128_pp> >();
+#endif
+}
diff --git a/src/algebra/knowledge_commitment/knowledge_commitment.hpp b/src/algebra/knowledge_commitment/knowledge_commitment.hpp
new file mode 100644 (file)
index 0000000..9024231
--- /dev/null
@@ -0,0 +1,84 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for:
+ - a knowledge commitment, and
+ - a knowledge commitment vector.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef KNOWLEDGE_COMMITMENT_HPP_
+#define KNOWLEDGE_COMMITMENT_HPP_
+
+#include "algebra/fields/fp.hpp"
+#include "common/data_structures/sparse_vector.hpp"
+
+namespace libsnark {
+
+/********************** Knowledge commitment *********************************/
+
+/**
+ * A knowledge commitment is a pair (g,h) where g is in T1 and h in T2,
+ * and T1 and T2 are groups (written additively).
+ *
+ * Such pairs form a group by defining:
+ * - "zero" = (0,0)
+ * - "one" = (1,1)
+ * - a * (g,h) + b * (g',h') := ( a * g + b * g', a * h + b * h').
+ */
+template<typename T1, typename T2>
+struct knowledge_commitment {
+
+    T1 g;
+    T2 h;
+
+    knowledge_commitment<T1,T2>() = default;
+    knowledge_commitment<T1,T2>(const knowledge_commitment<T1,T2> &other) = default;
+    knowledge_commitment<T1,T2>(knowledge_commitment<T1,T2> &&other) = default;
+    knowledge_commitment<T1,T2>(const T1 &g, const T2 &h);
+
+    knowledge_commitment<T1,T2>& operator=(const knowledge_commitment<T1,T2> &other) = default;
+    knowledge_commitment<T1,T2>& operator=(knowledge_commitment<T1,T2> &&other) = default;
+    knowledge_commitment<T1,T2> operator+(const knowledge_commitment<T1, T2> &other) const;
+
+    bool is_zero() const;
+    bool operator==(const knowledge_commitment<T1,T2> &other) const;
+    bool operator!=(const knowledge_commitment<T1,T2> &other) const;
+
+    static knowledge_commitment<T1,T2> zero();
+    static knowledge_commitment<T1,T2> one();
+
+    void print() const;
+
+    static size_t size_in_bits();
+};
+
+template<typename T1, typename T2, mp_size_t m>
+knowledge_commitment<T1,T2> operator*(const bigint<m> &lhs, const knowledge_commitment<T1,T2> &rhs);
+
+template<typename T1, typename T2, mp_size_t m, const bigint<m> &modulus_p>
+knowledge_commitment<T1,T2> operator*(const Fp_model<m, modulus_p> &lhs, const knowledge_commitment<T1,T2> &rhs);
+
+template<typename T1,typename T2>
+std::ostream& operator<<(std::ostream& out, const knowledge_commitment<T1,T2> &kc);
+
+template<typename T1,typename T2>
+std::istream& operator>>(std::istream& in, knowledge_commitment<T1,T2> &kc);
+
+/******************** Knowledge commitment vector ****************************/
+
+/**
+ * A knowledge commitment vector is a sparse vector of knowledge commitments.
+ */
+template<typename T1, typename T2>
+using knowledge_commitment_vector = sparse_vector<knowledge_commitment<T1, T2> >;
+
+} // libsnark
+
+#include "algebra/knowledge_commitment/knowledge_commitment.tcc"
+
+#endif // KNOWLEDGE_COMMITMENT_HPP_
diff --git a/src/algebra/knowledge_commitment/knowledge_commitment.tcc b/src/algebra/knowledge_commitment/knowledge_commitment.tcc
new file mode 100644 (file)
index 0000000..15b2926
--- /dev/null
@@ -0,0 +1,111 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for:
+ - a knowledge commitment, and
+ - a knowledge commitment vector.
+
+ See knowledge_commitment.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef KNOWLEDGE_COMMITMENT_TCC_
+#define KNOWLEDGE_COMMITMENT_TCC_
+
+namespace libsnark {
+
+template<typename T1, typename T2>
+knowledge_commitment<T1,T2>::knowledge_commitment(const T1 &g, const T2 &h) :
+    g(g), h(h)
+{
+}
+
+template<typename T1, typename T2>
+knowledge_commitment<T1,T2> knowledge_commitment<T1,T2>::zero()
+{
+    return knowledge_commitment<T1,T2>(T1::zero(), T2::zero());
+}
+
+template<typename T1, typename T2>
+knowledge_commitment<T1,T2> knowledge_commitment<T1,T2>::one()
+{
+    return knowledge_commitment<T1,T2>(T1::one(), T2::one());
+}
+
+template<typename T1, typename T2>
+knowledge_commitment<T1,T2> knowledge_commitment<T1,T2>::operator+(const knowledge_commitment<T1,T2> &other) const
+{
+    return knowledge_commitment<T1,T2>(this->g + other.g,
+                                       this->h + other.h);
+}
+
+template<typename T1, typename T2>
+bool knowledge_commitment<T1,T2>::is_zero() const
+{
+    return (g.is_zero() && h.is_zero());
+}
+
+template<typename T1, typename T2>
+bool knowledge_commitment<T1,T2>::operator==(const knowledge_commitment<T1,T2> &other) const
+{
+    return (this->g == other.g &&
+            this->h == other.h);
+}
+
+template<typename T1, typename T2>
+bool knowledge_commitment<T1,T2>::operator!=(const knowledge_commitment<T1,T2> &other) const
+{
+    return !((*this) == other);
+}
+
+template<typename T1, typename T2, mp_size_t m>
+knowledge_commitment<T1,T2> operator*(const bigint<m> &lhs, const knowledge_commitment<T1,T2> &rhs)
+{
+    return knowledge_commitment<T1,T2>(lhs * rhs.g,
+                                       lhs * rhs.h);
+}
+
+template<typename T1, typename T2, mp_size_t m, const bigint<m> &modulus_p>
+knowledge_commitment<T1,T2> operator*(const Fp_model<m, modulus_p> &lhs, const knowledge_commitment<T1,T2> &rhs)
+{
+    return (lhs.as_bigint()) * rhs;
+}
+
+template<typename T1, typename T2>
+void knowledge_commitment<T1,T2>::print() const
+{
+    printf("knowledge_commitment.g:\n");
+    g.print();
+    printf("knowledge_commitment.h:\n");
+    h.print();
+}
+
+template<typename T1, typename T2>
+size_t knowledge_commitment<T1,T2>::size_in_bits()
+{
+        return T1::size_in_bits() + T2::size_in_bits();
+}
+
+template<typename T1,typename T2>
+std::ostream& operator<<(std::ostream& out, const knowledge_commitment<T1,T2> &kc)
+{
+    out << kc.g << OUTPUT_SEPARATOR << kc.h;
+    return out;
+}
+
+template<typename T1,typename T2>
+std::istream& operator>>(std::istream& in, knowledge_commitment<T1,T2> &kc)
+{
+    in >> kc.g;
+    consume_OUTPUT_SEPARATOR(in);
+    in >> kc.h;
+    return in;
+}
+
+} // libsnark
+
+#endif // KNOWLEDGE_COMMITMENT_TCC_
diff --git a/src/algebra/scalar_multiplication/kc_multiexp.hpp b/src/algebra/scalar_multiplication/kc_multiexp.hpp
new file mode 100644 (file)
index 0000000..4e8b556
--- /dev/null
@@ -0,0 +1,55 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef KC_MULTIEXP_HPP_
+#define KC_MULTIEXP_HPP_
+
+/*
+  Split out from multiexp to prevent cyclical
+  dependencies. I.e. previously multiexp dependend on
+  knowledge_commitment, which dependend on sparse_vector, which
+  dependend on multiexp (to do accumulate).
+
+  Will probably go away in more general exp refactoring.
+*/
+
+#include "algebra/knowledge_commitment/knowledge_commitment.hpp"
+
+namespace libsnark {
+
+template<typename T1, typename T2, mp_size_t n>
+knowledge_commitment<T1,T2> opt_window_wnaf_exp(const knowledge_commitment<T1,T2> &base,
+                                                const bigint<n> &scalar, const size_t scalar_bits);
+
+template<typename T1, typename T2, typename FieldT>
+knowledge_commitment<T1, T2> kc_multi_exp_with_mixed_addition(const knowledge_commitment_vector<T1, T2> &vec,
+                                                                const size_t min_idx,
+                                                                const size_t max_idx,
+                                                                typename std::vector<FieldT>::const_iterator scalar_start,
+                                                                typename std::vector<FieldT>::const_iterator scalar_end,
+                                                                const size_t chunks,
+                                                                const bool use_multiexp=false);
+
+template<typename T1, typename T2>
+void kc_batch_to_special(std::vector<knowledge_commitment<T1, T2> > &vec);
+
+template<typename T1, typename T2, typename FieldT>
+knowledge_commitment_vector<T1, T2> kc_batch_exp(const size_t scalar_size,
+                                                 const size_t T1_window,
+                                                 const size_t T2_window,
+                                                 const window_table<T1> &T1_table,
+                                                 const window_table<T2> &T2_table,
+                                                 const FieldT &T1_coeff,
+                                                 const FieldT &T2_coeff,
+                                                 const std::vector<FieldT> &v,
+                                                 const size_t suggested_num_chunks);
+
+} // libsnark
+
+#include "algebra/scalar_multiplication/kc_multiexp.tcc"
+
+#endif // KC_MULTIEXP_HPP_
diff --git a/src/algebra/scalar_multiplication/kc_multiexp.tcc b/src/algebra/scalar_multiplication/kc_multiexp.tcc
new file mode 100644 (file)
index 0000000..e9c08d4
--- /dev/null
@@ -0,0 +1,274 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef KC_MULTIEXP_TCC_
+#define KC_MULTIEXP_TCC_
+
+namespace libsnark {
+
+template<typename T1, typename T2, mp_size_t n>
+knowledge_commitment<T1,T2> opt_window_wnaf_exp(const knowledge_commitment<T1,T2> &base,
+                                                const bigint<n> &scalar, const size_t scalar_bits)
+{
+    return knowledge_commitment<T1,T2>(opt_window_wnaf_exp(base.g, scalar, scalar_bits),
+                                       opt_window_wnaf_exp(base.h, scalar, scalar_bits));
+}
+
+template<typename T1, typename T2, typename FieldT>
+knowledge_commitment<T1, T2> kc_multi_exp_with_mixed_addition(const knowledge_commitment_vector<T1, T2> &vec,
+                                                                const size_t min_idx,
+                                                                const size_t max_idx,
+                                                                typename std::vector<FieldT>::const_iterator scalar_start,
+                                                                typename std::vector<FieldT>::const_iterator scalar_end,
+                                                                const size_t chunks,
+                                                                const bool use_multiexp)
+{
+    enter_block("Process scalar vector");
+    auto index_it = std::lower_bound(vec.indices.begin(), vec.indices.end(), min_idx);
+    const size_t offset = index_it - vec.indices.begin();
+
+    auto value_it = vec.values.begin() + offset;
+
+    const FieldT zero = FieldT::zero();
+    const FieldT one = FieldT::one();
+
+    std::vector<FieldT> p;
+    std::vector<knowledge_commitment<T1, T2> > g;
+
+    knowledge_commitment<T1, T2> acc = knowledge_commitment<T1, T2>::zero();
+
+    size_t num_skip = 0;
+    size_t num_add = 0;
+    size_t num_other = 0;
+
+    const size_t scalar_length = std::distance(scalar_start, scalar_end);
+
+    while (index_it != vec.indices.end() && *index_it < max_idx)
+    {
+        const size_t scalar_position = (*index_it) - min_idx;
+        assert(scalar_position < scalar_length);
+
+        const FieldT scalar = *(scalar_start + scalar_position);
+
+        if (scalar == zero)
+        {
+            // do nothing
+            ++num_skip;
+        }
+        else if (scalar == one)
+        {
+#ifdef USE_MIXED_ADDITION
+            acc.g = acc.g.mixed_add(value_it->g);
+            acc.h = acc.h.mixed_add(value_it->h);
+#else
+            acc.g = acc.g + value_it->g;
+            acc.h = acc.h + value_it->h;
+#endif
+            ++num_add;
+        }
+        else
+        {
+            p.emplace_back(scalar);
+            g.emplace_back(*value_it);
+            ++num_other;
+        }
+
+        ++index_it;
+        ++value_it;
+    }
+
+    //print_indent(); printf("* Elements of w skipped: %zu (%0.2f%%)\n", num_skip, 100.*num_skip/(num_skip+num_add+num_other));
+    //print_indent(); printf("* Elements of w processed with special addition: %zu (%0.2f%%)\n", num_add, 100.*num_add/(num_skip+num_add+num_other));
+    //print_indent(); printf("* Elements of w remaining: %zu (%0.2f%%)\n", num_other, 100.*num_other/(num_skip+num_add+num_other));
+    leave_block("Process scalar vector");
+
+    return acc + multi_exp<knowledge_commitment<T1, T2>, FieldT>(g.begin(), g.end(), p.begin(), p.end(), chunks, use_multiexp);
+}
+
+template<typename T1, typename T2>
+void kc_batch_to_special(std::vector<knowledge_commitment<T1, T2> > &vec)
+{
+    enter_block("Batch-convert knowledge-commitments to special form");
+
+    std::vector<T1> g_vec;
+    g_vec.reserve(vec.size());
+
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        if (!vec[i].g.is_zero())
+        {
+            g_vec.emplace_back(vec[i].g);
+        }
+    }
+
+    batch_to_special_all_non_zeros<T1>(g_vec);
+    auto g_it = g_vec.begin();
+    T1 T1_zero_special = T1::zero();
+    T1_zero_special.to_special();
+
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        if (!vec[i].g.is_zero())
+        {
+            vec[i].g = *g_it;
+            ++g_it;
+        }
+        else
+        {
+            vec[i].g = T1_zero_special;
+        }
+    }
+
+    g_vec.clear();
+
+    std::vector<T2> h_vec;
+    h_vec.reserve(vec.size());
+
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        if (!vec[i].h.is_zero())
+        {
+            h_vec.emplace_back(vec[i].h);
+        }
+    }
+
+    batch_to_special_all_non_zeros<T2>(h_vec);
+    auto h_it = h_vec.begin();
+    T2 T2_zero_special = T2::zero();
+    T2_zero_special.to_special();
+
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        if (!vec[i].h.is_zero())
+        {
+            vec[i].h = *h_it;
+            ++h_it;
+        }
+        else
+        {
+            vec[i].h = T2_zero_special;
+        }
+    }
+
+    g_vec.clear();
+
+    leave_block("Batch-convert knowledge-commitments to special form");
+}
+
+template<typename T1, typename T2, typename FieldT>
+knowledge_commitment_vector<T1, T2> kc_batch_exp_internal(const size_t scalar_size,
+                                                          const size_t T1_window,
+                                                          const size_t T2_window,
+                                                          const window_table<T1> &T1_table,
+                                                          const window_table<T2> &T2_table,
+                                                          const FieldT &T1_coeff,
+                                                          const FieldT &T2_coeff,
+                                                          const std::vector<FieldT> &v,
+                                                          const size_t start_pos,
+                                                          const size_t end_pos,
+                                                          const size_t expected_size)
+{
+    knowledge_commitment_vector<T1, T2> res;
+
+    res.values.reserve(expected_size);
+    res.indices.reserve(expected_size);
+
+    for (size_t pos = start_pos; pos != end_pos; ++pos)
+    {
+        if (!v[pos].is_zero())
+        {
+            res.values.emplace_back(knowledge_commitment<T1, T2>(windowed_exp(scalar_size, T1_window, T1_table, T1_coeff * v[pos]),
+                                                                 windowed_exp(scalar_size, T2_window, T2_table, T2_coeff * v[pos])));
+            res.indices.emplace_back(pos);
+        }
+    }
+
+    return res;
+}
+
+template<typename T1, typename T2, typename FieldT>
+knowledge_commitment_vector<T1, T2> kc_batch_exp(const size_t scalar_size,
+                                                 const size_t T1_window,
+                                                 const size_t T2_window,
+                                                 const window_table<T1> &T1_table,
+                                                 const window_table<T2> &T2_table,
+                                                 const FieldT &T1_coeff,
+                                                 const FieldT &T2_coeff,
+                                                 const std::vector<FieldT> &v,
+                                                 const size_t suggested_num_chunks)
+{
+    knowledge_commitment_vector<T1, T2> res;
+    res.domain_size_ = v.size();
+
+    size_t nonzero = 0;
+    for (size_t i = 0; i < v.size(); ++i)
+    {
+        nonzero += (v[i].is_zero() ? 0 : 1);
+    }
+
+    const size_t num_chunks = std::max((size_t)1, std::min(nonzero, suggested_num_chunks));
+
+    if (!inhibit_profiling_info)
+    {
+        print_indent(); printf("Non-zero coordinate count: %zu/%zu (%0.2f%%)\n", nonzero, v.size(), 100.*nonzero/v.size());
+    }
+
+    std::vector<knowledge_commitment_vector<T1, T2> > tmp(num_chunks);
+    std::vector<size_t> chunk_pos(num_chunks+1);
+
+    const size_t chunk_size = nonzero / num_chunks;
+    const size_t last_chunk = nonzero - chunk_size * (num_chunks - 1);
+
+    chunk_pos[0] = 0;
+
+    size_t cnt = 0;
+    size_t chunkno = 1;
+
+    for (size_t i = 0; i < v.size(); ++i)
+    {
+        cnt += (v[i].is_zero() ? 0 : 1);
+        if (cnt == chunk_size && chunkno < num_chunks)
+        {
+            chunk_pos[chunkno] = i;
+            cnt = 0;
+            ++chunkno;
+        }
+    }
+
+    chunk_pos[num_chunks] = v.size();
+
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+    for (size_t i = 0; i < num_chunks; ++i)
+    {
+        tmp[i] = kc_batch_exp_internal<T1, T2, FieldT>(scalar_size, T1_window, T2_window, T1_table, T2_table, T1_coeff, T2_coeff, v,
+                                                       chunk_pos[i], chunk_pos[i+1], i == num_chunks - 1 ? last_chunk : chunk_size);
+#ifdef USE_MIXED_ADDITION
+        kc_batch_to_special<T1, T2>(tmp[i].values);
+#endif
+    }
+
+    if (num_chunks == 1)
+    {
+        tmp[0].domain_size_ = v.size();
+        return tmp[0];
+    }
+    else
+    {
+        for (size_t i = 0; i < num_chunks; ++i)
+        {
+            res.values.insert(res.values.end(), tmp[i].values.begin(), tmp[i].values.end());
+            res.indices.insert(res.indices.end(), tmp[i].indices.begin(), tmp[i].indices.end());
+        }
+        return res;
+    }
+}
+
+} // libsnark
+
+#endif // KC_MULTIEXP_TCC_
diff --git a/src/algebra/scalar_multiplication/multiexp.hpp b/src/algebra/scalar_multiplication/multiexp.hpp
new file mode 100644 (file)
index 0000000..eaf72d6
--- /dev/null
@@ -0,0 +1,110 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for multi-exponentiation routines.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MULTIEXP_HPP_
+#define MULTIEXP_HPP_
+
+namespace libsnark {
+
+/**
+ * Naive multi-exponentiation individually multiplies each base by the
+ * corresponding scalar and adds up the results.
+ */
+template<typename T, typename FieldT>
+T naive_exp(typename std::vector<T>::const_iterator vec_start,
+            typename std::vector<T>::const_iterator vec_end,
+            typename std::vector<FieldT>::const_iterator scalar_start,
+            typename std::vector<FieldT>::const_iterator scalar_end);
+
+template<typename T, typename FieldT>
+T naive_plain_exp(typename std::vector<T>::const_iterator vec_start,
+                  typename std::vector<T>::const_iterator vec_end,
+                  typename std::vector<FieldT>::const_iterator scalar_start,
+                  typename std::vector<FieldT>::const_iterator scalar_end);
+
+/**
+ * Naive multi-exponentiation uses a variant of the Bos-Coster algorithm [1],
+ * and implementation suggestions from [2].
+ *
+ * [1] = Bos and Coster, "Addition chain heuristics", CRYPTO '89
+ * [2] = Bernstein, Duif, Lange, Schwabe, and Yang, "High-speed high-security signatures", CHES '11
+ */
+template<typename T, typename FieldT>
+T multi_exp(typename std::vector<T>::const_iterator vec_start,
+            typename std::vector<T>::const_iterator vec_end,
+            typename std::vector<FieldT>::const_iterator scalar_start,
+            typename std::vector<FieldT>::const_iterator scalar_end,
+            const size_t chunks,
+            const bool use_multiexp=false);
+
+
+/**
+ * A variant of multi_exp that takes advantage of the method mixed_add (instead of the operator '+').
+ */
+template<typename T, typename FieldT>
+T multi_exp_with_mixed_addition(typename std::vector<T>::const_iterator vec_start,
+                                  typename std::vector<T>::const_iterator vec_end,
+                                  typename std::vector<FieldT>::const_iterator scalar_start,
+                                  typename std::vector<FieldT>::const_iterator scalar_end,
+                                  const size_t chunks,
+                                  const bool use_multiexp);
+
+/**
+ * A window table stores window sizes for different instance sizes for fixed-base multi-scalar multiplications.
+ */
+template<typename T>
+using window_table = std::vector<std::vector<T> >;
+
+/**
+ * Compute window size for the given number of scalars.
+ */
+template<typename T>
+size_t get_exp_window_size(const size_t num_scalars);
+
+/**
+ * Compute table of window sizes.
+ */
+template<typename T>
+window_table<T> get_window_table(const size_t scalar_size,
+                                 const size_t window,
+                                 const T &g);
+
+template<typename T, typename FieldT>
+T windowed_exp(const size_t scalar_size,
+               const size_t window,
+               const window_table<T> &powers_of_g,
+               const FieldT &pow);
+
+template<typename T, typename FieldT>
+std::vector<T> batch_exp(const size_t scalar_size,
+                         const size_t window,
+                         const window_table<T> &table,
+                         const std::vector<FieldT> &v);
+
+template<typename T, typename FieldT>
+std::vector<T> batch_exp_with_coeff(const size_t scalar_size,
+                                    const size_t window,
+                                    const window_table<T> &table,
+                                    const FieldT &coeff,
+                                    const std::vector<FieldT> &v);
+
+// defined in every curve
+template<typename T>
+void batch_to_special_all_non_zeros(std::vector<T> &vec);
+
+template<typename T>
+void batch_to_special(std::vector<T> &vec);
+
+} // libsnark
+
+#include "algebra/scalar_multiplication/multiexp.tcc"
+
+#endif // MULTIEXP_HPP_
diff --git a/src/algebra/scalar_multiplication/multiexp.tcc b/src/algebra/scalar_multiplication/multiexp.tcc
new file mode 100644 (file)
index 0000000..a6b14c4
--- /dev/null
@@ -0,0 +1,590 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for multi-exponentiation routines.
+
+ See multiexp.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MULTIEXP_TCC_
+#define MULTIEXP_TCC_
+
+#include "algebra/fields/fp_aux.tcc"
+
+#include <algorithm>
+#include <cassert>
+#include <type_traits>
+
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+#include "algebra/scalar_multiplication/wnaf.hpp"
+
+namespace libsnark {
+
+template<mp_size_t n>
+class ordered_exponent {
+// to use std::push_heap and friends later
+public:
+    size_t idx;
+    bigint<n> r;
+
+    ordered_exponent(const size_t idx, const bigint<n> &r) : idx(idx), r(r) {};
+
+    bool operator<(const ordered_exponent<n> &other) const
+    {
+#if defined(__x86_64__) && defined(USE_ASM)
+        if (n == 3)
+        {
+            long res;
+            __asm__
+                ("// check for overflow           \n\t"
+                 "mov $0, %[res]                  \n\t"
+                 ADD_CMP(16)
+                 ADD_CMP(8)
+                 ADD_CMP(0)
+                 "jmp done%=                      \n\t"
+                 "subtract%=:                     \n\t"
+                 "mov $1, %[res]                  \n\t"
+                 "done%=:                         \n\t"
+                 : [res] "=&r" (res)
+                 : [A] "r" (other.r.data), [mod] "r" (this->r.data)
+                 : "cc", "%rax");
+            return res;
+        }
+        else if (n == 4)
+        {
+            long res;
+            __asm__
+                ("// check for overflow           \n\t"
+                 "mov $0, %[res]                  \n\t"
+                 ADD_CMP(24)
+                 ADD_CMP(16)
+                 ADD_CMP(8)
+                 ADD_CMP(0)
+                 "jmp done%=                      \n\t"
+                 "subtract%=:                     \n\t"
+                 "mov $1, %[res]                  \n\t"
+                 "done%=:                         \n\t"
+                 : [res] "=&r" (res)
+                 : [A] "r" (other.r.data), [mod] "r" (this->r.data)
+                 : "cc", "%rax");
+            return res;
+        }
+        else if (n == 5)
+        {
+            long res;
+            __asm__
+                ("// check for overflow           \n\t"
+                 "mov $0, %[res]                  \n\t"
+                 ADD_CMP(32)
+                 ADD_CMP(24)
+                 ADD_CMP(16)
+                 ADD_CMP(8)
+                 ADD_CMP(0)
+                 "jmp done%=                      \n\t"
+                 "subtract%=:                     \n\t"
+                 "mov $1, %[res]                  \n\t"
+                 "done%=:                         \n\t"
+                 : [res] "=&r" (res)
+                 : [A] "r" (other.r.data), [mod] "r" (this->r.data)
+                 : "cc", "%rax");
+            return res;
+        }
+        else
+#endif
+        {
+            return (mpn_cmp(this->r.data, other.r.data, n) < 0);
+        }
+    }
+};
+
+template<typename T, typename FieldT>
+T naive_exp(typename std::vector<T>::const_iterator vec_start,
+            typename std::vector<T>::const_iterator vec_end,
+            typename std::vector<FieldT>::const_iterator scalar_start,
+            typename std::vector<FieldT>::const_iterator scalar_end)
+{
+    T result(T::zero());
+
+    typename std::vector<T>::const_iterator vec_it;
+    typename std::vector<FieldT>::const_iterator scalar_it;
+
+    for (vec_it = vec_start, scalar_it = scalar_start; vec_it != vec_end; ++vec_it, ++scalar_it)
+    {
+        bigint<FieldT::num_limbs> scalar_bigint = scalar_it->as_bigint();
+        result = result + opt_window_wnaf_exp(*vec_it, scalar_bigint, scalar_bigint.num_bits());
+    }
+    assert(scalar_it == scalar_end);
+
+    return result;
+}
+
+template<typename T, typename FieldT>
+T naive_plain_exp(typename std::vector<T>::const_iterator vec_start,
+                  typename std::vector<T>::const_iterator vec_end,
+                  typename std::vector<FieldT>::const_iterator scalar_start,
+                  typename std::vector<FieldT>::const_iterator scalar_end)
+{
+    T result(T::zero());
+
+    typename std::vector<T>::const_iterator vec_it;
+    typename std::vector<FieldT>::const_iterator scalar_it;
+
+    for (vec_it = vec_start, scalar_it = scalar_start; vec_it != vec_end; ++vec_it, ++scalar_it)
+    {
+        result = result + (*scalar_it) * (*vec_it);
+    }
+    assert(scalar_it == scalar_end);
+
+    return result;
+}
+
+/*
+  The multi-exponentiation algorithm below is a variant of the Bos-Coster algorithm
+  [Bos and Coster, "Addition chain heuristics", CRYPTO '89].
+  The implementation uses suggestions from
+  [Bernstein, Duif, Lange, Schwabe, and Yang, "High-speed high-security signatures", CHES '11].
+*/
+template<typename T, typename FieldT>
+T multi_exp_inner(typename std::vector<T>::const_iterator vec_start,
+                  typename std::vector<T>::const_iterator vec_end,
+                  typename std::vector<FieldT>::const_iterator scalar_start,
+                  typename std::vector<FieldT>::const_iterator scalar_end)
+{
+    const mp_size_t n = std::remove_reference<decltype(*scalar_start)>::type::num_limbs;
+
+    if (vec_start == vec_end)
+    {
+        return T::zero();
+    }
+
+    if (vec_start + 1 == vec_end)
+    {
+        return (*scalar_start)*(*vec_start);
+    }
+
+    std::vector<ordered_exponent<n> > opt_q;
+    const size_t vec_len = scalar_end - scalar_start;
+    const size_t odd_vec_len = (vec_len % 2 == 1 ? vec_len : vec_len + 1);
+    opt_q.reserve(odd_vec_len);
+    std::vector<T> g;
+    g.reserve(odd_vec_len);
+
+    typename std::vector<T>::const_iterator vec_it;
+    typename std::vector<FieldT>::const_iterator scalar_it;
+    size_t i;
+    for (i=0, vec_it = vec_start, scalar_it = scalar_start; vec_it != vec_end; ++vec_it, ++scalar_it, ++i)
+    {
+        g.emplace_back(*vec_it);
+
+        opt_q.emplace_back(ordered_exponent<n>(i, scalar_it->as_bigint()));
+    }
+    std::make_heap(opt_q.begin(),opt_q.end());
+    assert(scalar_it == scalar_end);
+
+    if (vec_len != odd_vec_len)
+    {
+        g.emplace_back(T::zero());
+        opt_q.emplace_back(ordered_exponent<n>(odd_vec_len - 1, bigint<n>(0ul)));
+    }
+    assert(g.size() % 2 == 1);
+    assert(opt_q.size() == g.size());
+
+    T opt_result = T::zero();
+
+    while (true)
+    {
+        ordered_exponent<n> &a = opt_q[0];
+        ordered_exponent<n> &b = (opt_q[1] < opt_q[2] ? opt_q[2] : opt_q[1]);
+
+        const size_t abits = a.r.num_bits();
+
+        if (b.r.is_zero())
+        {
+            // opt_result = opt_result + (a.r * g[a.idx]);
+            opt_result = opt_result + opt_window_wnaf_exp(g[a.idx], a.r, abits);
+            break;
+        }
+
+        const size_t bbits = b.r.num_bits();
+        const size_t limit = (abits-bbits >= 20 ? 20 : abits-bbits);
+
+        if (bbits < 1ul<<limit)
+        {
+            /*
+              In this case, exponentiating to the power of a is cheaper than
+              subtracting b from a multiple times, so let's do it directly
+            */
+            // opt_result = opt_result + (a.r * g[a.idx]);
+            opt_result = opt_result + opt_window_wnaf_exp(g[a.idx], a.r, abits);
+#ifdef DEBUG
+            printf("Skipping the following pair (%zu bit number vs %zu bit):\n", abits, bbits);
+            a.r.print();
+            b.r.print();
+#endif
+            a.r.clear();
+        }
+        else
+        {
+            // x A + y B => (x-y) A + y (B+A)
+            mpn_sub_n(a.r.data, a.r.data, b.r.data, n);
+            g[b.idx] = g[b.idx] + g[a.idx];
+        }
+
+        // regardless of whether a was cleared or subtracted from we push it down, then take back up
+
+        /* heapify A down */
+        size_t a_pos = 0;
+        while (2*a_pos + 2< odd_vec_len)
+        {
+            // this is a max-heap so to maintain a heap property we swap with the largest of the two
+            if (opt_q[2*a_pos+1] < opt_q[2*a_pos+2])
+            {
+                std::swap(opt_q[a_pos], opt_q[2*a_pos+2]);
+                a_pos = 2*a_pos+2;
+            }
+            else
+            {
+                std::swap(opt_q[a_pos], opt_q[2*a_pos+1]);
+                a_pos = 2*a_pos+1;
+            }
+        }
+
+        /* now heapify A up appropriate amount of times */
+        while (a_pos > 0 && opt_q[(a_pos-1)/2] < opt_q[a_pos])
+        {
+            std::swap(opt_q[a_pos], opt_q[(a_pos-1)/2]);
+            a_pos = (a_pos-1) / 2;
+        }
+    }
+
+    return opt_result;
+}
+
+template<typename T, typename FieldT>
+T multi_exp(typename std::vector<T>::const_iterator vec_start,
+            typename std::vector<T>::const_iterator vec_end,
+            typename std::vector<FieldT>::const_iterator scalar_start,
+            typename std::vector<FieldT>::const_iterator scalar_end,
+            const size_t chunks,
+            const bool use_multiexp)
+{
+    const size_t total = vec_end - vec_start;
+    if (total < chunks)
+    {
+        return naive_exp<T, FieldT>(vec_start, vec_end, scalar_start, scalar_end);
+    }
+
+    const size_t one = total/chunks;
+
+    std::vector<T> partial(chunks, T::zero());
+
+    if (use_multiexp)
+    {
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+        for (size_t i = 0; i < chunks; ++i)
+        {
+            partial[i] = multi_exp_inner<T, FieldT>(vec_start + i*one,
+                                                    (i == chunks-1 ? vec_end : vec_start + (i+1)*one),
+                                                    scalar_start + i*one,
+                                                    (i == chunks-1 ? scalar_end : scalar_start + (i+1)*one));
+        }
+    }
+    else
+    {
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+        for (size_t i = 0; i < chunks; ++i)
+        {
+            partial[i] = naive_exp<T, FieldT>(vec_start + i*one,
+                                              (i == chunks-1 ? vec_end : vec_start + (i+1)*one),
+                                              scalar_start + i*one,
+                                              (i == chunks-1 ? scalar_end : scalar_start + (i+1)*one));
+        }
+    }
+
+    T final = T::zero();
+
+    for (size_t i = 0; i < chunks; ++i)
+    {
+        final = final + partial[i];
+    }
+
+    return final;
+}
+
+template<typename T, typename FieldT>
+T multi_exp_with_mixed_addition(typename std::vector<T>::const_iterator vec_start,
+                                typename std::vector<T>::const_iterator vec_end,
+                                typename std::vector<FieldT>::const_iterator scalar_start,
+                                typename std::vector<FieldT>::const_iterator scalar_end,
+                                const size_t chunks,
+                                const bool use_multiexp)
+{
+    assert(std::distance(vec_start, vec_end) == std::distance(scalar_start, scalar_end));
+    enter_block("Process scalar vector");
+    auto value_it = vec_start;
+    auto scalar_it = scalar_start;
+
+    const FieldT zero = FieldT::zero();
+    const FieldT one = FieldT::one();
+    std::vector<FieldT> p;
+    std::vector<T> g;
+
+    T acc = T::zero();
+
+    size_t num_skip = 0;
+    size_t num_add = 0;
+    size_t num_other = 0;
+
+    for (; scalar_it != scalar_end; ++scalar_it, ++value_it)
+    {
+        if (*scalar_it == zero)
+        {
+            // do nothing
+            ++num_skip;
+        }
+        else if (*scalar_it == one)
+        {
+#ifdef USE_MIXED_ADDITION
+            acc = acc.mixed_add(*value_it);
+#else
+            acc = acc + (*value_it);
+#endif
+            ++num_add;
+        }
+        else
+        {
+            p.emplace_back(*scalar_it);
+            g.emplace_back(*value_it);
+            ++num_other;
+        }
+    }
+    //print_indent(); printf("* Elements of w skipped: %zu (%0.2f%%)\n", num_skip, 100.*num_skip/(num_skip+num_add+num_other));
+    //print_indent(); printf("* Elements of w processed with special addition: %zu (%0.2f%%)\n", num_add, 100.*num_add/(num_skip+num_add+num_other));
+    //print_indent(); printf("* Elements of w remaining: %zu (%0.2f%%)\n", num_other, 100.*num_other/(num_skip+num_add+num_other));
+
+    leave_block("Process scalar vector");
+
+    return acc + multi_exp<T, FieldT>(g.begin(), g.end(), p.begin(), p.end(), chunks, use_multiexp);
+}
+
+template<typename T>
+size_t get_exp_window_size(const size_t num_scalars)
+{
+    if (T::fixed_base_exp_window_table.empty())
+    {
+#ifdef LOWMEM
+        return 14;
+#else
+        return 17;
+#endif
+    }
+    size_t window = 1;
+    for (long i = T::fixed_base_exp_window_table.size()-1; i >= 0; --i)
+    {
+#ifdef DEBUG
+        if (!inhibit_profiling_info)
+        {
+            printf("%ld %zu %zu\n", i, num_scalars, T::fixed_base_exp_window_table[i]);
+        }
+#endif
+        if (T::fixed_base_exp_window_table[i] != 0 && num_scalars >= T::fixed_base_exp_window_table[i])
+        {
+            window = i+1;
+            break;
+        }
+    }
+
+    if (!inhibit_profiling_info)
+    {
+        print_indent(); printf("Choosing window size %zu for %zu elements\n", window, num_scalars);
+    }
+
+#ifdef LOWMEM
+    window = std::min((size_t)14, window);
+#endif
+    return window;
+}
+
+template<typename T>
+window_table<T> get_window_table(const size_t scalar_size,
+                                 const size_t window,
+                                 const T &g)
+{
+    const size_t in_window = 1ul<<window;
+    const size_t outerc = (scalar_size+window-1)/window;
+    const size_t last_in_window = 1ul<<(scalar_size - (outerc-1)*window);
+#ifdef DEBUG
+    if (!inhibit_profiling_info)
+    {
+        print_indent(); printf("* scalar_size=%zu; window=%zu; in_window=%zu; outerc=%zu\n", scalar_size, window, in_window, outerc);
+    }
+#endif
+
+    window_table<T> powers_of_g(outerc, std::vector<T>(in_window, T::zero()));
+
+    T gouter = g;
+
+    for (size_t outer = 0; outer < outerc; ++outer)
+    {
+        T ginner = T::zero();
+        size_t cur_in_window = outer == outerc-1 ? last_in_window : in_window;
+        for (size_t inner = 0; inner < cur_in_window; ++inner)
+        {
+            powers_of_g[outer][inner] = ginner;
+            ginner = ginner + gouter;
+        }
+
+        for (size_t i = 0; i < window; ++i)
+        {
+            gouter = gouter + gouter;
+        }
+    }
+
+    return powers_of_g;
+}
+
+template<typename T, typename FieldT>
+T windowed_exp(const size_t scalar_size,
+               const size_t window,
+               const window_table<T> &powers_of_g,
+               const FieldT &pow)
+{
+    const size_t outerc = (scalar_size+window-1)/window;
+    const bigint<FieldT::num_limbs> pow_val = pow.as_bigint();
+
+    /* exp */
+    T res = powers_of_g[0][0];
+
+    for (size_t outer = 0; outer < outerc; ++outer)
+    {
+        size_t inner = 0;
+        for (size_t i = 0; i < window; ++i)
+        {
+            if (pow_val.test_bit(outer*window + i))
+            {
+                inner |= 1u << i;
+            }
+        }
+
+        res = res + powers_of_g[outer][inner];
+    }
+
+    return res;
+}
+
+template<typename T, typename FieldT>
+std::vector<T> batch_exp(const size_t scalar_size,
+                         const size_t window,
+                         const window_table<T> &table,
+                         const std::vector<FieldT> &v)
+{
+    if (!inhibit_profiling_info)
+    {
+        print_indent();
+    }
+    std::vector<T> res(v.size(), table[0][0]);
+
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+    for (size_t i = 0; i < v.size(); ++i)
+    {
+        res[i] = windowed_exp(scalar_size, window, table, v[i]);
+
+        if (!inhibit_profiling_info && (i % 10000 == 0))
+        {
+            printf(".");
+            fflush(stdout);
+        }
+    }
+
+    if (!inhibit_profiling_info)
+    {
+        printf(" DONE!\n");
+    }
+
+    return res;
+}
+
+template<typename T, typename FieldT>
+std::vector<T> batch_exp_with_coeff(const size_t scalar_size,
+                                    const size_t window,
+                                    const window_table<T> &table,
+                                    const FieldT &coeff,
+                                    const std::vector<FieldT> &v)
+{
+    if (!inhibit_profiling_info)
+    {
+        print_indent();
+    }
+    std::vector<T> res(v.size(), table[0][0]);
+
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+    for (size_t i = 0; i < v.size(); ++i)
+    {
+        res[i] = windowed_exp(scalar_size, window, table, coeff * v[i]);
+
+        if (!inhibit_profiling_info && (i % 10000 == 0))
+        {
+            printf(".");
+            fflush(stdout);
+        }
+    }
+
+    if (!inhibit_profiling_info)
+    {
+        printf(" DONE!\n");
+    }
+
+    return res;
+}
+
+template<typename T>
+void batch_to_special(std::vector<T> &vec)
+{
+    enter_block("Batch-convert elements to special form");
+
+    std::vector<T> non_zero_vec;
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        if (!vec[i].is_zero())
+        {
+            non_zero_vec.emplace_back(vec[i]);
+        }
+    }
+
+    batch_to_special_all_non_zeros<T>(non_zero_vec);
+    auto it = non_zero_vec.begin();
+    T zero_special = T::zero();
+    zero_special.to_special();
+
+    for (size_t i = 0; i < vec.size(); ++i)
+    {
+        if (!vec[i].is_zero())
+        {
+            vec[i] = *it;
+            ++it;
+        }
+        else
+        {
+            vec[i] = zero_special;
+        }
+    }
+    leave_block("Batch-convert elements to special form");
+}
+
+} // libsnark
+
+#endif // MULTIEXP_TCC_
diff --git a/src/algebra/scalar_multiplication/wnaf.hpp b/src/algebra/scalar_multiplication/wnaf.hpp
new file mode 100644 (file)
index 0000000..a7ecd59
--- /dev/null
@@ -0,0 +1,39 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for wNAF ("width-w Non-Adjacent Form") exponentiation routines.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef WNAF_HPP_
+#define WNAF_HPP_
+
+namespace libsnark {
+
+/**
+ * Find the wNAF representation of the given scalar relative to the given window size.
+ */
+template<mp_size_t n>
+std::vector<long> find_wnaf(const size_t window_size, const bigint<n> &scalar);
+
+/**
+ * In additive notation, use wNAF exponentiation (with the given window size) to compute scalar * base.
+ */
+template<typename T, mp_size_t n>
+T fixed_window_wnaf_exp(const size_t window_size, const T &base, const bigint<n> &scalar);
+
+/**
+ * In additive notation, use wNAF exponentiation (with the window size determined by T) to compute scalar * base.
+ */
+template<typename T, mp_size_t n>
+T opt_window_wnaf_exp(const T &base, const bigint<n> &scalar, const size_t scalar_bits);
+
+} // libsnark
+
+#include "algebra/scalar_multiplication/wnaf.tcc"
+
+#endif // WNAF_HPP_
diff --git a/src/algebra/scalar_multiplication/wnaf.tcc b/src/algebra/scalar_multiplication/wnaf.tcc
new file mode 100644 (file)
index 0000000..a5e47e8
--- /dev/null
@@ -0,0 +1,123 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for wNAF ("weighted Non-Adjacent Form") exponentiation routines.
+
+ See wnaf.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef WNAF_TCC_
+#define WNAF_TCC_
+
+namespace libsnark {
+
+template<mp_size_t n>
+std::vector<long> find_wnaf(const size_t window_size, const bigint<n> &scalar)
+{
+    const size_t length = scalar.max_bits(); // upper bound
+    std::vector<long> res(length+1);
+    bigint<n> c = scalar;
+    long j = 0;
+    while (!c.is_zero())
+    {
+        long u;
+        if ((c.data[0] & 1) == 1)
+        {
+            u = c.data[0] % (1u << (window_size+1));
+            if (u > (1 << window_size))
+            {
+                u = u - (1 << (window_size+1));
+            }
+
+            if (u > 0)
+            {
+                mpn_sub_1(c.data, c.data, n, u);
+            }
+            else
+            {
+                mpn_add_1(c.data, c.data, n, -u);
+            }
+        }
+        else
+        {
+            u = 0;
+        }
+        res[j] = u;
+        ++j;
+
+        mpn_rshift(c.data, c.data, n, 1); // c = c/2
+    }
+
+    return res;
+}
+
+template<typename T, mp_size_t n>
+T fixed_window_wnaf_exp(const size_t window_size, const T &base, const bigint<n> &scalar)
+{
+    std::vector<long> naf = find_wnaf(window_size, scalar);
+    std::vector<T> table(1ul<<(window_size-1));
+    T tmp = base;
+    T dbl = base.dbl();
+    for (size_t i = 0; i < 1ul<<(window_size-1); ++i)
+    {
+        table[i] = tmp;
+        tmp = tmp + dbl;
+    }
+
+    T res = T::zero();
+    bool found_nonzero = false;
+    for (long i = naf.size()-1; i >= 0; --i)
+    {
+        if (found_nonzero)
+        {
+            res = res.dbl();
+        }
+
+        if (naf[i] != 0)
+        {
+            found_nonzero = true;
+            if (naf[i] > 0)
+            {
+                res = res + table[naf[i]/2];
+            }
+            else
+            {
+                res = res - table[(-naf[i])/2];
+            }
+        }
+    }
+
+    return res;
+}
+
+template<typename T, mp_size_t n>
+T opt_window_wnaf_exp(const T &base, const bigint<n> &scalar, const size_t scalar_bits)
+{
+    size_t best = 0;
+    for (long i = T::wnaf_window_table.size() - 1; i >= 0; --i)
+    {
+        if (scalar_bits >= T::wnaf_window_table[i])
+        {
+            best = i+1;
+            break;
+        }
+    }
+
+    if (best > 0)
+    {
+        return fixed_window_wnaf_exp(best, base, scalar);
+    }
+    else
+    {
+        return scalar * base;
+    }
+}
+
+} // libsnark
+
+#endif // WNAF_TCC_
diff --git a/src/common/assert_except.hpp b/src/common/assert_except.hpp
new file mode 100644 (file)
index 0000000..7819230
--- /dev/null
@@ -0,0 +1,12 @@
+#ifndef ASSERT_except_H
+#define ASSERT_except_H
+
+#include <exception>
+
+inline void assert_except(bool condition) {
+    if (!condition) {
+        throw std::runtime_error("Assertion failed.");
+    }
+}
+
+#endif
diff --git a/src/common/data_structures/accumulation_vector.hpp b/src/common/data_structures/accumulation_vector.hpp
new file mode 100644 (file)
index 0000000..37e0c98
--- /dev/null
@@ -0,0 +1,74 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for an accumulation vector.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef ACCUMULATION_VECTOR_HPP_
+#define ACCUMULATION_VECTOR_HPP_
+
+#include "common/data_structures/sparse_vector.hpp"
+
+namespace libsnark {
+
+template<typename T>
+class accumulation_vector;
+
+template<typename T>
+std::ostream& operator<<(std::ostream &out, const accumulation_vector<T> &v);
+
+template<typename T>
+std::istream& operator>>(std::istream &in, accumulation_vector<T> &v);
+
+/**
+ * An accumulation vector comprises an accumulation value and a sparse vector.
+ * The method "accumulate_chunk" allows one to accumlate portions of the sparse
+ * vector into the accumualation value.
+ */
+template<typename T>
+class accumulation_vector {
+public:
+    T first;
+    sparse_vector<T> rest;
+
+    accumulation_vector() = default;
+    accumulation_vector(const accumulation_vector<T> &other) = default;
+    accumulation_vector(accumulation_vector<T> &&other) = default;
+    accumulation_vector(T &&first, sparse_vector<T> &&rest) : first(std::move(first)), rest(std::move(rest)) {};
+    accumulation_vector(T &&first, std::vector<T> &&v) : first(std::move(first)), rest(std::move(v)) {}
+    accumulation_vector(std::vector<T> &&v) : first(T::zero()), rest(std::move(v)) {};
+
+    accumulation_vector<T>& operator=(const accumulation_vector<T> &other) = default;
+    accumulation_vector<T>& operator=(accumulation_vector<T> &&other) = default;
+
+    bool operator==(const accumulation_vector<T> &other) const;
+
+    bool is_fully_accumulated() const;
+
+    size_t domain_size() const;
+    size_t size() const;
+    size_t size_in_bits() const;
+
+    template<typename FieldT>
+    accumulation_vector<T> accumulate_chunk(const typename std::vector<FieldT>::const_iterator &it_begin,
+                                            const typename std::vector<FieldT>::const_iterator &it_end,
+                                            const size_t offset) const;
+
+};
+
+template<typename T>
+std::ostream& operator<<(std::ostream &out, const accumulation_vector<T> &v);
+
+template<typename T>
+std::istream& operator>>(std::istream &in, accumulation_vector<T> &v);
+
+} // libsnark
+
+#include "common/data_structures/accumulation_vector.tcc"
+
+#endif // ACCUMULATION_VECTOR_HPP_
diff --git a/src/common/data_structures/accumulation_vector.tcc b/src/common/data_structures/accumulation_vector.tcc
new file mode 100644 (file)
index 0000000..9e524ab
--- /dev/null
@@ -0,0 +1,84 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for an accumulation vector.
+
+ See accumulation_vector.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef ACCUMULATION_VECTOR_TCC_
+#define ACCUMULATION_VECTOR_TCC_
+
+namespace libsnark {
+
+template<typename T>
+bool accumulation_vector<T>::operator==(const accumulation_vector<T> &other) const
+{
+    return (this->first == other.first && this->rest == other.rest);
+}
+
+template<typename T>
+bool accumulation_vector<T>::is_fully_accumulated() const
+{
+    return rest.empty();
+}
+
+template<typename T>
+size_t accumulation_vector<T>::domain_size() const
+{
+    return rest.domain_size();
+}
+
+template<typename T>
+size_t accumulation_vector<T>::size() const
+{
+    return rest.domain_size();
+}
+
+template<typename T>
+size_t accumulation_vector<T>::size_in_bits() const
+{
+    const size_t first_size_in_bits = T::size_in_bits();
+    const size_t rest_size_in_bits = rest.size_in_bits();
+    return first_size_in_bits + rest_size_in_bits;
+}
+
+template<typename T>
+template<typename FieldT>
+accumulation_vector<T> accumulation_vector<T>::accumulate_chunk(const typename std::vector<FieldT>::const_iterator &it_begin,
+                                                                const typename std::vector<FieldT>::const_iterator &it_end,
+                                                                const size_t offset) const
+{
+    std::pair<T, sparse_vector<T> > acc_result = rest.template accumulate<FieldT>(it_begin, it_end, offset);
+    T new_first = first + acc_result.first;
+    return accumulation_vector<T>(std::move(new_first), std::move(acc_result.second));
+}
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const accumulation_vector<T> &v)
+{
+    out << v.first << OUTPUT_NEWLINE;
+    out << v.rest << OUTPUT_NEWLINE;
+
+    return out;
+}
+
+template<typename T>
+std::istream& operator>>(std::istream& in, accumulation_vector<T> &v)
+{
+    in >> v.first;
+    consume_OUTPUT_NEWLINE(in);
+    in >> v.rest;
+    consume_OUTPUT_NEWLINE(in);
+
+    return in;
+}
+
+} // libsnark
+
+#endif // ACCUMULATION_VECTOR_TCC_
diff --git a/src/common/data_structures/merkle_tree.hpp b/src/common/data_structures/merkle_tree.hpp
new file mode 100644 (file)
index 0000000..6f0c851
--- /dev/null
@@ -0,0 +1,71 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for a Merkle tree.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_TREE_HPP_
+#define MERKLE_TREE_HPP_
+
+#include <map>
+#include <vector>
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+/**
+ * A Merkle tree is maintained as two maps:
+ * - a map from addresses to values, and
+ * - a map from addresses to hashes.
+ *
+ * The second map maintains the intermediate hashes of a Merkle tree
+ * built atop the values currently stored in the tree (the
+ * implementation admits a very efficient support for sparse
+ * trees). Besides offering methods to load and store values, the
+ * class offers methods to retrieve the root of the Merkle tree and to
+ * obtain the authentication paths for (the value at) a given address.
+ */
+
+typedef bit_vector merkle_authentication_node;
+typedef std::vector<merkle_authentication_node> merkle_authentication_path;
+
+template<typename HashT>
+class merkle_tree {
+private:
+
+    typedef typename HashT::hash_value_type hash_value_type;
+    typedef typename HashT::merkle_authentication_path_type merkle_authentication_path_type;
+
+public:
+
+    std::vector<hash_value_type> hash_defaults;
+    std::map<size_t, bit_vector> values;
+    std::map<size_t, hash_value_type> hashes;
+
+    size_t depth;
+    size_t value_size;
+    size_t digest_size;
+
+    merkle_tree(const size_t depth, const size_t value_size);
+    merkle_tree(const size_t depth, const size_t value_size, const std::vector<bit_vector> &contents_as_vector);
+    merkle_tree(const size_t depth, const size_t value_size, const std::map<size_t, bit_vector> &contents);
+
+    bit_vector get_value(const size_t address) const;
+    void set_value(const size_t address, const bit_vector &value);
+
+    hash_value_type get_root() const;
+    merkle_authentication_path_type get_path(const size_t address) const;
+
+    void dump() const;
+};
+
+} // libsnark
+
+#include "common/data_structures/merkle_tree.tcc"
+
+#endif // MERKLE_TREE_HPP_
diff --git a/src/common/data_structures/merkle_tree.tcc b/src/common/data_structures/merkle_tree.tcc
new file mode 100644 (file)
index 0000000..281700b
--- /dev/null
@@ -0,0 +1,246 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for Merkle tree.
+
+ See merkle_tree.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_TREE_TCC
+#define MERKLE_TREE_TCC
+
+#include <algorithm>
+
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+template<typename HashT>
+typename HashT::hash_value_type two_to_one_CRH(const typename HashT::hash_value_type &l,
+                                               const typename HashT::hash_value_type &r)
+{
+    typename HashT::hash_value_type new_input;
+    new_input.insert(new_input.end(), l.begin(), l.end());
+    new_input.insert(new_input.end(), r.begin(), r.end());
+
+    const size_t digest_size = HashT::get_digest_len();
+    assert(l.size() == digest_size);
+    assert(r.size() == digest_size);
+
+    return HashT::get_hash(new_input);
+}
+
+template<typename HashT>
+merkle_tree<HashT>::merkle_tree(const size_t depth, const size_t value_size) :
+    depth(depth), value_size(value_size)
+{
+    assert(depth < sizeof(size_t) * 8);
+
+    digest_size = HashT::get_digest_len();
+    assert(value_size <= digest_size);
+
+    hash_value_type last(digest_size);
+    hash_defaults.reserve(depth+1);
+    hash_defaults.emplace_back(last);
+    for (size_t i = 0; i < depth; ++i)
+    {
+        last = two_to_one_CRH<HashT>(last, last);
+        hash_defaults.emplace_back(last);
+    }
+
+    std::reverse(hash_defaults.begin(), hash_defaults.end());
+}
+
+template<typename HashT>
+merkle_tree<HashT>::merkle_tree(const size_t depth,
+                                const size_t value_size,
+                                const std::vector<bit_vector> &contents_as_vector) :
+    merkle_tree<HashT>(depth, value_size)
+{
+    assert(log2(contents_as_vector.size()) <= depth);
+    for (size_t address = 0; address < contents_as_vector.size(); ++address)
+    {
+        const size_t idx = address + (1ul<<depth) - 1;
+        values[idx] = contents_as_vector[address];
+        hashes[idx] = contents_as_vector[address];
+        hashes[idx].resize(digest_size);
+    }
+
+    size_t idx_begin = (1ul<<depth) - 1;
+    size_t idx_end = contents_as_vector.size() + ((1ul<<depth) - 1);
+
+    for (int layer = depth; layer > 0; --layer)
+    {
+        for (size_t idx = idx_begin; idx < idx_end; idx += 2)
+        {
+            hash_value_type l = hashes[idx]; // this is sound, because idx_begin is always a left child
+            hash_value_type r = (idx + 1 < idx_end ? hashes[idx+1] : hash_defaults[layer]);
+
+            hash_value_type h = two_to_one_CRH<HashT>(l, r);
+            hashes[(idx-1)/2] = h;
+        }
+
+        idx_begin = (idx_begin-1)/2;
+        idx_end = (idx_end-1)/2;
+    }
+}
+
+template<typename HashT>
+merkle_tree<HashT>::merkle_tree(const size_t depth,
+                                const size_t value_size,
+                                const std::map<size_t, bit_vector> &contents) :
+    merkle_tree<HashT>(depth, value_size)
+{
+
+    if (!contents.empty())
+    {
+        assert(contents.rbegin()->first < 1ul<<depth);
+
+        for (auto it = contents.begin(); it != contents.end(); ++it)
+        {
+            const size_t address = it->first;
+            const bit_vector value = it->second;
+            const size_t idx = address + (1ul<<depth) - 1;
+
+            values[address] = value;
+            hashes[idx] = value;
+            hashes[idx].resize(digest_size);
+        }
+
+        auto last_it = hashes.end();
+
+        for (int layer = depth; layer > 0; --layer)
+        {
+            auto next_last_it = hashes.begin();
+
+            for (auto it = hashes.begin(); it != last_it; ++it)
+            {
+                const size_t idx = it->first;
+                const hash_value_type hash = it->second;
+
+                if (idx % 2 == 0)
+                {
+                    // this is the right child of its parent and by invariant we are missing the left child
+                    hashes[(idx-1)/2] = two_to_one_CRH<HashT>(hash_defaults[layer], hash);
+                }
+                else
+                {
+                    if (std::next(it) == last_it || std::next(it)->first != idx + 1)
+                    {
+                        // this is the left child of its parent and is missing its right child
+                        hashes[(idx-1)/2] = two_to_one_CRH<HashT>(hash, hash_defaults[layer]);
+                    }
+                    else
+                    {
+                        // typical case: this is the left child of the parent and adjecent to it there is a right child
+                        hashes[(idx-1)/2] = two_to_one_CRH<HashT>(hash, std::next(it)->second);
+                        ++it;
+                    }
+                }
+            }
+
+            last_it = next_last_it;
+        }
+    }
+}
+
+template<typename HashT>
+bit_vector merkle_tree<HashT>::get_value(const size_t address) const
+{
+    assert(log2(address) <= depth);
+
+    auto it = values.find(address);
+    bit_vector padded_result = (it == values.end() ? bit_vector(digest_size) : it->second);
+    padded_result.resize(value_size);
+
+    return padded_result;
+}
+
+template<typename HashT>
+void merkle_tree<HashT>::set_value(const size_t address,
+                                   const bit_vector &value)
+{
+    assert(log2(address) <= depth);
+    size_t idx = address + (1ul<<depth) - 1;
+
+    assert(value.size() == value_size);
+    values[address] = value;
+    hashes[idx] = value;
+    hashes[idx].resize(digest_size);
+
+    for (int layer = depth-1; layer >=0; --layer)
+    {
+        idx = (idx-1)/2;
+
+        auto it = hashes.find(2*idx+1);
+        hash_value_type l = (it == hashes.end() ? hash_defaults[layer+1] : it->second);
+
+        it = hashes.find(2*idx+2);
+        hash_value_type r = (it == hashes.end() ? hash_defaults[layer+1] : it->second);
+
+        hash_value_type h = two_to_one_CRH<HashT>(l, r);
+        hashes[idx] = h;
+    }
+}
+
+template<typename HashT>
+typename HashT::hash_value_type merkle_tree<HashT>::get_root() const
+{
+    auto it = hashes.find(0);
+    return (it == hashes.end() ? hash_defaults[0] : it->second);
+}
+
+template<typename HashT>
+typename HashT::merkle_authentication_path_type merkle_tree<HashT>::get_path(const size_t address) const
+{
+    typename HashT::merkle_authentication_path_type result(depth);
+    assert(log2(address) <= depth);
+    size_t idx = address + (1ul<<depth) - 1;
+
+    for (size_t layer = depth; layer > 0; --layer)
+    {
+        size_t sibling_idx = ((idx + 1) ^ 1) - 1;
+        auto it = hashes.find(sibling_idx);
+        if (layer == depth)
+        {
+            auto it2 = values.find(sibling_idx - ((1ul<<depth) - 1));
+            result[layer-1] = (it2 == values.end() ? bit_vector(value_size, false) : it2->second);
+            result[layer-1].resize(digest_size);
+        }
+        else
+        {
+            result[layer-1] = (it == hashes.end() ? hash_defaults[layer] : it->second);
+        }
+
+        idx = (idx-1)/2;
+    }
+
+    return result;
+}
+
+template<typename HashT>
+void merkle_tree<HashT>::dump() const
+{
+    for (size_t i = 0; i < 1ul<<depth; ++i)
+    {
+        auto it = values.find(i);
+        printf("[%zu] -> ", i);
+        const bit_vector value = (it == values.end() ? bit_vector(value_size) : it->second);
+        for (bool b : value)
+        {
+            printf("%d", b ? 1 : 0);
+        }
+        printf("\n");
+    }
+    printf("\n");
+}
+
+} // libsnark
+
+#endif // MERKLE_TREE_TCC
diff --git a/src/common/data_structures/sparse_vector.hpp b/src/common/data_structures/sparse_vector.hpp
new file mode 100644 (file)
index 0000000..8b134f4
--- /dev/null
@@ -0,0 +1,79 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for a sparse vector.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SPARSE_VECTOR_HPP_
+#define SPARSE_VECTOR_HPP_
+
+#include <vector>
+
+namespace libsnark {
+
+template<typename T>
+struct sparse_vector;
+
+template<typename T>
+std::ostream& operator<<(std::ostream &out, const sparse_vector<T> &v);
+
+template<typename T>
+std::istream& operator>>(std::istream &in, sparse_vector<T> &v);
+
+/**
+ * A sparse vector is a list of indices along with corresponding values.
+ * The indices are selected from the set {0,1,...,domain_size-1}.
+ */
+template<typename T>
+struct sparse_vector {
+
+    std::vector<size_t> indices;
+    std::vector<T> values;
+    size_t domain_size_ = 0;
+
+    sparse_vector() = default;
+    sparse_vector(const sparse_vector<T> &other) = default;
+    sparse_vector(sparse_vector<T> &&other) = default;
+    sparse_vector(std::vector<T> &&v); /* constructor from std::vector */
+
+    sparse_vector<T>& operator=(const sparse_vector<T> &other) = default;
+    sparse_vector<T>& operator=(sparse_vector<T> &&other) = default;
+
+    T operator[](const size_t idx) const;
+
+    bool operator==(const sparse_vector<T> &other) const;
+    bool operator==(const std::vector<T> &other) const;
+
+    bool is_valid() const;
+    bool empty() const;
+
+    size_t domain_size() const; // return domain_size_
+    size_t size() const; // return the number of indices (representing the number of non-zero entries)
+    size_t size_in_bits() const; // return the number bits needed to store the sparse vector
+
+    /* return a pair consisting of the accumulated value and the sparse vector of non-accumuated values */
+    template<typename FieldT>
+    std::pair<T, sparse_vector<T> > accumulate(const typename std::vector<FieldT>::const_iterator &it_begin,
+                                               const typename std::vector<FieldT>::const_iterator &it_end,
+                                               const size_t offset) const;
+
+    friend std::ostream& operator<< <T>(std::ostream &out, const sparse_vector<T> &v);
+    friend std::istream& operator>> <T>(std::istream &in, sparse_vector<T> &v);
+};
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const sparse_vector<T> &v);
+
+template<typename T>
+std::istream& operator>>(std::istream& in, sparse_vector<T> &v);
+
+} // libsnark
+
+#include "common/data_structures/sparse_vector.tcc"
+
+#endif // SPARSE_VECTOR_HPP_
diff --git a/src/common/data_structures/sparse_vector.tcc b/src/common/data_structures/sparse_vector.tcc
new file mode 100644 (file)
index 0000000..cfc5d75
--- /dev/null
@@ -0,0 +1,316 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for a sparse vector.
+
+ See sparse_vector.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SPARSE_VECTOR_TCC_
+#define SPARSE_VECTOR_TCC_
+
+#include "algebra/scalar_multiplication/multiexp.hpp"
+
+#include <numeric>
+
+namespace libsnark {
+
+template<typename T>
+sparse_vector<T>::sparse_vector(std::vector<T> &&v) :
+    values(std::move(v)), domain_size_(values.size())
+{
+    indices.resize(domain_size_);
+    std::iota(indices.begin(), indices.end(), 0);
+}
+
+template<typename T>
+T sparse_vector<T>::operator[](const size_t idx) const
+{
+    auto it = std::lower_bound(indices.begin(), indices.end(), idx);
+    return (it != indices.end() && *it == idx) ? values[it - indices.begin()] : T();
+}
+
+template<typename T>
+bool sparse_vector<T>::operator==(const sparse_vector<T> &other) const
+{
+    if (this->domain_size_ != other.domain_size_)
+    {
+        return false;
+    }
+
+    size_t this_pos = 0, other_pos = 0;
+    while (this_pos < this->indices.size() && other_pos < other.indices.size())
+    {
+        if (this->indices[this_pos] == other.indices[other_pos])
+        {
+            if (this->values[this_pos] != other.values[other_pos])
+            {
+                return false;
+            }
+            ++this_pos;
+            ++other_pos;
+        }
+        else if (this->indices[this_pos] < other.indices[other_pos])
+        {
+            if (!this->values[this_pos].is_zero())
+            {
+                return false;
+            }
+            ++this_pos;
+        }
+        else
+        {
+            if (!other.values[other_pos].is_zero())
+            {
+                return false;
+            }
+            ++other_pos;
+        }
+    }
+
+    /* at least one of the vectors has been exhausted, so other must be empty */
+    while (this_pos < this->indices.size())
+    {
+        if (!this->values[this_pos].is_zero())
+        {
+            return false;
+        }
+        ++this_pos;
+    }
+
+    while (other_pos < other.indices.size())
+    {
+        if (!other.values[other_pos].is_zero())
+        {
+            return false;
+        }
+        ++other_pos;
+    }
+
+    return true;
+}
+
+template<typename T>
+bool sparse_vector<T>::operator==(const std::vector<T> &other) const
+{
+    if (this->domain_size_ < other.size())
+    {
+        return false;
+    }
+
+    size_t j = 0;
+    for (size_t i = 0; i < other.size(); ++i)
+    {
+        if (this->indices[j] == i)
+        {
+            if (this->values[j] != other[j])
+            {
+                return false;
+            }
+            ++j;
+        }
+        else
+        {
+            if (!other[j].is_zero())
+            {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+template<typename T>
+bool sparse_vector<T>::is_valid() const
+{
+    if (values.size() == indices.size() && values.size() <= domain_size_)
+    {
+        return false;
+    }
+
+    for (size_t i = 0; i + 1 < indices.size(); ++i)
+    {
+        if (indices[i] >= indices[i+1])
+        {
+            return false;
+        }
+    }
+
+    if (!indices.empty() && indices[indices.size()-1] >= domain_size_)
+    {
+        return false;
+    }
+
+    return true;
+}
+
+template<typename T>
+bool sparse_vector<T>::empty() const
+{
+    return indices.empty();
+}
+
+template<typename T>
+size_t sparse_vector<T>::domain_size() const
+{
+    return domain_size_;
+}
+
+template<typename T>
+size_t sparse_vector<T>::size() const
+{
+    return indices.size();
+}
+
+template<typename T>
+size_t sparse_vector<T>::size_in_bits() const
+{
+    return indices.size() * (sizeof(size_t) * 8 + T::size_in_bits());
+}
+
+template<typename T>
+template<typename FieldT>
+std::pair<T, sparse_vector<T> > sparse_vector<T>::accumulate(const typename std::vector<FieldT>::const_iterator &it_begin,
+                                                             const typename std::vector<FieldT>::const_iterator &it_end,
+                                                             const size_t offset) const
+{
+    // TODO: does not really belong here.
+    const size_t chunks = 1;
+    const bool use_multiexp = true;
+
+    T accumulated_value = T::zero();
+    sparse_vector<T> resulting_vector;
+    resulting_vector.domain_size_ = domain_size_;
+
+    const size_t range_len = it_end - it_begin;
+    bool in_block = false;
+    size_t first_pos = -1, last_pos = -1; // g++ -flto emits unitialized warning, even though in_block guards for such cases.
+
+    for (size_t i = 0; i < indices.size(); ++i)
+    {
+        const bool matching_pos = (offset <= indices[i] && indices[i] < offset + range_len);
+        // printf("i = %zu, pos[i] = %zu, offset = %zu, w_size = %zu\n", i, indices[i], offset, w_size);
+        bool copy_over;
+
+        if (in_block)
+        {
+            if (matching_pos && last_pos == i-1)
+            {
+                // block can be extended, do it
+                last_pos = i;
+                copy_over = false;
+            }
+            else
+            {
+                // block has ended here
+                in_block = false;
+                copy_over = true;
+
+#ifdef DEBUG
+                print_indent(); printf("doing multiexp for w_%zu ... w_%zu\n", indices[first_pos], indices[last_pos]);
+#endif
+                accumulated_value = accumulated_value + multi_exp<T, FieldT>(values.begin() + first_pos,
+                                                                             values.begin() + last_pos + 1,
+                                                                             it_begin + (indices[first_pos] - offset),
+                                                                             it_begin + (indices[last_pos] - offset) + 1,
+                                                                             chunks, use_multiexp);
+            }
+        }
+        else
+        {
+            if (matching_pos)
+            {
+                // block can be started
+                first_pos = i;
+                last_pos = i;
+                in_block = true;
+                copy_over = false;
+            }
+            else
+            {
+                copy_over = true;
+            }
+        }
+
+        if (copy_over)
+        {
+            resulting_vector.indices.emplace_back(indices[i]);
+            resulting_vector.values.emplace_back(values[i]);
+        }
+    }
+
+    if (in_block)
+    {
+#ifdef DEBUG
+        print_indent(); printf("doing multiexp for w_%zu ... w_%zu\n", indices[first_pos], indices[last_pos]);
+#endif
+        accumulated_value = accumulated_value + multi_exp<T, FieldT>(values.begin() + first_pos,
+                                                                     values.begin() + last_pos + 1,
+                                                                     it_begin + (indices[first_pos] - offset),
+                                                                     it_begin + (indices[last_pos] - offset) + 1,
+                                                                     chunks, use_multiexp);
+    }
+
+    return std::make_pair(accumulated_value, resulting_vector);
+}
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const sparse_vector<T> &v)
+{
+    out << v.domain_size_ << "\n";
+    out << v.indices.size() << "\n";
+    for (const size_t& i : v.indices)
+    {
+        out << i << "\n";
+    }
+
+    out << v.values.size() << "\n";
+    for (const T& t : v.values)
+    {
+        out << t << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+template<typename T>
+std::istream& operator>>(std::istream& in, sparse_vector<T> &v)
+{
+    in >> v.domain_size_;
+    consume_newline(in);
+
+    size_t s;
+    in >> s;
+    consume_newline(in);
+    v.indices.resize(s);
+    for (size_t i = 0; i < s; ++i)
+    {
+        in >> v.indices[i];
+        consume_newline(in);
+    }
+
+    v.values.clear();
+    in >> s;
+    consume_newline(in);
+    v.values.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        T t;
+        in >> t;
+        consume_OUTPUT_NEWLINE(in);
+        v.values.emplace_back(t);
+    }
+
+    return in;
+}
+
+} // libsnark
+
+#endif // SPARSE_VECTOR_TCC_
diff --git a/src/common/default_types/ec_pp.hpp b/src/common/default_types/ec_pp.hpp
new file mode 100644 (file)
index 0000000..b08c2da
--- /dev/null
@@ -0,0 +1,53 @@
+/** @file
+ *****************************************************************************
+
+ This file defines default_ec_pp based on the CURVE=... make flag, which selects
+ which elliptic curve is used to implement group arithmetic and pairings.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef EC_PP_HPP_
+#define EC_PP_HPP_
+
+/************************ Pick the elliptic curve ****************************/
+
+#ifdef CURVE_ALT_BN128
+#include "algebra/curves/alt_bn128/alt_bn128_pp.hpp"
+namespace libsnark {
+typedef alt_bn128_pp default_ec_pp;
+} // libsnark
+#endif
+
+#ifdef CURVE_BN128
+#include "algebra/curves/bn128/bn128_pp.hpp"
+namespace libsnark {
+typedef bn128_pp default_ec_pp;
+} // libsnark
+#endif
+
+#ifdef CURVE_EDWARDS
+#include "algebra/curves/edwards/edwards_pp.hpp"
+namespace libsnark {
+typedef edwards_pp default_ec_pp;
+} // libsnark
+#endif
+
+#ifdef CURVE_MNT4
+#include "algebra/curves/mnt/mnt4/mnt4_pp.hpp"
+namespace libsnark {
+typedef mnt4_pp default_ec_pp;
+} // libsnark
+#endif
+
+#ifdef CURVE_MNT6
+#include "algebra/curves/mnt/mnt6/mnt6_pp.hpp"
+namespace libsnark {
+typedef mnt6_pp default_ec_pp;
+} // libsnark
+#endif
+
+#endif // EC_PP_HPP_
diff --git a/src/common/default_types/r1cs_ppzksnark_pp.hpp b/src/common/default_types/r1cs_ppzksnark_pp.hpp
new file mode 100644 (file)
index 0000000..c819b4a
--- /dev/null
@@ -0,0 +1,22 @@
+/** @file
+ *****************************************************************************
+
+ This file defines default_r1cs_ppzksnark_pp based on the elliptic curve
+ choice selected in ec_pp.hpp.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_PPZKSNARK_PP_HPP_
+#define R1CS_PPZKSNARK_PP_HPP_
+
+#include "common/default_types/ec_pp.hpp"
+
+namespace libsnark {
+typedef default_ec_pp default_r1cs_ppzksnark_pp;
+} // libsnark
+
+#endif // R1CS_PPZKSNARK_PP_HPP_
diff --git a/src/common/profiling.cpp b/src/common/profiling.cpp
new file mode 100644 (file)
index 0000000..d227203
--- /dev/null
@@ -0,0 +1,379 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of functions for profiling code blocks.
+
+ See profiling.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "common/profiling.hpp"
+#include <cassert>
+#include <stdexcept>
+#include <chrono>
+#include <cstdio>
+#include <list>
+#include <vector>
+#include <ctime>
+#include "common/default_types/ec_pp.hpp"
+#include "common/utils.hpp"
+
+#ifndef NO_PROCPS
+#include <proc/readproc.h>
+#endif
+
+namespace libsnark {
+
+long long get_nsec_time()
+{
+    auto timepoint = std::chrono::high_resolution_clock::now();
+    return std::chrono::duration_cast<std::chrono::nanoseconds>(timepoint.time_since_epoch()).count();
+}
+
+/* Return total CPU time consumsed by all threads of the process, in nanoseconds. */
+long long get_nsec_cpu_time()
+{
+    ::timespec ts;
+    if ( ::clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts) )
+        throw ::std::runtime_error("clock_gettime(CLOCK_PROCESS_CPUTIME_ID) failed");
+        // If we expected this to work, don't silently ignore failures, because that would hide the problem and incur an unnecessarily system-call overhead. So if we ever observe this exception, we should probably add a suitable #ifdef .
+        //TODO: clock_gettime(CLOCK_PROCESS_CPUTIME_ID) is not supported by native Windows. What about Cygwin? Should we #ifdef on CLOCK_PROCESS_CPUTIME_ID or on __linux__?
+    return ts.tv_sec * 1000000000ll + ts.tv_nsec;
+}
+
+long long start_time, last_time;
+long long start_cpu_time, last_cpu_time;
+
+void start_profiling()
+{
+    printf("Reset time counters for profiling\n");
+
+    last_time = start_time = get_nsec_time();
+    last_cpu_time = start_cpu_time = get_nsec_cpu_time();
+}
+
+std::map<std::string, size_t> invocation_counts;
+std::map<std::string, long long> enter_times;
+std::map<std::string, long long> last_times;
+std::map<std::string, long long> cumulative_times;
+//TODO: Instead of analogous maps for time and cpu_time, use a single struct-valued map
+std::map<std::string, long long> enter_cpu_times;
+std::map<std::string, long long> last_cpu_times;
+std::map<std::pair<std::string, std::string>, long long> op_counts;
+std::map<std::pair<std::string, std::string>, long long> cumulative_op_counts; // ((msg, data_point), value)
+    // TODO: Convert op_counts and cumulative_op_counts from pair to structs
+size_t indentation = 0;
+
+std::vector<std::string> block_names;
+
+std::list<std::pair<std::string, long long*> > op_data_points = {
+#ifdef PROFILE_OP_COUNTS
+    std::make_pair("Fradd", &Fr<default_ec_pp>::add_cnt),
+    std::make_pair("Frsub", &Fr<default_ec_pp>::sub_cnt),
+    std::make_pair("Frmul", &Fr<default_ec_pp>::mul_cnt),
+    std::make_pair("Frinv", &Fr<default_ec_pp>::inv_cnt),
+    std::make_pair("Fqadd", &Fq<default_ec_pp>::add_cnt),
+    std::make_pair("Fqsub", &Fq<default_ec_pp>::sub_cnt),
+    std::make_pair("Fqmul", &Fq<default_ec_pp>::mul_cnt),
+    std::make_pair("Fqinv", &Fq<default_ec_pp>::inv_cnt),
+    std::make_pair("G1add", &G1<default_ec_pp>::add_cnt),
+    std::make_pair("G1dbl", &G1<default_ec_pp>::dbl_cnt),
+    std::make_pair("G2add", &G2<default_ec_pp>::add_cnt),
+    std::make_pair("G2dbl", &G2<default_ec_pp>::dbl_cnt)
+#endif
+};
+
+bool inhibit_profiling_info = false;
+bool inhibit_profiling_counters = false;
+
+void clear_profiling_counters()
+{
+    invocation_counts.clear();
+    last_times.clear();
+    last_cpu_times.clear();
+    cumulative_times.clear();
+}
+
+void print_cumulative_time_entry(const std::string &key, const long long factor)
+{
+    const double total_ms = (cumulative_times.at(key) * 1e-6);
+    const size_t cnt = invocation_counts.at(key);
+    const double avg_ms = total_ms / cnt;
+    printf("   %-45s: %12.5fms = %lld * %0.5fms (%zu invocations, %0.5fms = %lld * %0.5fms per invocation)\n", key.c_str(), total_ms, factor, total_ms/factor, cnt, avg_ms, factor, avg_ms/factor);
+}
+
+void print_cumulative_times(const long long factor)
+{
+    printf("Dumping times:\n");
+    for (auto& kv : cumulative_times)
+    {
+        print_cumulative_time_entry(kv.first, factor);
+    }
+}
+
+void print_cumulative_op_counts(const bool only_fq)
+{
+#ifdef PROFILE_OP_COUNTS
+    printf("Dumping operation counts:\n");
+    for (auto& msg : invocation_counts)
+    {
+        printf("  %-45s: ", msg.first.c_str());
+        bool first = true;
+        for (auto& data_point : op_data_points)
+        {
+            if (only_fq && data_point.first.compare(0, 2, "Fq") != 0)
+            {
+                continue;
+            }
+
+            if (!first)
+            {
+                printf(", ");
+            }
+            printf("%-5s = %7.0f (%3zu)",
+                   data_point.first.c_str(),
+                   1. * cumulative_op_counts[std::make_pair(msg.first, data_point.first)] / msg.second,
+                   msg.second);
+            first = false;
+        }
+        printf("\n");
+    }
+#else
+    UNUSED(only_fq);
+#endif
+}
+
+void print_op_profiling(const std::string &msg)
+{
+#ifdef PROFILE_OP_COUNTS
+    printf("\n");
+    print_indent();
+
+    printf("(opcounts) = (");
+    bool first = true;
+    for (std::pair<std::string, long long*> p : op_data_points)
+    {
+        if (!first)
+        {
+            printf(", ");
+        }
+
+        printf("%s=%lld", p.first.c_str(), *(p.second)-op_counts[std::make_pair(msg, p.first)]);
+        first = false;
+    }
+    printf(")");
+#else
+    UNUSED(msg);
+#endif
+}
+
+static void print_times_from_last_and_start(long long     now, long long     last,
+                                            long long cpu_now, long long cpu_last)
+{
+    long long time_from_start = now - start_time;
+    long long time_from_last = now - last;
+
+    long long cpu_time_from_start = cpu_now - start_cpu_time;
+    long long cpu_time_from_last = cpu_now - cpu_last;
+
+    if (time_from_last != 0) {
+        double parallelism_from_last = 1.0 * cpu_time_from_last / time_from_last;
+        printf("[%0.4fs x%0.2f]", time_from_last * 1e-9, parallelism_from_last);
+    } else {
+        printf("[             ]");
+    }
+    if (time_from_start != 0) {
+        double parallelism_from_start = 1.0 * cpu_time_from_start / time_from_start;
+        printf("\t(%0.4fs x%0.2f from start)", time_from_start * 1e-9, parallelism_from_start);
+    }
+}
+
+void print_time(const char* msg)
+{
+    if (inhibit_profiling_info)
+    {
+        return;
+    }
+
+    long long now = get_nsec_time();
+    long long cpu_now = get_nsec_cpu_time();
+
+    printf("%-35s\t", msg);
+    print_times_from_last_and_start(now, last_time, cpu_now, last_cpu_time);
+#ifdef PROFILE_OP_COUNTS
+    print_op_profiling(msg);
+#endif
+    printf("\n");
+
+    fflush(stdout);
+    last_time = now;
+    last_cpu_time = cpu_now;
+}
+
+void print_header(const char *msg)
+{
+    printf("\n================================================================================\n");
+    printf("%s\n", msg);
+    printf("================================================================================\n\n");
+}
+
+void print_indent()
+{
+    for (size_t i = 0; i < indentation; ++i)
+    {
+        printf("  ");
+    }
+}
+
+void op_profiling_enter(const std::string &msg)
+{
+    for (std::pair<std::string, long long*> p : op_data_points)
+    {
+        op_counts[std::make_pair(msg, p.first)] = *(p.second);
+    }
+}
+
+void enter_block(const std::string &msg, const bool indent)
+{
+    if (inhibit_profiling_counters)
+    {
+        return;
+    }
+
+    block_names.emplace_back(msg);
+    long long t = get_nsec_time();
+    enter_times[msg] = t;
+    long long cpu_t = get_nsec_cpu_time();
+    enter_cpu_times[msg] = cpu_t;
+
+    if (inhibit_profiling_info)
+    {
+        return;
+    }
+
+#ifdef MULTICORE
+#pragma omp critical
+#endif
+    {
+        op_profiling_enter(msg);
+
+        print_indent();
+        printf("(enter) %-35s\t", msg.c_str());
+        print_times_from_last_and_start(t, t, cpu_t, cpu_t);
+        printf("\n");
+        fflush(stdout);
+
+        if (indent)
+        {
+            ++indentation;
+        }
+    }
+}
+
+void leave_block(const std::string &msg, const bool indent)
+{
+    if (inhibit_profiling_counters)
+    {
+        return;
+    }
+
+#ifndef MULTICORE
+    assert(*(--block_names.end()) == msg);
+#endif
+    block_names.pop_back();
+
+    ++invocation_counts[msg];
+
+    long long t = get_nsec_time();
+    last_times[msg] = (t - enter_times[msg]);
+    cumulative_times[msg] += (t - enter_times[msg]);
+
+    long long cpu_t = get_nsec_cpu_time();
+    last_cpu_times[msg] = (cpu_t - enter_cpu_times[msg]);
+
+#ifdef PROFILE_OP_COUNTS
+    for (std::pair<std::string, long long*> p : op_data_points)
+    {
+        cumulative_op_counts[std::make_pair(msg, p.first)] += *(p.second)-op_counts[std::make_pair(msg, p.first)];
+    }
+#endif
+
+    if (inhibit_profiling_info)
+    {
+        return;
+    }
+
+#ifdef MULTICORE
+#pragma omp critical
+#endif
+    {
+        if (indent)
+        {
+            --indentation;
+        }
+
+        print_indent();
+        printf("(leave) %-35s\t", msg.c_str());
+        print_times_from_last_and_start(t, enter_times[msg], cpu_t, enter_cpu_times[msg]);
+        print_op_profiling(msg);
+        printf("\n");
+        fflush(stdout);
+    }
+}
+
+void print_mem(const std::string &s)
+{
+#ifndef NO_PROCPS
+    struct proc_t usage;
+    look_up_our_self(&usage);
+    if (s.empty())
+    {
+        printf("* Peak vsize (physical memory+swap) in mebibytes: %lu\n", usage.vsize >> 20);
+    }
+    else
+    {
+        printf("* Peak vsize (physical memory+swap) in mebibytes (%s): %lu\n", s.c_str(), usage.vsize >> 20);
+    }
+#else
+    printf("* Memory profiling not supported in NO_PROCPS mode\n");
+#endif
+}
+
+void print_compilation_info()
+{
+#ifdef __GNUC__
+    printf("g++ version: %s\n", __VERSION__);
+    //printf("Compiled on %s %s\n", __DATE__, __TIME__);
+#endif
+#ifdef STATIC
+    printf("STATIC: yes\n");
+#else
+    printf("STATIC: no\n");
+#endif
+#ifdef MULTICORE
+    printf("MULTICORE: yes\n");
+#else
+    printf("MULTICORE: no\n");
+#endif
+#ifdef DEBUG
+    printf("DEBUG: yes\n");
+#else
+    printf("DEBUG: no\n");
+#endif
+#ifdef PROFILE_OP_COUNTS
+    printf("PROFILE_OP_COUNTS: yes\n");
+#else
+    printf("PROFILE_OP_COUNTS: no\n");
+#endif
+#ifdef _GLIBCXX_DEBUG
+    printf("_GLIBCXX_DEBUG: yes\n");
+#else
+    printf("_GLIBCXX_DEBUG: no\n");
+#endif
+}
+
+} // libsnark
diff --git a/src/common/profiling.hpp b/src/common/profiling.hpp
new file mode 100644 (file)
index 0000000..9619117
--- /dev/null
@@ -0,0 +1,51 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of functions for profiling code blocks.
+
+ Reports time, operation counts, memory usage, and others.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef PROFILING_HPP_
+#define PROFILING_HPP_
+
+#include <cstddef>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace libsnark {
+
+void start_profiling();
+long long get_nsec_time();
+void print_time(const char* msg);
+void print_header(const char* msg);
+
+void print_indent();
+
+extern bool inhibit_profiling_info;
+extern bool inhibit_profiling_counters;
+extern std::map<std::string, size_t> invocation_counts;
+extern std::map<std::string, long long> last_times;
+extern std::map<std::string, long long> cumulative_times;
+
+void clear_profiling_counters();
+
+void print_cumulative_time_entry(const std::string &key, const long long factor=1);
+void print_cumulative_times(const long long factor=1);
+void print_cumulative_op_counts(const bool only_fq=false);
+
+void enter_block(const std::string &msg, const bool indent=true);
+void leave_block(const std::string &msg, const bool indent=true);
+
+void print_mem(const std::string &s = "");
+void print_compilation_info();
+
+} // libsnark
+
+#endif // PROFILING_HPP_
diff --git a/src/common/serialization.hpp b/src/common/serialization.hpp
new file mode 100644 (file)
index 0000000..c931c65
--- /dev/null
@@ -0,0 +1,104 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of serialization routines and constants.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SERIALIZATION_HPP_
+#define SERIALIZATION_HPP_
+
+#include <istream>
+#include <map>
+#include <ostream>
+#include <set>
+#include <vector>
+
+namespace libsnark {
+
+/*
+ * @todo
+ * The serialization is fragile. Shoud be rewritten using a standard, portable-format
+ * library like boost::serialize.
+ *
+ * However, for now the following conventions are used within the code.
+ *
+ * All algebraic objects support either binary or decimal output using
+ * the standard C++ stream operators (operator<<, operator>>).
+ *
+ * The binary mode is activated by defining a BINARY_OUTPUT
+ * preprocessor macro (e.g. g++ -DBINARY_OUTPUT ...).
+ *
+ * Binary output assumes that the stream is to be binary read at its
+ * current position so any white space should be consumed beforehand.
+ *
+ * Consecutive algebraic objects are separated by OUTPUT_NEWLINE and
+ * within themselves (e.g. X and Y coordinates for field elements) with
+ * OUTPUT_SEPARATOR (as defined below).
+ *
+ * Therefore to dump two integers, two Fp elements and another integer
+ * one would:
+ *
+ * out << 3 << "\n";
+ * out << 4 << "\n";
+ * out << FieldT(56) << OUTPUT_NEWLINE;
+ * out << FieldT(78) << OUTPUT_NEWLINE;
+ * out << 9 << "\n";
+ *
+ * Then reading back it its reader's responsibility (!) to consume "\n"
+ * after 4, but Fp::operator<< will correctly consume OUTPUT_NEWLINE.
+ *
+ * The reader should also consume "\n" after 9, so that another field
+ * element can be properly chained. This is especially important for
+ * binary output.
+ *
+ * The binary serialization of algebraic objects is currently *not*
+ * portable between machines of different word sizes.
+ */
+
+#ifdef BINARY_OUTPUT
+#define OUTPUT_NEWLINE ""
+#define OUTPUT_SEPARATOR ""
+#else
+#define OUTPUT_NEWLINE "\n"
+#define OUTPUT_SEPARATOR " "
+#endif
+
+inline void consume_newline(std::istream &in);
+inline void consume_OUTPUT_NEWLINE(std::istream &in);
+inline void consume_OUTPUT_SEPARATOR(std::istream &in);
+
+inline void output_bool(std::ostream &out, const bool b);
+
+inline void output_bool_vector(std::ostream &out, const std::vector<bool> &v);
+
+template<typename T>
+T reserialize(const T &obj);
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const std::vector<T> &v);
+
+template<typename T>
+std::istream& operator>>(std::ostream& out, std::vector<T> &v);
+
+template<typename T1, typename T2>
+std::ostream& operator<<(std::ostream& out, const std::map<T1, T2> &m);
+
+template<typename T1, typename T2>
+std::istream& operator>>(std::istream& in, std::map<T1, T2> &m);
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const std::set<T> &s);
+
+template<typename T>
+std::istream& operator>>(std::istream& in, std::set<T> &s);
+
+} // libsnark
+
+#include "common/serialization.tcc"
+
+#endif // SERIALIZATION_HPP_
diff --git a/src/common/serialization.tcc b/src/common/serialization.tcc
new file mode 100644 (file)
index 0000000..398f978
--- /dev/null
@@ -0,0 +1,180 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of serialization routines.
+
+ See serialization.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SERIALIZATION_TCC_
+#define SERIALIZATION_TCC_
+
+#include <cassert>
+#include <sstream>
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+inline void consume_newline(std::istream &in)
+{
+    char c;
+    in.read(&c, 1);
+}
+
+inline void consume_OUTPUT_NEWLINE(std::istream &in)
+{
+#ifdef BINARY_OUTPUT
+    // nothing to consume
+    UNUSED(in);
+#else
+    char c;
+    in.read(&c, 1);
+#endif
+}
+
+inline void consume_OUTPUT_SEPARATOR(std::istream &in)
+{
+#ifdef BINARY_OUTPUT
+    // nothing to consume
+    UNUSED(in);
+#else
+    char c;
+    in.read(&c, 1);
+#endif
+}
+
+inline void output_bool(std::ostream &out, const bool b)
+{
+    out << (b ? 1 : 0) << "\n";
+}
+
+inline void output_bool_vector(std::ostream &out, const std::vector<bool> &v)
+{
+    out << v.size() << "\n";
+    for (const bool b : v)
+    {
+        output_bool(out, b);
+    }
+}
+
+template<typename T>
+T reserialize(const T &obj)
+{
+    std::stringstream ss;
+    ss << obj;
+    T tmp;
+    ss >> tmp;
+    assert(obj == tmp);
+    return tmp;
+}
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const std::vector<T> &v)
+{
+    static_assert(!std::is_same<T, bool>::value, "this does not work for std::vector<bool>");
+    out << v.size() << "\n";
+    for (const T& t : v)
+    {
+        out << t << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+template<typename T>
+std::istream& operator>>(std::istream& in, std::vector<T> &v)
+{
+    static_assert(!std::is_same<T, bool>::value, "this does not work for std::vector<bool>");
+    size_t size;
+    in >> size;
+    consume_newline(in);
+
+    v.resize(0);
+    for (size_t i = 0; i < size; ++i)
+    {
+        T elt;
+        in >> elt;
+        consume_OUTPUT_NEWLINE(in);
+        v.push_back(elt);
+    }
+
+    return in;
+}
+
+template<typename T1, typename T2>
+std::ostream& operator<<(std::ostream& out, const std::map<T1, T2> &m)
+{
+    out << m.size() << "\n";
+
+    for (auto &it : m)
+    {
+        out << it.first << "\n";
+        out << it.second << "\n";
+    }
+
+    return out;
+}
+
+template<typename T1, typename T2>
+std::istream& operator>>(std::istream& in, std::map<T1, T2> &m)
+{
+    m.clear();
+    size_t size;
+    in >> size;
+    consume_newline(in);
+
+    for (size_t i = 0; i < size; ++i)
+    {
+        T1 k;
+        T2 v;
+        in >> k;
+        consume_newline(in);
+        in >> v;
+        consume_newline(in);
+        m[k] = v;
+    }
+
+    return in;
+}
+
+template<typename T>
+std::ostream& operator<<(std::ostream& out, const std::set<T> &s)
+{
+    out << s.size() << "\n";
+
+    for (auto &el : s)
+    {
+        out << el << "\n";
+    }
+
+    return out;
+}
+
+
+template<typename T>
+std::istream& operator>>(std::istream& in, std::set<T> &s)
+{
+    s.clear();
+    size_t size;
+    in >> size;
+    consume_newline(in);
+
+    for (size_t i = 0; i < size; ++i)
+    {
+        T el;
+        in >> el;
+        consume_newline(in);
+        s.insert(el);
+    }
+
+    return in;
+}
+
+}
+
+#endif // SERIALIZATION_TCC_
diff --git a/src/common/template_utils.hpp b/src/common/template_utils.hpp
new file mode 100644 (file)
index 0000000..8dbfd26
--- /dev/null
@@ -0,0 +1,26 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of functions for supporting the use of templates.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef TEMPLATE_UTILS_HPP_
+#define TEMPLATE_UTILS_HPP_
+
+namespace libsnark {
+
+/* A commonly used SFINAE helper type */
+template<typename T>
+struct void_type
+{
+    typedef void type;
+};
+
+} // libsnark
+
+#endif // TEMPLATE_UTILS_HPP_
diff --git a/src/common/utils.cpp b/src/common/utils.cpp
new file mode 100644 (file)
index 0000000..dd114fd
--- /dev/null
@@ -0,0 +1,102 @@
+/** @file
+ *****************************************************************************
+ Implementation of misc math and serialization utility functions
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <cstdarg>
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+size_t log2(size_t n)
+/* returns ceil(log2(n)), so 1ul<<log2(n) is the smallest power of 2,
+   that is not less than n. */
+{
+    size_t r = ((n & (n-1)) == 0 ? 0 : 1); // add 1 if n is not power of 2
+
+    while (n > 1)
+    {
+        n >>= 1;
+        r++;
+    }
+
+    return r;
+}
+
+size_t bitreverse(size_t n, const size_t l)
+{
+    size_t r = 0;
+    for (size_t k = 0; k < l; ++k)
+    {
+        r = (r << 1) | (n & 1);
+        n >>= 1;
+    }
+    return r;
+}
+
+bit_vector int_list_to_bits(const std::initializer_list<unsigned long> &l, const size_t wordsize)
+{
+    bit_vector res(wordsize*l.size());
+    for (size_t i = 0; i < l.size(); ++i)
+    {
+        for (size_t j = 0; j < wordsize; ++j)
+        {
+            res[i*wordsize + j] = (*(l.begin()+i) & (1ul<<(wordsize-1-j)));
+        }
+    }
+    return res;
+}
+
+long long div_ceil(long long x, long long y)
+{
+    return (x + (y-1)) / y;
+}
+
+bool is_little_endian()
+{
+    uint64_t a = 0x12345678;
+    unsigned char *c = (unsigned char*)(&a);
+    return (*c = 0x78);
+}
+
+std::string FORMAT(const std::string &prefix, const char* format, ...)
+{
+    const static size_t MAX_FMT = 256;
+    char buf[MAX_FMT];
+    va_list args;
+    va_start(args, format);
+    vsnprintf(buf, MAX_FMT, format, args);
+    va_end(args);
+
+    return prefix + std::string(buf);
+}
+
+void serialize_bit_vector(std::ostream &out, const bit_vector &v)
+{
+    out << v.size() << "\n";
+    for (size_t i = 0; i < v.size(); ++i)
+    {
+        out << v[i] << "\n";
+    }
+}
+
+void deserialize_bit_vector(std::istream &in, bit_vector &v)
+{
+    size_t size;
+    in >> size;
+    v.resize(size);
+    for (size_t i = 0; i < size; ++i)
+    {
+        bool b;
+        in >> b;
+        v[i] = b;
+    }
+}
+} // libsnark
diff --git a/src/common/utils.hpp b/src/common/utils.hpp
new file mode 100644 (file)
index 0000000..d7d9e89
--- /dev/null
@@ -0,0 +1,57 @@
+/** @file
+ *****************************************************************************
+ Declaration of misc math and serialization utility functions
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef UTILS_HPP_
+#define UTILS_HPP_
+
+#include <cassert>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <vector>
+
+namespace libsnark {
+
+typedef std::vector<bool> bit_vector;
+
+/// returns ceil(log2(n)), so 1ul<<log2(n) is the smallest power of 2, that is not less than n
+size_t log2(size_t n);
+
+inline size_t exp2(size_t k) { return 1ul << k; }
+
+size_t bitreverse(size_t n, const size_t l);
+bit_vector int_list_to_bits(const std::initializer_list<unsigned long> &l, const size_t wordsize);
+long long div_ceil(long long x, long long y);
+
+bool is_little_endian();
+
+std::string FORMAT(const std::string &prefix, const char* format, ...);
+
+/* A variadic template to suppress unused argument warnings */
+template<typename ... Types>
+void UNUSED(Types&&...) {}
+
+#ifdef DEBUG
+#define FMT FORMAT
+#else
+#define FMT(...) (UNUSED(__VA_ARGS__), "")
+#endif
+
+void serialize_bit_vector(std::ostream &out, const bit_vector &v);
+void deserialize_bit_vector(std::istream &in, bit_vector &v);
+
+template<typename T>
+size_t size_in_bits(const std::vector<T> &v);
+
+#define ARRAY_SIZE(arr) (sizeof(arr)/sizeof(arr[0]))
+
+} // libsnark
+
+#include "common/utils.tcc" /* note that utils has a templatized part (utils.tcc) and non-templatized part (utils.cpp) */
+#endif // UTILS_HPP_
diff --git a/src/common/utils.tcc b/src/common/utils.tcc
new file mode 100644 (file)
index 0000000..f97178f
--- /dev/null
@@ -0,0 +1,23 @@
+/** @file
+ *****************************************************************************
+ Implementation of templatized utility functions
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef UTILS_TCC_
+#define UTILS_TCC_
+
+namespace libsnark {
+
+template<typename T>
+size_t size_in_bits(const std::vector<T> &v)
+{
+    return v.size() * T::size_in_bits();
+}
+
+} // libsnark
+
+#endif // UTILS_TCC_
diff --git a/src/gadgetlib1/constraint_profiling.cpp b/src/gadgetlib1/constraint_profiling.cpp
new file mode 100644 (file)
index 0000000..bc17e63
--- /dev/null
@@ -0,0 +1,48 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for profiling constraints.
+
+ See constraint_profiling.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "gadgetlib1/constraint_profiling.hpp"
+#include "common/profiling.hpp"
+
+namespace libsnark {
+
+size_t constraint_profiling_indent = 0;
+std::vector<constraint_profiling_entry> constraint_profiling_table;
+
+size_t PRINT_CONSTRAINT_PROFILING()
+{
+    size_t accounted = 0;
+    print_indent();
+    printf("Constraint profiling:\n");
+    for (constraint_profiling_entry &ent : constraint_profiling_table)
+    {
+        if (ent.indent == 0)
+        {
+            accounted += ent.count;
+        }
+
+        print_indent();
+        for (size_t i = 0; i < ent.indent; ++i)
+        {
+            printf("  ");
+        }
+        printf("* Number of constraints in [%s]: %zu\n", ent.annotation.c_str(), ent.count);
+    }
+
+    constraint_profiling_table.clear();
+    constraint_profiling_indent = 0;
+
+    return accounted;
+}
+
+}
diff --git a/src/gadgetlib1/constraint_profiling.hpp b/src/gadgetlib1/constraint_profiling.hpp
new file mode 100644 (file)
index 0000000..df8a55d
--- /dev/null
@@ -0,0 +1,42 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for profiling constraints.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef CONSTRAINT_PROFILING_HPP_
+#define CONSTRAINT_PROFILING_HPP_
+
+#include <cstddef>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace libsnark {
+
+extern size_t constraint_profiling_indent;
+
+struct constraint_profiling_entry {
+    size_t indent;
+    std::string annotation;
+    size_t count;
+};
+
+extern std::vector<constraint_profiling_entry> constraint_profiling_table;
+
+#define PROFILE_CONSTRAINTS(pb, annotation)                             \
+    for (size_t _num_constraints_before = pb.num_constraints(), _iter = (++constraint_profiling_indent, 0), _cp_pos = constraint_profiling_table.size(); \
+         _iter == 0;                                                    \
+         constraint_profiling_table.insert(constraint_profiling_table.begin() + _cp_pos, constraint_profiling_entry{--constraint_profiling_indent, annotation, pb.num_constraints() - _num_constraints_before}), \
+         _iter = 1)
+
+size_t PRINT_CONSTRAINT_PROFILING(); // returns # of top level constraints
+
+} // libsnark
+
+#endif // CONSTRAINT_PROFILING_HPP_
diff --git a/src/gadgetlib1/examples/simple_example.hpp b/src/gadgetlib1/examples/simple_example.hpp
new file mode 100644 (file)
index 0000000..faa3a96
--- /dev/null
@@ -0,0 +1,23 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SIMPLE_EXAMPLE_HPP_
+#define SIMPLE_EXAMPLE_HPP_
+
+#include "examples/r1cs_examples.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+r1cs_example<FieldT> gen_r1cs_example_from_protoboard(const size_t num_constraints,
+                                                      const size_t num_inputs);
+
+} // libsnark
+
+#include "gadgetlib1/examples/simple_example.tcc"
+
+#endif // SIMPLE_EXAMPLE_HPP_
diff --git a/src/gadgetlib1/examples/simple_example.tcc b/src/gadgetlib1/examples/simple_example.tcc
new file mode 100644 (file)
index 0000000..9d500b5
--- /dev/null
@@ -0,0 +1,54 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SIMPLE_EXAMPLE_TCC_
+#define SIMPLE_EXAMPLE_TCC_
+
+#include <cassert>
+#include "gadgetlib1/gadgets/basic_gadgets.hpp"
+
+namespace libsnark {
+
+/* NOTE: all examples here actually generate one constraint less to account for soundness constraint in QAP */
+
+template<typename FieldT>
+r1cs_example<FieldT> gen_r1cs_example_from_protoboard(const size_t num_constraints,
+                                                      const size_t num_inputs)
+{
+    const size_t new_num_constraints = num_constraints - 1;
+
+    /* construct dummy example: inner products of two vectors */
+    protoboard<FieldT> pb;
+    pb_variable_array<FieldT> A;
+    pb_variable_array<FieldT> B;
+    pb_variable<FieldT> res;
+
+    // the variables on the protoboard are (ONE (constant 1 term), res, A[0], ..., A[num_constraints-1], B[0], ..., B[num_constraints-1])
+    res.allocate(pb, "res");
+    A.allocate(pb, new_num_constraints, "A");
+    B.allocate(pb, new_num_constraints, "B");
+
+    inner_product_gadget<FieldT> compute_inner_product(pb, A, B, res, "compute_inner_product");
+    compute_inner_product.generate_r1cs_constraints();
+
+    /* fill in random example */
+    for (size_t i = 0; i < new_num_constraints; ++i)
+    {
+        pb.val(A[i]) = FieldT::random_element();
+        pb.val(B[i]) = FieldT::random_element();
+    }
+
+    compute_inner_product.generate_r1cs_witness();
+
+    pb.constraint_system.num_inputs = num_inputs;
+    const r1cs_variable_assignment<FieldT> va = pb.values;
+    const r1cs_variable_assignment<FieldT> input(va.begin(), va.begin() + num_inputs);
+    return r1cs_example<FieldT>(pb.constraint_system, input, va, num_inputs);
+}
+
+} // libsnark
+#endif // R1CS_EXAMPLES_TCC_
diff --git a/src/gadgetlib1/gadget.hpp b/src/gadgetlib1/gadget.hpp
new file mode 100644 (file)
index 0000000..dbeaa9d
--- /dev/null
@@ -0,0 +1,27 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef GADGET_HPP_
+#define GADGET_HPP_
+
+#include "gadgetlib1/protoboard.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+class gadget {
+protected:
+    protoboard<FieldT> &pb;
+    const std::string annotation_prefix;
+public:
+    gadget(protoboard<FieldT> &pb, const std::string &annotation_prefix="");
+};
+
+} // libsnark
+#include "gadgetlib1/gadget.tcc"
+
+#endif // GADGET_HPP_
diff --git a/src/gadgetlib1/gadget.tcc b/src/gadgetlib1/gadget.tcc
new file mode 100644 (file)
index 0000000..120229b
--- /dev/null
@@ -0,0 +1,23 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef GADGET_TCC_
+#define GADGET_TCC_
+
+namespace libsnark {
+
+template<typename FieldT>
+gadget<FieldT>::gadget(protoboard<FieldT> &pb, const std::string &annotation_prefix) :
+    pb(pb), annotation_prefix(annotation_prefix)
+{
+#ifdef DEBUG
+    assert(annotation_prefix != "");
+#endif
+}
+
+} // libsnark
+#endif // GADGET_TCC_
diff --git a/src/gadgetlib1/gadgets/basic_gadgets.hpp b/src/gadgetlib1/gadgets/basic_gadgets.hpp
new file mode 100644 (file)
index 0000000..08e596b
--- /dev/null
@@ -0,0 +1,351 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BASIC_GADGETS_HPP_
+#define BASIC_GADGETS_HPP_
+
+#include <cassert>
+#include <memory>
+
+#include "gadgetlib1/gadget.hpp"
+
+namespace libsnark {
+
+/* forces lc to take value 0 or 1 by adding constraint lc * (1-lc) = 0 */
+template<typename FieldT>
+void generate_boolean_r1cs_constraint(protoboard<FieldT> &pb, const pb_linear_combination<FieldT> &lc, const std::string &annotation_prefix="");
+
+template<typename FieldT>
+void generate_r1cs_equals_const_constraint(protoboard<FieldT> &pb, const pb_linear_combination<FieldT> &lc, const FieldT& c, const std::string &annotation_prefix="");
+
+template<typename FieldT>
+class packing_gadget : public gadget<FieldT> {
+private:
+    /* no internal variables */
+public:
+    const pb_linear_combination_array<FieldT> bits;
+    const pb_linear_combination<FieldT> packed;
+
+    packing_gadget(protoboard<FieldT> &pb,
+                   const pb_linear_combination_array<FieldT> &bits,
+                   const pb_linear_combination<FieldT> &packed,
+                   const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), bits(bits), packed(packed) {}
+
+    void generate_r1cs_constraints(const bool enforce_bitness);
+    /* adds constraint result = \sum  bits[i] * 2^i */
+
+    void generate_r1cs_witness_from_packed();
+    void generate_r1cs_witness_from_bits();
+};
+
+template<typename FieldT>
+class multipacking_gadget : public gadget<FieldT> {
+private:
+    std::vector<packing_gadget<FieldT> > packers;
+public:
+    const pb_linear_combination_array<FieldT> bits;
+    const pb_linear_combination_array<FieldT> packed_vars;
+
+    const size_t chunk_size;
+    const size_t num_chunks;
+    // const size_t last_chunk_size;
+
+    multipacking_gadget(protoboard<FieldT> &pb,
+                        const pb_linear_combination_array<FieldT> &bits,
+                        const pb_linear_combination_array<FieldT> &packed_vars,
+                        const size_t chunk_size,
+                        const std::string &annotation_prefix="");
+    void generate_r1cs_constraints(const bool enforce_bitness);
+    void generate_r1cs_witness_from_packed();
+    void generate_r1cs_witness_from_bits();
+};
+
+template<typename FieldT>
+class field_vector_copy_gadget : public gadget<FieldT> {
+public:
+    const pb_variable_array<FieldT> source;
+    const pb_variable_array<FieldT> target;
+    const pb_linear_combination<FieldT> do_copy;
+
+    field_vector_copy_gadget(protoboard<FieldT> &pb,
+                             const pb_variable_array<FieldT> &source,
+                             const pb_variable_array<FieldT> &target,
+                             const pb_linear_combination<FieldT> &do_copy,
+                             const std::string &annotation_prefix="");
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+class bit_vector_copy_gadget : public gadget<FieldT> {
+public:
+    const pb_variable_array<FieldT> source_bits;
+    const pb_variable_array<FieldT> target_bits;
+    const pb_linear_combination<FieldT> do_copy;
+
+    pb_variable_array<FieldT> packed_source;
+    pb_variable_array<FieldT> packed_target;
+
+    std::shared_ptr<multipacking_gadget<FieldT> > pack_source;
+    std::shared_ptr<multipacking_gadget<FieldT> > pack_target;
+    std::shared_ptr<field_vector_copy_gadget<FieldT> > copier;
+
+    const size_t chunk_size;
+    const size_t num_chunks;
+
+    bit_vector_copy_gadget(protoboard<FieldT> &pb,
+                           const pb_variable_array<FieldT> &source_bits,
+                           const pb_variable_array<FieldT> &target_bits,
+                           const pb_linear_combination<FieldT> &do_copy,
+                           const size_t chunk_size,
+                           const std::string &annotation_prefix="");
+    void generate_r1cs_constraints(const bool enforce_source_bitness, const bool enforce_target_bitness);
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+class dual_variable_gadget : public gadget<FieldT> {
+private:
+    std::shared_ptr<packing_gadget<FieldT> > consistency_check;
+public:
+    pb_variable<FieldT> packed;
+    pb_variable_array<FieldT> bits;
+
+    dual_variable_gadget(protoboard<FieldT> &pb,
+                         const size_t width,
+                         const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix)
+    {
+        packed.allocate(pb, FMT(this->annotation_prefix, " packed"));
+        bits.allocate(pb, width, FMT(this->annotation_prefix, " bits"));
+        consistency_check.reset(new packing_gadget<FieldT>(pb,
+                                                           bits,
+                                                           packed,
+                                                           FMT(this->annotation_prefix, " consistency_check")));
+    }
+
+    dual_variable_gadget(protoboard<FieldT> &pb,
+                         const pb_variable_array<FieldT> &bits,
+                         const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), bits(bits)
+    {
+        packed.allocate(pb, FMT(this->annotation_prefix, " packed"));
+        consistency_check.reset(new packing_gadget<FieldT>(pb,
+                                                           bits,
+                                                           packed,
+                                                           FMT(this->annotation_prefix, " consistency_check")));
+    }
+
+    dual_variable_gadget(protoboard<FieldT> &pb,
+                         const pb_variable<FieldT> &packed,
+                         const size_t width,
+                         const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), packed(packed)
+    {
+        bits.allocate(pb, width, FMT(this->annotation_prefix, " bits"));
+        consistency_check.reset(new packing_gadget<FieldT>(pb,
+                                                           bits,
+                                                           packed,
+                                                           FMT(this->annotation_prefix, " consistency_check")));
+    }
+
+    void generate_r1cs_constraints(const bool enforce_bitness);
+    void generate_r1cs_witness_from_packed();
+    void generate_r1cs_witness_from_bits();
+};
+
+/*
+  the gadgets below are Fp specific:
+  I * X = R
+  (1-R) * X = 0
+
+  if X = 0 then R = 0
+  if X != 0 then R = 1 and I = X^{-1}
+*/
+
+template<typename FieldT>
+class disjunction_gadget : public gadget<FieldT> {
+private:
+    pb_variable<FieldT> inv;
+public:
+    const pb_variable_array<FieldT> inputs;
+    const pb_variable<FieldT> output;
+
+    disjunction_gadget(protoboard<FieldT>& pb,
+                       const pb_variable_array<FieldT> &inputs,
+                       const pb_variable<FieldT> &output,
+                       const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), inputs(inputs), output(output)
+    {
+        assert(inputs.size() >= 1);
+        inv.allocate(pb, FMT(this->annotation_prefix, " inv"));
+    }
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+void test_disjunction_gadget(const size_t n);
+
+template<typename FieldT>
+class conjunction_gadget : public gadget<FieldT> {
+private:
+    pb_variable<FieldT> inv;
+public:
+    const pb_variable_array<FieldT> inputs;
+    const pb_variable<FieldT> output;
+
+    conjunction_gadget(protoboard<FieldT>& pb,
+                       const pb_variable_array<FieldT> &inputs,
+                       const pb_variable<FieldT> &output,
+                       const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), inputs(inputs), output(output)
+    {
+        assert(inputs.size() >= 1);
+        inv.allocate(pb, FMT(this->annotation_prefix, " inv"));
+    }
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+void test_conjunction_gadget(const size_t n);
+
+template<typename FieldT>
+class comparison_gadget : public gadget<FieldT> {
+private:
+    pb_variable_array<FieldT> alpha;
+    pb_variable<FieldT> alpha_packed;
+    std::shared_ptr<packing_gadget<FieldT> > pack_alpha;
+
+    std::shared_ptr<disjunction_gadget<FieldT> > all_zeros_test;
+    pb_variable<FieldT> not_all_zeros;
+public:
+    const size_t n;
+    const pb_linear_combination<FieldT> A;
+    const pb_linear_combination<FieldT> B;
+    const pb_variable<FieldT> less;
+    const pb_variable<FieldT> less_or_eq;
+
+    comparison_gadget(protoboard<FieldT>& pb,
+                      const size_t n,
+                      const pb_linear_combination<FieldT> &A,
+                      const pb_linear_combination<FieldT> &B,
+                      const pb_variable<FieldT> &less,
+                      const pb_variable<FieldT> &less_or_eq,
+                      const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), n(n), A(A), B(B), less(less), less_or_eq(less_or_eq)
+    {
+        alpha.allocate(pb, n, FMT(this->annotation_prefix, " alpha"));
+        alpha.emplace_back(less_or_eq); // alpha[n] is less_or_eq
+
+        alpha_packed.allocate(pb, FMT(this->annotation_prefix, " alpha_packed"));
+        not_all_zeros.allocate(pb, FMT(this->annotation_prefix, " not_all_zeros"));
+
+        pack_alpha.reset(new packing_gadget<FieldT>(pb, alpha, alpha_packed,
+                                                    FMT(this->annotation_prefix, " pack_alpha")));
+
+        all_zeros_test.reset(new disjunction_gadget<FieldT>(pb,
+                                                            pb_variable_array<FieldT>(alpha.begin(), alpha.begin() + n),
+                                                            not_all_zeros,
+                                                            FMT(this->annotation_prefix, " all_zeros_test")));
+    };
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+void test_comparison_gadget(const size_t n);
+
+template<typename FieldT>
+class inner_product_gadget : public gadget<FieldT> {
+private:
+    /* S_i = \sum_{k=0}^{i+1} A[i] * B[i] */
+    pb_variable_array<FieldT> S;
+public:
+    const pb_linear_combination_array<FieldT> A;
+    const pb_linear_combination_array<FieldT> B;
+    const pb_variable<FieldT> result;
+
+    inner_product_gadget(protoboard<FieldT>& pb,
+                         const pb_linear_combination_array<FieldT> &A,
+                         const pb_linear_combination_array<FieldT> &B,
+                         const pb_variable<FieldT> &result,
+                         const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), A(A), B(B), result(result)
+    {
+        assert(A.size() >= 1);
+        assert(A.size() == B.size());
+
+        S.allocate(pb, A.size()-1, FMT(this->annotation_prefix, " S"));
+    }
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+void test_inner_product_gadget(const size_t n);
+
+template<typename FieldT>
+class loose_multiplexing_gadget : public gadget<FieldT> {
+/*
+  this implements loose multiplexer:
+  index not in bounds -> success_flag = 0
+  index in bounds && success_flag = 1 -> result is correct
+  however if index is in bounds we can also set success_flag to 0 (and then result will be forced to be 0)
+*/
+public:
+    pb_variable_array<FieldT> alpha;
+private:
+    std::shared_ptr<inner_product_gadget<FieldT> > compute_result;
+public:
+    const pb_linear_combination_array<FieldT> arr;
+    const pb_variable<FieldT> index;
+    const pb_variable<FieldT> result;
+    const pb_variable<FieldT> success_flag;
+
+    loose_multiplexing_gadget(protoboard<FieldT>& pb,
+                              const pb_linear_combination_array<FieldT> &arr,
+                              const pb_variable<FieldT> &index,
+                              const pb_variable<FieldT> &result,
+                              const pb_variable<FieldT> &success_flag,
+                              const std::string &annotation_prefix="") :
+        gadget<FieldT>(pb, annotation_prefix), arr(arr), index(index), result(result), success_flag(success_flag)
+    {
+        alpha.allocate(pb, arr.size(), FMT(this->annotation_prefix, " alpha"));
+        compute_result.reset(new inner_product_gadget<FieldT>(pb, alpha, arr, result, FMT(this->annotation_prefix, " compute_result")));
+    };
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+void test_loose_multiplexing_gadget(const size_t n);
+
+template<typename FieldT, typename VarT>
+void create_linear_combination_constraints(protoboard<FieldT> &pb,
+                                           const std::vector<FieldT> &base,
+                                           const std::vector<std::pair<VarT, FieldT> > &v,
+                                           const VarT &target,
+                                           const std::string &annotation_prefix);
+
+template<typename FieldT, typename VarT>
+void create_linear_combination_witness(protoboard<FieldT> &pb,
+                                       const std::vector<FieldT> &base,
+                                       const std::vector<std::pair<VarT, FieldT> > &v,
+                                       const VarT &target);
+
+} // libsnark
+#include "gadgetlib1/gadgets/basic_gadgets.tcc"
+
+#endif // BASIC_GADGETS_HPP_
diff --git a/src/gadgetlib1/gadgets/basic_gadgets.tcc b/src/gadgetlib1/gadgets/basic_gadgets.tcc
new file mode 100644 (file)
index 0000000..213b190
--- /dev/null
@@ -0,0 +1,705 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef BASIC_GADGETS_TCC_
+#define BASIC_GADGETS_TCC_
+
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+void generate_boolean_r1cs_constraint(protoboard<FieldT> &pb, const pb_linear_combination<FieldT> &lc, const std::string &annotation_prefix)
+/* forces lc to take value 0 or 1 by adding constraint lc * (1-lc) = 0 */
+{
+    pb.add_r1cs_constraint(r1cs_constraint<FieldT>(lc, 1-lc, 0),
+                           FMT(annotation_prefix, " boolean_r1cs_constraint"));
+}
+
+template<typename FieldT>
+void generate_r1cs_equals_const_constraint(protoboard<FieldT> &pb, const pb_linear_combination<FieldT> &lc, const FieldT& c, const std::string &annotation_prefix)
+{
+    pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1, lc, c),
+                           FMT(annotation_prefix, " constness_constraint"));
+}
+
+template<typename FieldT>
+void packing_gadget<FieldT>::generate_r1cs_constraints(const bool enforce_bitness)
+/* adds constraint result = \sum  bits[i] * 2^i */
+{
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1, pb_packing_sum<FieldT>(bits), packed), FMT(this->annotation_prefix, " packing_constraint"));
+
+    if (enforce_bitness)
+    {
+        for (size_t i = 0; i < bits.size(); ++i)
+        {
+            generate_boolean_r1cs_constraint<FieldT>(this->pb, bits[i], FMT(this->annotation_prefix, " bitness_%zu", i));
+        }
+    }
+}
+
+template<typename FieldT>
+void packing_gadget<FieldT>::generate_r1cs_witness_from_packed()
+{
+    packed.evaluate(this->pb);
+    assert(this->pb.lc_val(packed).as_bigint().num_bits() <= bits.size());
+    bits.fill_with_bits_of_field_element(this->pb, this->pb.lc_val(packed));
+}
+
+template<typename FieldT>
+void packing_gadget<FieldT>::generate_r1cs_witness_from_bits()
+{
+    bits.evaluate(this->pb);
+    this->pb.lc_val(packed) = bits.get_field_element_from_bits(this->pb);
+}
+
+template<typename FieldT>
+multipacking_gadget<FieldT>::multipacking_gadget(protoboard<FieldT> &pb,
+                                                 const pb_linear_combination_array<FieldT> &bits,
+                                                 const pb_linear_combination_array<FieldT> &packed_vars,
+                                                 const size_t chunk_size,
+                                                 const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix), bits(bits), packed_vars(packed_vars),
+    chunk_size(chunk_size),
+    num_chunks(div_ceil(bits.size(), chunk_size))
+    // last_chunk_size(bits.size() - (num_chunks-1) * chunk_size)
+{
+    assert(packed_vars.size() == num_chunks);
+    for (size_t i = 0; i < num_chunks; ++i)
+    {
+        packers.emplace_back(packing_gadget<FieldT>(this->pb, pb_linear_combination_array<FieldT>(bits.begin() + i * chunk_size,
+                                                                                                  bits.begin() + std::min((i+1) * chunk_size, bits.size())),
+                                                    packed_vars[i], FMT(this->annotation_prefix, " packers_%zu", i)));
+    }
+}
+
+template<typename FieldT>
+void multipacking_gadget<FieldT>::generate_r1cs_constraints(const bool enforce_bitness)
+{
+    for (size_t i = 0; i < num_chunks; ++i)
+    {
+        packers[i].generate_r1cs_constraints(enforce_bitness);
+    }
+}
+
+template<typename FieldT>
+void multipacking_gadget<FieldT>::generate_r1cs_witness_from_packed()
+{
+    for (size_t i = 0; i < num_chunks; ++i)
+    {
+        packers[i].generate_r1cs_witness_from_packed();
+    }
+}
+
+template<typename FieldT>
+void multipacking_gadget<FieldT>::generate_r1cs_witness_from_bits()
+{
+    for (size_t i = 0; i < num_chunks; ++i)
+    {
+        packers[i].generate_r1cs_witness_from_bits();
+    }
+}
+
+template<typename FieldT>
+size_t multipacking_num_chunks(const size_t num_bits)
+{
+    return div_ceil(num_bits, FieldT::capacity());
+}
+
+template<typename FieldT>
+field_vector_copy_gadget<FieldT>::field_vector_copy_gadget(protoboard<FieldT> &pb,
+                                                           const pb_variable_array<FieldT> &source,
+                                                           const pb_variable_array<FieldT> &target,
+                                                           const pb_linear_combination<FieldT> &do_copy,
+                                                           const std::string &annotation_prefix) :
+gadget<FieldT>(pb, annotation_prefix), source(source), target(target), do_copy(do_copy)
+{
+    assert(source.size() == target.size());
+}
+
+template<typename FieldT>
+void field_vector_copy_gadget<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < source.size(); ++i)
+    {
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(do_copy, source[i] - target[i], 0),
+                                     FMT(this->annotation_prefix, " copying_check_%zu", i));
+    }
+}
+
+template<typename FieldT>
+void field_vector_copy_gadget<FieldT>::generate_r1cs_witness()
+{
+    do_copy.evaluate(this->pb);
+    assert(this->pb.lc_val(do_copy) == FieldT::one() || this->pb.lc_val(do_copy) == FieldT::zero());
+    if (this->pb.lc_val(do_copy) != FieldT::zero())
+    {
+        for (size_t i = 0; i < source.size(); ++i)
+        {
+            this->pb.val(target[i]) = this->pb.val(source[i]);
+        }
+    }
+}
+
+template<typename FieldT>
+bit_vector_copy_gadget<FieldT>::bit_vector_copy_gadget(protoboard<FieldT> &pb,
+                                                       const pb_variable_array<FieldT> &source_bits,
+                                                       const pb_variable_array<FieldT> &target_bits,
+                                                       const pb_linear_combination<FieldT> &do_copy,
+                                                       const size_t chunk_size,
+                                                       const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix), source_bits(source_bits), target_bits(target_bits), do_copy(do_copy),
+    chunk_size(chunk_size), num_chunks(div_ceil(source_bits.size(), chunk_size))
+{
+    assert(source_bits.size() == target_bits.size());
+
+    packed_source.allocate(pb, num_chunks, FMT(annotation_prefix, " packed_source"));
+    pack_source.reset(new multipacking_gadget<FieldT>(pb, source_bits, packed_source, chunk_size, FMT(annotation_prefix, " pack_source")));
+
+    packed_target.allocate(pb, num_chunks, FMT(annotation_prefix, " packed_target"));
+    pack_target.reset(new multipacking_gadget<FieldT>(pb, target_bits, packed_target, chunk_size, FMT(annotation_prefix, " pack_target")));
+
+    copier.reset(new field_vector_copy_gadget<FieldT>(pb, packed_source, packed_target, do_copy, FMT(annotation_prefix, " copier")));
+}
+
+template<typename FieldT>
+void bit_vector_copy_gadget<FieldT>::generate_r1cs_constraints(const bool enforce_source_bitness, const bool enforce_target_bitness)
+{
+    pack_source->generate_r1cs_constraints(enforce_source_bitness);
+    pack_target->generate_r1cs_constraints(enforce_target_bitness);
+
+    copier->generate_r1cs_constraints();
+}
+
+template<typename FieldT>
+void bit_vector_copy_gadget<FieldT>::generate_r1cs_witness()
+{
+    do_copy.evaluate(this->pb);
+    assert(this->pb.lc_val(do_copy) == FieldT::zero() || this->pb.lc_val(do_copy) == FieldT::one());
+    if (this->pb.lc_val(do_copy) == FieldT::one())
+    {
+        for (size_t i = 0; i < source_bits.size(); ++i)
+        {
+            this->pb.val(target_bits[i]) = this->pb.val(source_bits[i]);
+        }
+    }
+
+    pack_source->generate_r1cs_witness_from_bits();
+    pack_target->generate_r1cs_witness_from_bits();
+}
+
+template<typename FieldT>
+void dual_variable_gadget<FieldT>::generate_r1cs_constraints(const bool enforce_bitness)
+{
+    consistency_check->generate_r1cs_constraints(enforce_bitness);
+}
+
+template<typename FieldT>
+void dual_variable_gadget<FieldT>::generate_r1cs_witness_from_packed()
+{
+    consistency_check->generate_r1cs_witness_from_packed();
+}
+
+template<typename FieldT>
+void dual_variable_gadget<FieldT>::generate_r1cs_witness_from_bits()
+{
+    consistency_check->generate_r1cs_witness_from_bits();
+}
+
+template<typename FieldT>
+void disjunction_gadget<FieldT>::generate_r1cs_constraints()
+{
+    /* inv * sum = output */
+    linear_combination<FieldT> a1, b1, c1;
+    a1.add_term(inv);
+    for (size_t i = 0; i < inputs.size(); ++i)
+    {
+        b1.add_term(inputs[i]);
+    }
+    c1.add_term(output);
+
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(a1, b1, c1), FMT(this->annotation_prefix, " inv*sum=output"));
+
+    /* (1-output) * sum = 0 */
+    linear_combination<FieldT> a2, b2, c2;
+    a2.add_term(ONE);
+    a2.add_term(output, -1);
+    for (size_t i = 0; i < inputs.size(); ++i)
+    {
+        b2.add_term(inputs[i]);
+    }
+    c2.add_term(ONE, 0);
+
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(a2, b2, c2), FMT(this->annotation_prefix, " (1-output)*sum=0"));
+}
+
+template<typename FieldT>
+void disjunction_gadget<FieldT>::generate_r1cs_witness()
+{
+    FieldT sum = FieldT::zero();
+
+    for (size_t i = 0; i < inputs.size(); ++i)
+    {
+        sum += this->pb.val(inputs[i]);
+    }
+
+    if (sum.is_zero())
+    {
+        this->pb.val(inv) = FieldT::zero();
+        this->pb.val(output) = FieldT::zero();
+    }
+    else
+    {
+        this->pb.val(inv) = sum.inverse();
+        this->pb.val(output) = FieldT::one();
+    }
+}
+
+template<typename FieldT>
+void test_disjunction_gadget(const size_t n)
+{
+    printf("testing disjunction_gadget on all %zu bit strings\n", n);
+
+    protoboard<FieldT> pb;
+    pb_variable_array<FieldT> inputs;
+    inputs.allocate(pb, n, "inputs");
+
+    pb_variable<FieldT> output;
+    output.allocate(pb, "output");
+
+    disjunction_gadget<FieldT> d(pb, inputs, output, "d");
+    d.generate_r1cs_constraints();
+
+    for (size_t w = 0; w < 1ul<<n; ++w)
+    {
+        for (size_t j = 0; j < n; ++j)
+        {
+            pb.val(inputs[j]) = FieldT((w & (1ul<<j)) ? 1 : 0);
+        }
+
+        d.generate_r1cs_witness();
+
+#ifdef DEBUG
+        printf("positive test for %zu\n", w);
+#endif
+        assert(pb.val(output) == (w ? FieldT::one() : FieldT::zero()));
+        assert(pb.is_satisfied());
+
+#ifdef DEBUG
+        printf("negative test for %zu\n", w);
+#endif
+        pb.val(output) = (w ? FieldT::zero() : FieldT::one());
+        assert(!pb.is_satisfied());
+    }
+
+    print_time("disjunction tests successful");
+}
+
+template<typename FieldT>
+void conjunction_gadget<FieldT>::generate_r1cs_constraints()
+{
+    /* inv * (n-sum) = 1-output */
+    linear_combination<FieldT> a1, b1, c1;
+    a1.add_term(inv);
+    b1.add_term(ONE, inputs.size());
+    for (size_t i = 0; i < inputs.size(); ++i)
+    {
+        b1.add_term(inputs[i], -1);
+    }
+    c1.add_term(ONE);
+    c1.add_term(output, -1);
+
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(a1, b1, c1), FMT(this->annotation_prefix, " inv*(n-sum)=(1-output)"));
+
+    /* output * (n-sum) = 0 */
+    linear_combination<FieldT> a2, b2, c2;
+    a2.add_term(output);
+    b2.add_term(ONE, inputs.size());
+    for (size_t i = 0; i < inputs.size(); ++i)
+    {
+        b2.add_term(inputs[i], -1);
+    }
+    c2.add_term(ONE, 0);
+
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(a2, b2, c2), FMT(this->annotation_prefix, " output*(n-sum)=0"));
+}
+
+template<typename FieldT>
+void conjunction_gadget<FieldT>::generate_r1cs_witness()
+{
+    FieldT sum = FieldT(inputs.size());
+
+    for (size_t i = 0; i < inputs.size(); ++i)
+    {
+        sum -= this->pb.val(inputs[i]);
+    }
+
+    if (sum.is_zero())
+    {
+        this->pb.val(inv) = FieldT::zero();
+        this->pb.val(output) = FieldT::one();
+    }
+    else
+    {
+        this->pb.val(inv) = sum.inverse();
+        this->pb.val(output) = FieldT::zero();
+    }
+}
+
+template<typename FieldT>
+void test_conjunction_gadget(const size_t n)
+{
+    printf("testing conjunction_gadget on all %zu bit strings\n", n);
+
+    protoboard<FieldT> pb;
+    pb_variable_array<FieldT> inputs;
+    inputs.allocate(pb, n, "inputs");
+
+    pb_variable<FieldT> output;
+    output.allocate(pb, "output");
+
+    conjunction_gadget<FieldT> c(pb, inputs, output, "c");
+    c.generate_r1cs_constraints();
+
+    for (size_t w = 0; w < 1ul<<n; ++w)
+    {
+        for (size_t j = 0; j < n; ++j)
+        {
+            pb.val(inputs[j]) = (w & (1ul<<j)) ? FieldT::one() : FieldT::zero();
+        }
+
+        c.generate_r1cs_witness();
+
+#ifdef DEBUG
+        printf("positive test for %zu\n", w);
+#endif
+        assert(pb.val(output) == (w == (1ul<<n) - 1 ? FieldT::one() : FieldT::zero()));
+        assert(pb.is_satisfied());
+
+#ifdef DEBUG
+        printf("negative test for %zu\n", w);
+#endif
+        pb.val(output) = (w == (1ul<<n) - 1 ? FieldT::zero() : FieldT::one());
+        assert(!pb.is_satisfied());
+    }
+
+    print_time("conjunction tests successful");
+}
+
+template<typename FieldT>
+void comparison_gadget<FieldT>::generate_r1cs_constraints()
+{
+    /*
+      packed(alpha) = 2^n + B - A
+
+      not_all_zeros = \bigvee_{i=0}^{n-1} alpha_i
+
+      if B - A > 0, then 2^n + B - A > 2^n,
+          so alpha_n = 1 and not_all_zeros = 1
+      if B - A = 0, then 2^n + B - A = 2^n,
+          so alpha_n = 1 and not_all_zeros = 0
+      if B - A < 0, then 2^n + B - A \in {0, 1, \ldots, 2^n-1},
+          so alpha_n = 0
+
+      therefore alpha_n = less_or_eq and alpha_n * not_all_zeros = less
+     */
+
+    /* not_all_zeros to be Boolean, alpha_i are Boolean by packing gadget */
+    generate_boolean_r1cs_constraint<FieldT>(this->pb, not_all_zeros,
+                                     FMT(this->annotation_prefix, " not_all_zeros"));
+
+    /* constraints for packed(alpha) = 2^n + B - A */
+    pack_alpha->generate_r1cs_constraints(true);
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1, (FieldT(2)^n) + B - A, alpha_packed), FMT(this->annotation_prefix, " main_constraint"));
+
+    /* compute result */
+    all_zeros_test->generate_r1cs_constraints();
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(less_or_eq, not_all_zeros, less),
+                                 FMT(this->annotation_prefix, " less"));
+}
+
+template<typename FieldT>
+void comparison_gadget<FieldT>::generate_r1cs_witness()
+{
+    A.evaluate(this->pb);
+    B.evaluate(this->pb);
+
+    /* unpack 2^n + B - A into alpha_packed */
+    this->pb.val(alpha_packed) = (FieldT(2)^n) + this->pb.lc_val(B) - this->pb.lc_val(A);
+    pack_alpha->generate_r1cs_witness_from_packed();
+
+    /* compute result */
+    all_zeros_test->generate_r1cs_witness();
+    this->pb.val(less) = this->pb.val(less_or_eq) * this->pb.val(not_all_zeros);
+}
+
+template<typename FieldT>
+void test_comparison_gadget(const size_t n)
+{
+    printf("testing comparison_gadget on all %zu bit inputs\n", n);
+
+    protoboard<FieldT> pb;
+
+    pb_variable<FieldT> A, B, less, less_or_eq;
+    A.allocate(pb, "A");
+    B.allocate(pb, "B");
+    less.allocate(pb, "less");
+    less_or_eq.allocate(pb, "less_or_eq");
+
+    comparison_gadget<FieldT> cmp(pb, n, A, B, less, less_or_eq, "cmp");
+    cmp.generate_r1cs_constraints();
+
+    for (size_t a = 0; a < 1ul<<n; ++a)
+    {
+        for (size_t b = 0; b < 1ul<<n; ++b)
+        {
+            pb.val(A) = FieldT(a);
+            pb.val(B) = FieldT(b);
+
+            cmp.generate_r1cs_witness();
+
+#ifdef DEBUG
+            printf("positive test for %zu < %zu\n", a, b);
+#endif
+            assert(pb.val(less) == (a < b ? FieldT::one() : FieldT::zero()));
+            assert(pb.val(less_or_eq) == (a <= b ? FieldT::one() : FieldT::zero()));
+            assert(pb.is_satisfied());
+        }
+    }
+
+    print_time("comparison tests successful");
+}
+
+template<typename FieldT>
+void inner_product_gadget<FieldT>::generate_r1cs_constraints()
+{
+    /*
+      S_i = \sum_{k=0}^{i+1} A[i] * B[i]
+      S[0] = A[0] * B[0]
+      S[i+1] - S[i] = A[i] * B[i]
+    */
+    for (size_t i = 0; i < A.size(); ++i)
+    {
+        this->pb.add_r1cs_constraint(
+            r1cs_constraint<FieldT>(A[i], B[i],
+                                    (i == A.size()-1 ? result : S[i]) + (i == 0 ? 0 * ONE : -S[i-1])),
+            FMT(this->annotation_prefix, " S_%zu", i));
+    }
+}
+
+template<typename FieldT>
+void inner_product_gadget<FieldT>::generate_r1cs_witness()
+{
+    FieldT total = FieldT::zero();
+    for (size_t i = 0; i < A.size(); ++i)
+    {
+        A[i].evaluate(this->pb);
+        B[i].evaluate(this->pb);
+
+        total += this->pb.lc_val(A[i]) * this->pb.lc_val(B[i]);
+        this->pb.val(i == A.size()-1 ? result : S[i]) = total;
+    }
+}
+
+template<typename FieldT>
+void test_inner_product_gadget(const size_t n)
+{
+    printf("testing inner_product_gadget on all %zu bit strings\n", n);
+
+    protoboard<FieldT> pb;
+    pb_variable_array<FieldT> A;
+    A.allocate(pb, n, "A");
+    pb_variable_array<FieldT> B;
+    B.allocate(pb, n, "B");
+
+    pb_variable<FieldT> result;
+    result.allocate(pb, "result");
+
+    inner_product_gadget<FieldT> g(pb, A, B, result, "g");
+    g.generate_r1cs_constraints();
+
+    for (size_t i = 0; i < 1ul<<n; ++i)
+    {
+        for (size_t j = 0; j < 1ul<<n; ++j)
+        {
+            size_t correct = 0;
+            for (size_t k = 0; k < n; ++k)
+            {
+                pb.val(A[k]) = (i & (1ul<<k) ? FieldT::one() : FieldT::zero());
+                pb.val(B[k]) = (j & (1ul<<k) ? FieldT::one() : FieldT::zero());
+                correct += ((i & (1ul<<k)) && (j & (1ul<<k)) ? 1 : 0);
+            }
+
+            g.generate_r1cs_witness();
+#ifdef DEBUG
+            printf("positive test for (%zu, %zu)\n", i, j);
+#endif
+            assert(pb.val(result) == FieldT(correct));
+            assert(pb.is_satisfied());
+
+#ifdef DEBUG
+            printf("negative test for (%zu, %zu)\n", i, j);
+#endif
+            pb.val(result) = FieldT(100*n+19);
+            assert(!pb.is_satisfied());
+        }
+    }
+
+    print_time("inner_product_gadget tests successful");
+}
+
+template<typename FieldT>
+void loose_multiplexing_gadget<FieldT>::generate_r1cs_constraints()
+{
+    /* \alpha_i (index - i) = 0 */
+    for (size_t i = 0; i < arr.size(); ++i)
+    {
+        this->pb.add_r1cs_constraint(
+            r1cs_constraint<FieldT>(alpha[i], index - i, 0),
+            FMT(this->annotation_prefix, " alpha_%zu", i));
+    }
+
+    /* 1 * (\sum \alpha_i) = success_flag */
+    linear_combination<FieldT> a, b, c;
+    a.add_term(ONE);
+    for (size_t i = 0; i < arr.size(); ++i)
+    {
+        b.add_term(alpha[i]);
+    }
+    c.add_term(success_flag);
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(a, b, c), FMT(this->annotation_prefix, " main_constraint"));
+
+    /* now success_flag is constrained to either 0 (if index is out of
+       range) or \alpha_i. constrain it and \alpha_i to zero */
+    generate_boolean_r1cs_constraint<FieldT>(this->pb, success_flag, FMT(this->annotation_prefix, " success_flag"));
+
+    /* compute result */
+    compute_result->generate_r1cs_constraints();
+}
+
+template<typename FieldT>
+void loose_multiplexing_gadget<FieldT>::generate_r1cs_witness()
+{
+    /* assumes that idx can be fit in ulong; true for our purposes for now */
+    const bigint<FieldT::num_limbs> valint = this->pb.val(index).as_bigint();
+    unsigned long idx = valint.as_ulong();
+    const bigint<FieldT::num_limbs> arrsize(arr.size());
+
+    if (idx >= arr.size() || mpn_cmp(valint.data, arrsize.data, FieldT::num_limbs) >= 0)
+    {
+        for (size_t i = 0; i < arr.size(); ++i)
+        {
+            this->pb.val(alpha[i]) = FieldT::zero();
+        }
+
+        this->pb.val(success_flag) = FieldT::zero();
+    }
+    else
+    {
+        for (size_t i = 0; i < arr.size(); ++i)
+        {
+            this->pb.val(alpha[i]) = (i == idx ? FieldT::one() : FieldT::zero());
+        }
+
+        this->pb.val(success_flag) = FieldT::one();
+    }
+
+    compute_result->generate_r1cs_witness();
+}
+
+template<typename FieldT>
+void test_loose_multiplexing_gadget(const size_t n)
+{
+    printf("testing loose_multiplexing_gadget on 2**%zu pb_variable<FieldT> array inputs\n", n);
+    protoboard<FieldT> pb;
+
+    pb_variable_array<FieldT> arr;
+    arr.allocate(pb, 1ul<<n, "arr");
+    pb_variable<FieldT> index, result, success_flag;
+    index.allocate(pb, "index");
+    result.allocate(pb, "result");
+    success_flag.allocate(pb, "success_flag");
+
+    loose_multiplexing_gadget<FieldT> g(pb, arr, index, result, success_flag, "g");
+    g.generate_r1cs_constraints();
+
+    for (size_t i = 0; i < 1ul<<n; ++i)
+    {
+        pb.val(arr[i]) = FieldT((19*i) % (1ul<<n));
+    }
+
+    for (int idx = -1; idx <= (int)(1ul<<n); ++idx)
+    {
+        pb.val(index) = FieldT(idx);
+        g.generate_r1cs_witness();
+
+        if (0 <= idx && idx <= (int)(1ul<<n) - 1)
+        {
+            printf("demuxing element %d (in bounds)\n", idx);
+            assert(pb.val(result) == FieldT((19*idx) % (1ul<<n)));
+            assert(pb.val(success_flag) == FieldT::one());
+            assert(pb.is_satisfied());
+            pb.val(result) -= FieldT::one();
+            assert(!pb.is_satisfied());
+        }
+        else
+        {
+            printf("demuxing element %d (out of bounds)\n", idx);
+            assert(pb.val(success_flag) == FieldT::zero());
+            assert(pb.is_satisfied());
+            pb.val(success_flag) = FieldT::one();
+            assert(!pb.is_satisfied());
+        }
+    }
+    printf("loose_multiplexing_gadget tests successful\n");
+}
+
+template<typename FieldT, typename VarT>
+void create_linear_combination_constraints(protoboard<FieldT> &pb,
+                                           const std::vector<FieldT> &base,
+                                           const std::vector<std::pair<VarT, FieldT> > &v,
+                                           const VarT &target,
+                                           const std::string &annotation_prefix)
+{
+    for (size_t i = 0; i < base.size(); ++i)
+    {
+        linear_combination<FieldT> a, b, c;
+
+        a.add_term(ONE);
+        b.add_term(ONE, base[i]);
+
+        for (auto &p : v)
+        {
+            b.add_term(p.first.all_vars[i], p.second);
+        }
+
+        c.add_term(target.all_vars[i]);
+
+        pb.add_r1cs_constraint(r1cs_constraint<FieldT>(a, b, c), FMT(annotation_prefix, " linear_combination_%zu", i));
+    }
+}
+
+template<typename FieldT, typename VarT>
+void create_linear_combination_witness(protoboard<FieldT> &pb,
+                                       const std::vector<FieldT> &base,
+                                       const std::vector<std::pair<VarT, FieldT> > &v,
+                                       const VarT &target)
+{
+    for (size_t i = 0; i < base.size(); ++i)
+    {
+        pb.val(target.all_vars[i]) = base[i];
+
+        for (auto &p : v)
+        {
+            pb.val(target.all_vars[i]) += p.second * pb.val(p.first.all_vars[i]);
+        }
+    }
+}
+
+} // libsnark
+#endif // BASIC_GADGETS_TCC_
diff --git a/src/gadgetlib1/gadgets/gadget_from_r1cs.hpp b/src/gadgetlib1/gadgets/gadget_from_r1cs.hpp
new file mode 100644 (file)
index 0000000..e4b8a2a
--- /dev/null
@@ -0,0 +1,45 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for a gadget that can be created from an R1CS constraint system.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef GADGET_FROM_R1CS_HPP_
+#define GADGET_FROM_R1CS_HPP_
+
+#include <map>
+
+#include "gadgetlib1/gadget.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+class gadget_from_r1cs : public gadget<FieldT> {
+
+private:
+    const std::vector<pb_variable_array<FieldT> > vars;
+    const r1cs_constraint_system<FieldT> cs;
+    std::map<size_t, size_t> cs_to_vars;
+
+public:
+
+    gadget_from_r1cs(protoboard<FieldT> &pb,
+                     const std::vector<pb_variable_array<FieldT> > &vars,
+                     const r1cs_constraint_system<FieldT> &cs,
+                     const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness(const r1cs_primary_input<FieldT> &primary_input,
+                               const r1cs_auxiliary_input<FieldT> &auxiliary_input);
+};
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/gadget_from_r1cs.tcc"
+
+#endif // GADGET_FROM_R1CS_HPP_
diff --git a/src/gadgetlib1/gadgets/gadget_from_r1cs.tcc b/src/gadgetlib1/gadgets/gadget_from_r1cs.tcc
new file mode 100644 (file)
index 0000000..bc59b45
--- /dev/null
@@ -0,0 +1,123 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for a gadget that can be created from an R1CS constraint system.
+
+ See gadget_from_r1cs.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef GADGET_FROM_R1CS_TCC_
+#define GADGET_FROM_R1CS_TCC_
+
+namespace libsnark {
+
+template<typename FieldT>
+gadget_from_r1cs<FieldT>::gadget_from_r1cs(protoboard<FieldT> &pb,
+                                           const std::vector<pb_variable_array<FieldT> > &vars,
+                                           const r1cs_constraint_system<FieldT> &cs,
+                                           const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    vars(vars),
+    cs(cs)
+{
+    cs_to_vars[0] = 0; /* constant term maps to constant term */
+
+    size_t cs_var_idx = 1;
+    for (auto va : vars)
+    {
+#ifdef DEBUG
+        printf("gadget_from_r1cs: translating a block of variables with length %zu\n", va.size());
+#endif
+        for (auto v : va)
+        {
+            cs_to_vars[cs_var_idx] = v.index;
+
+#ifdef DEBUG
+            if (v.index != 0)
+            {
+                // handle annotations, except for re-annotating constant term
+                const std::map<size_t, std::string>::const_iterator it = cs.variable_annotations.find(cs_var_idx);
+
+                std::string annotation = FMT(annotation_prefix, " variable_%zu", cs_var_idx);
+                if (it != cs.variable_annotations.end())
+                {
+                    annotation = annotation_prefix + " " + it->second;
+                }
+
+                pb.augment_variable_annotation(v, annotation);
+            }
+#endif
+            ++cs_var_idx;
+        }
+    }
+
+#ifdef DEBUG
+    printf("gadget_from_r1cs: sum of all block lengths: %zu\n", cs_var_idx-1);
+    printf("gadget_from_r1cs: cs.num_variables(): %zu\n", cs.num_variables());
+#endif
+
+    assert(cs_var_idx - 1 == cs.num_variables());
+}
+
+template<typename FieldT>
+void gadget_from_r1cs<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < cs.num_constraints(); ++i)
+    {
+        const r1cs_constraint<FieldT> &constr = cs.constraints[i];
+        r1cs_constraint<FieldT> translated_constr;
+
+        for (const linear_term<FieldT> &t: constr.a.terms)
+        {
+            translated_constr.a.terms.emplace_back(linear_term<FieldT>(pb_variable<FieldT>(cs_to_vars[t.index]), t.coeff));
+        }
+
+        for (const linear_term<FieldT> &t: constr.b.terms)
+        {
+            translated_constr.b.terms.emplace_back(linear_term<FieldT>(pb_variable<FieldT>(cs_to_vars[t.index]), t.coeff));
+        }
+
+        for (const linear_term<FieldT> &t: constr.c.terms)
+        {
+            translated_constr.c.terms.emplace_back(linear_term<FieldT>(pb_variable<FieldT>(cs_to_vars[t.index]), t.coeff));
+        }
+
+        std::string annotation = FMT(this->annotation_prefix, " constraint_%zu", i);
+
+#ifdef DEBUG
+        auto it = cs.constraint_annotations.find(i);
+        if (it != cs.constraint_annotations.end())
+        {
+            annotation = this->annotation_prefix + " " + it->second;
+        }
+#endif
+        this->pb.add_r1cs_constraint(translated_constr, annotation);
+    }
+}
+
+template<typename FieldT>
+void gadget_from_r1cs<FieldT>::generate_r1cs_witness(const r1cs_primary_input<FieldT> &primary_input,
+                                                     const r1cs_auxiliary_input<FieldT> &auxiliary_input)
+{
+    assert(cs.num_inputs() == primary_input.size());
+    assert(cs.num_variables() == primary_input.size() + auxiliary_input.size());
+
+    for (size_t i = 0; i < primary_input.size(); ++i)
+    {
+        this->pb.val(pb_variable<FieldT>(cs_to_vars[i+1])) = primary_input[i];
+    }
+
+    for (size_t i = 0; i < auxiliary_input.size(); ++i)
+    {
+        this->pb.val(pb_variable<FieldT>(cs_to_vars[primary_input.size()+i+1])) = auxiliary_input[i];
+    }
+}
+
+} // libsnark
+
+#endif // GADGET_FROM_R1CS_TCC_
diff --git a/src/gadgetlib1/gadgets/hashes/digest_selector_gadget.hpp b/src/gadgetlib1/gadgets/hashes/digest_selector_gadget.hpp
new file mode 100644 (file)
index 0000000..a7598b9
--- /dev/null
@@ -0,0 +1,42 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#ifndef DIGEST_SELECTOR_GADGET_HPP_
+#define DIGEST_SELECTOR_GADGET_HPP_
+
+#include <vector>
+
+#include "gadgetlib1/gadgets/basic_gadgets.hpp"
+#include "gadgetlib1/gadgets/hashes/hash_io.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+class digest_selector_gadget : public gadget<FieldT> {
+public:
+    size_t digest_size;
+    digest_variable<FieldT> input;
+    pb_linear_combination<FieldT> is_right;
+    digest_variable<FieldT> left;
+    digest_variable<FieldT> right;
+
+    digest_selector_gadget(protoboard<FieldT> &pb,
+                           const size_t digest_size,
+                           const digest_variable<FieldT> &input,
+                           const pb_linear_combination<FieldT> &is_right,
+                           const digest_variable<FieldT> &left,
+                           const digest_variable<FieldT> &right,
+                           const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/hashes/digest_selector_gadget.tcc"
+
+#endif // DIGEST_SELECTOR_GADGET_HPP_
diff --git a/src/gadgetlib1/gadgets/hashes/digest_selector_gadget.tcc b/src/gadgetlib1/gadgets/hashes/digest_selector_gadget.tcc
new file mode 100644 (file)
index 0000000..422ee17
--- /dev/null
@@ -0,0 +1,62 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#ifndef DIGEST_SELECTOR_GADGET_TCC_
+#define DIGEST_SELECTOR_GADGET_TCC_
+
+namespace libsnark {
+
+template<typename FieldT>
+digest_selector_gadget<FieldT>::digest_selector_gadget(protoboard<FieldT> &pb,
+                                                       const size_t digest_size,
+                                                       const digest_variable<FieldT> &input,
+                                                       const pb_linear_combination<FieldT> &is_right,
+                                                       const digest_variable<FieldT> &left,
+                                                       const digest_variable<FieldT> &right,
+                                                       const std::string &annotation_prefix) :
+gadget<FieldT>(pb, annotation_prefix), digest_size(digest_size), input(input), is_right(is_right), left(left), right(right)
+{
+}
+
+template<typename FieldT>
+void digest_selector_gadget<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < digest_size; ++i)
+    {
+        /*
+          input = is_right * right + (1-is_right) * left
+          input - left = is_right(right - left)
+        */
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(is_right, right.bits[i] - left.bits[i], input.bits[i] - left.bits[i]),
+                                     FMT(this->annotation_prefix, " propagate_%zu", i));
+    }
+}
+
+template<typename FieldT>
+void digest_selector_gadget<FieldT>::generate_r1cs_witness()
+{
+    is_right.evaluate(this->pb);
+
+    assert(this->pb.lc_val(is_right) == FieldT::one() || this->pb.lc_val(is_right) == FieldT::zero());
+    if (this->pb.lc_val(is_right) == FieldT::one())
+    {
+        for (size_t i = 0; i < digest_size; ++i)
+        {
+            this->pb.val(right.bits[i]) = this->pb.val(input.bits[i]);
+        }
+    }
+    else
+    {
+        for (size_t i = 0; i < digest_size; ++i)
+        {
+            this->pb.val(left.bits[i]) = this->pb.val(input.bits[i]);
+        }
+    }
+}
+
+} // libsnark
+
+#endif // DIGEST_SELECTOR_GADGET_TCC_
diff --git a/src/gadgetlib1/gadgets/hashes/hash_io.hpp b/src/gadgetlib1/gadgets/hashes/hash_io.hpp
new file mode 100644 (file)
index 0000000..80ca19c
--- /dev/null
@@ -0,0 +1,63 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#ifndef HASH_IO_HPP_
+#define HASH_IO_HPP_
+#include <cstddef>
+#include <vector>
+#include "gadgetlib1/gadgets/basic_gadgets.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+class digest_variable : public gadget<FieldT> {
+public:
+    size_t digest_size;
+    pb_variable_array<FieldT> bits;
+
+    digest_variable<FieldT>(protoboard<FieldT> &pb,
+                            const size_t digest_size,
+                            const std::string &annotation_prefix);
+
+    digest_variable<FieldT>(protoboard<FieldT> &pb,
+                            const size_t digest_size,
+                            const pb_variable_array<FieldT> &partial_bits,
+                            const pb_variable<FieldT> &padding,
+                            const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness(const bit_vector& contents);
+    bit_vector get_digest() const;
+};
+
+template<typename FieldT>
+class block_variable : public gadget<FieldT> {
+public:
+    size_t block_size;
+    pb_variable_array<FieldT> bits;
+
+    block_variable(protoboard<FieldT> &pb,
+                   const size_t block_size,
+                   const std::string &annotation_prefix);
+
+    block_variable(protoboard<FieldT> &pb,
+                   const std::vector<pb_variable_array<FieldT> > &parts,
+                   const std::string &annotation_prefix);
+
+    block_variable(protoboard<FieldT> &pb,
+                   const digest_variable<FieldT> &left,
+                   const digest_variable<FieldT> &right,
+                   const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness(const bit_vector& contents);
+    bit_vector get_block() const;
+};
+
+} // libsnark
+#include "gadgetlib1/gadgets/hashes/hash_io.tcc"
+
+#endif // HASH_IO_HPP_
diff --git a/src/gadgetlib1/gadgets/hashes/hash_io.tcc b/src/gadgetlib1/gadgets/hashes/hash_io.tcc
new file mode 100644 (file)
index 0000000..b122d8f
--- /dev/null
@@ -0,0 +1,105 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#ifndef HASH_IO_TCC_
+#define HASH_IO_TCC_
+
+namespace libsnark {
+
+template<typename FieldT>
+digest_variable<FieldT>::digest_variable(protoboard<FieldT> &pb,
+                                         const size_t digest_size,
+                                         const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix), digest_size(digest_size)
+{
+    bits.allocate(pb, digest_size, FMT(this->annotation_prefix, " bits"));
+}
+
+template<typename FieldT>
+digest_variable<FieldT>::digest_variable(protoboard<FieldT> &pb,
+                                         const size_t digest_size,
+                                         const pb_variable_array<FieldT> &partial_bits,
+                                         const pb_variable<FieldT> &padding,
+                                         const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix), digest_size(digest_size)
+{
+    assert(bits.size() <= digest_size);
+    bits = partial_bits;
+    while (bits.size() != digest_size)
+    {
+        bits.emplace_back(padding);
+    }
+}
+
+template<typename FieldT>
+void digest_variable<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < digest_size; ++i)
+    {
+        generate_boolean_r1cs_constraint<FieldT>(this->pb, bits[i], FMT(this->annotation_prefix, " bits_%zu", i));
+    }
+}
+
+template<typename FieldT>
+void digest_variable<FieldT>::generate_r1cs_witness(const bit_vector& contents)
+{
+    bits.fill_with_bits(this->pb, contents);
+}
+
+template<typename FieldT>
+bit_vector digest_variable<FieldT>::get_digest() const
+{
+    return bits.get_bits(this->pb);
+}
+
+template<typename FieldT>
+block_variable<FieldT>::block_variable(protoboard<FieldT> &pb,
+                                       const size_t block_size,
+                                       const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix), block_size(block_size)
+{
+    bits.allocate(pb, block_size, FMT(this->annotation_prefix, " bits"));
+}
+
+template<typename FieldT>
+block_variable<FieldT>::block_variable(protoboard<FieldT> &pb,
+                                       const std::vector<pb_variable_array<FieldT> > &parts,
+                                       const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix)
+{
+    for (auto &part : parts)
+    {
+        bits.insert(bits.end(), part.begin(), part.end());
+    }
+}
+
+template<typename FieldT>
+block_variable<FieldT>::block_variable(protoboard<FieldT> &pb,
+                                       const digest_variable<FieldT> &left,
+                                       const digest_variable<FieldT> &right,
+                                       const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix)
+{
+    assert(left.bits.size() == right.bits.size());
+    block_size = 2 * left.bits.size();
+    bits.insert(bits.end(), left.bits.begin(), left.bits.end());
+    bits.insert(bits.end(), right.bits.begin(), right.bits.end());
+}
+
+template<typename FieldT>
+void block_variable<FieldT>::generate_r1cs_witness(const bit_vector& contents)
+{
+    bits.fill_with_bits(this->pb, contents);
+}
+
+template<typename FieldT>
+bit_vector block_variable<FieldT>::get_block() const
+{
+    return bits.get_bits(this->pb);
+}
+
+} // libsnark
+#endif // HASH_IO_TCC_
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/sha256_aux.hpp b/src/gadgetlib1/gadgets/hashes/sha256/sha256_aux.hpp
new file mode 100644 (file)
index 0000000..e0c7a7e
--- /dev/null
@@ -0,0 +1,160 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for auxiliary gadgets for the SHA256 gadget.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SHA256_AUX_HPP_
+#define SHA256_AUX_HPP_
+
+#include "gadgetlib1/gadgets/basic_gadgets.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+class lastbits_gadget : public gadget<FieldT> {
+public:
+    pb_variable<FieldT> X;
+    size_t X_bits;
+    pb_variable<FieldT> result;
+    pb_linear_combination_array<FieldT> result_bits;
+
+    pb_linear_combination_array<FieldT> full_bits;
+    std::shared_ptr<packing_gadget<FieldT> > unpack_bits;
+    std::shared_ptr<packing_gadget<FieldT> > pack_result;
+
+    lastbits_gadget(protoboard<FieldT> &pb,
+                    const pb_variable<FieldT> &X,
+                    const size_t X_bits,
+                    const pb_variable<FieldT> &result,
+                    const pb_linear_combination_array<FieldT> &result_bits,
+                    const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+class XOR3_gadget : public gadget<FieldT> {
+private:
+    pb_variable<FieldT> tmp;
+public:
+    pb_linear_combination<FieldT> A;
+    pb_linear_combination<FieldT> B;
+    pb_linear_combination<FieldT> C;
+    bool assume_C_is_zero;
+    pb_linear_combination<FieldT> out;
+
+    XOR3_gadget(protoboard<FieldT> &pb,
+                const pb_linear_combination<FieldT> &A,
+                const pb_linear_combination<FieldT> &B,
+                const pb_linear_combination<FieldT> &C,
+                const bool assume_C_is_zero,
+                const pb_linear_combination<FieldT> &out,
+                const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+/* Page 10 of http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf */
+template<typename FieldT>
+class small_sigma_gadget : public gadget<FieldT> {
+private:
+    pb_variable_array<FieldT> W;
+    pb_variable<FieldT> result;
+public:
+    pb_variable_array<FieldT> result_bits;
+    std::vector<std::shared_ptr<XOR3_gadget<FieldT> > > compute_bits;
+    std::shared_ptr<packing_gadget<FieldT> > pack_result;
+
+    small_sigma_gadget(protoboard<FieldT> &pb,
+                       const pb_variable_array<FieldT> &W,
+                       const pb_variable<FieldT> &result,
+                       const size_t rot1,
+                       const size_t rot2,
+                       const size_t shift,
+                       const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+/* Page 10 of http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf */
+template<typename FieldT>
+class big_sigma_gadget : public gadget<FieldT> {
+private:
+    pb_linear_combination_array<FieldT> W;
+    pb_variable<FieldT> result;
+public:
+    pb_variable_array<FieldT> result_bits;
+    std::vector<std::shared_ptr<XOR3_gadget<FieldT> > > compute_bits;
+    std::shared_ptr<packing_gadget<FieldT> > pack_result;
+
+    big_sigma_gadget(protoboard<FieldT> &pb,
+                     const pb_linear_combination_array<FieldT> &W,
+                     const pb_variable<FieldT> &result,
+                     const size_t rot1,
+                     const size_t rot2,
+                     const size_t rot3,
+                     const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+/* Page 10 of http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf */
+template<typename FieldT>
+class choice_gadget : public gadget<FieldT> {
+private:
+    pb_variable_array<FieldT> result_bits;
+public:
+    pb_linear_combination_array<FieldT> X;
+    pb_linear_combination_array<FieldT> Y;
+    pb_linear_combination_array<FieldT> Z;
+    pb_variable<FieldT> result;
+    std::shared_ptr<packing_gadget<FieldT> > pack_result;
+
+    choice_gadget(protoboard<FieldT> &pb,
+                  const pb_linear_combination_array<FieldT> &X,
+                  const pb_linear_combination_array<FieldT> &Y,
+                  const pb_linear_combination_array<FieldT> &Z,
+                  const pb_variable<FieldT> &result, const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+/* Page 10 of http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf */
+template<typename FieldT>
+class majority_gadget : public gadget<FieldT> {
+private:
+    pb_variable_array<FieldT> result_bits;
+    std::shared_ptr<packing_gadget<FieldT> > pack_result;
+public:
+    pb_linear_combination_array<FieldT> X;
+    pb_linear_combination_array<FieldT> Y;
+    pb_linear_combination_array<FieldT> Z;
+    pb_variable<FieldT> result;
+
+    majority_gadget(protoboard<FieldT> &pb,
+                    const pb_linear_combination_array<FieldT> &X,
+                    const pb_linear_combination_array<FieldT> &Y,
+                    const pb_linear_combination_array<FieldT> &Z,
+                    const pb_variable<FieldT> &result,
+                    const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/hashes/sha256/sha256_aux.tcc"
+
+#endif // SHA256_AUX_HPP_
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/sha256_aux.tcc b/src/gadgetlib1/gadgets/hashes/sha256/sha256_aux.tcc
new file mode 100644 (file)
index 0000000..8ab67be
--- /dev/null
@@ -0,0 +1,297 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for auxiliary gadgets for the SHA256 gadget.
+
+ See sha256_aux.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SHA256_AUX_TCC_
+#define SHA256_AUX_TCC_
+
+namespace libsnark {
+
+template<typename FieldT>
+lastbits_gadget<FieldT>::lastbits_gadget(protoboard<FieldT> &pb,
+                                         const pb_variable<FieldT> &X,
+                                         const size_t X_bits,
+                                         const pb_variable<FieldT> &result,
+                                         const pb_linear_combination_array<FieldT> &result_bits,
+                                         const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    X(X),
+    X_bits(X_bits),
+    result(result),
+    result_bits(result_bits)
+{
+    full_bits = result_bits;
+    for (size_t i = result_bits.size(); i < X_bits; ++i)
+    {
+        pb_variable<FieldT> full_bits_overflow;
+        full_bits_overflow.allocate(pb, FMT(this->annotation_prefix, " full_bits_%zu", i));
+        full_bits.emplace_back(full_bits_overflow);
+    }
+
+    unpack_bits.reset(new packing_gadget<FieldT>(pb, full_bits, X, FMT(this->annotation_prefix, " unpack_bits")));
+    pack_result.reset(new packing_gadget<FieldT>(pb, result_bits, result, FMT(this->annotation_prefix, " pack_result")));
+}
+
+template<typename FieldT>
+void lastbits_gadget<FieldT>::generate_r1cs_constraints()
+{
+    unpack_bits->generate_r1cs_constraints(true);
+    pack_result->generate_r1cs_constraints(false);
+}
+
+template<typename FieldT>
+void lastbits_gadget<FieldT>::generate_r1cs_witness()
+{
+    unpack_bits->generate_r1cs_witness_from_packed();
+    pack_result->generate_r1cs_witness_from_bits();
+}
+
+template<typename FieldT>
+XOR3_gadget<FieldT>::XOR3_gadget(protoboard<FieldT> &pb,
+                                 const pb_linear_combination<FieldT> &A,
+                                 const pb_linear_combination<FieldT> &B,
+                                 const pb_linear_combination<FieldT> &C,
+                                 const bool assume_C_is_zero,
+                                 const pb_linear_combination<FieldT> &out,
+                                 const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    A(A),
+    B(B),
+    C(C),
+    assume_C_is_zero(assume_C_is_zero),
+    out(out)
+{
+    if (!assume_C_is_zero)
+    {
+        tmp.allocate(pb, FMT(this->annotation_prefix, " tmp"));
+    }
+}
+
+template<typename FieldT>
+void XOR3_gadget<FieldT>::generate_r1cs_constraints()
+{
+    /*
+      tmp = A + B - 2AB i.e. tmp = A xor B
+      out = tmp + C - 2tmp C i.e. out = tmp xor C
+    */
+    if (assume_C_is_zero)
+    {
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(2*A, B, A + B - out), FMT(this->annotation_prefix, " implicit_tmp_equals_out"));
+    }
+    else
+    {
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(2*A, B, A + B - tmp), FMT(this->annotation_prefix, " tmp"));
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(2 * tmp, C, tmp + C - out), FMT(this->annotation_prefix, " out"));
+    }
+}
+
+template<typename FieldT>
+void XOR3_gadget<FieldT>::generate_r1cs_witness()
+{
+    if (assume_C_is_zero)
+    {
+        this->pb.lc_val(out) = this->pb.lc_val(A) + this->pb.lc_val(B) - FieldT(2) * this->pb.lc_val(A) * this->pb.lc_val(B);
+    }
+    else
+    {
+        this->pb.val(tmp) = this->pb.lc_val(A) + this->pb.lc_val(B) - FieldT(2) * this->pb.lc_val(A) * this->pb.lc_val(B);
+        this->pb.lc_val(out) = this->pb.val(tmp) + this->pb.lc_val(C) - FieldT(2) * this->pb.val(tmp) * this->pb.lc_val(C);
+    }
+}
+
+#define SHA256_GADGET_ROTR(A, i, k) A[((i)+(k)) % 32]
+
+/* Page 10 of http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf */
+template<typename FieldT>
+small_sigma_gadget<FieldT>::small_sigma_gadget(protoboard<FieldT> &pb,
+                                               const pb_variable_array<FieldT> &W,
+                                               const pb_variable<FieldT> &result,
+                                               const size_t rot1,
+                                               const size_t rot2,
+                                               const size_t shift,
+                                               const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    W(W),
+    result(result)
+{
+    result_bits.allocate(pb, 32, FMT(this->annotation_prefix, " result_bits"));
+    compute_bits.resize(32);
+    for (size_t i = 0; i < 32; ++i)
+    {
+        compute_bits[i].reset(new XOR3_gadget<FieldT>(pb, SHA256_GADGET_ROTR(W, i, rot1), SHA256_GADGET_ROTR(W, i, rot2),
+                                              (i + shift < 32 ? W[i+shift] : ONE),
+                                              (i + shift >= 32), result_bits[i],
+                                              FMT(this->annotation_prefix, " compute_bits_%zu", i)));
+    }
+    pack_result.reset(new packing_gadget<FieldT>(pb, result_bits, result, FMT(this->annotation_prefix, " pack_result")));
+}
+
+template<typename FieldT>
+void small_sigma_gadget<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        compute_bits[i]->generate_r1cs_constraints();
+    }
+
+    pack_result->generate_r1cs_constraints(false);
+}
+
+template<typename FieldT>
+void small_sigma_gadget<FieldT>::generate_r1cs_witness()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        compute_bits[i]->generate_r1cs_witness();
+    }
+
+    pack_result->generate_r1cs_witness_from_bits();
+}
+
+template<typename FieldT>
+big_sigma_gadget<FieldT>::big_sigma_gadget(protoboard<FieldT> &pb,
+                                           const pb_linear_combination_array<FieldT> &W,
+                                           const pb_variable<FieldT> &result,
+                                           const size_t rot1,
+                                           const size_t rot2,
+                                           const size_t rot3,
+                                           const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    W(W),
+    result(result)
+{
+    result_bits.allocate(pb, 32, FMT(this->annotation_prefix, " result_bits"));
+    compute_bits.resize(32);
+    for (size_t i = 0; i < 32; ++i)
+    {
+        compute_bits[i].reset(new XOR3_gadget<FieldT>(pb, SHA256_GADGET_ROTR(W, i, rot1), SHA256_GADGET_ROTR(W, i, rot2), SHA256_GADGET_ROTR(W, i, rot3), false, result_bits[i],
+                                                      FMT(this->annotation_prefix, " compute_bits_%zu", i)));
+    }
+
+    pack_result.reset(new packing_gadget<FieldT>(pb, result_bits, result, FMT(this->annotation_prefix, " pack_result")));
+}
+
+template<typename FieldT>
+void big_sigma_gadget<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        compute_bits[i]->generate_r1cs_constraints();
+    }
+
+    pack_result->generate_r1cs_constraints(false);
+}
+
+template<typename FieldT>
+void big_sigma_gadget<FieldT>::generate_r1cs_witness()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        compute_bits[i]->generate_r1cs_witness();
+    }
+
+    pack_result->generate_r1cs_witness_from_bits();
+}
+
+/* Page 10 of http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf */
+template<typename FieldT>
+choice_gadget<FieldT>::choice_gadget(protoboard<FieldT> &pb,
+                                     const pb_linear_combination_array<FieldT> &X,
+                                     const pb_linear_combination_array<FieldT> &Y,
+                                     const pb_linear_combination_array<FieldT> &Z,
+                                     const pb_variable<FieldT> &result, const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    X(X),
+    Y(Y),
+    Z(Z),
+    result(result)
+{
+    result_bits.allocate(pb, 32, FMT(this->annotation_prefix, " result_bits"));
+    pack_result.reset(new packing_gadget<FieldT>(pb, result_bits, result, FMT(this->annotation_prefix, " result")));
+}
+
+template<typename FieldT>
+void choice_gadget<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        /*
+          result = x * y + (1-x) * z
+          result - z = x * (y - z)
+        */
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(X[i], Y[i] - Z[i], result_bits[i] - Z[i]), FMT(this->annotation_prefix, " result_bits_%zu", i));
+    }
+    pack_result->generate_r1cs_constraints(false);
+}
+
+template<typename FieldT>
+void choice_gadget<FieldT>::generate_r1cs_witness()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        this->pb.val(result_bits[i]) = this->pb.lc_val(X[i]) * this->pb.lc_val(Y[i]) + (FieldT::one() - this->pb.lc_val(X[i])) * this->pb.lc_val(Z[i]);
+    }
+    pack_result->generate_r1cs_witness_from_bits();
+}
+
+/* Page 10 of http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf */
+template<typename FieldT>
+majority_gadget<FieldT>::majority_gadget(protoboard<FieldT> &pb,
+                                         const pb_linear_combination_array<FieldT> &X,
+                                         const pb_linear_combination_array<FieldT> &Y,
+                                         const pb_linear_combination_array<FieldT> &Z,
+                                         const pb_variable<FieldT> &result,
+                                         const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    X(X),
+    Y(Y),
+    Z(Z),
+    result(result)
+{
+    result_bits.allocate(pb, 32, FMT(this->annotation_prefix, " result_bits"));
+    pack_result.reset(new packing_gadget<FieldT>(pb, result_bits, result, FMT(this->annotation_prefix, " result")));
+}
+
+template<typename FieldT>
+void majority_gadget<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        /*
+          2*result + aux = x + y + z
+          x, y, z, aux -- bits
+          aux = x + y + z - 2*result
+        */
+        generate_boolean_r1cs_constraint<FieldT>(this->pb, result_bits[i], FMT(this->annotation_prefix, " result_%zu", i));
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(X[i] + Y[i] + Z[i] - 2 * result_bits[i],
+                                                             1 - (X[i] + Y[i] + Z[i] -  2 * result_bits[i]),
+                                                             0),
+                                     FMT(this->annotation_prefix, " result_bits_%zu", i));
+    }
+    pack_result->generate_r1cs_constraints(false);
+}
+
+template<typename FieldT>
+void majority_gadget<FieldT>::generate_r1cs_witness()
+{
+    for (size_t i = 0; i < 32; ++i)
+    {
+        const long v = (this->pb.lc_val(X[i]) + this->pb.lc_val(Y[i]) + this->pb.lc_val(Z[i])).as_ulong();
+        this->pb.val(result_bits[i]) = FieldT(v / 2);
+    }
+
+    pack_result->generate_r1cs_witness_from_bits();
+}
+
+} // libsnark
+
+#endif // SHA256_AUX_TCC_
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/sha256_components.hpp b/src/gadgetlib1/gadgets/hashes/sha256/sha256_components.hpp
new file mode 100644 (file)
index 0000000..c2f31e3
--- /dev/null
@@ -0,0 +1,108 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for gadgets for the SHA256 message schedule and round function.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SHA256_COMPONENTS_HPP_
+#define SHA256_COMPONENTS_HPP_
+
+#include "gadgetlib1/gadgets/basic_gadgets.hpp"
+#include "gadgetlib1/gadgets/hashes/hash_io.hpp"
+#include "gadgetlib1/gadgets/hashes/sha256/sha256_aux.hpp"
+
+namespace libsnark {
+
+const size_t SHA256_digest_size = 256;
+const size_t SHA256_block_size = 512;
+
+template<typename FieldT>
+pb_linear_combination_array<FieldT> SHA256_default_IV(protoboard<FieldT> &pb);
+
+template<typename FieldT>
+class sha256_message_schedule_gadget : public gadget<FieldT> {
+public:
+    std::vector<pb_variable_array<FieldT> > W_bits;
+    std::vector<std::shared_ptr<packing_gadget<FieldT> > > pack_W;
+
+    std::vector<pb_variable<FieldT> > sigma0;
+    std::vector<pb_variable<FieldT> > sigma1;
+    std::vector<std::shared_ptr<small_sigma_gadget<FieldT> > > compute_sigma0;
+    std::vector<std::shared_ptr<small_sigma_gadget<FieldT> > > compute_sigma1;
+    std::vector<pb_variable<FieldT> > unreduced_W;
+    std::vector<std::shared_ptr<lastbits_gadget<FieldT> > > mod_reduce_W;
+public:
+    pb_variable_array<FieldT> M;
+    pb_variable_array<FieldT> packed_W;
+    sha256_message_schedule_gadget(protoboard<FieldT> &pb,
+                                   const pb_variable_array<FieldT> &M,
+                                   const pb_variable_array<FieldT> &packed_W,
+                                   const std::string &annotation_prefix);
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+template<typename FieldT>
+class sha256_round_function_gadget : public gadget<FieldT> {
+public:
+    pb_variable<FieldT> sigma0;
+    pb_variable<FieldT> sigma1;
+    std::shared_ptr<big_sigma_gadget<FieldT> > compute_sigma0;
+    std::shared_ptr<big_sigma_gadget<FieldT> > compute_sigma1;
+    pb_variable<FieldT> choice;
+    pb_variable<FieldT> majority;
+    std::shared_ptr<choice_gadget<FieldT> > compute_choice;
+    std::shared_ptr<majority_gadget<FieldT> > compute_majority;
+    pb_variable<FieldT> packed_d;
+    std::shared_ptr<packing_gadget<FieldT> > pack_d;
+    pb_variable<FieldT> packed_h;
+    std::shared_ptr<packing_gadget<FieldT> > pack_h;
+    pb_variable<FieldT> unreduced_new_a;
+    pb_variable<FieldT> unreduced_new_e;
+    std::shared_ptr<lastbits_gadget<FieldT> > mod_reduce_new_a;
+    std::shared_ptr<lastbits_gadget<FieldT> > mod_reduce_new_e;
+    pb_variable<FieldT> packed_new_a;
+    pb_variable<FieldT> packed_new_e;
+public:
+    pb_linear_combination_array<FieldT> a;
+    pb_linear_combination_array<FieldT> b;
+    pb_linear_combination_array<FieldT> c;
+    pb_linear_combination_array<FieldT> d;
+    pb_linear_combination_array<FieldT> e;
+    pb_linear_combination_array<FieldT> f;
+    pb_linear_combination_array<FieldT> g;
+    pb_linear_combination_array<FieldT> h;
+    pb_variable<FieldT> W;
+    long K;
+    pb_linear_combination_array<FieldT> new_a;
+    pb_linear_combination_array<FieldT> new_e;
+
+    sha256_round_function_gadget(protoboard<FieldT> &pb,
+                                 const pb_linear_combination_array<FieldT> &a,
+                                 const pb_linear_combination_array<FieldT> &b,
+                                 const pb_linear_combination_array<FieldT> &c,
+                                 const pb_linear_combination_array<FieldT> &d,
+                                 const pb_linear_combination_array<FieldT> &e,
+                                 const pb_linear_combination_array<FieldT> &f,
+                                 const pb_linear_combination_array<FieldT> &g,
+                                 const pb_linear_combination_array<FieldT> &h,
+                                 const pb_variable<FieldT> &W,
+                                 const long &K,
+                                 const pb_linear_combination_array<FieldT> &new_a,
+                                 const pb_linear_combination_array<FieldT> &new_e,
+                                 const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/hashes/sha256/sha256_components.tcc"
+
+#endif // SHA256_COMPONENTS_HPP_
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/sha256_components.tcc b/src/gadgetlib1/gadgets/hashes/sha256/sha256_components.tcc
new file mode 100644 (file)
index 0000000..e8f233a
--- /dev/null
@@ -0,0 +1,250 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for gadgets for the SHA256 message schedule and round function.
+
+ See sha256_components.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SHA256_COMPONENTS_TCC_
+#define SHA256_COMPONENTS_TCC_
+
+namespace libsnark {
+
+const unsigned long SHA256_K[64] =  {
+    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+};
+
+const unsigned long SHA256_H[8] = {
+    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
+};
+
+template<typename FieldT>
+pb_linear_combination_array<FieldT> SHA256_default_IV(protoboard<FieldT> &pb)
+{
+    pb_linear_combination_array<FieldT> result;
+    result.reserve(SHA256_digest_size);
+
+    for (size_t i = 0; i < SHA256_digest_size; ++i)
+    {
+        int iv_val = (SHA256_H[i / 32] >> (31-(i % 32))) & 1;
+
+        pb_linear_combination<FieldT> iv_element;
+        iv_element.assign(pb, iv_val * ONE);
+        iv_element.evaluate(pb);
+
+        result.emplace_back(iv_element);
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+sha256_message_schedule_gadget<FieldT>::sha256_message_schedule_gadget(protoboard<FieldT> &pb,
+                                                                       const pb_variable_array<FieldT> &M,
+                                                                       const pb_variable_array<FieldT> &packed_W,
+                                                                       const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    M(M),
+    packed_W(packed_W)
+{
+    W_bits.resize(64);
+
+    pack_W.resize(16);
+    for (size_t i = 0; i < 16; ++i)
+    {
+        W_bits[i] = pb_variable_array<FieldT>(M.rbegin() + (15-i) * 32, M.rbegin() + (16-i) * 32);
+        pack_W[i].reset(new packing_gadget<FieldT>(pb, W_bits[i], packed_W[i], FMT(this->annotation_prefix, " pack_W_%zu", i)));
+    }
+
+    /* NB: some of those will be un-allocated */
+    sigma0.resize(64);
+    sigma1.resize(64);
+    compute_sigma0.resize(64);
+    compute_sigma1.resize(64);
+    unreduced_W.resize(64);
+    mod_reduce_W.resize(64);
+
+    for (size_t i = 16; i < 64; ++i)
+    {
+        /* allocate result variables for sigma0/sigma1 invocations */
+        sigma0[i].allocate(pb, FMT(this->annotation_prefix, " sigma0_%zu", i));
+        sigma1[i].allocate(pb, FMT(this->annotation_prefix, " sigma1_%zu", i));
+
+        /* compute sigma0/sigma1 */
+        compute_sigma0[i].reset(new small_sigma_gadget<FieldT>(pb, W_bits[i-15], sigma0[i], 7, 18, 3, FMT(this->annotation_prefix, " compute_sigma0_%zu", i)));
+        compute_sigma1[i].reset(new small_sigma_gadget<FieldT>(pb, W_bits[i-2], sigma1[i], 17, 19, 10, FMT(this->annotation_prefix, " compute_sigma1_%zu", i)));
+
+        /* unreduced_W = sigma0(W_{i-15}) + sigma1(W_{i-2}) + W_{i-7} + W_{i-16} before modulo 2^32 */
+        unreduced_W[i].allocate(pb, FMT(this->annotation_prefix, "unreduced_W_%zu", i));
+
+        /* allocate the bit representation of packed_W[i] */
+        W_bits[i].allocate(pb, 32, FMT(this->annotation_prefix, " W_bits_%zu", i));
+
+        /* and finally reduce this into packed and bit representations */
+        mod_reduce_W[i].reset(new lastbits_gadget<FieldT>(pb, unreduced_W[i], 32+2, packed_W[i], W_bits[i], FMT(this->annotation_prefix, " mod_reduce_W_%zu", i)));
+    }
+}
+
+template<typename FieldT>
+void sha256_message_schedule_gadget<FieldT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < 16; ++i)
+    {
+        pack_W[i]->generate_r1cs_constraints(false); // do not enforce bitness here; caller be aware.
+    }
+
+    for (size_t i = 16; i < 64; ++i)
+    {
+        compute_sigma0[i]->generate_r1cs_constraints();
+        compute_sigma1[i]->generate_r1cs_constraints();
+
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1,
+                                                             sigma0[i] + sigma1[i] + packed_W[i-16] + packed_W[i-7],
+                                                             unreduced_W[i]),
+            FMT(this->annotation_prefix, " unreduced_W_%zu", i));
+
+        mod_reduce_W[i]->generate_r1cs_constraints();
+    }
+}
+
+template<typename FieldT>
+void sha256_message_schedule_gadget<FieldT>::generate_r1cs_witness()
+{
+    for (size_t i = 0; i < 16; ++i)
+    {
+        pack_W[i]->generate_r1cs_witness_from_bits();
+    }
+
+    for (size_t i = 16; i < 64; ++i)
+    {
+        compute_sigma0[i]->generate_r1cs_witness();
+        compute_sigma1[i]->generate_r1cs_witness();
+
+        this->pb.val(unreduced_W[i]) = this->pb.val(sigma0[i]) + this->pb.val(sigma1[i]) + this->pb.val(packed_W[i-16]) + this->pb.val(packed_W[i-7]);
+        mod_reduce_W[i]->generate_r1cs_witness();
+    }
+}
+
+template<typename FieldT>
+sha256_round_function_gadget<FieldT>::sha256_round_function_gadget(protoboard<FieldT> &pb,
+                                                                   const pb_linear_combination_array<FieldT> &a,
+                                                                   const pb_linear_combination_array<FieldT> &b,
+                                                                   const pb_linear_combination_array<FieldT> &c,
+                                                                   const pb_linear_combination_array<FieldT> &d,
+                                                                   const pb_linear_combination_array<FieldT> &e,
+                                                                   const pb_linear_combination_array<FieldT> &f,
+                                                                   const pb_linear_combination_array<FieldT> &g,
+                                                                   const pb_linear_combination_array<FieldT> &h,
+                                                                   const pb_variable<FieldT> &W,
+                                                                   const long &K,
+                                                                   const pb_linear_combination_array<FieldT> &new_a,
+                                                                   const pb_linear_combination_array<FieldT> &new_e,
+                                                                   const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    a(a),
+    b(b),
+    c(c),
+    d(d),
+    e(e),
+    f(f),
+    g(g),
+    h(h),
+    W(W),
+    K(K),
+    new_a(new_a),
+    new_e(new_e)
+{
+    /* compute sigma0 and sigma1 */
+    sigma0.allocate(pb, FMT(this->annotation_prefix, " sigma0"));
+    sigma1.allocate(pb, FMT(this->annotation_prefix, " sigma1"));
+    compute_sigma0.reset(new big_sigma_gadget<FieldT>(pb, a, sigma0, 2, 13, 22, FMT(this->annotation_prefix, " compute_sigma0")));
+    compute_sigma1.reset(new big_sigma_gadget<FieldT>(pb, e, sigma1, 6, 11, 25, FMT(this->annotation_prefix, " compute_sigma1")));
+
+    /* compute choice */
+    choice.allocate(pb, FMT(this->annotation_prefix, " choice"));
+    compute_choice.reset(new choice_gadget<FieldT>(pb, e, f, g, choice, FMT(this->annotation_prefix, " compute_choice")));
+
+    /* compute majority */
+    majority.allocate(pb, FMT(this->annotation_prefix, " majority"));
+    compute_majority.reset(new majority_gadget<FieldT>(pb, a, b, c, majority, FMT(this->annotation_prefix, " compute_majority")));
+
+    /* pack d */
+    packed_d.allocate(pb, FMT(this->annotation_prefix, " packed_d"));
+    pack_d.reset(new packing_gadget<FieldT>(pb, d, packed_d, FMT(this->annotation_prefix, " pack_d")));
+
+    /* pack h */
+    packed_h.allocate(pb, FMT(this->annotation_prefix, " packed_h"));
+    pack_h.reset(new packing_gadget<FieldT>(pb, h, packed_h, FMT(this->annotation_prefix, " pack_h")));
+
+    /* compute the actual results for the round */
+    unreduced_new_a.allocate(pb, FMT(this->annotation_prefix, " unreduced_new_a"));
+    unreduced_new_e.allocate(pb, FMT(this->annotation_prefix, " unreduced_new_e"));
+
+    packed_new_a.allocate(pb, FMT(this->annotation_prefix, " packed_new_a"));
+    packed_new_e.allocate(pb, FMT(this->annotation_prefix, " packed_new_e"));
+
+    mod_reduce_new_a.reset(new lastbits_gadget<FieldT>(pb, unreduced_new_a, 32+3, packed_new_a, new_a, FMT(this->annotation_prefix, " mod_reduce_new_a")));
+    mod_reduce_new_e.reset(new lastbits_gadget<FieldT>(pb, unreduced_new_e, 32+3, packed_new_e, new_e, FMT(this->annotation_prefix, " mod_reduce_new_e")));
+}
+
+template<typename FieldT>
+void sha256_round_function_gadget<FieldT>::generate_r1cs_constraints()
+{
+    compute_sigma0->generate_r1cs_constraints();
+    compute_sigma1->generate_r1cs_constraints();
+
+    compute_choice->generate_r1cs_constraints();
+    compute_majority->generate_r1cs_constraints();
+
+    pack_d->generate_r1cs_constraints(false);
+    pack_h->generate_r1cs_constraints(false);
+
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1,
+                                                         packed_h + sigma1 + choice + K + W + sigma0 + majority,
+                                                         unreduced_new_a),
+        FMT(this->annotation_prefix, " unreduced_new_a"));
+
+    this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1,
+                                                         packed_d + packed_h + sigma1 + choice + K + W,
+                                                         unreduced_new_e),
+        FMT(this->annotation_prefix, " unreduced_new_e"));
+
+    mod_reduce_new_a->generate_r1cs_constraints();
+    mod_reduce_new_e->generate_r1cs_constraints();
+}
+
+template<typename FieldT>
+void sha256_round_function_gadget<FieldT>::generate_r1cs_witness()
+{
+    compute_sigma0->generate_r1cs_witness();
+    compute_sigma1->generate_r1cs_witness();
+
+    compute_choice->generate_r1cs_witness();
+    compute_majority->generate_r1cs_witness();
+
+    pack_d->generate_r1cs_witness_from_bits();
+    pack_h->generate_r1cs_witness_from_bits();
+
+    this->pb.val(unreduced_new_a) = this->pb.val(packed_h) + this->pb.val(sigma1) + this->pb.val(choice) + FieldT(K) + this->pb.val(W) + this->pb.val(sigma0) + this->pb.val(majority);
+    this->pb.val(unreduced_new_e) = this->pb.val(packed_d) + this->pb.val(packed_h) + this->pb.val(sigma1) + this->pb.val(choice) + FieldT(K) + this->pb.val(W);
+
+    mod_reduce_new_a->generate_r1cs_witness();
+    mod_reduce_new_e->generate_r1cs_witness();
+}
+
+} // libsnark
+
+#endif // SHA256_COMPONENTS_TCC_
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/sha256_gadget.hpp b/src/gadgetlib1/gadgets/hashes/sha256/sha256_gadget.hpp
new file mode 100644 (file)
index 0000000..8cb6365
--- /dev/null
@@ -0,0 +1,98 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for top-level SHA256 gadgets.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SHA256_GADGET_HPP_
+#define SHA256_GADGET_HPP_
+
+#include "common/data_structures/merkle_tree.hpp"
+#include "gadgetlib1/gadgets/basic_gadgets.hpp"
+#include "gadgetlib1/gadgets/hashes/hash_io.hpp"
+#include "gadgetlib1/gadgets/hashes/sha256/sha256_components.hpp"
+
+namespace libsnark {
+
+/**
+ * Gadget for the SHA256 compression function.
+ */
+template<typename FieldT>
+class sha256_compression_function_gadget : public gadget<FieldT> {
+public:
+    std::vector<pb_linear_combination_array<FieldT> > round_a;
+    std::vector<pb_linear_combination_array<FieldT> > round_b;
+    std::vector<pb_linear_combination_array<FieldT> > round_c;
+    std::vector<pb_linear_combination_array<FieldT> > round_d;
+    std::vector<pb_linear_combination_array<FieldT> > round_e;
+    std::vector<pb_linear_combination_array<FieldT> > round_f;
+    std::vector<pb_linear_combination_array<FieldT> > round_g;
+    std::vector<pb_linear_combination_array<FieldT> > round_h;
+
+    pb_variable_array<FieldT> packed_W;
+    std::shared_ptr<sha256_message_schedule_gadget<FieldT> > message_schedule;
+    std::vector<sha256_round_function_gadget<FieldT> > round_functions;
+
+    pb_variable_array<FieldT> unreduced_output;
+    pb_variable_array<FieldT> reduced_output;
+    std::vector<lastbits_gadget<FieldT> > reduce_output;
+public:
+    pb_linear_combination_array<FieldT> prev_output;
+    pb_variable_array<FieldT> new_block;
+    digest_variable<FieldT> output;
+
+    sha256_compression_function_gadget(protoboard<FieldT> &pb,
+                                       const pb_linear_combination_array<FieldT> &prev_output,
+                                       const pb_variable_array<FieldT> &new_block,
+                                       const digest_variable<FieldT> &output,
+                                       const std::string &annotation_prefix);
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+};
+
+/**
+ * Gadget for the SHA256 compression function, viewed as a 2-to-1 hash
+ * function, and using the same initialization vector as in SHA256
+ * specification. Thus, any collision for
+ * sha256_two_to_one_hash_gadget trivially extends to a collision for
+ * full SHA256 (by appending the same padding).
+ */
+template<typename FieldT>
+class sha256_two_to_one_hash_gadget : public gadget<FieldT> {
+public:
+    typedef bit_vector hash_value_type;
+    typedef merkle_authentication_path merkle_authentication_path_type;
+
+    std::shared_ptr<sha256_compression_function_gadget<FieldT> > f;
+
+    sha256_two_to_one_hash_gadget(protoboard<FieldT> &pb,
+                                  const digest_variable<FieldT> &left,
+                                  const digest_variable<FieldT> &right,
+                                  const digest_variable<FieldT> &output,
+                                  const std::string &annotation_prefix);
+    sha256_two_to_one_hash_gadget(protoboard<FieldT> &pb,
+                                  const size_t block_length,
+                                  const block_variable<FieldT> &input_block,
+                                  const digest_variable<FieldT> &output,
+                                  const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints(const bool ensure_output_bitness=true); // TODO: ignored for now
+    void generate_r1cs_witness();
+
+    static size_t get_block_len();
+    static size_t get_digest_len();
+    static bit_vector get_hash(const bit_vector &input);
+
+    static size_t expected_constraints(const bool ensure_output_bitness=true); // TODO: ignored for now
+};
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/hashes/sha256/sha256_gadget.tcc"
+
+#endif // SHA256_GADGET_HPP_
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/sha256_gadget.tcc b/src/gadgetlib1/gadgets/hashes/sha256/sha256_gadget.tcc
new file mode 100644 (file)
index 0000000..fc7ac98
--- /dev/null
@@ -0,0 +1,230 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for top-level SHA256 gadgets.
+
+ See sha256_gadget.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef SHA256_GADGET_TCC_
+#define SHA256_GADGET_TCC_
+
+namespace libsnark {
+
+template<typename FieldT>
+sha256_compression_function_gadget<FieldT>::sha256_compression_function_gadget(protoboard<FieldT> &pb,
+                                                                               const pb_linear_combination_array<FieldT> &prev_output,
+                                                                               const pb_variable_array<FieldT> &new_block,
+                                                                               const digest_variable<FieldT> &output,
+                                                                               const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    prev_output(prev_output),
+    new_block(new_block),
+    output(output)
+{
+    /* message schedule and inputs for it */
+    packed_W.allocate(pb, 64, FMT(this->annotation_prefix, " packed_W"));
+    message_schedule.reset(new sha256_message_schedule_gadget<FieldT>(pb, new_block, packed_W, FMT(this->annotation_prefix, " message_schedule")));
+
+    /* initalize */
+    round_a.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 7*32, prev_output.rbegin() + 8*32));
+    round_b.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 6*32, prev_output.rbegin() + 7*32));
+    round_c.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 5*32, prev_output.rbegin() + 6*32));
+    round_d.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 4*32, prev_output.rbegin() + 5*32));
+    round_e.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 3*32, prev_output.rbegin() + 4*32));
+    round_f.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 2*32, prev_output.rbegin() + 3*32));
+    round_g.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 1*32, prev_output.rbegin() + 2*32));
+    round_h.push_back(pb_linear_combination_array<FieldT>(prev_output.rbegin() + 0*32, prev_output.rbegin() + 1*32));
+
+    /* do the rounds */
+    for (size_t i = 0; i < 64; ++i)
+    {
+        round_h.push_back(round_g[i]);
+        round_g.push_back(round_f[i]);
+        round_f.push_back(round_e[i]);
+        round_d.push_back(round_c[i]);
+        round_c.push_back(round_b[i]);
+        round_b.push_back(round_a[i]);
+
+        pb_variable_array<FieldT> new_round_a_variables;
+        new_round_a_variables.allocate(pb, 32, FMT(this->annotation_prefix, " new_round_a_variables_%zu", i+1));
+        round_a.emplace_back(new_round_a_variables);
+
+        pb_variable_array<FieldT> new_round_e_variables;
+        new_round_e_variables.allocate(pb, 32, FMT(this->annotation_prefix, " new_round_e_variables_%zu", i+1));
+        round_e.emplace_back(new_round_e_variables);
+
+        round_functions.push_back(sha256_round_function_gadget<FieldT>(pb,
+                                                                       round_a[i], round_b[i], round_c[i], round_d[i],
+                                                                       round_e[i], round_f[i], round_g[i], round_h[i],
+                                                                       packed_W[i], SHA256_K[i], round_a[i+1], round_e[i+1],
+                                                                       FMT(this->annotation_prefix, " round_functions_%zu", i)));
+    }
+
+    /* finalize */
+    unreduced_output.allocate(pb, 8, FMT(this->annotation_prefix, " unreduced_output"));
+    reduced_output.allocate(pb, 8, FMT(this->annotation_prefix, " reduced_output"));
+    for (size_t i = 0; i < 8; ++i)
+    {
+        reduce_output.push_back(lastbits_gadget<FieldT>(pb,
+                                                        unreduced_output[i],
+                                                        32+1,
+                                                        reduced_output[i],
+                                                        pb_variable_array<FieldT>(output.bits.rbegin() + (7-i) * 32, output.bits.rbegin() + (8-i) * 32),
+                                                        FMT(this->annotation_prefix, " reduce_output_%zu", i)));
+    }
+}
+
+template<typename FieldT>
+void sha256_compression_function_gadget<FieldT>::generate_r1cs_constraints()
+{
+    message_schedule->generate_r1cs_constraints();
+    for (size_t i = 0; i < 64; ++i)
+    {
+        round_functions[i].generate_r1cs_constraints();
+    }
+
+    for (size_t i = 0; i < 4; ++i)
+    {
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1,
+                                                             round_functions[3-i].packed_d + round_functions[63-i].packed_new_a,
+                                                             unreduced_output[i]),
+            FMT(this->annotation_prefix, " unreduced_output_%zu", i));
+
+        this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(1,
+                                                             round_functions[3-i].packed_h + round_functions[63-i].packed_new_e,
+                                                             unreduced_output[4+i]),
+            FMT(this->annotation_prefix, " unreduced_output_%zu", 4+i));
+    }
+
+    for (size_t i = 0; i < 8; ++i)
+    {
+        reduce_output[i].generate_r1cs_constraints();
+    }
+}
+
+template<typename FieldT>
+void sha256_compression_function_gadget<FieldT>::generate_r1cs_witness()
+{
+    message_schedule->generate_r1cs_witness();
+
+#ifdef DEBUG
+    printf("Input:\n");
+    for (size_t j = 0; j < 16; ++j)
+    {
+        printf("%lx ", this->pb.val(packed_W[j]).as_ulong());
+    }
+    printf("\n");
+#endif
+
+    for (size_t i = 0; i < 64; ++i)
+    {
+        round_functions[i].generate_r1cs_witness();
+    }
+
+    for (size_t i = 0; i < 4; ++i)
+    {
+        this->pb.val(unreduced_output[i]) = this->pb.val(round_functions[3-i].packed_d) + this->pb.val(round_functions[63-i].packed_new_a);
+        this->pb.val(unreduced_output[4+i]) = this->pb.val(round_functions[3-i].packed_h) + this->pb.val(round_functions[63-i].packed_new_e);
+    }
+
+    for (size_t i = 0; i < 8; ++i)
+    {
+        reduce_output[i].generate_r1cs_witness();
+    }
+
+#ifdef DEBUG
+    printf("Output:\n");
+    for (size_t j = 0; j < 8; ++j)
+    {
+        printf("%lx ", this->pb.val(reduced_output[j]).as_ulong());
+    }
+    printf("\n");
+#endif
+}
+
+template<typename FieldT>
+sha256_two_to_one_hash_gadget<FieldT>::sha256_two_to_one_hash_gadget(protoboard<FieldT> &pb,
+                                                                     const digest_variable<FieldT> &left,
+                                                                     const digest_variable<FieldT> &right,
+                                                                     const digest_variable<FieldT> &output,
+                                                                     const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix)
+{
+    /* concatenate block = left || right */
+    pb_variable_array<FieldT> block;
+    block.insert(block.end(), left.bits.begin(), left.bits.end());
+    block.insert(block.end(), right.bits.begin(), right.bits.end());
+
+    /* compute the hash itself */
+    f.reset(new sha256_compression_function_gadget<FieldT>(pb, SHA256_default_IV<FieldT>(pb), block, output, FMT(this->annotation_prefix, " f")));
+}
+
+template<typename FieldT>
+sha256_two_to_one_hash_gadget<FieldT>::sha256_two_to_one_hash_gadget(protoboard<FieldT> &pb,
+                                                                     const size_t block_length,
+                                                                     const block_variable<FieldT> &input_block,
+                                                                     const digest_variable<FieldT> &output,
+                                                                     const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix)
+{
+    assert(block_length == SHA256_block_size);
+    assert(input_block.bits.size() == block_length);
+    f.reset(new sha256_compression_function_gadget<FieldT>(pb, SHA256_default_IV<FieldT>(pb), input_block.bits, output, FMT(this->annotation_prefix, " f")));
+}
+
+template<typename FieldT>
+void sha256_two_to_one_hash_gadget<FieldT>::generate_r1cs_constraints(const bool ensure_output_bitness)
+{
+    UNUSED(ensure_output_bitness);
+    f->generate_r1cs_constraints();
+}
+
+template<typename FieldT>
+void sha256_two_to_one_hash_gadget<FieldT>::generate_r1cs_witness()
+{
+    f->generate_r1cs_witness();
+}
+
+template<typename FieldT>
+size_t sha256_two_to_one_hash_gadget<FieldT>::get_block_len()
+{
+    return SHA256_block_size;
+}
+
+template<typename FieldT>
+size_t sha256_two_to_one_hash_gadget<FieldT>::get_digest_len()
+{
+    return SHA256_digest_size;
+}
+
+template<typename FieldT>
+bit_vector sha256_two_to_one_hash_gadget<FieldT>::get_hash(const bit_vector &input)
+{
+    protoboard<FieldT> pb;
+
+    block_variable<FieldT> input_variable(pb, SHA256_block_size, "input");
+    digest_variable<FieldT> output_variable(pb, SHA256_digest_size, "output");
+    sha256_two_to_one_hash_gadget<FieldT> f(pb, SHA256_block_size, input_variable, output_variable, "f");
+
+    input_variable.generate_r1cs_witness(input);
+    f.generate_r1cs_witness();
+
+    return output_variable.get_digest();
+}
+
+template<typename FieldT>
+size_t sha256_two_to_one_hash_gadget<FieldT>::expected_constraints(const bool ensure_output_bitness)
+{
+    UNUSED(ensure_output_bitness);
+    return 27280; /* hardcoded for now */
+}
+
+} // libsnark
+
+#endif // SHA256_GADGET_TCC_
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/tests/generate_sha256_gadget_tests.py b/src/gadgetlib1/gadgets/hashes/sha256/tests/generate_sha256_gadget_tests.py
new file mode 100644 (file)
index 0000000..452317f
--- /dev/null
@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+##
+# @author     This file is part of libsnark, developed by SCIPR Lab
+#             and contributors (see AUTHORS).
+# @copyright  MIT license (see LICENSE file)
+
+import random
+import pypy_sha256 # PyPy's implementation of SHA256 compression function; see copyright and authorship notice within.
+
+BLOCK_LEN = 512
+BLOCK_BYTES = BLOCK_LEN // 8
+HASH_LEN = 256
+HASH_BYTES = HASH_LEN // 8
+
+def gen_random_bytes(n):
+    return [random.randint(0, 255) for i in xrange(n)]
+
+def words_to_bytes(arr):
+    return sum(([x >> 24, (x >> 16) & 0xff, (x >> 8) & 0xff, x & 0xff] for x in arr), [])
+
+def bytes_to_words(arr):
+    l = len(arr)
+    assert l % 4 == 0
+    return [(arr[i*4 + 3] << 24) + (arr[i*4+2] << 16) + (arr[i*4+1] << 8) + arr[i*4] for i in xrange(l//4)]
+
+def cpp_val(s, log_radix=32):
+    if log_radix == 8:
+        hexfmt = '0x%02x'
+    elif log_radix == 32:
+        hexfmt = '0x%08x'
+        s = bytes_to_words(s)
+    else:
+        raise
+    return 'int_list_to_bits({%s}, %d)' % (', '.join(hexfmt % x for x in s), log_radix)
+
+def H_bytes(x):
+    assert len(x) == BLOCK_BYTES
+    state = pypy_sha256.sha_init()
+    state['data'] = words_to_bytes(bytes_to_words(x))
+    pypy_sha256.sha_transform(state)
+    return words_to_bytes(bytes_to_words(words_to_bytes(state['digest'])))
+
+def generate_sha256_gadget_tests():
+    left = gen_random_bytes(HASH_BYTES)
+    right = gen_random_bytes(HASH_BYTES)
+    hash = H_bytes(left + right)
+
+    print "const bit_vector left_bv = %s;" % cpp_val(left)
+    print "const bit_vector right_bv = %s;" % cpp_val(right)
+    print "const bit_vector hash_bv = %s;" % cpp_val(hash)
+
+if __name__ == '__main__':
+    random.seed(0) # for reproducibility
+    generate_sha256_gadget_tests()
+
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/tests/pypy_sha256.py b/src/gadgetlib1/gadgets/hashes/sha256/tests/pypy_sha256.py
new file mode 100644 (file)
index 0000000..496989c
--- /dev/null
@@ -0,0 +1,263 @@
+#!/usr/bin/env python
+#
+# SHA256 compression function implementation below is a verbatim copy of PyPy's implementation from
+# https://bitbucket.org/pypy/pypy/raw/f1f064b3faf1e012f7a9a9ab08f18074637ebe8a/lib_pypy/_sha256.py .
+#
+# It is licensed under the MIT license and copyright PyPy Copyright holders 2003-2015
+# See https://bitbucket.org/pypy/pypy/src/tip/LICENSE for the full copyright notice.
+#
+
+SHA_BLOCKSIZE = 64
+SHA_DIGESTSIZE = 32
+
+
+def new_shaobject():
+    return {
+        'digest': [0]*8,
+        'count_lo': 0,
+        'count_hi': 0,
+        'data': [0]* SHA_BLOCKSIZE,
+        'local': 0,
+        'digestsize': 0
+    }
+
+ROR = lambda x, y: (((x & 0xffffffff) >> (y & 31)) | (x << (32 - (y & 31)))) & 0xffffffff
+Ch = lambda x, y, z: (z ^ (x & (y ^ z)))
+Maj = lambda x, y, z: (((x | y) & z) | (x & y))
+S = lambda x, n: ROR(x, n)
+R = lambda x, n: (x & 0xffffffff) >> n
+Sigma0 = lambda x: (S(x, 2) ^ S(x, 13) ^ S(x, 22))
+Sigma1 = lambda x: (S(x, 6) ^ S(x, 11) ^ S(x, 25))
+Gamma0 = lambda x: (S(x, 7) ^ S(x, 18) ^ R(x, 3))
+Gamma1 = lambda x: (S(x, 17) ^ S(x, 19) ^ R(x, 10))
+
+def sha_transform(sha_info):
+    W = []
+
+    d = sha_info['data']
+    for i in range(0,16):
+        W.append( (d[4*i]<<24) + (d[4*i+1]<<16) + (d[4*i+2]<<8) + d[4*i+3])
+
+    for i in range(16,64):
+        W.append( (Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16]) & 0xffffffff )
+
+    ss = sha_info['digest'][:]
+
+    def RND(a,b,c,d,e,f,g,h,i,ki):
+        t0 = h + Sigma1(e) + Ch(e, f, g) + ki + W[i];
+        t1 = Sigma0(a) + Maj(a, b, c);
+        d += t0;
+        h  = t0 + t1;
+        return d & 0xffffffff, h & 0xffffffff
+
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],0,0x428a2f98);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],1,0x71374491);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],2,0xb5c0fbcf);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],3,0xe9b5dba5);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],4,0x3956c25b);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],5,0x59f111f1);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],6,0x923f82a4);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],7,0xab1c5ed5);
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],8,0xd807aa98);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],9,0x12835b01);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],10,0x243185be);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],11,0x550c7dc3);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],12,0x72be5d74);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],13,0x80deb1fe);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],14,0x9bdc06a7);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],15,0xc19bf174);
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],16,0xe49b69c1);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],17,0xefbe4786);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],18,0x0fc19dc6);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],19,0x240ca1cc);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],20,0x2de92c6f);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],21,0x4a7484aa);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],22,0x5cb0a9dc);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],23,0x76f988da);
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],24,0x983e5152);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],25,0xa831c66d);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],26,0xb00327c8);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],27,0xbf597fc7);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],28,0xc6e00bf3);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],29,0xd5a79147);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],30,0x06ca6351);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],31,0x14292967);
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],32,0x27b70a85);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],33,0x2e1b2138);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],34,0x4d2c6dfc);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],35,0x53380d13);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],36,0x650a7354);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],37,0x766a0abb);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],38,0x81c2c92e);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],39,0x92722c85);
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],40,0xa2bfe8a1);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],41,0xa81a664b);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],42,0xc24b8b70);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],43,0xc76c51a3);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],44,0xd192e819);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],45,0xd6990624);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],46,0xf40e3585);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],47,0x106aa070);
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],48,0x19a4c116);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],49,0x1e376c08);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],50,0x2748774c);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],51,0x34b0bcb5);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],52,0x391c0cb3);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],53,0x4ed8aa4a);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],54,0x5b9cca4f);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],55,0x682e6ff3);
+    ss[3], ss[7] = RND(ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],56,0x748f82ee);
+    ss[2], ss[6] = RND(ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],57,0x78a5636f);
+    ss[1], ss[5] = RND(ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],ss[5],58,0x84c87814);
+    ss[0], ss[4] = RND(ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],ss[4],59,0x8cc70208);
+    ss[7], ss[3] = RND(ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],ss[3],60,0x90befffa);
+    ss[6], ss[2] = RND(ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],ss[2],61,0xa4506ceb);
+    ss[5], ss[1] = RND(ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],ss[1],62,0xbef9a3f7);
+    ss[4], ss[0] = RND(ss[1],ss[2],ss[3],ss[4],ss[5],ss[6],ss[7],ss[0],63,0xc67178f2);
+
+    dig = []
+    for i, x in enumerate(sha_info['digest']):
+        dig.append( (x + ss[i]) & 0xffffffff )
+    sha_info['digest'] = dig
+
+def sha_init():
+    sha_info = new_shaobject()
+    sha_info['digest'] = [0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19]
+    sha_info['count_lo'] = 0
+    sha_info['count_hi'] = 0
+    sha_info['local'] = 0
+    sha_info['digestsize'] = 32
+    return sha_info
+
+def sha224_init():
+    sha_info = new_shaobject()
+    sha_info['digest'] = [0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939, 0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4]
+    sha_info['count_lo'] = 0
+    sha_info['count_hi'] = 0
+    sha_info['local'] = 0
+    sha_info['digestsize'] = 28
+    return sha_info
+
+def sha_update(sha_info, buffer):
+    if isinstance(buffer, str):
+        raise TypeError("Unicode strings must be encoded before hashing")
+    count = len(buffer)
+    buffer_idx = 0
+    clo = (sha_info['count_lo'] + (count << 3)) & 0xffffffff
+    if clo < sha_info['count_lo']:
+        sha_info['count_hi'] += 1
+    sha_info['count_lo'] = clo
+
+    sha_info['count_hi'] += (count >> 29)
+
+    if sha_info['local']:
+        i = SHA_BLOCKSIZE - sha_info['local']
+        if i > count:
+            i = count
+
+        # copy buffer
+        sha_info['data'][sha_info['local']:sha_info['local']+i] = buffer[buffer_idx:buffer_idx+i]
+
+        count -= i
+        buffer_idx += i
+
+        sha_info['local'] += i
+        if sha_info['local'] == SHA_BLOCKSIZE:
+            sha_transform(sha_info)
+            sha_info['local'] = 0
+        else:
+            return
+
+    while count >= SHA_BLOCKSIZE:
+        # copy buffer
+        sha_info['data'] = list(buffer[buffer_idx:buffer_idx + SHA_BLOCKSIZE])
+        count -= SHA_BLOCKSIZE
+        buffer_idx += SHA_BLOCKSIZE
+        sha_transform(sha_info)
+
+
+    # copy buffer
+    pos = sha_info['local']
+    sha_info['data'][pos:pos+count] = buffer[buffer_idx:buffer_idx + count]
+    sha_info['local'] = count
+
+def sha_final(sha_info):
+    lo_bit_count = sha_info['count_lo']
+    hi_bit_count = sha_info['count_hi']
+    count = (lo_bit_count >> 3) & 0x3f
+    sha_info['data'][count] = 0x80;
+    count += 1
+    if count > SHA_BLOCKSIZE - 8:
+        # zero the bytes in data after the count
+        sha_info['data'] = sha_info['data'][:count] + ([0] * (SHA_BLOCKSIZE - count))
+        sha_transform(sha_info)
+        # zero bytes in data
+        sha_info['data'] = [0] * SHA_BLOCKSIZE
+    else:
+        sha_info['data'] = sha_info['data'][:count] + ([0] * (SHA_BLOCKSIZE - count))
+
+    sha_info['data'][56] = (hi_bit_count >> 24) & 0xff
+    sha_info['data'][57] = (hi_bit_count >> 16) & 0xff
+    sha_info['data'][58] = (hi_bit_count >>  8) & 0xff
+    sha_info['data'][59] = (hi_bit_count >>  0) & 0xff
+    sha_info['data'][60] = (lo_bit_count >> 24) & 0xff
+    sha_info['data'][61] = (lo_bit_count >> 16) & 0xff
+    sha_info['data'][62] = (lo_bit_count >>  8) & 0xff
+    sha_info['data'][63] = (lo_bit_count >>  0) & 0xff
+
+    sha_transform(sha_info)
+
+    dig = []
+    for i in sha_info['digest']:
+        dig.extend([ ((i>>24) & 0xff), ((i>>16) & 0xff), ((i>>8) & 0xff), (i & 0xff) ])
+    return ''.join([chr(i) for i in dig])
+
+class sha256(object):
+    digest_size = digestsize = SHA_DIGESTSIZE
+    block_size = SHA_BLOCKSIZE
+
+    def __init__(self, s=None):
+        self._sha = sha_init()
+        if s:
+            sha_update(self._sha, s)
+
+    def update(self, s):
+        sha_update(self._sha, s)
+
+    def digest(self):
+        return sha_final(self._sha.copy())[:self._sha['digestsize']]
+
+    def hexdigest(self):
+        return ''.join(['%.2x' % ord(i) for i in self.digest()])
+
+    def copy(self):
+        new = sha256.__new__(sha256)
+        new._sha = self._sha.copy()
+        return new
+
+class sha224(sha256):
+    digest_size = digestsize = 28
+
+    def __init__(self, s=None):
+        self._sha = sha224_init()
+        if s:
+            sha_update(self._sha, s)
+
+    def copy(self):
+        new = sha224.__new__(sha224)
+        new._sha = self._sha.copy()
+        return new
+
+def test():
+    a_str = "just a test string"
+
+    assert 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855' == sha256().hexdigest()
+    assert 'd7b553c6f09ac85d142415f857c5310f3bbbe7cdd787cce4b985acedd585266f' == sha256(a_str).hexdigest()
+    assert '8113ebf33c97daa9998762aacafe750c7cefc2b2f173c90c59663a57fe626f21' == sha256(a_str*7).hexdigest()
+
+    s = sha256(a_str)
+    s.update(a_str)
+    assert '03d9963e05a094593190b6fc794cb1a3e1ac7d7883f0b5855268afeccc70d461' == s.hexdigest()
+
+if __name__ == "__main__":
+    test()
diff --git a/src/gadgetlib1/gadgets/hashes/sha256/tests/test_sha256_gadget.cpp b/src/gadgetlib1/gadgets/hashes/sha256/tests/test_sha256_gadget.cpp
new file mode 100644 (file)
index 0000000..471928f
--- /dev/null
@@ -0,0 +1,46 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#include "common/default_types/ec_pp.hpp"
+#include "common/utils.hpp"
+#include "common/profiling.hpp"
+#include "gadgetlib1/gadgets/hashes/sha256/sha256_gadget.hpp"
+
+using namespace libsnark;
+
+template<typename FieldT>
+void test_two_to_one()
+{
+    protoboard<FieldT> pb;
+
+    digest_variable<FieldT> left(pb, SHA256_digest_size, "left");
+    digest_variable<FieldT> right(pb, SHA256_digest_size, "right");
+    digest_variable<FieldT> output(pb, SHA256_digest_size, "output");
+
+    sha256_two_to_one_hash_gadget<FieldT> f(pb, left, right, output, "f");
+    f.generate_r1cs_constraints();
+    printf("Number of constraints for sha256_two_to_one_hash_gadget: %zu\n", pb.num_constraints());
+
+    const bit_vector left_bv = int_list_to_bits({0x426bc2d8, 0x4dc86782, 0x81e8957a, 0x409ec148, 0xe6cffbe8, 0xafe6ba4f, 0x9c6f1978, 0xdd7af7e9}, 32);
+    const bit_vector right_bv = int_list_to_bits({0x038cce42, 0xabd366b8, 0x3ede7e00, 0x9130de53, 0x72cdf73d, 0xee825114, 0x8cb48d1b, 0x9af68ad0}, 32);
+    const bit_vector hash_bv = int_list_to_bits({0xeffd0b7f, 0x1ccba116, 0x2ee816f7, 0x31c62b48, 0x59305141, 0x990e5c0a, 0xce40d33d, 0x0b1167d1}, 32);
+
+    left.generate_r1cs_witness(left_bv);
+    right.generate_r1cs_witness(right_bv);
+
+    f.generate_r1cs_witness();
+    output.generate_r1cs_witness(hash_bv);
+
+    assert(pb.is_satisfied());
+}
+
+int main(void)
+{
+    start_profiling();
+    default_ec_pp::init_public_params();
+    test_two_to_one<Fr<default_ec_pp> >();
+}
diff --git a/src/gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.hpp b/src/gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.hpp
new file mode 100644 (file)
index 0000000..0efa7cf
--- /dev/null
@@ -0,0 +1,38 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_AUTHENTICATION_PATH_VARIABLE_HPP_
+#define MERKLE_AUTHENTICATION_PATH_VARIABLE_HPP_
+
+#include "common/data_structures/merkle_tree.hpp"
+#include "gadgetlib1/gadget.hpp"
+#include "gadgetlib1/gadgets/hashes/hash_io.hpp"
+
+namespace libsnark {
+
+template<typename FieldT, typename HashT>
+class merkle_authentication_path_variable : public gadget<FieldT> {
+public:
+
+    const size_t tree_depth;
+    std::vector<digest_variable<FieldT> > left_digests;
+    std::vector<digest_variable<FieldT> > right_digests;
+
+    merkle_authentication_path_variable(protoboard<FieldT> &pb,
+                                        const size_t tree_depth,
+                                        const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness(const size_t address, const merkle_authentication_path &path);
+    merkle_authentication_path get_authentication_path(const size_t address) const;
+};
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.tcc"
+
+#endif // MERKLE_AUTHENTICATION_PATH_VARIABLE_HPP
diff --git a/src/gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.tcc b/src/gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.tcc
new file mode 100644 (file)
index 0000000..d773051
--- /dev/null
@@ -0,0 +1,76 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_AUTHENTICATION_PATH_VARIABLE_TCC_
+#define MERKLE_AUTHENTICATION_PATH_VARIABLE_TCC_
+
+namespace libsnark {
+
+template<typename FieldT, typename HashT>
+merkle_authentication_path_variable<FieldT, HashT>::merkle_authentication_path_variable(protoboard<FieldT> &pb,
+                                                                                        const size_t tree_depth,
+                                                                                        const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    tree_depth(tree_depth)
+{
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        left_digests.emplace_back(digest_variable<FieldT>(pb, HashT::get_digest_len(), FMT(annotation_prefix, " left_digests_%zu", i)));
+        right_digests.emplace_back(digest_variable<FieldT>(pb, HashT::get_digest_len(), FMT(annotation_prefix, " right_digests_%zu", i)));
+    }
+}
+
+template<typename FieldT, typename HashT>
+void merkle_authentication_path_variable<FieldT, HashT>::generate_r1cs_constraints()
+{
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        left_digests[i].generate_r1cs_constraints();
+        right_digests[i].generate_r1cs_constraints();
+    }
+}
+
+template<typename FieldT, typename HashT>
+void merkle_authentication_path_variable<FieldT, HashT>::generate_r1cs_witness(const size_t address, const merkle_authentication_path &path)
+{
+    assert(path.size() == tree_depth);
+
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        if (address & (1ul << (tree_depth-1-i)))
+        {
+            left_digests[i].generate_r1cs_witness(path[i]);
+        }
+        else
+        {
+            right_digests[i].generate_r1cs_witness(path[i]);
+        }
+    }
+}
+
+template<typename FieldT, typename HashT>
+merkle_authentication_path merkle_authentication_path_variable<FieldT, HashT>::get_authentication_path(const size_t address) const
+{
+    merkle_authentication_path result;
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        if (address & (1ul << (tree_depth-1-i)))
+        {
+            result.emplace_back(left_digests[i].get_digest());
+        }
+        else
+        {
+            result.emplace_back(right_digests[i].get_digest());
+        }
+    }
+
+    return result;
+}
+
+} // libsnark
+
+#endif // MERKLE_AUTHENTICATION_PATH_VARIABLE_TCC
diff --git a/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.hpp b/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.hpp
new file mode 100644 (file)
index 0000000..b1e3a4f
--- /dev/null
@@ -0,0 +1,73 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for the Merkle tree check read gadget.
+
+ The gadget checks the following: given a root R, address A, value V, and
+ authentication path P, check that P is a valid authentication path for the
+ value V as the A-th leaf in a Merkle tree with root R.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_TREE_CHECK_READ_GADGET_HPP_
+#define MERKLE_TREE_CHECK_READ_GADGET_HPP_
+
+#include "common/data_structures/merkle_tree.hpp"
+#include "gadgetlib1/gadget.hpp"
+#include "gadgetlib1/gadgets/hashes/hash_io.hpp"
+#include "gadgetlib1/gadgets/hashes/digest_selector_gadget.hpp"
+#include "gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.hpp"
+
+namespace libsnark {
+
+template<typename FieldT, typename HashT>
+class merkle_tree_check_read_gadget : public gadget<FieldT> {
+private:
+
+    std::vector<HashT> hashers;
+    std::vector<block_variable<FieldT> > hasher_inputs;
+    std::vector<digest_selector_gadget<FieldT> > propagators;
+    std::vector<digest_variable<FieldT> > internal_output;
+
+    std::shared_ptr<digest_variable<FieldT> > computed_root;
+    std::shared_ptr<bit_vector_copy_gadget<FieldT> > check_root;
+
+public:
+
+    const size_t digest_size;
+    const size_t tree_depth;
+    pb_linear_combination_array<FieldT> address_bits;
+    digest_variable<FieldT> leaf;
+    digest_variable<FieldT> root;
+    merkle_authentication_path_variable<FieldT, HashT> path;
+    pb_linear_combination<FieldT> read_successful;
+
+    merkle_tree_check_read_gadget(protoboard<FieldT> &pb,
+                                  const size_t tree_depth,
+                                  const pb_linear_combination_array<FieldT> &address_bits,
+                                  const digest_variable<FieldT> &leaf_digest,
+                                  const digest_variable<FieldT> &root_digest,
+                                  const merkle_authentication_path_variable<FieldT, HashT> &path,
+                                  const pb_linear_combination<FieldT> &read_successful,
+                                  const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+
+    static size_t root_size_in_bits();
+    /* for debugging purposes */
+    static size_t expected_constraints(const size_t tree_depth);
+};
+
+template<typename FieldT, typename HashT>
+void test_merkle_tree_check_read_gadget();
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.tcc"
+
+#endif // MERKLE_TREE_CHECK_READ_GADGET_HPP_
diff --git a/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.tcc b/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.tcc
new file mode 100644 (file)
index 0000000..6002a58
--- /dev/null
@@ -0,0 +1,196 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for the Merkle tree check read.
+
+ See merkle_tree_check_read_gadget.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_TREE_CHECK_READ_GADGET_TCC_
+#define MERKLE_TREE_CHECK_READ_GADGET_TCC_
+
+namespace libsnark {
+
+template<typename FieldT, typename HashT>
+merkle_tree_check_read_gadget<FieldT, HashT>::merkle_tree_check_read_gadget(protoboard<FieldT> &pb,
+                                                                            const size_t tree_depth,
+                                                                            const pb_linear_combination_array<FieldT> &address_bits,
+                                                                            const digest_variable<FieldT> &leaf,
+                                                                            const digest_variable<FieldT> &root,
+                                                                            const merkle_authentication_path_variable<FieldT, HashT> &path,
+                                                                            const pb_linear_combination<FieldT> &read_successful,
+                                                                            const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    digest_size(HashT::get_digest_len()),
+    tree_depth(tree_depth),
+    address_bits(address_bits),
+    leaf(leaf),
+    root(root),
+    path(path),
+    read_successful(read_successful)
+{
+    /*
+       The tricky part here is ordering. For Merkle tree
+       authentication paths, path[0] corresponds to one layer below
+       the root (and path[tree_depth-1] corresponds to the layer
+       containing the leaf), while address_bits has the reverse order:
+       address_bits[0] is LSB, and corresponds to layer containing the
+       leaf, and address_bits[tree_depth-1] is MSB, and corresponds to
+       the subtree directly under the root.
+    */
+    assert(tree_depth > 0);
+    assert(tree_depth == address_bits.size());
+
+    for (size_t i = 0; i < tree_depth-1; ++i)
+    {
+        internal_output.emplace_back(digest_variable<FieldT>(pb, digest_size, FMT(this->annotation_prefix, " internal_output_%zu", i)));
+    }
+
+    computed_root.reset(new digest_variable<FieldT>(pb, digest_size, FMT(this->annotation_prefix, " computed_root")));
+
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        block_variable<FieldT> inp(pb, path.left_digests[i], path.right_digests[i], FMT(this->annotation_prefix, " inp_%zu", i));
+        hasher_inputs.emplace_back(inp);
+        hashers.emplace_back(HashT(pb, 2*digest_size, inp, (i == 0 ? *computed_root : internal_output[i-1]),
+                                   FMT(this->annotation_prefix, " load_hashers_%zu", i)));
+    }
+
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        /*
+          The propagators take a computed hash value (or leaf in the
+          base case) and propagate it one layer up, either in the left
+          or the right slot of authentication_path_variable.
+        */
+        propagators.emplace_back(digest_selector_gadget<FieldT>(pb, digest_size, i < tree_depth - 1 ? internal_output[i] : leaf,
+                                                                address_bits[tree_depth-1-i], path.left_digests[i], path.right_digests[i],
+                                                                FMT(this->annotation_prefix, " digest_selector_%zu", i)));
+    }
+
+    check_root.reset(new bit_vector_copy_gadget<FieldT>(pb, computed_root->bits, root.bits, read_successful, FieldT::capacity(), FMT(annotation_prefix, " check_root")));
+}
+
+template<typename FieldT, typename HashT>
+void merkle_tree_check_read_gadget<FieldT, HashT>::generate_r1cs_constraints()
+{
+    /* ensure correct hash computations */
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        // Note that we check root outside and have enforced booleanity of path.left_digests/path.right_digests outside in path.generate_r1cs_constraints
+        hashers[i].generate_r1cs_constraints(false);
+    }
+
+    /* ensure consistency of path.left_digests/path.right_digests with internal_output */
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        propagators[i].generate_r1cs_constraints();
+    }
+
+    check_root->generate_r1cs_constraints(false, false);
+}
+
+template<typename FieldT, typename HashT>
+void merkle_tree_check_read_gadget<FieldT, HashT>::generate_r1cs_witness()
+{
+    /* do the hash computations bottom-up */
+    for (int i = tree_depth-1; i >= 0; --i)
+    {
+        /* propagate previous input */
+        propagators[i].generate_r1cs_witness();
+
+        /* compute hash */
+        hashers[i].generate_r1cs_witness();
+    }
+
+    check_root->generate_r1cs_witness();
+}
+
+template<typename FieldT, typename HashT>
+size_t merkle_tree_check_read_gadget<FieldT, HashT>::root_size_in_bits()
+{
+    return HashT::get_digest_len();
+}
+
+template<typename FieldT, typename HashT>
+size_t merkle_tree_check_read_gadget<FieldT, HashT>::expected_constraints(const size_t tree_depth)
+{
+    /* NB: this includes path constraints */
+    const size_t hasher_constraints = tree_depth * HashT::expected_constraints(false);
+    const size_t propagator_constraints = tree_depth * HashT::get_digest_len();
+    const size_t authentication_path_constraints = 2 * tree_depth * HashT::get_digest_len();
+    const size_t check_root_constraints = 3 * div_ceil(HashT::get_digest_len(), FieldT::capacity());
+
+    return hasher_constraints + propagator_constraints + authentication_path_constraints + check_root_constraints;
+}
+
+template<typename FieldT, typename HashT>
+void test_merkle_tree_check_read_gadget()
+{
+    /* prepare test */
+    const size_t digest_len = HashT::get_digest_len();
+    const size_t tree_depth = 16;
+    std::vector<merkle_authentication_node> path(tree_depth);
+
+    bit_vector prev_hash(digest_len);
+    std::generate(prev_hash.begin(), prev_hash.end(), [&]() { return std::rand() % 2; });
+    bit_vector leaf = prev_hash;
+
+    bit_vector address_bits;
+
+    size_t address = 0;
+    for (long level = tree_depth-1; level >= 0; --level)
+    {
+        const bool computed_is_right = (std::rand() % 2);
+        address |= (computed_is_right ? 1ul << (tree_depth-1-level) : 0);
+        address_bits.push_back(computed_is_right);
+        bit_vector other(digest_len);
+        std::generate(other.begin(), other.end(), [&]() { return std::rand() % 2; });
+
+        bit_vector block = prev_hash;
+        block.insert(computed_is_right ? block.begin() : block.end(), other.begin(), other.end());
+        bit_vector h = HashT::get_hash(block);
+
+        path[level] = other;
+
+        prev_hash = h;
+    }
+    bit_vector root = prev_hash;
+
+    /* execute test */
+    protoboard<FieldT> pb;
+    pb_variable_array<FieldT> address_bits_va;
+    address_bits_va.allocate(pb, tree_depth, "address_bits");
+    digest_variable<FieldT> leaf_digest(pb, digest_len, "input_block");
+    digest_variable<FieldT> root_digest(pb, digest_len, "output_digest");
+    merkle_authentication_path_variable<FieldT, HashT> path_var(pb, tree_depth, "path_var");
+    merkle_tree_check_read_gadget<FieldT, HashT> ml(pb, tree_depth, address_bits_va, leaf_digest, root_digest, path_var, ONE, "ml");
+
+    path_var.generate_r1cs_constraints();
+    ml.generate_r1cs_constraints();
+
+    address_bits_va.fill_with_bits(pb, address_bits);
+    assert(address_bits_va.get_field_element_from_bits(pb).as_ulong() == address);
+    leaf_digest.generate_r1cs_witness(leaf);
+    path_var.generate_r1cs_witness(address, path);
+    ml.generate_r1cs_witness();
+
+    /* make sure that read checker didn't accidentally overwrite anything */
+    address_bits_va.fill_with_bits(pb, address_bits);
+    leaf_digest.generate_r1cs_witness(leaf);
+    root_digest.generate_r1cs_witness(root);
+    assert(pb.is_satisfied());
+
+    const size_t num_constraints = pb.num_constraints();
+    const size_t expected_constraints = merkle_tree_check_read_gadget<FieldT, HashT>::expected_constraints(tree_depth);
+    assert(num_constraints == expected_constraints);
+}
+
+} // libsnark
+
+#endif // MERKLE_TREE_CHECK_READ_GADGET_TCC_
diff --git a/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.hpp b/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.hpp
new file mode 100644 (file)
index 0000000..2d6840d
--- /dev/null
@@ -0,0 +1,91 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for the Merkle tree check read gadget.
+
+ The gadget checks the following: given two roots R1 and R2, address A, two
+ values V1 and V2, and authentication path P, check that
+ - P is a valid authentication path for the value V1 as the A-th leaf in a Merkle tree with root R1, and
+ - P is a valid authentication path for the value V2 as the A-th leaf in a Merkle tree with root R2.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_TREE_CHECK_UPDATE_GADGET_HPP_
+#define MERKLE_TREE_CHECK_UPDATE_GADGET_HPP_
+
+#include "common/data_structures/merkle_tree.hpp"
+#include "gadgetlib1/gadget.hpp"
+#include "gadgetlib1/gadgets/hashes/crh_gadget.hpp"
+#include "gadgetlib1/gadgets/hashes/hash_io.hpp"
+#include "gadgetlib1/gadgets/hashes/digest_selector_gadget.hpp"
+#include "gadgetlib1/gadgets/merkle_tree/merkle_authentication_path_variable.hpp"
+
+namespace libsnark {
+
+template<typename FieldT, typename HashT>
+class merkle_tree_check_update_gadget : public gadget<FieldT> {
+private:
+
+    std::vector<HashT> prev_hashers;
+    std::vector<block_variable<FieldT> > prev_hasher_inputs;
+    std::vector<digest_selector_gadget<FieldT> > prev_propagators;
+    std::vector<digest_variable<FieldT> > prev_internal_output;
+
+    std::vector<HashT> next_hashers;
+    std::vector<block_variable<FieldT> > next_hasher_inputs;
+    std::vector<digest_selector_gadget<FieldT> > next_propagators;
+    std::vector<digest_variable<FieldT> > next_internal_output;
+
+    std::shared_ptr<digest_variable<FieldT> > computed_next_root;
+    std::shared_ptr<bit_vector_copy_gadget<FieldT> > check_next_root;
+
+public:
+
+    const size_t digest_size;
+    const size_t tree_depth;
+
+    pb_variable_array<FieldT> address_bits;
+    digest_variable<FieldT> prev_leaf_digest;
+    digest_variable<FieldT> prev_root_digest;
+    merkle_authentication_path_variable<FieldT, HashT> prev_path;
+    digest_variable<FieldT> next_leaf_digest;
+    digest_variable<FieldT> next_root_digest;
+    merkle_authentication_path_variable<FieldT, HashT> next_path;
+    pb_linear_combination<FieldT> update_successful;
+
+    /* Note that while it is necessary to generate R1CS constraints
+       for prev_path, it is not necessary to do so for next_path. See
+       comment in the implementation of generate_r1cs_constraints() */
+
+    merkle_tree_check_update_gadget(protoboard<FieldT> &pb,
+                                    const size_t tree_depth,
+                                    const pb_variable_array<FieldT> &address_bits,
+                                    const digest_variable<FieldT> &prev_leaf_digest,
+                                    const digest_variable<FieldT> &prev_root_digest,
+                                    const merkle_authentication_path_variable<FieldT, HashT> &prev_path,
+                                    const digest_variable<FieldT> &next_leaf_digest,
+                                    const digest_variable<FieldT> &next_root_digest,
+                                    const merkle_authentication_path_variable<FieldT, HashT> &next_path,
+                                    const pb_linear_combination<FieldT> &update_successful,
+                                    const std::string &annotation_prefix);
+
+    void generate_r1cs_constraints();
+    void generate_r1cs_witness();
+
+    static size_t root_size_in_bits();
+    /* for debugging purposes */
+    static size_t expected_constraints(const size_t tree_depth);
+};
+
+template<typename FieldT, typename HashT>
+void test_merkle_tree_check_update_gadget();
+
+} // libsnark
+
+#include "gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.tcc"
+
+#endif // MERKLE_TREE_CHECK_UPDATE_GADGET_HPP_
diff --git a/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.tcc b/src/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.tcc
new file mode 100644 (file)
index 0000000..1ac08ed
--- /dev/null
@@ -0,0 +1,265 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for the Merkle tree check update gadget.
+
+ See merkle_tree_check_update_gadget.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef MERKLE_TREE_CHECK_UPDATE_GADGET_TCC_
+#define MERKLE_TREE_CHECK_UPDATE_GADGET_TCC_
+
+namespace libsnark {
+
+template<typename FieldT, typename HashT>
+merkle_tree_check_update_gadget<FieldT, HashT>::merkle_tree_check_update_gadget(protoboard<FieldT> &pb,
+                                                                                const size_t tree_depth,
+                                                                                const pb_variable_array<FieldT> &address_bits,
+                                                                                const digest_variable<FieldT> &prev_leaf_digest,
+                                                                                const digest_variable<FieldT> &prev_root_digest,
+                                                                                const merkle_authentication_path_variable<FieldT, HashT> &prev_path,
+                                                                                const digest_variable<FieldT> &next_leaf_digest,
+                                                                                const digest_variable<FieldT> &next_root_digest,
+                                                                                const merkle_authentication_path_variable<FieldT, HashT> &next_path,
+                                                                                const pb_linear_combination<FieldT> &update_successful,
+                                                                                const std::string &annotation_prefix) :
+    gadget<FieldT>(pb, annotation_prefix),
+    digest_size(HashT::get_digest_len()),
+    tree_depth(tree_depth),
+    address_bits(address_bits),
+    prev_leaf_digest(prev_leaf_digest),
+    prev_root_digest(prev_root_digest),
+    prev_path(prev_path),
+    next_leaf_digest(next_leaf_digest),
+    next_root_digest(next_root_digest),
+    next_path(next_path),
+    update_successful(update_successful)
+{
+    assert(tree_depth > 0);
+    assert(tree_depth == address_bits.size());
+
+    for (size_t i = 0; i < tree_depth-1; ++i)
+    {
+        prev_internal_output.emplace_back(digest_variable<FieldT>(pb, digest_size, FMT(this->annotation_prefix, " prev_internal_output_%zu", i)));
+        next_internal_output.emplace_back(digest_variable<FieldT>(pb, digest_size, FMT(this->annotation_prefix, " next_internal_output_%zu", i)));
+    }
+
+    computed_next_root.reset(new digest_variable<FieldT>(pb, digest_size, FMT(this->annotation_prefix, " computed_root")));
+
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        block_variable<FieldT> prev_inp(pb, prev_path.left_digests[i], prev_path.right_digests[i], FMT(this->annotation_prefix, " prev_inp_%zu", i));
+        prev_hasher_inputs.emplace_back(prev_inp);
+        prev_hashers.emplace_back(HashT(pb, 2*digest_size, prev_inp, (i == 0 ? prev_root_digest : prev_internal_output[i-1]),
+                                                                  FMT(this->annotation_prefix, " prev_hashers_%zu", i)));
+
+        block_variable<FieldT> next_inp(pb, next_path.left_digests[i], next_path.right_digests[i], FMT(this->annotation_prefix, " next_inp_%zu", i));
+        next_hasher_inputs.emplace_back(next_inp);
+        next_hashers.emplace_back(HashT(pb, 2*digest_size, next_inp, (i == 0 ? *computed_next_root : next_internal_output[i-1]),
+                                                                  FMT(this->annotation_prefix, " next_hashers_%zu", i)));
+    }
+
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        prev_propagators.emplace_back(digest_selector_gadget<FieldT>(pb, digest_size, i < tree_depth -1 ? prev_internal_output[i] : prev_leaf_digest,
+                                                                     address_bits[tree_depth-1-i], prev_path.left_digests[i], prev_path.right_digests[i],
+                                                                     FMT(this->annotation_prefix, " prev_propagators_%zu", i)));
+        next_propagators.emplace_back(digest_selector_gadget<FieldT>(pb, digest_size, i < tree_depth -1 ? next_internal_output[i] : next_leaf_digest,
+                                                                     address_bits[tree_depth-1-i], next_path.left_digests[i], next_path.right_digests[i],
+                                                                     FMT(this->annotation_prefix, " next_propagators_%zu", i)));
+    }
+
+    check_next_root.reset(new bit_vector_copy_gadget<FieldT>(pb, computed_next_root->bits, next_root_digest.bits, update_successful, FieldT::capacity(), FMT(annotation_prefix, " check_next_root")));
+}
+
+template<typename FieldT, typename HashT>
+void merkle_tree_check_update_gadget<FieldT, HashT>::generate_r1cs_constraints()
+{
+    /* ensure correct hash computations */
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        prev_hashers[i].generate_r1cs_constraints(false); // we check root outside and prev_left/prev_right above
+        next_hashers[i].generate_r1cs_constraints(true); // however we must check right side hashes
+    }
+
+    /* ensure consistency of internal_left/internal_right with internal_output */
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        prev_propagators[i].generate_r1cs_constraints();
+        next_propagators[i].generate_r1cs_constraints();
+    }
+
+    /* ensure that prev auxiliary input and next auxiliary input match */
+    for (size_t i = 0; i < tree_depth; ++i)
+    {
+        for (size_t j = 0; j < digest_size; ++j)
+        {
+            /*
+              addr * (prev_left - next_left) + (1 - addr) * (prev_right - next_right) = 0
+              addr * (prev_left - next_left - prev_right + next_right) = next_right - prev_right
+            */
+            this->pb.add_r1cs_constraint(r1cs_constraint<FieldT>(address_bits[tree_depth-1-i],
+                                                                 prev_path.left_digests[i].bits[j] - next_path.left_digests[i].bits[j] - prev_path.right_digests[i].bits[j] + next_path.right_digests[i].bits[j],
+                                                                 next_path.right_digests[i].bits[j] - prev_path.right_digests[i].bits[j]),
+                                         FMT(this->annotation_prefix, " aux_check_%zu_%zu", i, j));
+        }
+    }
+
+    /* Note that while it is necessary to generate R1CS constraints
+       for prev_path, it is not necessary to do so for next_path.
+
+       This holds, because { next_path.left_inputs[i],
+       next_path.right_inputs[i] } is a pair { hash_output,
+       auxiliary_input }. The bitness for hash_output is enforced
+       above by next_hashers[i].generate_r1cs_constraints.
+
+       Because auxiliary input is the same for prev_path and next_path
+       (enforced above), we have that auxiliary_input part is also
+       constrained to be boolean, because prev_path is *all*
+       constrained to be all boolean. */
+
+    check_next_root->generate_r1cs_constraints(false, false);
+}
+
+template<typename FieldT, typename HashT>
+void merkle_tree_check_update_gadget<FieldT, HashT>::generate_r1cs_witness()
+{
+    /* do the hash computations bottom-up */
+    for (int i = tree_depth-1; i >= 0; --i)
+    {
+        /* ensure consistency of prev_path and next_path */
+        if (this->pb.val(address_bits[tree_depth-1-i]) == FieldT::one())
+        {
+            next_path.left_digests[i].generate_r1cs_witness(prev_path.left_digests[i].get_digest());
+        }
+        else
+        {
+            next_path.right_digests[i].generate_r1cs_witness(prev_path.right_digests[i].get_digest());
+        }
+
+        /* propagate previous input */
+        prev_propagators[i].generate_r1cs_witness();
+        next_propagators[i].generate_r1cs_witness();
+
+        /* compute hash */
+        prev_hashers[i].generate_r1cs_witness();
+        next_hashers[i].generate_r1cs_witness();
+    }
+
+    check_next_root->generate_r1cs_witness();
+}
+
+template<typename FieldT, typename HashT>
+size_t merkle_tree_check_update_gadget<FieldT, HashT>::root_size_in_bits()
+{
+    return HashT::get_digest_len();
+}
+
+template<typename FieldT, typename HashT>
+size_t merkle_tree_check_update_gadget<FieldT, HashT>::expected_constraints(const size_t tree_depth)
+{
+    /* NB: this includes path constraints */
+    const size_t prev_hasher_constraints = tree_depth * HashT::expected_constraints(false);
+    const size_t next_hasher_constraints = tree_depth * HashT::expected_constraints(true);
+    const size_t prev_authentication_path_constraints = 2 * tree_depth * HashT::get_digest_len();
+    const size_t prev_propagator_constraints = tree_depth * HashT::get_digest_len();
+    const size_t next_propagator_constraints = tree_depth * HashT::get_digest_len();
+    const size_t check_next_root_constraints = 3 * div_ceil(HashT::get_digest_len(), FieldT::capacity());
+    const size_t aux_equality_constraints = tree_depth * HashT::get_digest_len();
+
+    return (prev_hasher_constraints + next_hasher_constraints + prev_authentication_path_constraints +
+            prev_propagator_constraints + next_propagator_constraints + check_next_root_constraints +
+            aux_equality_constraints);
+}
+
+template<typename FieldT, typename HashT>
+void test_merkle_tree_check_update_gadget()
+{
+    /* prepare test */
+    const size_t digest_len = HashT::get_digest_len();
+
+    const size_t tree_depth = 16;
+    std::vector<merkle_authentication_node> prev_path(tree_depth);
+
+    bit_vector prev_load_hash(digest_len);
+    std::generate(prev_load_hash.begin(), prev_load_hash.end(), [&]() { return std::rand() % 2; });
+    bit_vector prev_store_hash(digest_len);
+    std::generate(prev_store_hash.begin(), prev_store_hash.end(), [&]() { return std::rand() % 2; });
+
+    bit_vector loaded_leaf = prev_load_hash;
+    bit_vector stored_leaf = prev_store_hash;
+
+    bit_vector address_bits;
+
+    size_t address = 0;
+    for (long level = tree_depth-1; level >= 0; --level)
+    {
+        const bool computed_is_right = (std::rand() % 2);
+        address |= (computed_is_right ? 1ul << (tree_depth-1-level) : 0);
+        address_bits.push_back(computed_is_right);
+        bit_vector other(digest_len);
+        std::generate(other.begin(), other.end(), [&]() { return std::rand() % 2; });
+
+        bit_vector load_block = prev_load_hash;
+        load_block.insert(computed_is_right ? load_block.begin() : load_block.end(), other.begin(), other.end());
+        bit_vector store_block = prev_store_hash;
+        store_block.insert(computed_is_right ? store_block.begin() : store_block.end(), other.begin(), other.end());
+
+        bit_vector load_h = HashT::get_hash(load_block);
+        bit_vector store_h = HashT::get_hash(store_block);
+
+        prev_path[level] = other;
+
+        prev_load_hash = load_h;
+        prev_store_hash = store_h;
+    }
+
+    bit_vector load_root = prev_load_hash;
+    bit_vector store_root = prev_store_hash;
+
+    /* execute the test */
+    protoboard<FieldT> pb;
+    pb_variable_array<FieldT> address_bits_va;
+    address_bits_va.allocate(pb, tree_depth, "address_bits");
+    digest_variable<FieldT> prev_leaf_digest(pb, digest_len, "prev_leaf_digest");
+    digest_variable<FieldT> prev_root_digest(pb, digest_len, "prev_root_digest");
+    merkle_authentication_path_variable<FieldT, HashT> prev_path_var(pb, tree_depth, "prev_path_var");
+    digest_variable<FieldT> next_leaf_digest(pb, digest_len, "next_leaf_digest");
+    digest_variable<FieldT> next_root_digest(pb, digest_len, "next_root_digest");
+    merkle_authentication_path_variable<FieldT, HashT> next_path_var(pb, tree_depth, "next_path_var");
+    merkle_tree_check_update_gadget<FieldT, HashT> mls(pb, tree_depth, address_bits_va,
+                                                       prev_leaf_digest, prev_root_digest, prev_path_var,
+                                                       next_leaf_digest, next_root_digest, next_path_var, ONE, "mls");
+
+    prev_path_var.generate_r1cs_constraints();
+    mls.generate_r1cs_constraints();
+
+    address_bits_va.fill_with_bits(pb, address_bits);
+    assert(address_bits_va.get_field_element_from_bits(pb).as_ulong() == address);
+    prev_leaf_digest.generate_r1cs_witness(loaded_leaf);
+    prev_path_var.generate_r1cs_witness(address, prev_path);
+    next_leaf_digest.generate_r1cs_witness(stored_leaf);
+    address_bits_va.fill_with_bits(pb, address_bits);
+    mls.generate_r1cs_witness();
+
+    /* make sure that update check will check for the right things */
+    prev_leaf_digest.generate_r1cs_witness(loaded_leaf);
+    next_leaf_digest.generate_r1cs_witness(stored_leaf);
+    prev_root_digest.generate_r1cs_witness(load_root);
+    next_root_digest.generate_r1cs_witness(store_root);
+    address_bits_va.fill_with_bits(pb, address_bits);
+    assert(pb.is_satisfied());
+
+    const size_t num_constraints = pb.num_constraints();
+    const size_t expected_constraints = merkle_tree_check_update_gadget<FieldT, HashT>::expected_constraints(tree_depth);
+    assert(num_constraints == expected_constraints);
+}
+
+} // libsnark
+
+#endif // MERKLE_TREE_CHECK_UPDATE_GADGET_TCC_
diff --git a/src/gadgetlib1/gadgets/merkle_tree/tests/test_merkle_tree_gadgets.cpp b/src/gadgetlib1/gadgets/merkle_tree/tests/test_merkle_tree_gadgets.cpp
new file mode 100644 (file)
index 0000000..8d52c57
--- /dev/null
@@ -0,0 +1,48 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifdef CURVE_BN128
+#include "algebra/curves/bn128/bn128_pp.hpp"
+#endif
+#include "algebra/curves/edwards/edwards_pp.hpp"
+#include "algebra/curves/mnt/mnt4/mnt4_pp.hpp"
+#include "algebra/curves/mnt/mnt6/mnt6_pp.hpp"
+#include "gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.hpp"
+#include "gadgetlib1/gadgets/merkle_tree/merkle_tree_check_update_gadget.hpp"
+#include "gadgetlib1/gadgets/hashes/sha256/sha256_gadget.hpp"
+
+using namespace libsnark;
+
+template<typename ppT>
+void test_all_merkle_tree_gadgets()
+{
+    typedef Fr<ppT> FieldT;
+    test_merkle_tree_check_read_gadget<FieldT, CRH_with_bit_out_gadget<FieldT> >();
+    test_merkle_tree_check_read_gadget<FieldT, sha256_two_to_one_hash_gadget<FieldT> >();
+
+    test_merkle_tree_check_update_gadget<FieldT, CRH_with_bit_out_gadget<FieldT> >();
+    test_merkle_tree_check_update_gadget<FieldT, sha256_two_to_one_hash_gadget<FieldT> >();
+}
+
+int main(void)
+{
+    start_profiling();
+
+#ifdef CURVE_BN128       // BN128 has fancy dependencies so it may be disabled
+    bn128_pp::init_public_params();
+    test_all_merkle_tree_gadgets<bn128_pp>();
+#endif
+
+    edwards_pp::init_public_params();
+    test_all_merkle_tree_gadgets<edwards_pp>();
+
+    mnt4_pp::init_public_params();
+    test_all_merkle_tree_gadgets<mnt4_pp>();
+
+    mnt6_pp::init_public_params();
+    test_all_merkle_tree_gadgets<mnt6_pp>();
+}
diff --git a/src/gadgetlib1/pb_variable.hpp b/src/gadgetlib1/pb_variable.hpp
new file mode 100644 (file)
index 0000000..fdf64d0
--- /dev/null
@@ -0,0 +1,144 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef PB_VARIABLE_HPP_
+#define PB_VARIABLE_HPP_
+
+#include <cstddef>
+#include <string>
+#include <vector>
+#include "common/utils.hpp"
+#include "relations/variable.hpp"
+
+namespace libsnark {
+
+typedef size_t lc_index_t;
+
+template<typename FieldT>
+class protoboard;
+
+template<typename FieldT>
+class pb_variable : public variable<FieldT> {
+public:
+    pb_variable(const var_index_t index = 0) : variable<FieldT>(index) {};
+
+    void allocate(protoboard<FieldT> &pb, const std::string &annotation="");
+};
+
+template<typename FieldT>
+class pb_variable_array : private std::vector<pb_variable<FieldT> >
+{
+    typedef std::vector<pb_variable<FieldT> > contents;
+public:
+    using typename contents::iterator;
+    using typename contents::const_iterator;
+    using typename contents::reverse_iterator;
+    using typename contents::const_reverse_iterator;
+
+    using contents::begin;
+    using contents::end;
+    using contents::rbegin;
+    using contents::rend;
+    using contents::emplace_back;
+    using contents::insert;
+    using contents::reserve;
+    using contents::size;
+    using contents::empty;
+    using contents::operator[];
+    using contents::resize;
+
+    pb_variable_array() : contents() {};
+    pb_variable_array(size_t count, const pb_variable<FieldT> &value) : contents(count, value) {};
+    pb_variable_array(typename contents::const_iterator first, typename contents::const_iterator last) : contents(first, last) {};
+    pb_variable_array(typename contents::const_reverse_iterator first, typename contents::const_reverse_iterator last) : contents(first, last) {};
+    void allocate(protoboard<FieldT> &pb, const size_t n, const std::string &annotation_prefix="");
+
+    void fill_with_field_elements(protoboard<FieldT> &pb, const std::vector<FieldT>& vals) const;
+    void fill_with_bits(protoboard<FieldT> &pb, const bit_vector& bits) const;
+    void fill_with_bits_of_ulong(protoboard<FieldT> &pb, const unsigned long i) const;
+    void fill_with_bits_of_field_element(protoboard<FieldT> &pb, const FieldT &r) const;
+
+    std::vector<FieldT> get_vals(const protoboard<FieldT> &pb) const;
+    bit_vector get_bits(const protoboard<FieldT> &pb) const;
+
+    FieldT get_field_element_from_bits(const protoboard<FieldT> &pb) const;
+};
+
+/* index 0 corresponds to the constant term (used in legacy code) */
+#define ONE pb_variable<FieldT>(0)
+
+template<typename FieldT>
+class pb_linear_combination : public linear_combination<FieldT> {
+public:
+    bool is_variable;
+    lc_index_t index;
+
+    pb_linear_combination();
+    pb_linear_combination(const pb_variable<FieldT> &var);
+
+    void assign(protoboard<FieldT> &pb, const linear_combination<FieldT> &lc);
+    void evaluate(protoboard<FieldT> &pb) const;
+
+    bool is_constant() const;
+    FieldT constant_term() const;
+};
+
+template<typename FieldT>
+class pb_linear_combination_array : private std::vector<pb_linear_combination<FieldT> >
+{
+    typedef std::vector<pb_linear_combination<FieldT> > contents;
+public:
+    using typename contents::iterator;
+    using typename contents::const_iterator;
+    using typename contents::reverse_iterator;
+    using typename contents::const_reverse_iterator;
+
+    using contents::begin;
+    using contents::end;
+    using contents::rbegin;
+    using contents::rend;
+    using contents::emplace_back;
+    using contents::insert;
+    using contents::reserve;
+    using contents::size;
+    using contents::empty;
+    using contents::operator[];
+    using contents::resize;
+
+    pb_linear_combination_array() : contents() {};
+    pb_linear_combination_array(const pb_variable_array<FieldT> &arr) { for (auto &v : arr) this->emplace_back(pb_linear_combination<FieldT>(v)); };
+    pb_linear_combination_array(size_t count) : contents(count) {};
+    pb_linear_combination_array(size_t count, const pb_linear_combination<FieldT> &value) : contents(count, value) {};
+    pb_linear_combination_array(typename contents::const_iterator first, typename contents::const_iterator last) : contents(first, last) {};
+    pb_linear_combination_array(typename contents::const_reverse_iterator first, typename contents::const_reverse_iterator last) : contents(first, last) {};
+
+    void evaluate(protoboard<FieldT> &pb) const;
+
+    void fill_with_field_elements(protoboard<FieldT> &pb, const std::vector<FieldT>& vals) const;
+    void fill_with_bits(protoboard<FieldT> &pb, const bit_vector& bits) const;
+    void fill_with_bits_of_ulong(protoboard<FieldT> &pb, const unsigned long i) const;
+    void fill_with_bits_of_field_element(protoboard<FieldT> &pb, const FieldT &r) const;
+
+    std::vector<FieldT> get_vals(const protoboard<FieldT> &pb) const;
+    bit_vector get_bits(const protoboard<FieldT> &pb) const;
+
+    FieldT get_field_element_from_bits(const protoboard<FieldT> &pb) const;
+};
+
+template<typename FieldT>
+linear_combination<FieldT> pb_sum(const pb_linear_combination_array<FieldT> &v);
+
+template<typename FieldT>
+linear_combination<FieldT> pb_packing_sum(const pb_linear_combination_array<FieldT> &v);
+
+template<typename FieldT>
+linear_combination<FieldT> pb_coeff_sum(const pb_linear_combination_array<FieldT> &v, const std::vector<FieldT> &coeffs);
+
+} // libsnark
+#include "gadgetlib1/pb_variable.tcc"
+
+#endif // PB_VARIABLE_HPP_
diff --git a/src/gadgetlib1/pb_variable.tcc b/src/gadgetlib1/pb_variable.tcc
new file mode 100644 (file)
index 0000000..b36b3f8
--- /dev/null
@@ -0,0 +1,330 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef PB_VARIABLE_TCC_
+#define PB_VARIABLE_TCC_
+#include <cassert>
+#include "gadgetlib1/protoboard.hpp"
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+void pb_variable<FieldT>::allocate(protoboard<FieldT> &pb, const std::string &annotation)
+{
+    this->index = pb.allocate_var_index(annotation);
+}
+
+/* allocates pb_variable<FieldT> array in MSB->LSB order */
+template<typename FieldT>
+void pb_variable_array<FieldT>::allocate(protoboard<FieldT> &pb, const size_t n, const std::string &annotation_prefix)
+{
+#ifdef DEBUG
+    assert(annotation_prefix != "");
+#endif
+    (*this).resize(n);
+
+    for (size_t i = 0; i < n; ++i)
+    {
+        (*this)[i].allocate(pb, FMT(annotation_prefix, "_%zu", i));
+    }
+}
+
+template<typename FieldT>
+void pb_variable_array<FieldT>::fill_with_field_elements(protoboard<FieldT> &pb, const std::vector<FieldT>& vals) const
+{
+    assert(this->size() == vals.size());
+    for (size_t i = 0; i < vals.size(); ++i)
+    {
+        pb.val((*this)[i]) = vals[i];
+    }
+}
+
+template<typename FieldT>
+void pb_variable_array<FieldT>::fill_with_bits(protoboard<FieldT> &pb, const bit_vector& bits) const
+{
+    assert(this->size() == bits.size());
+    for (size_t i = 0; i < bits.size(); ++i)
+    {
+        pb.val((*this)[i]) = (bits[i] ? FieldT::one() : FieldT::zero());
+    }
+}
+
+template<typename FieldT>
+void pb_variable_array<FieldT>::fill_with_bits_of_field_element(protoboard<FieldT> &pb, const FieldT &r) const
+{
+    const bigint<FieldT::num_limbs> rint = r.as_bigint();
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        pb.val((*this)[i]) = rint.test_bit(i) ? FieldT::one() : FieldT::zero();
+    }
+}
+
+template<typename FieldT>
+void pb_variable_array<FieldT>::fill_with_bits_of_ulong(protoboard<FieldT> &pb, const unsigned long i) const
+{
+    this->fill_with_bits_of_field_element(pb, FieldT(i, true));
+}
+
+template<typename FieldT>
+std::vector<FieldT> pb_variable_array<FieldT>::get_vals(const protoboard<FieldT> &pb) const
+{
+    std::vector<FieldT> result(this->size());
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        result[i] = pb.val((*this)[i]);
+    }
+    return result;
+}
+
+template<typename FieldT>
+bit_vector pb_variable_array<FieldT>::get_bits(const protoboard<FieldT> &pb) const
+{
+    bit_vector result;
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        const FieldT v = pb.val((*this)[i]);
+        assert(v == FieldT::zero() || v == FieldT::one());
+        result.push_back(v == FieldT::one());
+    }
+    return result;
+}
+
+template<typename FieldT>
+FieldT pb_variable_array<FieldT>::get_field_element_from_bits(const protoboard<FieldT> &pb) const
+{
+    FieldT result = FieldT::zero();
+
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        /* push in the new bit */
+        const FieldT v = pb.val((*this)[this->size()-1-i]);
+        assert(v == FieldT::zero() || v == FieldT::one());
+        result += result + v;
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+pb_linear_combination<FieldT>::pb_linear_combination()
+{
+    this->is_variable = false;
+    this->index = 0;
+}
+
+template<typename FieldT>
+pb_linear_combination<FieldT>::pb_linear_combination(const pb_variable<FieldT> &var)
+{
+    this->is_variable = true;
+    this->index = var.index;
+    this->terms.emplace_back(linear_term<FieldT>(var));
+}
+
+template<typename FieldT>
+void pb_linear_combination<FieldT>::assign(protoboard<FieldT> &pb, const linear_combination<FieldT> &lc)
+{
+    assert(this->is_variable == false);
+    this->index = pb.allocate_lc_index();
+    this->terms = lc.terms;
+}
+
+template<typename FieldT>
+void pb_linear_combination<FieldT>::evaluate(protoboard<FieldT> &pb) const
+{
+    if (this->is_variable)
+    {
+        return; // do nothing
+    }
+
+    FieldT sum = 0;
+    for (auto term : this->terms)
+    {
+        sum += term.coeff * pb.val(pb_variable<FieldT>(term.index));
+    }
+
+    pb.lc_val(*this) = sum;
+}
+
+template<typename FieldT>
+bool pb_linear_combination<FieldT>::is_constant() const
+{
+    if (is_variable)
+    {
+        return (index == 0);
+    }
+    else
+    {
+        for (auto term : this->terms)
+        {
+            if (term.index != 0)
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
+
+template<typename FieldT>
+FieldT pb_linear_combination<FieldT>::constant_term() const
+{
+    if (is_variable)
+    {
+        return (index == 0 ? FieldT::one() : FieldT::zero());
+    }
+    else
+    {
+        FieldT result = FieldT::zero();
+        for (auto term : this->terms)
+        {
+            if (term.index == 0)
+            {
+                result += term.coeff;
+            }
+        }
+        return result;
+    }
+}
+
+template<typename FieldT>
+void pb_linear_combination_array<FieldT>::evaluate(protoboard<FieldT> &pb) const
+{
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        (*this)[i].evaluate(pb);
+    }
+}
+
+template<typename FieldT>
+void pb_linear_combination_array<FieldT>::fill_with_field_elements(protoboard<FieldT> &pb, const std::vector<FieldT>& vals) const
+{
+    assert(this->size() == vals.size());
+    for (size_t i = 0; i < vals.size(); ++i)
+    {
+        pb.lc_val((*this)[i]) = vals[i];
+    }
+}
+
+template<typename FieldT>
+void pb_linear_combination_array<FieldT>::fill_with_bits(protoboard<FieldT> &pb, const bit_vector& bits) const
+{
+    assert(this->size() == bits.size());
+    for (size_t i = 0; i < bits.size(); ++i)
+    {
+        pb.lc_val((*this)[i]) = (bits[i] ? FieldT::one() : FieldT::zero());
+    }
+}
+
+template<typename FieldT>
+void pb_linear_combination_array<FieldT>::fill_with_bits_of_field_element(protoboard<FieldT> &pb, const FieldT &r) const
+{
+    const bigint<FieldT::num_limbs> rint = r.as_bigint();
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        pb.lc_val((*this)[i]) = rint.test_bit(i) ? FieldT::one() : FieldT::zero();
+    }
+}
+
+template<typename FieldT>
+void pb_linear_combination_array<FieldT>::fill_with_bits_of_ulong(protoboard<FieldT> &pb, const unsigned long i) const
+{
+    this->fill_with_bits_of_field_element(pb, FieldT(i));
+}
+
+template<typename FieldT>
+std::vector<FieldT> pb_linear_combination_array<FieldT>::get_vals(const protoboard<FieldT> &pb) const
+{
+    std::vector<FieldT> result(this->size());
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        result[i] = pb.lc_val((*this)[i]);
+    }
+    return result;
+}
+
+template<typename FieldT>
+bit_vector pb_linear_combination_array<FieldT>::get_bits(const protoboard<FieldT> &pb) const
+{
+    bit_vector result;
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        const FieldT v = pb.lc_val((*this)[i]);
+        assert(v == FieldT::zero() || v == FieldT::one());
+        result.push_back(v == FieldT::one());
+    }
+    return result;
+}
+
+template<typename FieldT>
+FieldT pb_linear_combination_array<FieldT>::get_field_element_from_bits(const protoboard<FieldT> &pb) const
+{
+    FieldT result = FieldT::zero();
+
+    for (size_t i = 0; i < this->size(); ++i)
+    {
+        /* push in the new bit */
+        const FieldT v = pb.lc_val((*this)[this->size()-1-i]);
+        assert(v == FieldT::zero() || v == FieldT::one());
+        result += result + v;
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> pb_sum(const pb_linear_combination_array<FieldT> &v)
+{
+    linear_combination<FieldT> result;
+    for (auto &term  : v)
+    {
+        result = result + term;
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> pb_packing_sum(const pb_linear_combination_array<FieldT> &v)
+{
+    FieldT twoi = FieldT::one(); // will hold 2^i entering each iteration
+    std::vector<linear_term<FieldT> > all_terms;
+    for (auto &lc : v)
+    {
+        for (auto &term : lc.terms)
+        {
+            all_terms.emplace_back(twoi * term);
+        }
+        twoi += twoi;
+    }
+
+    return linear_combination<FieldT>(all_terms);
+}
+
+template<typename FieldT>
+linear_combination<FieldT> pb_coeff_sum(const pb_linear_combination_array<FieldT> &v, const std::vector<FieldT> &coeffs)
+{
+    assert(v.size() == coeffs.size());
+    std::vector<linear_term<FieldT> > all_terms;
+
+    auto coeff_it = coeffs.begin();
+    for (auto &lc : v)
+    {
+        for (auto &term : lc.terms)
+        {
+            all_terms.emplace_back((*coeff_it) * term);
+        }
+        ++coeff_it;
+    }
+
+    return linear_combination<FieldT>(all_terms);
+}
+
+
+} // libsnark
+#endif // PB_VARIABLE_TCC
diff --git a/src/gadgetlib1/protoboard.hpp b/src/gadgetlib1/protoboard.hpp
new file mode 100644 (file)
index 0000000..a910a6d
--- /dev/null
@@ -0,0 +1,75 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef PROTOBOARD_HPP_
+#define PROTOBOARD_HPP_
+
+#include <algorithm>
+#include <cassert>
+#include <cstdio>
+#include <string>
+#include <vector>
+#include "gadgetlib1/pb_variable.hpp"
+#include "relations/constraint_satisfaction_problems/r1cs/r1cs.hpp"
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+class r1cs_constraint;
+
+template<typename FieldT>
+class r1cs_constraint_system;
+
+template<typename FieldT>
+class protoboard {
+private:
+    FieldT constant_term; /* only here, because pb.val() needs to be able to return reference to the constant 1 term */
+    r1cs_variable_assignment<FieldT> values; /* values[0] will hold the value of the first allocated variable of the protoboard, *NOT* constant 1 */
+    var_index_t next_free_var;
+    lc_index_t next_free_lc;
+    std::vector<FieldT> lc_values;
+public:
+    r1cs_constraint_system<FieldT> constraint_system;
+    
+    protoboard();
+
+    void clear_values();
+
+    FieldT& val(const pb_variable<FieldT> &var);
+    FieldT val(const pb_variable<FieldT> &var) const;
+
+    FieldT& lc_val(const pb_linear_combination<FieldT> &lc);
+    FieldT lc_val(const pb_linear_combination<FieldT> &lc) const;
+
+    void add_r1cs_constraint(const r1cs_constraint<FieldT> &constr, const std::string &annotation="");
+    void augment_variable_annotation(const pb_variable<FieldT> &v, const std::string &postfix);
+    bool is_satisfied() const;
+    void dump_variables() const;
+
+    size_t num_constraints() const;
+    size_t num_inputs() const;
+    size_t num_variables() const;
+
+    void set_input_sizes(const size_t primary_input_size);
+
+    r1cs_variable_assignment<FieldT> full_variable_assignment() const;
+    r1cs_primary_input<FieldT> primary_input() const;
+    r1cs_auxiliary_input<FieldT> auxiliary_input() const;
+    r1cs_constraint_system<FieldT> get_constraint_system() const;
+
+    friend class pb_variable<FieldT>;
+    friend class pb_linear_combination<FieldT>;
+
+private:
+    var_index_t allocate_var_index(const std::string &annotation="");
+    lc_index_t allocate_lc_index();
+};
+
+} // libsnark
+#include "gadgetlib1/protoboard.tcc"
+#endif // PROTOBOARD_HPP_
diff --git a/src/gadgetlib1/protoboard.tcc b/src/gadgetlib1/protoboard.tcc
new file mode 100644 (file)
index 0000000..882af28
--- /dev/null
@@ -0,0 +1,189 @@
+/** @file
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef PROTOBOARD_TCC_
+#define PROTOBOARD_TCC_
+
+#include <cstdio>
+#include <cstdarg>
+#include "common/profiling.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+protoboard<FieldT>::protoboard()
+{
+    constant_term = FieldT::one();
+
+#ifdef DEBUG
+    constraint_system.variable_annotations[0] = "ONE";
+#endif
+
+    next_free_var = 1; /* to account for constant 1 term */
+    next_free_lc = 0;
+}
+
+template<typename FieldT>
+void protoboard<FieldT>::clear_values()
+{
+    std::fill(values.begin(), values.end(), FieldT::zero());
+}
+
+template<typename FieldT>
+var_index_t protoboard<FieldT>::allocate_var_index(const std::string &annotation)
+{
+#ifdef DEBUG
+    assert(annotation != "");
+    constraint_system.variable_annotations[next_free_var] = annotation;
+#else
+    UNUSED(annotation);
+#endif
+    ++constraint_system.auxiliary_input_size;
+    values.emplace_back(FieldT::zero());
+    return next_free_var++;
+}
+
+template<typename FieldT>
+lc_index_t protoboard<FieldT>::allocate_lc_index()
+{
+    lc_values.emplace_back(FieldT::zero());
+    return next_free_lc++;
+}
+
+template<typename FieldT>
+FieldT& protoboard<FieldT>::val(const pb_variable<FieldT> &var)
+{
+    assert(var.index <= values.size());
+    return (var.index == 0 ? constant_term : values[var.index-1]);
+}
+
+template<typename FieldT>
+FieldT protoboard<FieldT>::val(const pb_variable<FieldT> &var) const
+{
+    assert(var.index <= values.size());
+    return (var.index == 0 ? constant_term : values[var.index-1]);
+}
+
+template<typename FieldT>
+FieldT& protoboard<FieldT>::lc_val(const pb_linear_combination<FieldT> &lc)
+{
+    if (lc.is_variable)
+    {
+        return this->val(pb_variable<FieldT>(lc.index));
+    }
+    else
+    {
+        assert(lc.index < lc_values.size());
+        return lc_values[lc.index];
+    }
+}
+
+template<typename FieldT>
+FieldT protoboard<FieldT>::lc_val(const pb_linear_combination<FieldT> &lc) const
+{
+    if (lc.is_variable)
+    {
+        return this->val(pb_variable<FieldT>(lc.index));
+    }
+    else
+    {
+        assert(lc.index < lc_values.size());
+        return lc_values[lc.index];
+    }
+}
+
+template<typename FieldT>
+void protoboard<FieldT>::add_r1cs_constraint(const r1cs_constraint<FieldT> &constr, const std::string &annotation)
+{
+#ifdef DEBUG
+    assert(annotation != "");
+    constraint_system.constraint_annotations[constraint_system.constraints.size()] = annotation;
+#else
+    UNUSED(annotation);
+#endif
+    constraint_system.constraints.emplace_back(constr);
+}
+
+template<typename FieldT>
+void protoboard<FieldT>::augment_variable_annotation(const pb_variable<FieldT> &v, const std::string &postfix)
+{
+#ifdef DEBUG
+    auto it = constraint_system.variable_annotations.find(v.index);
+    constraint_system.variable_annotations[v.index] = (it == constraint_system.variable_annotations.end() ? "" : it->second + " ") + postfix;
+#endif
+}
+
+template<typename FieldT>
+bool protoboard<FieldT>::is_satisfied() const
+{
+    return constraint_system.is_satisfied(primary_input(), auxiliary_input());
+}
+
+template<typename FieldT>
+void protoboard<FieldT>::dump_variables() const
+{
+#ifdef DEBUG
+    for (size_t i = 0; i < constraint_system.num_variables; ++i)
+    {
+        printf("%-40s --> ", constraint_system.variable_annotations[i].c_str());
+        values[i].as_bigint().print_hex();
+    }
+#endif
+}
+
+template<typename FieldT>
+size_t protoboard<FieldT>::num_constraints() const
+{
+    return constraint_system.num_constraints();
+}
+
+template<typename FieldT>
+size_t protoboard<FieldT>::num_inputs() const
+{
+    return constraint_system.num_inputs();
+}
+
+template<typename FieldT>
+size_t protoboard<FieldT>::num_variables() const
+{
+    return next_free_var - 1;
+}
+
+template<typename FieldT>
+void protoboard<FieldT>::set_input_sizes(const size_t primary_input_size)
+{
+    assert(primary_input_size <= num_variables());
+    constraint_system.primary_input_size = primary_input_size;
+    constraint_system.auxiliary_input_size = num_variables() - primary_input_size;
+}
+
+template<typename FieldT>
+r1cs_variable_assignment<FieldT> protoboard<FieldT>::full_variable_assignment() const
+{
+    return values;
+}
+
+template<typename FieldT>
+r1cs_primary_input<FieldT> protoboard<FieldT>::primary_input() const
+{
+    return r1cs_primary_input<FieldT>(values.begin(), values.begin() + num_inputs());
+}
+
+template<typename FieldT>
+r1cs_auxiliary_input<FieldT> protoboard<FieldT>::auxiliary_input() const
+{
+    return r1cs_primary_input<FieldT>(values.begin() + num_inputs(), values.end());
+}
+
+template<typename FieldT>
+r1cs_constraint_system<FieldT> protoboard<FieldT>::get_constraint_system() const
+{
+    return constraint_system;
+}
+
+} // libsnark
+#endif // PROTOBOARD_TCC_
diff --git a/src/reductions/r1cs_to_qap/r1cs_to_qap.hpp b/src/reductions/r1cs_to_qap/r1cs_to_qap.hpp
new file mode 100644 (file)
index 0000000..b3cde71
--- /dev/null
@@ -0,0 +1,70 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for a R1CS-to-QAP reduction, that is, constructing
+ a QAP ("Quadratic Arithmetic Program") from a R1CS ("Rank-1 Constraint System").
+
+ QAPs are defined in \[GGPR13], and construced for R1CS also in \[GGPR13].
+
+ The implementation of the reduction follows, extends, and optimizes
+ the efficient approach described in Appendix E of \[BCGTV13].
+
+ References:
+
+ \[BCGTV13]
+ "SNARKs for C: Verifying Program Executions Succinctly and in Zero Knowledge",
+ Eli Ben-Sasson, Alessandro Chiesa, Daniel Genkin, Eran Tromer, Madars Virza,
+ CRYPTO 2013,
+ <http://eprint.iacr.org/2013/507>
+
+ \[GGPR13]:
+ "Quadratic span programs and succinct NIZKs without PCPs",
+ Rosario Gennaro, Craig Gentry, Bryan Parno, Mariana Raykova,
+ EUROCRYPT 2013,
+ <http://eprint.iacr.org/2012/215>
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_TO_QAP_HPP_
+#define R1CS_TO_QAP_HPP_
+
+#include "relations/arithmetic_programs/qap/qap.hpp"
+#include "relations/constraint_satisfaction_problems/r1cs/r1cs.hpp"
+
+namespace libsnark {
+
+/**
+ * Instance map for the R1CS-to-QAP reduction.
+ */
+template<typename FieldT>
+qap_instance<FieldT> r1cs_to_qap_instance_map(const r1cs_constraint_system<FieldT> &cs);
+
+/**
+ * Instance map for the R1CS-to-QAP reduction followed by evaluation of the resulting QAP instance.
+ */
+template<typename FieldT>
+qap_instance_evaluation<FieldT> r1cs_to_qap_instance_map_with_evaluation(const r1cs_constraint_system<FieldT> &cs,
+                                                                         const FieldT &t);
+
+/**
+ * Witness map for the R1CS-to-QAP reduction.
+ *
+ * The witness map takes zero knowledge into account when d1,d2,d3 are random.
+ */
+template<typename FieldT>
+qap_witness<FieldT> r1cs_to_qap_witness_map(const r1cs_constraint_system<FieldT> &cs,
+                                            const r1cs_primary_input<FieldT> &primary_input,
+                                            const r1cs_auxiliary_input<FieldT> &auxiliary_input,
+                                            const FieldT &d1,
+                                            const FieldT &d2,
+                                            const FieldT &d3);
+
+} // libsnark
+
+#include "reductions/r1cs_to_qap/r1cs_to_qap.tcc"
+
+#endif // R1CS_TO_QAP_HPP_
diff --git a/src/reductions/r1cs_to_qap/r1cs_to_qap.tcc b/src/reductions/r1cs_to_qap/r1cs_to_qap.tcc
new file mode 100644 (file)
index 0000000..3d0bee2
--- /dev/null
@@ -0,0 +1,338 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for a R1CS-to-QAP reduction.
+
+ See r1cs_to_qap.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_TO_QAP_TCC_
+#define R1CS_TO_QAP_TCC_
+
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+#include "algebra/evaluation_domain/evaluation_domain.hpp"
+
+namespace libsnark {
+
+/**
+ * Instance map for the R1CS-to-QAP reduction.
+ *
+ * Namely, given a R1CS constraint system cs, construct a QAP instance for which:
+ *   A := (A_0(z),A_1(z),...,A_m(z))
+ *   B := (B_0(z),B_1(z),...,B_m(z))
+ *   C := (C_0(z),C_1(z),...,C_m(z))
+ * where
+ *   m = number of variables of the QAP
+ * and
+ *   each A_i,B_i,C_i is expressed in the Lagrange basis.
+ */
+template<typename FieldT>
+qap_instance<FieldT> r1cs_to_qap_instance_map(const r1cs_constraint_system<FieldT> &cs)
+{
+    enter_block("Call to r1cs_to_qap_instance_map");
+
+    const std::shared_ptr<evaluation_domain<FieldT> > domain = get_evaluation_domain<FieldT>(cs.num_constraints() + cs.num_inputs() + 1);
+
+    std::vector<std::map<size_t, FieldT> > A_in_Lagrange_basis(cs.num_variables()+1);
+    std::vector<std::map<size_t, FieldT> > B_in_Lagrange_basis(cs.num_variables()+1);
+    std::vector<std::map<size_t, FieldT> > C_in_Lagrange_basis(cs.num_variables()+1);
+
+    enter_block("Compute polynomials A, B, C in Lagrange basis");
+    /**
+     * add and process the constraints
+     *     input_i * 0 = 0
+     * to ensure soundness of input consistency
+     */
+    for (size_t i = 0; i <= cs.num_inputs(); ++i)
+    {
+        A_in_Lagrange_basis[i][cs.num_constraints() + i] = FieldT::one();
+    }
+    /* process all other constraints */
+    for (size_t i = 0; i < cs.num_constraints(); ++i)
+    {
+        for (size_t j = 0; j < cs.constraints[i].a.terms.size(); ++j)
+        {
+            A_in_Lagrange_basis[cs.constraints[i].a.terms[j].index][i] +=
+                cs.constraints[i].a.terms[j].coeff;
+        }
+
+        for (size_t j = 0; j < cs.constraints[i].b.terms.size(); ++j)
+        {
+            B_in_Lagrange_basis[cs.constraints[i].b.terms[j].index][i] +=
+                cs.constraints[i].b.terms[j].coeff;
+        }
+
+        for (size_t j = 0; j < cs.constraints[i].c.terms.size(); ++j)
+        {
+            C_in_Lagrange_basis[cs.constraints[i].c.terms[j].index][i] +=
+                cs.constraints[i].c.terms[j].coeff;
+        }
+    }
+    leave_block("Compute polynomials A, B, C in Lagrange basis");
+
+    leave_block("Call to r1cs_to_qap_instance_map");
+
+    return qap_instance<FieldT>(domain,
+                                cs.num_variables(),
+                                domain->m,
+                                cs.num_inputs(),
+                                std::move(A_in_Lagrange_basis),
+                                std::move(B_in_Lagrange_basis),
+                                std::move(C_in_Lagrange_basis));
+}
+
+/**
+ * Instance map for the R1CS-to-QAP reduction followed by evaluation of the resulting QAP instance.
+ *
+ * Namely, given a R1CS constraint system cs and a field element t, construct
+ * a QAP instance (evaluated at t) for which:
+ *   At := (A_0(t),A_1(t),...,A_m(t))
+ *   Bt := (B_0(t),B_1(t),...,B_m(t))
+ *   Ct := (C_0(t),C_1(t),...,C_m(t))
+ *   Ht := (1,t,t^2,...,t^n)
+ *   Zt := Z(t) = "vanishing polynomial of a certain set S, evaluated at t"
+ * where
+ *   m = number of variables of the QAP
+ *   n = degree of the QAP
+ */
+template<typename FieldT>
+qap_instance_evaluation<FieldT> r1cs_to_qap_instance_map_with_evaluation(const r1cs_constraint_system<FieldT> &cs,
+                                                                         const FieldT &t)
+{
+    enter_block("Call to r1cs_to_qap_instance_map_with_evaluation");
+
+    const std::shared_ptr<evaluation_domain<FieldT> > domain = get_evaluation_domain<FieldT>(cs.num_constraints() + cs.num_inputs() + 1);
+
+    std::vector<FieldT> At, Bt, Ct, Ht;
+
+    At.resize(cs.num_variables()+1, FieldT::zero());
+    Bt.resize(cs.num_variables()+1, FieldT::zero());
+    Ct.resize(cs.num_variables()+1, FieldT::zero());
+    Ht.reserve(domain->m+1);
+
+    const FieldT Zt = domain->compute_Z(t);
+
+    enter_block("Compute evaluations of A, B, C, H at t");
+    const std::vector<FieldT> u = domain->lagrange_coeffs(t);
+    /**
+     * add and process the constraints
+     *     input_i * 0 = 0
+     * to ensure soundness of input consistency
+     */
+    for (size_t i = 0; i <= cs.num_inputs(); ++i)
+    {
+        At[i] = u[cs.num_constraints() + i];
+    }
+    /* process all other constraints */
+    for (size_t i = 0; i < cs.num_constraints(); ++i)
+    {
+        for (size_t j = 0; j < cs.constraints[i].a.terms.size(); ++j)
+        {
+            At[cs.constraints[i].a.terms[j].index] +=
+                u[i]*cs.constraints[i].a.terms[j].coeff;
+        }
+
+        for (size_t j = 0; j < cs.constraints[i].b.terms.size(); ++j)
+        {
+            Bt[cs.constraints[i].b.terms[j].index] +=
+                u[i]*cs.constraints[i].b.terms[j].coeff;
+        }
+
+        for (size_t j = 0; j < cs.constraints[i].c.terms.size(); ++j)
+        {
+            Ct[cs.constraints[i].c.terms[j].index] +=
+                u[i]*cs.constraints[i].c.terms[j].coeff;
+        }
+    }
+
+    FieldT ti = FieldT::one();
+    for (size_t i = 0; i < domain->m+1; ++i)
+    {
+        Ht.emplace_back(ti);
+        ti *= t;
+    }
+    leave_block("Compute evaluations of A, B, C, H at t");
+
+    leave_block("Call to r1cs_to_qap_instance_map_with_evaluation");
+
+    return qap_instance_evaluation<FieldT>(domain,
+                                           cs.num_variables(),
+                                           domain->m,
+                                           cs.num_inputs(),
+                                           t,
+                                           std::move(At),
+                                           std::move(Bt),
+                                           std::move(Ct),
+                                           std::move(Ht),
+                                           Zt);
+}
+
+/**
+ * Witness map for the R1CS-to-QAP reduction.
+ *
+ * The witness map takes zero knowledge into account when d1,d2,d3 are random.
+ *
+ * More precisely, compute the coefficients
+ *     h_0,h_1,...,h_n
+ * of the polynomial
+ *     H(z) := (A(z)*B(z)-C(z))/Z(z)
+ * where
+ *   A(z) := A_0(z) + \sum_{k=1}^{m} w_k A_k(z) + d1 * Z(z)
+ *   B(z) := B_0(z) + \sum_{k=1}^{m} w_k B_k(z) + d2 * Z(z)
+ *   C(z) := C_0(z) + \sum_{k=1}^{m} w_k C_k(z) + d3 * Z(z)
+ *   Z(z) := "vanishing polynomial of set S"
+ * and
+ *   m = number of variables of the QAP
+ *   n = degree of the QAP
+ *
+ * This is done as follows:
+ *  (1) compute evaluations of A,B,C on S = {sigma_1,...,sigma_n}
+ *  (2) compute coefficients of A,B,C
+ *  (3) compute evaluations of A,B,C on T = "coset of S"
+ *  (4) compute evaluation of H on T
+ *  (5) compute coefficients of H
+ *  (6) patch H to account for d1,d2,d3 (i.e., add coefficients of the polynomial (A d2 + B d1 - d3) + d1*d2*Z )
+ *
+ * The code below is not as simple as the above high-level description due to
+ * some reshuffling to save space.
+ */
+template<typename FieldT>
+qap_witness<FieldT> r1cs_to_qap_witness_map(const r1cs_constraint_system<FieldT> &cs,
+                                            const r1cs_primary_input<FieldT> &primary_input,
+                                            const r1cs_auxiliary_input<FieldT> &auxiliary_input,
+                                            const FieldT &d1,
+                                            const FieldT &d2,
+                                            const FieldT &d3)
+{
+    enter_block("Call to r1cs_to_qap_witness_map");
+
+    /* sanity check */
+    assert(cs.is_satisfied(primary_input, auxiliary_input));
+
+    const std::shared_ptr<evaluation_domain<FieldT> > domain = get_evaluation_domain<FieldT>(cs.num_constraints() + cs.num_inputs() + 1);
+
+    r1cs_variable_assignment<FieldT> full_variable_assignment = primary_input;
+    full_variable_assignment.insert(full_variable_assignment.end(), auxiliary_input.begin(), auxiliary_input.end());
+
+    enter_block("Compute evaluation of polynomials A, B on set S");
+    std::vector<FieldT> aA(domain->m, FieldT::zero()), aB(domain->m, FieldT::zero());
+
+    /* account for the additional constraints input_i * 0 = 0 */
+    for (size_t i = 0; i <= cs.num_inputs(); ++i)
+    {
+        aA[i+cs.num_constraints()] = (i > 0 ? full_variable_assignment[i-1] : FieldT::one());
+    }
+    /* account for all other constraints */
+    for (size_t i = 0; i < cs.num_constraints(); ++i)
+    {
+        aA[i] += cs.constraints[i].a.evaluate(full_variable_assignment);
+        aB[i] += cs.constraints[i].b.evaluate(full_variable_assignment);
+    }
+    leave_block("Compute evaluation of polynomials A, B on set S");
+
+    enter_block("Compute coefficients of polynomial A");
+    domain->iFFT(aA);
+    leave_block("Compute coefficients of polynomial A");
+
+    enter_block("Compute coefficients of polynomial B");
+    domain->iFFT(aB);
+    leave_block("Compute coefficients of polynomial B");
+
+    enter_block("Compute ZK-patch");
+    std::vector<FieldT> coefficients_for_H(domain->m+1, FieldT::zero());
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+    /* add coefficients of the polynomial (d2*A + d1*B - d3) + d1*d2*Z */
+    for (size_t i = 0; i < domain->m; ++i)
+    {
+        coefficients_for_H[i] = d2*aA[i] + d1*aB[i];
+    }
+    coefficients_for_H[0] -= d3;
+    domain->add_poly_Z(d1*d2, coefficients_for_H);
+    leave_block("Compute ZK-patch");
+
+    enter_block("Compute evaluation of polynomial A on set T");
+    domain->cosetFFT(aA, FieldT::multiplicative_generator);
+    leave_block("Compute evaluation of polynomial A on set T");
+
+    enter_block("Compute evaluation of polynomial B on set T");
+    domain->cosetFFT(aB, FieldT::multiplicative_generator);
+    leave_block("Compute evaluation of polynomial B on set T");
+
+    enter_block("Compute evaluation of polynomial H on set T");
+    std::vector<FieldT> &H_tmp = aA; // can overwrite aA because it is not used later
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+    for (size_t i = 0; i < domain->m; ++i)
+    {
+        H_tmp[i] = aA[i]*aB[i];
+    }
+    std::vector<FieldT>().swap(aB); // destroy aB
+
+    enter_block("Compute evaluation of polynomial C on set S");
+    std::vector<FieldT> aC(domain->m, FieldT::zero());
+    for (size_t i = 0; i < cs.num_constraints(); ++i)
+    {
+        aC[i] += cs.constraints[i].c.evaluate(full_variable_assignment);
+    }
+    leave_block("Compute evaluation of polynomial C on set S");
+
+    enter_block("Compute coefficients of polynomial C");
+    domain->iFFT(aC);
+    leave_block("Compute coefficients of polynomial C");
+
+    enter_block("Compute evaluation of polynomial C on set T");
+    domain->cosetFFT(aC, FieldT::multiplicative_generator);
+    leave_block("Compute evaluation of polynomial C on set T");
+
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+    for (size_t i = 0; i < domain->m; ++i)
+    {
+        H_tmp[i] = (H_tmp[i]-aC[i]);
+    }
+
+    enter_block("Divide by Z on set T");
+    domain->divide_by_Z_on_coset(H_tmp);
+    leave_block("Divide by Z on set T");
+
+    leave_block("Compute evaluation of polynomial H on set T");
+
+    enter_block("Compute coefficients of polynomial H");
+    domain->icosetFFT(H_tmp, FieldT::multiplicative_generator);
+    leave_block("Compute coefficients of polynomial H");
+
+    enter_block("Compute sum of H and ZK-patch");
+#ifdef MULTICORE
+#pragma omp parallel for
+#endif
+    for (size_t i = 0; i < domain->m; ++i)
+    {
+        coefficients_for_H[i] += H_tmp[i];
+    }
+    leave_block("Compute sum of H and ZK-patch");
+
+    leave_block("Call to r1cs_to_qap_witness_map");
+
+    return qap_witness<FieldT>(cs.num_variables(),
+                               domain->m,
+                               cs.num_inputs(),
+                               d1,
+                               d2,
+                               d3,
+                               full_variable_assignment,
+                               std::move(coefficients_for_H));
+}
+
+} // libsnark
+
+#endif // R1CS_TO_QAP_TCC_
diff --git a/src/relations/arithmetic_programs/qap/qap.hpp b/src/relations/arithmetic_programs/qap/qap.hpp
new file mode 100644 (file)
index 0000000..4991d20
--- /dev/null
@@ -0,0 +1,193 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for a QAP ("Quadratic Arithmetic Program").
+
+ QAPs are defined in \[GGPR13].
+
+ References:
+
+ \[GGPR13]:
+ "Quadratic span programs and succinct NIZKs without PCPs",
+ Rosario Gennaro, Craig Gentry, Bryan Parno, Mariana Raykova,
+ EUROCRYPT 2013,
+ <http://eprint.iacr.org/2012/215>
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef QAP_HPP_
+#define QAP_HPP_
+
+#include "algebra/evaluation_domain/evaluation_domain.hpp"
+
+namespace libsnark {
+
+/* forward declaration */
+template<typename FieldT>
+class qap_witness;
+
+/**
+ * A QAP instance.
+ *
+ * Specifically, the datastructure stores:
+ * - a choice of domain (corresponding to a certain subset of the field);
+ * - the number of variables, the degree, and the number of inputs; and
+ * - coefficients of the A,B,C polynomials in the Lagrange basis.
+ *
+ * There is no need to store the Z polynomial because it is uniquely
+ * determined by the domain (as Z is its vanishing polynomial).
+ */
+template<typename FieldT>
+class qap_instance {
+private:
+    size_t num_variables_;
+    size_t degree_;
+    size_t num_inputs_;
+
+public:
+    std::shared_ptr<evaluation_domain<FieldT> > domain;
+
+    std::vector<std::map<size_t, FieldT> > A_in_Lagrange_basis;
+    std::vector<std::map<size_t, FieldT> > B_in_Lagrange_basis;
+    std::vector<std::map<size_t, FieldT> > C_in_Lagrange_basis;
+
+    qap_instance(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                 const size_t num_variables,
+                 const size_t degree,
+                 const size_t num_inputs,
+                 const std::vector<std::map<size_t, FieldT> > &A_in_Lagrange_basis,
+                 const std::vector<std::map<size_t, FieldT> > &B_in_Lagrange_basis,
+                 const std::vector<std::map<size_t, FieldT> > &C_in_Lagrange_basis);
+
+    qap_instance(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                 const size_t num_variables,
+                 const size_t degree,
+                 const size_t num_inputs,
+                 std::vector<std::map<size_t, FieldT> > &&A_in_Lagrange_basis,
+                 std::vector<std::map<size_t, FieldT> > &&B_in_Lagrange_basis,
+                 std::vector<std::map<size_t, FieldT> > &&C_in_Lagrange_basis);
+
+    qap_instance(const qap_instance<FieldT> &other) = default;
+    qap_instance(qap_instance<FieldT> &&other) = default;
+    qap_instance& operator=(const qap_instance<FieldT> &other) = default;
+    qap_instance& operator=(qap_instance<FieldT> &&other) = default;
+
+    size_t num_variables() const;
+    size_t degree() const;
+    size_t num_inputs() const;
+
+    bool is_satisfied(const qap_witness<FieldT> &witness) const;
+};
+
+/**
+ * A QAP instance evaluation is a QAP instance that is evaluated at a field element t.
+ *
+ * Specifically, the datastructure stores:
+ * - a choice of domain (corresponding to a certain subset of the field);
+ * - the number of variables, the degree, and the number of inputs;
+ * - a field element t;
+ * - evaluations of the A,B,C (and Z) polynomials at t;
+ * - evaluations of all monomials of t;
+ * - counts about how many of the above evaluations are in fact non-zero.
+ */
+template<typename FieldT>
+class qap_instance_evaluation {
+private:
+    size_t num_variables_;
+    size_t degree_;
+    size_t num_inputs_;
+public:
+    std::shared_ptr<evaluation_domain<FieldT> > domain;
+
+    FieldT t;
+
+    std::vector<FieldT> At, Bt, Ct, Ht;
+
+    FieldT Zt;
+
+    qap_instance_evaluation(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                            const size_t num_variables,
+                            const size_t degree,
+                            const size_t num_inputs,
+                            const FieldT &t,
+                            const std::vector<FieldT> &At,
+                            const std::vector<FieldT> &Bt,
+                            const std::vector<FieldT> &Ct,
+                            const std::vector<FieldT> &Ht,
+                            const FieldT &Zt);
+    qap_instance_evaluation(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                            const size_t num_variables,
+                            const size_t degree,
+                            const size_t num_inputs,
+                            const FieldT &t,
+                            std::vector<FieldT> &&At,
+                            std::vector<FieldT> &&Bt,
+                            std::vector<FieldT> &&Ct,
+                            std::vector<FieldT> &&Ht,
+                            const FieldT &Zt);
+
+    qap_instance_evaluation(const qap_instance_evaluation<FieldT> &other) = default;
+    qap_instance_evaluation(qap_instance_evaluation<FieldT> &&other) = default;
+    qap_instance_evaluation& operator=(const qap_instance_evaluation<FieldT> &other) = default;
+    qap_instance_evaluation& operator=(qap_instance_evaluation<FieldT> &&other) = default;
+
+    size_t num_variables() const;
+    size_t degree() const;
+    size_t num_inputs() const;
+
+    bool is_satisfied(const qap_witness<FieldT> &witness) const;
+};
+
+/**
+ * A QAP witness.
+ */
+template<typename FieldT>
+class qap_witness {
+private:
+    size_t num_variables_;
+    size_t degree_;
+    size_t num_inputs_;
+
+public:
+    FieldT d1, d2, d3;
+
+    std::vector<FieldT> coefficients_for_ABCs;
+    std::vector<FieldT> coefficients_for_H;
+
+    qap_witness(const size_t num_variables,
+                const size_t degree,
+                const size_t num_inputs,
+                const FieldT &d1,
+                const FieldT &d2,
+                const FieldT &d3,
+                const std::vector<FieldT> &coefficients_for_ABCs,
+                const std::vector<FieldT> &coefficients_for_H);
+
+    qap_witness(const size_t num_variables,
+                const size_t degree,
+                const size_t num_inputs,
+                const FieldT &d1,
+                const FieldT &d2,
+                const FieldT &d3,
+                const std::vector<FieldT> &coefficients_for_ABCs,
+                std::vector<FieldT> &&coefficients_for_H);
+
+    qap_witness(const qap_witness<FieldT> &other) = default;
+    qap_witness(qap_witness<FieldT> &&other) = default;
+    qap_witness& operator=(const qap_witness<FieldT> &other) = default;
+    qap_witness& operator=(qap_witness<FieldT> &&other) = default;
+
+    size_t num_variables() const;
+    size_t degree() const;
+    size_t num_inputs() const;
+};
+
+} // libsnark
+
+#include "relations/arithmetic_programs/qap/qap.tcc"
+
+#endif // QAP_HPP_
diff --git a/src/relations/arithmetic_programs/qap/qap.tcc b/src/relations/arithmetic_programs/qap/qap.tcc
new file mode 100644 (file)
index 0000000..a4a3c96
--- /dev/null
@@ -0,0 +1,324 @@
+/** @file
+*****************************************************************************
+
+Implementation of interfaces for a QAP ("Quadratic Arithmetic Program").
+
+See qap.hpp .
+
+*****************************************************************************
+* @author     This file is part of libsnark, developed by SCIPR Lab
+*             and contributors (see AUTHORS).
+* @copyright  MIT license (see LICENSE file)
+*****************************************************************************/
+
+#ifndef QAP_TCC_
+#define QAP_TCC_
+
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+#include "algebra/evaluation_domain/evaluation_domain.hpp"
+#include "algebra/scalar_multiplication/multiexp.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+qap_instance<FieldT>::qap_instance(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                                   const size_t num_variables,
+                                   const size_t degree,
+                                   const size_t num_inputs,
+                                   const std::vector<std::map<size_t, FieldT> > &A_in_Lagrange_basis,
+                                   const std::vector<std::map<size_t, FieldT> > &B_in_Lagrange_basis,
+                                   const std::vector<std::map<size_t, FieldT> > &C_in_Lagrange_basis) :
+    num_variables_(num_variables),
+    degree_(degree),
+    num_inputs_(num_inputs),
+    domain(domain),
+    A_in_Lagrange_basis(A_in_Lagrange_basis),
+    B_in_Lagrange_basis(B_in_Lagrange_basis),
+    C_in_Lagrange_basis(C_in_Lagrange_basis)
+{
+}
+
+template<typename FieldT>
+qap_instance<FieldT>::qap_instance(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                                   const size_t num_variables,
+                                   const size_t degree,
+                                   const size_t num_inputs,
+                                   std::vector<std::map<size_t, FieldT> > &&A_in_Lagrange_basis,
+                                   std::vector<std::map<size_t, FieldT> > &&B_in_Lagrange_basis,
+                                   std::vector<std::map<size_t, FieldT> > &&C_in_Lagrange_basis) :
+    num_variables_(num_variables),
+    degree_(degree),
+    num_inputs_(num_inputs),
+    domain(domain),
+    A_in_Lagrange_basis(std::move(A_in_Lagrange_basis)),
+    B_in_Lagrange_basis(std::move(B_in_Lagrange_basis)),
+    C_in_Lagrange_basis(std::move(C_in_Lagrange_basis))
+{
+}
+
+template<typename FieldT>
+size_t qap_instance<FieldT>::num_variables() const
+{
+    return num_variables_;
+}
+
+template<typename FieldT>
+size_t qap_instance<FieldT>::degree() const
+{
+    return degree_;
+}
+
+template<typename FieldT>
+size_t qap_instance<FieldT>::num_inputs() const
+{
+    return num_inputs_;
+}
+
+template<typename FieldT>
+bool qap_instance<FieldT>::is_satisfied(const qap_witness<FieldT> &witness) const
+{
+    const FieldT t = FieldT::random_element();
+
+    std::vector<FieldT> At(this->num_variables()+1, FieldT::zero());
+    std::vector<FieldT> Bt(this->num_variables()+1, FieldT::zero());
+    std::vector<FieldT> Ct(this->num_variables()+1, FieldT::zero());
+    std::vector<FieldT> Ht(this->degree()+1);
+
+    const FieldT Zt = this->domain->compute_Z(t);
+
+    const std::vector<FieldT> u = this->domain->lagrange_coeffs(t);
+
+    for (size_t i = 0; i < this->num_variables()+1; ++i)
+    {
+        for (auto &el : A_in_Lagrange_basis[i])
+        {
+            At[i] += u[el.first] * el.second;
+        }
+
+        for (auto &el : B_in_Lagrange_basis[i])
+        {
+            Bt[i] += u[el.first] * el.second;
+        }
+
+        for (auto &el : C_in_Lagrange_basis[i])
+        {
+            Ct[i] += u[el.first] * el.second;
+        }
+    }
+
+    FieldT ti = FieldT::one();
+    for (size_t i = 0; i < this->degree()+1; ++i)
+    {
+        Ht[i] = ti;
+        ti *= t;
+    }
+
+    const qap_instance_evaluation<FieldT> eval_qap_inst(this->domain,
+                                                        this->num_variables(),
+                                                        this->degree(),
+                                                        this->num_inputs(),
+                                                        t,
+                                                        std::move(At),
+                                                        std::move(Bt),
+                                                        std::move(Ct),
+                                                        std::move(Ht),
+                                                        Zt);
+    return eval_qap_inst.is_satisfied(witness);
+}
+
+template<typename FieldT>
+qap_instance_evaluation<FieldT>::qap_instance_evaluation(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                                                         const size_t num_variables,
+                                                         const size_t degree,
+                                                         const size_t num_inputs,
+                                                         const FieldT &t,
+                                                         const std::vector<FieldT> &At,
+                                                         const std::vector<FieldT> &Bt,
+                                                         const std::vector<FieldT> &Ct,
+                                                         const std::vector<FieldT> &Ht,
+                                                         const FieldT &Zt) :
+    num_variables_(num_variables),
+    degree_(degree),
+    num_inputs_(num_inputs),
+    domain(domain),
+    t(t),
+    At(At),
+    Bt(Bt),
+    Ct(Ct),
+    Ht(Ht),
+    Zt(Zt)
+{
+}
+
+template<typename FieldT>
+qap_instance_evaluation<FieldT>::qap_instance_evaluation(const std::shared_ptr<evaluation_domain<FieldT> > &domain,
+                                                         const size_t num_variables,
+                                                         const size_t degree,
+                                                         const size_t num_inputs,
+                                                         const FieldT &t,
+                                                         std::vector<FieldT> &&At,
+                                                         std::vector<FieldT> &&Bt,
+                                                         std::vector<FieldT> &&Ct,
+                                                         std::vector<FieldT> &&Ht,
+                                                         const FieldT &Zt) :
+    num_variables_(num_variables),
+    degree_(degree),
+    num_inputs_(num_inputs),
+    domain(domain),
+    t(t),
+    At(std::move(At)),
+    Bt(std::move(Bt)),
+    Ct(std::move(Ct)),
+    Ht(std::move(Ht)),
+    Zt(Zt)
+{
+}
+
+template<typename FieldT>
+size_t qap_instance_evaluation<FieldT>::num_variables() const
+{
+    return num_variables_;
+}
+
+template<typename FieldT>
+size_t qap_instance_evaluation<FieldT>::degree() const
+{
+    return degree_;
+}
+
+template<typename FieldT>
+size_t qap_instance_evaluation<FieldT>::num_inputs() const
+{
+    return num_inputs_;
+}
+
+template<typename FieldT>
+bool qap_instance_evaluation<FieldT>::is_satisfied(const qap_witness<FieldT> &witness) const
+{
+
+    if (this->num_variables() != witness.num_variables())
+    {
+        return false;
+    }
+
+    if (this->degree() != witness.degree())
+    {
+        return false;
+    }
+
+    if (this->num_inputs() != witness.num_inputs())
+    {
+        return false;
+    }
+
+    if (this->num_variables() != witness.coefficients_for_ABCs.size())
+    {
+        return false;
+    }
+
+    if (this->degree()+1 != witness.coefficients_for_H.size())
+    {
+        return false;
+    }
+
+    if (this->At.size() != this->num_variables()+1 || this->Bt.size() != this->num_variables()+1 || this->Ct.size() != this->num_variables()+1)
+    {
+        return false;
+    }
+
+    if (this->Ht.size() != this->degree()+1)
+    {
+        return false;
+    }
+
+    if (this->Zt != this->domain->compute_Z(this->t))
+    {
+        return false;
+    }
+
+    FieldT ans_A = this->At[0] + witness.d1*this->Zt;
+    FieldT ans_B = this->Bt[0] + witness.d2*this->Zt;
+    FieldT ans_C = this->Ct[0] + witness.d3*this->Zt;
+    FieldT ans_H = FieldT::zero();
+
+    ans_A = ans_A + naive_plain_exp<FieldT, FieldT>(this->At.begin()+1, this->At.begin()+1+this->num_variables(),
+                                                    witness.coefficients_for_ABCs.begin(), witness.coefficients_for_ABCs.begin()+this->num_variables());
+    ans_B = ans_B + naive_plain_exp<FieldT, FieldT>(this->Bt.begin()+1, this->Bt.begin()+1+this->num_variables(),
+                                                    witness.coefficients_for_ABCs.begin(), witness.coefficients_for_ABCs.begin()+this->num_variables());
+    ans_C = ans_C + naive_plain_exp<FieldT, FieldT>(this->Ct.begin()+1, this->Ct.begin()+1+this->num_variables(),
+                                                    witness.coefficients_for_ABCs.begin(), witness.coefficients_for_ABCs.begin()+this->num_variables());
+    ans_H = ans_H + naive_plain_exp<FieldT, FieldT>(this->Ht.begin(), this->Ht.begin()+this->degree()+1,
+                                                    witness.coefficients_for_H.begin(), witness.coefficients_for_H.begin()+this->degree()+1);
+
+    if (ans_A * ans_B - ans_C != ans_H * this->Zt)
+    {
+        return false;
+    }
+
+    return true;
+}
+
+template<typename FieldT>
+qap_witness<FieldT>::qap_witness(const size_t num_variables,
+                                 const size_t degree,
+                                 const size_t num_inputs,
+                                 const FieldT &d1,
+                                 const FieldT &d2,
+                                 const FieldT &d3,
+                                 const std::vector<FieldT> &coefficients_for_ABCs,
+                                 const std::vector<FieldT> &coefficients_for_H) :
+    num_variables_(num_variables),
+    degree_(degree),
+    num_inputs_(num_inputs),
+    d1(d1),
+    d2(d2),
+    d3(d3),
+    coefficients_for_ABCs(coefficients_for_ABCs),
+    coefficients_for_H(coefficients_for_H)
+{
+}
+
+template<typename FieldT>
+qap_witness<FieldT>::qap_witness(const size_t num_variables,
+                                 const size_t degree,
+                                 const size_t num_inputs,
+                                 const FieldT &d1,
+                                 const FieldT &d2,
+                                 const FieldT &d3,
+                                 const std::vector<FieldT> &coefficients_for_ABCs,
+                                 std::vector<FieldT> &&coefficients_for_H) :
+    num_variables_(num_variables),
+    degree_(degree),
+    num_inputs_(num_inputs),
+    d1(d1),
+    d2(d2),
+    d3(d3),
+    coefficients_for_ABCs(coefficients_for_ABCs),
+    coefficients_for_H(std::move(coefficients_for_H))
+{
+}
+
+
+template<typename FieldT>
+size_t qap_witness<FieldT>::num_variables() const
+{
+    return num_variables_;
+}
+
+template<typename FieldT>
+size_t qap_witness<FieldT>::degree() const
+{
+    return degree_;
+}
+
+template<typename FieldT>
+size_t qap_witness<FieldT>::num_inputs() const
+{
+    return num_inputs_;
+}
+
+
+} // libsnark
+
+#endif // QAP_TCC_
diff --git a/src/relations/arithmetic_programs/qap/tests/test_qap.cpp b/src/relations/arithmetic_programs/qap/tests/test_qap.cpp
new file mode 100644 (file)
index 0000000..d8aadda
--- /dev/null
@@ -0,0 +1,115 @@
+/**
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#include <algorithm>
+#include <cassert>
+#include <cstdio>
+#include <cstring>
+#include <vector>
+
+#include "algebra/curves/mnt/mnt6/mnt6_pp.hpp"
+#include "algebra/fields/field_utils.hpp"
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+#include "reductions/r1cs_to_qap/r1cs_to_qap.hpp"
+#include "relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp"
+
+using namespace libsnark;
+
+template<typename FieldT>
+void test_qap(const size_t qap_degree, const size_t num_inputs, const bool binary_input)
+{
+    /*
+      We construct an instance where the QAP degree is qap_degree.
+      So we generate an instance of R1CS where the number of constraints qap_degree - num_inputs - 1.
+      See the transformation from R1CS to QAP for why this is the case.
+      So we need that qap_degree >= num_inputs + 1.
+    */
+    assert(num_inputs + 1 <= qap_degree);
+    enter_block("Call to test_qap");
+
+    const size_t num_constraints = qap_degree - num_inputs - 1;
+
+    print_indent(); printf("* QAP degree: %zu\n", qap_degree);
+    print_indent(); printf("* Number of inputs: %zu\n", num_inputs);
+    print_indent(); printf("* Number of R1CS constraints: %zu\n", num_constraints);
+    print_indent(); printf("* Input type: %s\n", binary_input ? "binary" : "field");
+
+    enter_block("Generate constraint system and assignment");
+    r1cs_example<FieldT> example;
+    if (binary_input)
+    {
+        example = generate_r1cs_example_with_binary_input<FieldT>(num_constraints, num_inputs);
+    }
+    else
+    {
+        example = generate_r1cs_example_with_field_input<FieldT>(num_constraints, num_inputs);
+    }
+    leave_block("Generate constraint system and assignment");
+
+    enter_block("Check satisfiability of constraint system");
+    assert(example.constraint_system.is_satisfied(example.primary_input, example.auxiliary_input));
+    leave_block("Check satisfiability of constraint system");
+
+    const FieldT t = FieldT::random_element(),
+    d1 = FieldT::random_element(),
+    d2 = FieldT::random_element(),
+    d3 = FieldT::random_element();
+
+    enter_block("Compute QAP instance 1");
+    qap_instance<FieldT> qap_inst_1 = r1cs_to_qap_instance_map(example.constraint_system);
+    leave_block("Compute QAP instance 1");
+
+    enter_block("Compute QAP instance 2");
+    qap_instance_evaluation<FieldT> qap_inst_2 = r1cs_to_qap_instance_map_with_evaluation(example.constraint_system, t);
+    leave_block("Compute QAP instance 2");
+
+    enter_block("Compute QAP witness");
+    qap_witness<FieldT> qap_wit = r1cs_to_qap_witness_map(example.constraint_system, example.primary_input, example.auxiliary_input, d1, d2, d3);
+    leave_block("Compute QAP witness");
+
+    enter_block("Check satisfiability of QAP instance 1");
+    assert(qap_inst_1.is_satisfied(qap_wit));
+    leave_block("Check satisfiability of QAP instance 1");
+
+    enter_block("Check satisfiability of QAP instance 2");
+    assert(qap_inst_2.is_satisfied(qap_wit));
+    leave_block("Check satisfiability of QAP instance 2");
+
+    leave_block("Call to test_qap");
+}
+
+int main()
+{
+    start_profiling();
+
+    mnt6_pp::init_public_params();
+
+    const size_t num_inputs = 10;
+
+    const size_t basic_domain_size = 1ul<<mnt6_Fr::s;
+    const size_t step_domain_size = (1ul<<10) + (1ul<<8);
+    const size_t extended_domain_size = 1ul<<(mnt6_Fr::s+1);
+    const size_t extended_domain_size_special = extended_domain_size-1;
+
+    enter_block("Test QAP with binary input");
+
+    test_qap<Fr<mnt6_pp> >(basic_domain_size, num_inputs, true);
+    test_qap<Fr<mnt6_pp> >(step_domain_size, num_inputs, true);
+    test_qap<Fr<mnt6_pp> >(extended_domain_size, num_inputs, true);
+    test_qap<Fr<mnt6_pp> >(extended_domain_size_special, num_inputs, true);
+
+    leave_block("Test QAP with binary input");
+
+    enter_block("Test QAP with field input");
+
+    test_qap<Fr<mnt6_pp> >(basic_domain_size, num_inputs, false);
+    test_qap<Fr<mnt6_pp> >(step_domain_size, num_inputs, false);
+    test_qap<Fr<mnt6_pp> >(extended_domain_size, num_inputs, false);
+    test_qap<Fr<mnt6_pp> >(extended_domain_size_special, num_inputs, false);
+
+    leave_block("Test QAP with field input");
+}
diff --git a/src/relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp b/src/relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp
new file mode 100644 (file)
index 0000000..47003e9
--- /dev/null
@@ -0,0 +1,73 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for a R1CS example, as well as functions to sample
+ R1CS examples with prescribed parameters (according to some distribution).
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_EXAMPLES_HPP_
+#define R1CS_EXAMPLES_HPP_
+
+#include "relations/constraint_satisfaction_problems/r1cs/r1cs.hpp"
+
+namespace libsnark {
+
+/**
+ * A R1CS example comprises a R1CS constraint system, R1CS input, and R1CS witness.
+ */
+template<typename FieldT>
+struct r1cs_example {
+    r1cs_constraint_system<FieldT> constraint_system;
+    r1cs_primary_input<FieldT> primary_input;
+    r1cs_auxiliary_input<FieldT> auxiliary_input;
+
+    r1cs_example<FieldT>() = default;
+    r1cs_example<FieldT>(const r1cs_example<FieldT> &other) = default;
+    r1cs_example<FieldT>(const r1cs_constraint_system<FieldT> &constraint_system,
+                         const r1cs_primary_input<FieldT> &primary_input,
+                         const r1cs_auxiliary_input<FieldT> &auxiliary_input) :
+        constraint_system(constraint_system),
+        primary_input(primary_input),
+        auxiliary_input(auxiliary_input)
+    {};
+    r1cs_example<FieldT>(r1cs_constraint_system<FieldT> &&constraint_system,
+                         r1cs_primary_input<FieldT> &&primary_input,
+                         r1cs_auxiliary_input<FieldT> &&auxiliary_input) :
+        constraint_system(std::move(constraint_system)),
+        primary_input(std::move(primary_input)),
+        auxiliary_input(std::move(auxiliary_input))
+    {};
+};
+
+/**
+ * Generate a R1CS example such that:
+ * - the number of constraints of the R1CS constraint system is num_constraints;
+ * - the number of variables of the R1CS constraint system is (approximately) num_constraints;
+ * - the number of inputs of the R1CS constraint system is num_inputs;
+ * - the R1CS input consists of ``full'' field elements (typically require the whole log|Field| bits to represent).
+ */
+template<typename FieldT>
+r1cs_example<FieldT> generate_r1cs_example_with_field_input(const size_t num_constraints,
+                                                            const size_t num_inputs);
+
+/**
+ * Generate a R1CS example such that:
+ * - the number of constraints of the R1CS constraint system is num_constraints;
+ * - the number of variables of the R1CS constraint system is (approximately) num_constraints;
+ * - the number of inputs of the R1CS constraint system is num_inputs;
+ * - the R1CS input consists of binary values (as opposed to ``full'' field elements).
+ */
+template<typename FieldT>
+r1cs_example<FieldT> generate_r1cs_example_with_binary_input(const size_t num_constraints,
+                                                             const size_t num_inputs);
+
+} // libsnark
+
+#include "relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.tcc"
+
+#endif // R1CS_EXAMPLES_HPP_
diff --git a/src/relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.tcc b/src/relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.tcc
new file mode 100644 (file)
index 0000000..defa077
--- /dev/null
@@ -0,0 +1,164 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of functions to sample R1CS examples with prescribed parameters
+ (according to some distribution).
+
+ See r1cs_examples.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_EXAMPLES_TCC_
+#define R1CS_EXAMPLES_TCC_
+
+#include <cassert>
+
+#include "common/utils.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+r1cs_example<FieldT> generate_r1cs_example_with_field_input(const size_t num_constraints,
+                                                            const size_t num_inputs)
+{
+    enter_block("Call to generate_r1cs_example_with_field_input");
+
+    assert(num_inputs <= num_constraints + 2);
+
+    r1cs_constraint_system<FieldT> cs;
+    cs.primary_input_size = num_inputs;
+    cs.auxiliary_input_size = 2 + num_constraints - num_inputs; // TODO: explain this
+
+    r1cs_variable_assignment<FieldT> full_variable_assignment;
+    FieldT a = FieldT::random_element();
+    FieldT b = FieldT::random_element();
+    full_variable_assignment.push_back(a);
+    full_variable_assignment.push_back(b);
+
+    for (size_t i = 0; i < num_constraints-1; ++i)
+    {
+        linear_combination<FieldT> A, B, C;
+
+        if (i % 2)
+        {
+            // a * b = c
+            A.add_term(i+1, 1);
+            B.add_term(i+2, 1);
+            C.add_term(i+3, 1);
+            FieldT tmp = a*b;
+            full_variable_assignment.push_back(tmp);
+            a = b; b = tmp;
+        }
+        else
+        {
+            // a + b = c
+            B.add_term(0, 1);
+            A.add_term(i+1, 1);
+            A.add_term(i+2, 1);
+            C.add_term(i+3, 1);
+            FieldT tmp = a+b;
+            full_variable_assignment.push_back(tmp);
+            a = b; b = tmp;
+        }
+
+        cs.add_constraint(r1cs_constraint<FieldT>(A, B, C));
+    }
+
+    linear_combination<FieldT> A, B, C;
+    FieldT fin = FieldT::zero();
+    for (size_t i = 1; i < cs.num_variables(); ++i)
+    {
+        A.add_term(i, 1);
+        B.add_term(i, 1);
+        fin = fin + full_variable_assignment[i-1];
+    }
+    C.add_term(cs.num_variables(), 1);
+    cs.add_constraint(r1cs_constraint<FieldT>(A, B, C));
+    full_variable_assignment.push_back(fin.squared());
+
+    /* split variable assignment */
+    r1cs_primary_input<FieldT> primary_input(full_variable_assignment.begin(), full_variable_assignment.begin() + num_inputs);
+    r1cs_primary_input<FieldT> auxiliary_input(full_variable_assignment.begin() + num_inputs, full_variable_assignment.end());
+
+    /* sanity checks */
+    assert(cs.num_variables() == full_variable_assignment.size());
+    assert(cs.num_variables() >= num_inputs);
+    assert(cs.num_inputs() == num_inputs);
+    assert(cs.num_constraints() == num_constraints);
+    assert(cs.is_satisfied(primary_input, auxiliary_input));
+
+    leave_block("Call to generate_r1cs_example_with_field_input");
+
+    return r1cs_example<FieldT>(std::move(cs), std::move(primary_input), std::move(auxiliary_input));
+}
+
+template<typename FieldT>
+r1cs_example<FieldT> generate_r1cs_example_with_binary_input(const size_t num_constraints,
+                                                             const size_t num_inputs)
+{
+    enter_block("Call to generate_r1cs_example_with_binary_input");
+
+    assert(num_inputs >= 1);
+
+    r1cs_constraint_system<FieldT> cs;
+    cs.primary_input_size = num_inputs;
+    cs.auxiliary_input_size = num_constraints; /* we will add one auxiliary variable per constraint */
+
+    r1cs_variable_assignment<FieldT> full_variable_assignment;
+    for (size_t i = 0; i < num_inputs; ++i)
+    {
+        full_variable_assignment.push_back(FieldT(std::rand() % 2));
+    }
+
+    size_t lastvar = num_inputs-1;
+    for (size_t i = 0; i < num_constraints; ++i)
+    {
+        ++lastvar;
+        const size_t u = (i == 0 ? std::rand() % num_inputs : std::rand() % i);
+        const size_t v = (i == 0 ? std::rand() % num_inputs : std::rand() % i);
+
+        /* chose two random bits and XOR them together:
+           res = u + v - 2 * u * v
+           2 * u * v = u + v - res
+        */
+        linear_combination<FieldT> A, B, C;
+        A.add_term(u+1, 2);
+        B.add_term(v+1, 1);
+        if (u == v)
+        {
+            C.add_term(u+1, 2);
+        }
+        else
+        {
+            C.add_term(u+1, 1);
+            C.add_term(v+1, 1);
+        }
+        C.add_term(lastvar+1, -FieldT::one());
+
+        cs.add_constraint(r1cs_constraint<FieldT>(A, B, C));
+        full_variable_assignment.push_back(full_variable_assignment[u] + full_variable_assignment[v] - full_variable_assignment[u] * full_variable_assignment[v] - full_variable_assignment[u] * full_variable_assignment[v]);
+    }
+
+    /* split variable assignment */
+    r1cs_primary_input<FieldT> primary_input(full_variable_assignment.begin(), full_variable_assignment.begin() + num_inputs);
+    r1cs_primary_input<FieldT> auxiliary_input(full_variable_assignment.begin() + num_inputs, full_variable_assignment.end());
+
+    /* sanity checks */
+    assert(cs.num_variables() == full_variable_assignment.size());
+    assert(cs.num_variables() >= num_inputs);
+    assert(cs.num_inputs() == num_inputs);
+    assert(cs.num_constraints() == num_constraints);
+    assert(cs.is_satisfied(primary_input, auxiliary_input));
+
+    leave_block("Call to generate_r1cs_example_with_binary_input");
+
+    return r1cs_example<FieldT>(std::move(cs), std::move(primary_input), std::move(auxiliary_input));
+}
+
+} // libsnark
+
+#endif // R1CS_EXAMPLES_TCC
diff --git a/src/relations/constraint_satisfaction_problems/r1cs/r1cs.hpp b/src/relations/constraint_satisfaction_problems/r1cs/r1cs.hpp
new file mode 100644 (file)
index 0000000..ca3acb3
--- /dev/null
@@ -0,0 +1,153 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for:
+ - a R1CS constraint,
+ - a R1CS variable assignment, and
+ - a R1CS constraint system.
+
+ Above, R1CS stands for "Rank-1 Constraint System".
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_HPP_
+#define R1CS_HPP_
+
+#include <cstdlib>
+#include <iostream>
+#include <map>
+#include <string>
+#include <vector>
+
+#include "relations/variable.hpp"
+
+namespace libsnark {
+
+/************************* R1CS constraint ***********************************/
+
+template<typename FieldT>
+class r1cs_constraint;
+
+template<typename FieldT>
+std::ostream& operator<<(std::ostream &out, const r1cs_constraint<FieldT> &c);
+
+template<typename FieldT>
+std::istream& operator>>(std::istream &in, r1cs_constraint<FieldT> &c);
+
+/**
+ * A R1CS constraint is a formal expression of the form
+ *
+ *                < A , X > * < B , X > = < C , X > ,
+ *
+ * where X = (x_0,x_1,...,x_m) is a vector of formal variables and A,B,C each
+ * consist of 1+m elements in <FieldT>.
+ *
+ * A R1CS constraint is used to construct a R1CS constraint system (see below).
+ */
+template<typename FieldT>
+class r1cs_constraint {
+public:
+
+    linear_combination<FieldT> a, b, c;
+
+    r1cs_constraint() {};
+    r1cs_constraint(const linear_combination<FieldT> &a,
+                    const linear_combination<FieldT> &b,
+                    const linear_combination<FieldT> &c);
+
+    r1cs_constraint(const std::initializer_list<linear_combination<FieldT> > &A,
+                    const std::initializer_list<linear_combination<FieldT> > &B,
+                    const std::initializer_list<linear_combination<FieldT> > &C);
+
+    bool operator==(const r1cs_constraint<FieldT> &other) const;
+
+    friend std::ostream& operator<< <FieldT>(std::ostream &out, const r1cs_constraint<FieldT> &c);
+    friend std::istream& operator>> <FieldT>(std::istream &in, r1cs_constraint<FieldT> &c);
+};
+
+/************************* R1CS variable assignment **************************/
+
+/**
+ * A R1CS variable assignment is a vector of <FieldT> elements that represents
+ * a candidate solution to a R1CS constraint system (see below).
+ */
+
+/* TODO: specify that it does *NOT* include the constant 1 */
+template<typename FieldT>
+using r1cs_primary_input = std::vector<FieldT>;
+
+template<typename FieldT>
+using r1cs_auxiliary_input = std::vector<FieldT>;
+
+template<typename FieldT>
+using r1cs_variable_assignment = std::vector<FieldT>; /* note the changed name! (TODO: remove this comment after primary_input transition is complete) */
+
+/************************* R1CS constraint system ****************************/
+
+template<typename FieldT>
+class r1cs_constraint_system;
+
+template<typename FieldT>
+std::ostream& operator<<(std::ostream &out, const r1cs_constraint_system<FieldT> &cs);
+
+template<typename FieldT>
+std::istream& operator>>(std::istream &in, r1cs_constraint_system<FieldT> &cs);
+
+/**
+ * A system of R1CS constraints looks like
+ *
+ *     { < A_k , X > * < B_k , X > = < C_k , X > }_{k=1}^{n}  .
+ *
+ * In other words, the system is satisfied if and only if there exist a
+ * USCS variable assignment for which each R1CS constraint is satisfied.
+ *
+ * NOTE:
+ * The 0-th variable (i.e., "x_{0}") always represents the constant 1.
+ * Thus, the 0-th variable is not included in num_variables.
+ */
+template<typename FieldT>
+class r1cs_constraint_system {
+public:
+    size_t primary_input_size;
+    size_t auxiliary_input_size;
+
+    std::vector<r1cs_constraint<FieldT> > constraints;
+
+    r1cs_constraint_system() : primary_input_size(0), auxiliary_input_size(0) {}
+
+    size_t num_inputs() const;
+    size_t num_variables() const;
+    size_t num_constraints() const;
+
+#ifdef DEBUG
+    std::map<size_t, std::string> constraint_annotations;
+    std::map<size_t, std::string> variable_annotations;
+#endif
+
+    bool is_valid() const;
+    bool is_satisfied(const r1cs_primary_input<FieldT> &primary_input,
+                      const r1cs_auxiliary_input<FieldT> &auxiliary_input) const;
+
+    void add_constraint(const r1cs_constraint<FieldT> &c);
+    void add_constraint(const r1cs_constraint<FieldT> &c, const std::string &annotation);
+
+    void swap_AB_if_beneficial();
+
+    bool operator==(const r1cs_constraint_system<FieldT> &other) const;
+
+    friend std::ostream& operator<< <FieldT>(std::ostream &out, const r1cs_constraint_system<FieldT> &cs);
+    friend std::istream& operator>> <FieldT>(std::istream &in, r1cs_constraint_system<FieldT> &cs);
+
+    void report_linear_constraint_statistics() const;
+};
+
+
+} // libsnark
+
+#include "relations/constraint_satisfaction_problems/r1cs/r1cs.tcc"
+
+#endif // R1CS_HPP_
diff --git a/src/relations/constraint_satisfaction_problems/r1cs/r1cs.tcc b/src/relations/constraint_satisfaction_problems/r1cs/r1cs.tcc
new file mode 100644 (file)
index 0000000..0faa56a
--- /dev/null
@@ -0,0 +1,310 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for:
+ - a R1CS constraint,
+ - a R1CS variable assignment, and
+ - a R1CS constraint system.
+
+ See r1cs.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_TCC_
+#define R1CS_TCC_
+
+#include <algorithm>
+#include <cassert>
+#include <set>
+#include "common/utils.hpp"
+#include "common/profiling.hpp"
+#include "algebra/fields/bigint.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+r1cs_constraint<FieldT>::r1cs_constraint(const linear_combination<FieldT> &a,
+                                         const linear_combination<FieldT> &b,
+                                         const linear_combination<FieldT> &c) :
+    a(a), b(b), c(c)
+{
+}
+
+template<typename FieldT>
+r1cs_constraint<FieldT>::r1cs_constraint(const std::initializer_list<linear_combination<FieldT> > &A,
+                                         const std::initializer_list<linear_combination<FieldT> > &B,
+                                         const std::initializer_list<linear_combination<FieldT> > &C)
+{
+    for (auto lc_A : A)
+    {
+        a.terms.insert(a.terms.end(), lc_A.terms.begin(), lc_A.terms.end());
+    }
+    for (auto lc_B : B)
+    {
+        b.terms.insert(b.terms.end(), lc_B.terms.begin(), lc_B.terms.end());
+    }
+    for (auto lc_C : C)
+    {
+        c.terms.insert(c.terms.end(), lc_C.terms.begin(), lc_C.terms.end());
+    }
+}
+
+template<typename FieldT>
+bool r1cs_constraint<FieldT>::operator==(const r1cs_constraint<FieldT> &other) const
+{
+    return (this->a == other.a &&
+            this->b == other.b &&
+            this->c == other.c);
+}
+
+template<typename FieldT>
+std::ostream& operator<<(std::ostream &out, const r1cs_constraint<FieldT> &c)
+{
+    out << c.a;
+    out << c.b;
+    out << c.c;
+
+    return out;
+}
+
+template<typename FieldT>
+std::istream& operator>>(std::istream &in, r1cs_constraint<FieldT> &c)
+{
+    in >> c.a;
+    in >> c.b;
+    in >> c.c;
+
+    return in;
+}
+
+template<typename FieldT>
+size_t r1cs_constraint_system<FieldT>::num_inputs() const
+{
+    return primary_input_size;
+}
+
+template<typename FieldT>
+size_t r1cs_constraint_system<FieldT>::num_variables() const
+{
+    return primary_input_size + auxiliary_input_size;
+}
+
+
+template<typename FieldT>
+size_t r1cs_constraint_system<FieldT>::num_constraints() const
+{
+    return constraints.size();
+}
+
+template<typename FieldT>
+bool r1cs_constraint_system<FieldT>::is_valid() const
+{
+    if (this->num_inputs() > this->num_variables()) return false;
+
+    for (size_t c = 0; c < constraints.size(); ++c)
+    {
+        if (!(constraints[c].a.is_valid(this->num_variables()) &&
+              constraints[c].b.is_valid(this->num_variables()) &&
+              constraints[c].c.is_valid(this->num_variables())))
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+template<typename FieldT>
+void dump_r1cs_constraint(const r1cs_constraint<FieldT> &constraint,
+                          const r1cs_variable_assignment<FieldT> &full_variable_assignment,
+                          const std::map<size_t, std::string> &variable_annotations)
+{
+    printf("terms for a:\n"); constraint.a.print_with_assignment(full_variable_assignment, variable_annotations);
+    printf("terms for b:\n"); constraint.b.print_with_assignment(full_variable_assignment, variable_annotations);
+    printf("terms for c:\n"); constraint.c.print_with_assignment(full_variable_assignment, variable_annotations);
+}
+
+template<typename FieldT>
+bool r1cs_constraint_system<FieldT>::is_satisfied(const r1cs_primary_input<FieldT> &primary_input,
+                                                  const r1cs_auxiliary_input<FieldT> &auxiliary_input) const
+{
+    assert(primary_input.size() == num_inputs());
+    assert(primary_input.size() + auxiliary_input.size() == num_variables());
+
+    r1cs_variable_assignment<FieldT> full_variable_assignment = primary_input;
+    full_variable_assignment.insert(full_variable_assignment.end(), auxiliary_input.begin(), auxiliary_input.end());
+
+    for (size_t c = 0; c < constraints.size(); ++c)
+    {
+        const FieldT ares = constraints[c].a.evaluate(full_variable_assignment);
+        const FieldT bres = constraints[c].b.evaluate(full_variable_assignment);
+        const FieldT cres = constraints[c].c.evaluate(full_variable_assignment);
+
+        if (!(ares*bres == cres))
+        {
+#ifdef DEBUG
+            auto it = constraint_annotations.find(c);
+            printf("constraint %zu (%s) unsatisfied\n", c, (it == constraint_annotations.end() ? "no annotation" : it->second.c_str()));
+            printf("<a,(1,x)> = "); ares.print();
+            printf("<b,(1,x)> = "); bres.print();
+            printf("<c,(1,x)> = "); cres.print();
+            printf("constraint was:\n");
+            dump_r1cs_constraint(constraints[c], full_variable_assignment, variable_annotations);
+#endif // DEBUG
+            return false;
+        }
+    }
+
+    return true;
+}
+
+template<typename FieldT>
+void r1cs_constraint_system<FieldT>::add_constraint(const r1cs_constraint<FieldT> &c)
+{
+    constraints.emplace_back(c);
+}
+
+template<typename FieldT>
+void r1cs_constraint_system<FieldT>::add_constraint(const r1cs_constraint<FieldT> &c, const std::string &annotation)
+{
+#ifdef DEBUG
+    constraint_annotations[constraints.size()] = annotation;
+#endif
+    constraints.emplace_back(c);
+}
+
+template<typename FieldT>
+void r1cs_constraint_system<FieldT>::swap_AB_if_beneficial()
+{
+    enter_block("Call to r1cs_constraint_system::swap_AB_if_beneficial");
+
+    enter_block("Estimate densities");
+    bit_vector touched_by_A(this->num_variables() + 1, false), touched_by_B(this->num_variables() + 1, false);
+
+    for (size_t i = 0; i < this->constraints.size(); ++i)
+    {
+        for (size_t j = 0; j < this->constraints[i].a.terms.size(); ++j)
+        {
+            touched_by_A[this->constraints[i].a.terms[j].index] = true;
+        }
+
+        for (size_t j = 0; j < this->constraints[i].b.terms.size(); ++j)
+        {
+            touched_by_B[this->constraints[i].b.terms[j].index] = true;
+        }
+    }
+
+    size_t non_zero_A_count = 0, non_zero_B_count = 0;
+    for (size_t i = 0; i < this->num_variables() + 1; ++i)
+    {
+        non_zero_A_count += touched_by_A[i] ? 1 : 0;
+        non_zero_B_count += touched_by_B[i] ? 1 : 0;
+    }
+
+    if (!inhibit_profiling_info)
+    {
+        print_indent(); printf("* Non-zero A-count (estimate): %zu\n", non_zero_A_count);
+        print_indent(); printf("* Non-zero B-count (estimate): %zu\n", non_zero_B_count);
+    }
+    leave_block("Estimate densities");
+
+    if (non_zero_B_count > non_zero_A_count)
+    {
+        enter_block("Perform the swap");
+        for (size_t i = 0; i < this->constraints.size(); ++i)
+        {
+            std::swap(this->constraints[i].a, this->constraints[i].b);
+        }
+        leave_block("Perform the swap");
+    }
+    else
+    {
+        print_indent(); printf("Swap is not beneficial, not performing\n");
+    }
+
+    leave_block("Call to r1cs_constraint_system::swap_AB_if_beneficial");
+}
+
+template<typename FieldT>
+bool r1cs_constraint_system<FieldT>::operator==(const r1cs_constraint_system<FieldT> &other) const
+{
+    return (this->constraints == other.constraints &&
+            this->primary_input_size == other.primary_input_size &&
+            this->auxiliary_input_size == other.auxiliary_input_size);
+}
+
+template<typename FieldT>
+std::ostream& operator<<(std::ostream &out, const r1cs_constraint_system<FieldT> &cs)
+{
+    out << cs.primary_input_size << "\n";
+    out << cs.auxiliary_input_size << "\n";
+
+    out << cs.num_constraints() << "\n";
+    for (const r1cs_constraint<FieldT>& c : cs.constraints)
+    {
+        out << c;
+    }
+
+    return out;
+}
+
+template<typename FieldT>
+std::istream& operator>>(std::istream &in, r1cs_constraint_system<FieldT> &cs)
+{
+    in >> cs.primary_input_size;
+    in >> cs.auxiliary_input_size;
+
+    cs.constraints.clear();
+
+    size_t s;
+    in >> s;
+
+    char b;
+    in.read(&b, 1);
+
+    cs.constraints.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        r1cs_constraint<FieldT> c;
+        in >> c;
+        cs.constraints.emplace_back(c);
+    }
+
+    return in;
+}
+
+template<typename FieldT>
+void r1cs_constraint_system<FieldT>::report_linear_constraint_statistics() const
+{
+#ifdef DEBUG
+    for (size_t i = 0; i < constraints.size(); ++i)
+    {
+        auto &constr = constraints[i];
+        bool a_is_const = true;
+        for (auto &t : constr.a.terms)
+        {
+            a_is_const = a_is_const && (t.index == 0);
+        }
+
+        bool b_is_const = true;
+        for (auto &t : constr.b.terms)
+        {
+            b_is_const = b_is_const && (t.index == 0);
+        }
+
+        if (a_is_const || b_is_const)
+        {
+            auto it = constraint_annotations.find(i);
+            printf("%s\n", (it == constraint_annotations.end() ? FORMAT("", "constraint_%zu", i) : it->second).c_str());
+        }
+    }
+#endif
+}
+
+} // libsnark
+#endif // R1CS_TCC_
diff --git a/src/relations/variable.hpp b/src/relations/variable.hpp
new file mode 100644 (file)
index 0000000..a9a1449
--- /dev/null
@@ -0,0 +1,213 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for:
+ - a variable (i.e., x_i),
+ - a linear term (i.e., a_i * x_i), and
+ - a linear combination (i.e., sum_i a_i * x_i).
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef VARIABLE_HPP_
+#define VARIABLE_HPP_
+
+#include <cstddef>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace libsnark {
+
+/**
+ * Mnemonic typedefs.
+ */
+typedef size_t var_index_t;
+typedef long integer_coeff_t;
+
+/**
+ * Forward declaration.
+ */
+template<typename FieldT>
+class linear_term;
+
+/**
+ * Forward declaration.
+ */
+template<typename FieldT>
+class linear_combination;
+
+/********************************* Variable **********************************/
+
+/**
+ * A variable represents a formal expresison of the form "x_{index}".
+ */
+template<typename FieldT>
+class variable {
+public:
+
+    var_index_t index;
+
+    variable(const var_index_t index = 0) : index(index) {};
+
+    linear_term<FieldT> operator*(const integer_coeff_t int_coeff) const;
+    linear_term<FieldT> operator*(const FieldT &field_coeff) const;
+
+    linear_combination<FieldT> operator+(const linear_combination<FieldT> &other) const;
+    linear_combination<FieldT> operator-(const linear_combination<FieldT> &other) const;
+
+    linear_term<FieldT> operator-() const;
+
+    bool operator==(const variable<FieldT> &other) const;
+};
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const integer_coeff_t int_coeff, const variable<FieldT> &var);
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const FieldT &field_coeff, const variable<FieldT> &var);
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const integer_coeff_t int_coeff, const variable<FieldT> &var);
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const FieldT &field_coeff, const variable<FieldT> &var);
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const integer_coeff_t int_coeff, const variable<FieldT> &var);
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const FieldT &field_coeff, const variable<FieldT> &var);
+
+
+/****************************** Linear term **********************************/
+
+/**
+ * A linear term represents a formal expression of the form "coeff * x_{index}".
+ */
+template<typename FieldT>
+class linear_term {
+public:
+
+    var_index_t index = 0;
+    FieldT coeff;
+
+    linear_term() {};
+    linear_term(const variable<FieldT> &var);
+    linear_term(const variable<FieldT> &var, const integer_coeff_t int_coeff);
+    linear_term(const variable<FieldT> &var, const FieldT &field_coeff);
+
+    linear_term<FieldT> operator*(const integer_coeff_t int_coeff) const;
+    linear_term<FieldT> operator*(const FieldT &field_coeff) const;
+
+    linear_combination<FieldT> operator+(const linear_combination<FieldT> &other) const;
+    linear_combination<FieldT> operator-(const linear_combination<FieldT> &other) const;
+
+    linear_term<FieldT> operator-() const;
+
+    bool operator==(const linear_term<FieldT> &other) const;
+};
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const integer_coeff_t int_coeff, const linear_term<FieldT> &lt);
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const FieldT &field_coeff, const linear_term<FieldT> &lt);
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const integer_coeff_t int_coeff, const linear_term<FieldT> &lt);
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const FieldT &field_coeff, const linear_term<FieldT> &lt);
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const integer_coeff_t int_coeff, const linear_term<FieldT> &lt);
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const FieldT &field_coeff, const linear_term<FieldT> &lt);
+
+
+/***************************** Linear combination ****************************/
+
+template<typename FieldT>
+class linear_combination;
+
+template<typename FieldT>
+std::ostream& operator<<(std::ostream &out, const linear_combination<FieldT> &lc);
+
+template<typename FieldT>
+std::istream& operator>>(std::istream &in, linear_combination<FieldT> &lc);
+
+/**
+ * A linear combination represents a formal expression of the form "sum_i coeff_i * x_{index_i}".
+ */
+template<typename FieldT>
+class linear_combination {
+public:
+
+    std::vector<linear_term<FieldT> > terms;
+
+    linear_combination() {};
+    linear_combination(const integer_coeff_t int_coeff);
+    linear_combination(const FieldT &field_coeff);
+    linear_combination(const variable<FieldT> &var);
+    linear_combination(const linear_term<FieldT> &lt);
+    linear_combination(const std::vector<linear_term<FieldT> > &all_terms);
+
+    /* for supporting range-based for loops over linear_combination */
+    typename std::vector<linear_term<FieldT> >::const_iterator begin() const;
+    typename std::vector<linear_term<FieldT> >::const_iterator end() const;
+
+    void add_term(const variable<FieldT> &var);
+    void add_term(const variable<FieldT> &var, const integer_coeff_t int_coeff);
+    void add_term(const variable<FieldT> &var, const FieldT &field_coeff);
+
+    void add_term(const linear_term<FieldT> &lt);
+
+    FieldT evaluate(const std::vector<FieldT> &assignment) const;
+
+    linear_combination<FieldT> operator*(const integer_coeff_t int_coeff) const;
+    linear_combination<FieldT> operator*(const FieldT &field_coeff) const;
+
+    linear_combination<FieldT> operator+(const linear_combination<FieldT> &other) const;
+
+    linear_combination<FieldT> operator-(const linear_combination<FieldT> &other) const;
+    linear_combination<FieldT> operator-() const;
+
+    bool operator==(const linear_combination<FieldT> &other) const;
+
+    bool is_valid(const size_t num_variables) const;
+
+    void print(const std::map<size_t, std::string> &variable_annotations = std::map<size_t, std::string>()) const;
+    void print_with_assignment(const std::vector<FieldT> &full_assignment, const std::map<size_t, std::string> &variable_annotations = std::map<size_t, std::string>()) const;
+
+    friend std::ostream& operator<< <FieldT>(std::ostream &out, const linear_combination<FieldT> &lc);
+    friend std::istream& operator>> <FieldT>(std::istream &in, linear_combination<FieldT> &lc);
+};
+
+template<typename FieldT>
+linear_combination<FieldT> operator*(const integer_coeff_t int_coeff, const linear_combination<FieldT> &lc);
+
+template<typename FieldT>
+linear_combination<FieldT> operator*(const FieldT &field_coeff, const linear_combination<FieldT> &lc);
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const integer_coeff_t int_coeff, const linear_combination<FieldT> &lc);
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const FieldT &field_coeff, const linear_combination<FieldT> &lc);
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const integer_coeff_t int_coeff, const linear_combination<FieldT> &lc);
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const FieldT &field_coeff, const linear_combination<FieldT> &lc);
+
+} // libsnark
+
+#include "relations/variable.tcc"
+
+#endif // VARIABLE_HPP_
diff --git a/src/relations/variable.tcc b/src/relations/variable.tcc
new file mode 100644 (file)
index 0000000..4c4cab9
--- /dev/null
@@ -0,0 +1,512 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of interfaces for:
+ - a variable (i.e., x_i),
+ - a linear term (i.e., a_i * x_i), and
+ - a linear combination (i.e., sum_i a_i * x_i).
+
+ See variabe.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef VARIABLE_TCC_
+#define VARIABLE_TCC_
+
+#include <algorithm>
+#include <cassert>
+
+#include "algebra/fields/bigint.hpp"
+
+namespace libsnark {
+
+template<typename FieldT>
+linear_term<FieldT> variable<FieldT>::operator*(const integer_coeff_t int_coeff) const
+{
+    return linear_term<FieldT>(*this, int_coeff);
+}
+
+template<typename FieldT>
+linear_term<FieldT> variable<FieldT>::operator*(const FieldT &field_coeff) const
+{
+    return linear_term<FieldT>(*this, field_coeff);
+}
+
+template<typename FieldT>
+linear_combination<FieldT> variable<FieldT>::operator+(const linear_combination<FieldT> &other) const
+{
+    linear_combination<FieldT> result;
+
+    result.add_term(*this);
+    result.terms.insert(result.terms.begin(), other.terms.begin(), other.terms.end());
+
+    return result;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> variable<FieldT>::operator-(const linear_combination<FieldT> &other) const
+{
+    return (*this) + (-other);
+}
+
+template<typename FieldT>
+linear_term<FieldT> variable<FieldT>::operator-() const
+{
+    return linear_term<FieldT>(*this, -FieldT::one());
+}
+
+template<typename FieldT>
+bool variable<FieldT>::operator==(const variable<FieldT> &other) const
+{
+    return (this->index == other.index);
+}
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const integer_coeff_t int_coeff, const variable<FieldT> &var)
+{
+    return linear_term<FieldT>(var, int_coeff);
+}
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const FieldT &field_coeff, const variable<FieldT> &var)
+{
+    return linear_term<FieldT>(var, field_coeff);
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const integer_coeff_t int_coeff, const variable<FieldT> &var)
+{
+    return linear_combination<FieldT>(int_coeff) + var;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const FieldT &field_coeff, const variable<FieldT> &var)
+{
+    return linear_combination<FieldT>(field_coeff) + var;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const integer_coeff_t int_coeff, const variable<FieldT> &var)
+{
+    return linear_combination<FieldT>(int_coeff) - var;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const FieldT &field_coeff, const variable<FieldT> &var)
+{
+    return linear_combination<FieldT>(field_coeff) - var;
+}
+
+template<typename FieldT>
+linear_term<FieldT>::linear_term(const variable<FieldT> &var) :
+    index(var.index), coeff(FieldT::one())
+{
+}
+
+template<typename FieldT>
+linear_term<FieldT>::linear_term(const variable<FieldT> &var, const integer_coeff_t int_coeff) :
+    index(var.index), coeff(FieldT(int_coeff))
+{
+}
+
+template<typename FieldT>
+linear_term<FieldT>::linear_term(const variable<FieldT> &var, const FieldT &coeff) :
+    index(var.index), coeff(coeff)
+{
+}
+
+template<typename FieldT>
+linear_term<FieldT> linear_term<FieldT>::operator*(const integer_coeff_t int_coeff) const
+{
+    return (this->operator*(FieldT(int_coeff)));
+}
+
+template<typename FieldT>
+linear_term<FieldT> linear_term<FieldT>::operator*(const FieldT &field_coeff) const
+{
+    return linear_term<FieldT>(this->index, field_coeff * this->coeff);
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const integer_coeff_t int_coeff, const linear_term<FieldT> &lt)
+{
+    return linear_combination<FieldT>(int_coeff) + lt;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const FieldT &field_coeff, const linear_term<FieldT> &lt)
+{
+    return linear_combination<FieldT>(field_coeff) + lt;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const integer_coeff_t int_coeff, const linear_term<FieldT> &lt)
+{
+    return linear_combination<FieldT>(int_coeff) - lt;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const FieldT &field_coeff, const linear_term<FieldT> &lt)
+{
+    return linear_combination<FieldT>(field_coeff) - lt;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> linear_term<FieldT>::operator+(const linear_combination<FieldT> &other) const
+{
+    return linear_combination<FieldT>(*this) + other;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> linear_term<FieldT>::operator-(const linear_combination<FieldT> &other) const
+{
+    return (*this) + (-other);
+}
+
+template<typename FieldT>
+linear_term<FieldT> linear_term<FieldT>::operator-() const
+{
+    return linear_term<FieldT>(this->index, -this->coeff);
+}
+
+template<typename FieldT>
+bool linear_term<FieldT>::operator==(const linear_term<FieldT> &other) const
+{
+    return (this->index == other.index &&
+            this->coeff == other.coeff);
+}
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const integer_coeff_t int_coeff, const linear_term<FieldT> &lt)
+{
+    return FieldT(int_coeff) * lt;
+}
+
+template<typename FieldT>
+linear_term<FieldT> operator*(const FieldT &field_coeff, const linear_term<FieldT> &lt)
+{
+    return linear_term<FieldT>(lt.index, field_coeff * lt.coeff);
+}
+
+template<typename FieldT>
+linear_combination<FieldT>::linear_combination(const integer_coeff_t int_coeff)
+{
+    this->add_term(linear_term<FieldT>(0, int_coeff));
+}
+
+template<typename FieldT>
+linear_combination<FieldT>::linear_combination(const FieldT &field_coeff)
+{
+    this->add_term(linear_term<FieldT>(0, field_coeff));
+}
+
+template<typename FieldT>
+linear_combination<FieldT>::linear_combination(const variable<FieldT> &var)
+{
+    this->add_term(var);
+}
+
+template<typename FieldT>
+linear_combination<FieldT>::linear_combination(const linear_term<FieldT> &lt)
+{
+    this->add_term(lt);
+}
+
+template<typename FieldT>
+typename std::vector<linear_term<FieldT> >::const_iterator linear_combination<FieldT>::begin() const
+{
+    return terms.begin();
+}
+
+template<typename FieldT>
+typename std::vector<linear_term<FieldT> >::const_iterator linear_combination<FieldT>::end() const
+{
+    return terms.end();
+}
+
+template<typename FieldT>
+void linear_combination<FieldT>::add_term(const variable<FieldT> &var)
+{
+    this->terms.emplace_back(linear_term<FieldT>(var.index, FieldT::one()));
+}
+
+template<typename FieldT>
+void linear_combination<FieldT>::add_term(const variable<FieldT> &var, const integer_coeff_t int_coeff)
+{
+    this->terms.emplace_back(linear_term<FieldT>(var.index, int_coeff));
+}
+
+template<typename FieldT>
+void linear_combination<FieldT>::add_term(const variable<FieldT> &var, const FieldT &coeff)
+{
+    this->terms.emplace_back(linear_term<FieldT>(var.index, coeff));
+}
+
+template<typename FieldT>
+void linear_combination<FieldT>::add_term(const linear_term<FieldT> &other)
+{
+    this->terms.emplace_back(other);
+}
+
+template<typename FieldT>
+linear_combination<FieldT> linear_combination<FieldT>::operator*(const integer_coeff_t int_coeff) const
+{
+    return (*this) * FieldT(int_coeff);
+}
+
+template<typename FieldT>
+FieldT linear_combination<FieldT>::evaluate(const std::vector<FieldT> &assignment) const
+{
+    FieldT acc = FieldT::zero();
+    for (auto &lt : terms)
+    {
+        acc += (lt.index == 0 ? FieldT::one() : assignment[lt.index-1]) * lt.coeff;
+    }
+    return acc;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> linear_combination<FieldT>::operator*(const FieldT &field_coeff) const
+{
+    linear_combination<FieldT> result;
+    result.terms.reserve(this->terms.size());
+    for (const linear_term<FieldT> &lt : this->terms)
+    {
+        result.terms.emplace_back(lt * field_coeff);
+    }
+    return result;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> linear_combination<FieldT>::operator+(const linear_combination<FieldT> &other) const
+{
+    linear_combination<FieldT> result;
+
+    auto it1 = this->terms.begin();
+    auto it2 = other.terms.begin();
+
+    /* invariant: it1 and it2 always point to unprocessed items in the corresponding linear combinations */
+    while (it1 != this->terms.end() && it2 != other.terms.end())
+    {
+        if (it1->index < it2->index)
+        {
+            result.terms.emplace_back(*it1);
+            ++it1;
+        }
+        else if (it1->index > it2->index)
+        {
+            result.terms.emplace_back(*it2);
+            ++it2;
+        }
+        else
+        {
+            /* it1->index == it2->index */
+            result.terms.emplace_back(linear_term<FieldT>(variable<FieldT>(it1->index), it1->coeff + it2->coeff));
+            ++it1;
+            ++it2;
+        }
+    }
+
+    if (it1 != this->terms.end())
+    {
+        result.terms.insert(result.terms.end(), it1, this->terms.end());
+    }
+    else
+    {
+        result.terms.insert(result.terms.end(), it2, other.terms.end());
+    }
+
+    return result;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> linear_combination<FieldT>::operator-(const linear_combination<FieldT> &other) const
+{
+    return (*this) + (-other);
+}
+
+template<typename FieldT>
+linear_combination<FieldT> linear_combination<FieldT>::operator-() const
+{
+    return (*this) * (-FieldT::one());
+}
+
+template<typename FieldT>
+bool linear_combination<FieldT>::operator==(const linear_combination<FieldT> &other) const
+{
+    return (this->terms == other.terms);
+}
+
+template<typename FieldT>
+bool linear_combination<FieldT>::is_valid(const size_t num_variables) const
+{
+    /* check that all terms in linear combination are sorted */
+    for (size_t i = 1; i < terms.size(); ++i)
+    {
+        if (terms[i-1].index >= terms[i].index)
+        {
+            return false;
+        }
+    }
+
+    /* check that the variables are in proper range. as the variables
+       are sorted, it suffices to check the last term */
+    if ((--terms.end())->index >= num_variables)
+    {
+        return false;
+    }
+
+    return true;
+}
+
+template<typename FieldT>
+void linear_combination<FieldT>::print(const std::map<size_t, std::string> &variable_annotations) const
+{
+    for (auto &lt : terms)
+    {
+        if (lt.index == 0)
+        {
+            printf("    1 * ");
+            lt.coeff.print();
+        }
+        else
+        {
+            auto it = variable_annotations.find(lt.index);
+            printf("    x_%zu (%s) * ", lt.index, (it == variable_annotations.end() ? "no annotation" : it->second.c_str()));
+            lt.coeff.print();
+        }
+    }
+}
+
+template<typename FieldT>
+void linear_combination<FieldT>::print_with_assignment(const std::vector<FieldT> &full_assignment, const std::map<size_t, std::string> &variable_annotations) const
+{
+    for (auto &lt : terms)
+    {
+        if (lt.index == 0)
+        {
+            printf("    1 * ");
+            lt.coeff.print();
+        }
+        else
+        {
+            printf("    x_%zu * ", lt.index);
+            lt.coeff.print();
+
+            auto it = variable_annotations.find(lt.index);
+            printf("    where x_%zu (%s) was assigned value ", lt.index,
+                   (it == variable_annotations.end() ? "no annotation" : it->second.c_str()));
+            full_assignment[lt.index-1].print();
+            printf("      i.e. negative of ");
+            (-full_assignment[lt.index-1]).print();
+        }
+    }
+}
+
+template<typename FieldT>
+std::ostream& operator<<(std::ostream &out, const linear_combination<FieldT> &lc)
+{
+    out << lc.terms.size() << "\n";
+    for (const linear_term<FieldT>& lt : lc.terms)
+    {
+        out << lt.index << "\n";
+        out << lt.coeff << OUTPUT_NEWLINE;
+    }
+
+    return out;
+}
+
+template<typename FieldT>
+std::istream& operator>>(std::istream &in, linear_combination<FieldT> &lc)
+{
+    lc.terms.clear();
+
+    size_t s;
+    in >> s;
+
+    consume_newline(in);
+
+    lc.terms.reserve(s);
+
+    for (size_t i = 0; i < s; ++i)
+    {
+        linear_term<FieldT> lt;
+        in >> lt.index;
+        consume_newline(in);
+        in >> lt.coeff;
+        consume_OUTPUT_NEWLINE(in);
+        lc.terms.emplace_back(lt);
+    }
+
+    return in;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator*(const integer_coeff_t int_coeff, const linear_combination<FieldT> &lc)
+{
+    return lc * int_coeff;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator*(const FieldT &field_coeff, const linear_combination<FieldT> &lc)
+{
+    return lc * field_coeff;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const integer_coeff_t int_coeff, const linear_combination<FieldT> &lc)
+{
+    return linear_combination<FieldT>(int_coeff) + lc;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator+(const FieldT &field_coeff, const linear_combination<FieldT> &lc)
+{
+    return linear_combination<FieldT>(field_coeff) + lc;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const integer_coeff_t int_coeff, const linear_combination<FieldT> &lc)
+{
+    return linear_combination<FieldT>(int_coeff) - lc;
+}
+
+template<typename FieldT>
+linear_combination<FieldT> operator-(const FieldT &field_coeff, const linear_combination<FieldT> &lc)
+{
+    return linear_combination<FieldT>(field_coeff) - lc;
+}
+
+template<typename FieldT>
+linear_combination<FieldT>::linear_combination(const std::vector<linear_term<FieldT> > &all_terms)
+{
+    if (all_terms.empty())
+    {
+        return;
+    }
+
+    terms = all_terms;
+    std::sort(terms.begin(), terms.end(), [](linear_term<FieldT> a, linear_term<FieldT> b) { return a.index < b.index; });
+
+    auto result_it = terms.begin();
+    for (auto it = ++terms.begin(); it != terms.end(); ++it)
+    {
+        if (it->index == result_it->index)
+        {
+            result_it->coeff += it->coeff;
+        }
+        else
+        {
+            *(++result_it) = *it;
+        }
+    }
+    terms.resize((result_it - terms.begin()) + 1);
+}
+
+} // libsnark
+
+#endif // VARIABLE_TCC
diff --git a/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.hpp b/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.hpp
new file mode 100644 (file)
index 0000000..fcd28ab
--- /dev/null
@@ -0,0 +1,35 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of functionality that runs the R1CS ppzkSNARK for
+ a given R1CS example.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef RUN_R1CS_PPZKSNARK_HPP_
+#define RUN_R1CS_PPZKSNARK_HPP_
+
+#include "relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp"
+
+namespace libsnark {
+
+/**
+ * Runs the ppzkSNARK (generator, prover, and verifier) for a given
+ * R1CS example (specified by a constraint system, input, and witness).
+ *
+ * Optionally, also test the serialization routines for keys and proofs.
+ * (This takes additional time.)
+ */
+template<typename ppT>
+bool run_r1cs_ppzksnark(const r1cs_example<Fr<ppT> > &example,
+                        const bool test_serialization);
+
+} // libsnark
+
+#include "zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.tcc"
+
+#endif // RUN_R1CS_PPZKSNARK_HPP_
diff --git a/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.tcc b/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.tcc
new file mode 100644 (file)
index 0000000..9bc8758
--- /dev/null
@@ -0,0 +1,114 @@
+/** @file
+ *****************************************************************************
+
+ Implementation of functionality that runs the R1CS ppzkSNARK for
+ a given R1CS example.
+
+ See run_r1cs_ppzksnark.hpp .
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef RUN_R1CS_PPZKSNARK_TCC_
+#define RUN_R1CS_PPZKSNARK_TCC_
+
+#include "zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp"
+
+#include <sstream>
+#include <type_traits>
+
+#include "common/profiling.hpp"
+
+namespace libsnark {
+
+template<typename ppT>
+typename std::enable_if<ppT::has_affine_pairing, void>::type
+test_affine_verifier(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                     const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                     const r1cs_ppzksnark_proof<ppT> &proof,
+                     const bool expected_answer)
+{
+    print_header("R1CS ppzkSNARK Affine Verifier");
+    const bool answer = r1cs_ppzksnark_affine_verifier_weak_IC<ppT>(vk, primary_input, proof);
+    assert(answer == expected_answer);
+}
+
+template<typename ppT>
+typename std::enable_if<!ppT::has_affine_pairing, void>::type
+test_affine_verifier(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                     const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                     const r1cs_ppzksnark_proof<ppT> &proof,
+                     const bool expected_answer)
+{
+    UNUSED(vk, primary_input, proof, expected_answer);
+    print_header("R1CS ppzkSNARK Affine Verifier");
+    printf("Affine verifier is not supported; not testing anything.\n");
+}
+
+/**
+ * The code below provides an example of all stages of running a R1CS ppzkSNARK.
+ *
+ * Of course, in a real-life scenario, we would have three distinct entities,
+ * mangled into one in the demonstration below. The three entities are as follows.
+ * (1) The "generator", which runs the ppzkSNARK generator on input a given
+ *     constraint system CS to create a proving and a verification key for CS.
+ * (2) The "prover", which runs the ppzkSNARK prover on input the proving key,
+ *     a primary input for CS, and an auxiliary input for CS.
+ * (3) The "verifier", which runs the ppzkSNARK verifier on input the verification key,
+ *     a primary input for CS, and a proof.
+ */
+template<typename ppT>
+bool run_r1cs_ppzksnark(const r1cs_example<Fr<ppT> > &example,
+                        const bool test_serialization)
+{
+    enter_block("Call to run_r1cs_ppzksnark");
+
+    print_header("R1CS ppzkSNARK Generator");
+    r1cs_ppzksnark_keypair<ppT> keypair = r1cs_ppzksnark_generator<ppT>(example.constraint_system);
+    printf("\n"); print_indent(); print_mem("after generator");
+
+    print_header("Preprocess verification key");
+    r1cs_ppzksnark_processed_verification_key<ppT> pvk = r1cs_ppzksnark_verifier_process_vk<ppT>(keypair.vk);
+
+    if (test_serialization)
+    {
+        enter_block("Test serialization of keys");
+        keypair.pk = reserialize<r1cs_ppzksnark_proving_key<ppT> >(keypair.pk);
+        keypair.vk = reserialize<r1cs_ppzksnark_verification_key<ppT> >(keypair.vk);
+        pvk = reserialize<r1cs_ppzksnark_processed_verification_key<ppT> >(pvk);
+        leave_block("Test serialization of keys");
+    }
+
+    print_header("R1CS ppzkSNARK Prover");
+    r1cs_ppzksnark_proof<ppT> proof = r1cs_ppzksnark_prover<ppT>(keypair.pk, example.primary_input, example.auxiliary_input);
+    printf("\n"); print_indent(); print_mem("after prover");
+
+    if (test_serialization)
+    {
+        enter_block("Test serialization of proof");
+        proof = reserialize<r1cs_ppzksnark_proof<ppT> >(proof);
+        leave_block("Test serialization of proof");
+    }
+
+    print_header("R1CS ppzkSNARK Verifier");
+    const bool ans = r1cs_ppzksnark_verifier_strong_IC<ppT>(keypair.vk, example.primary_input, proof);
+    printf("\n"); print_indent(); print_mem("after verifier");
+    printf("* The verification result is: %s\n", (ans ? "PASS" : "FAIL"));
+
+    print_header("R1CS ppzkSNARK Online Verifier");
+    const bool ans2 = r1cs_ppzksnark_online_verifier_strong_IC<ppT>(pvk, example.primary_input, proof);
+    assert(ans == ans2);
+
+    test_affine_verifier<ppT>(keypair.vk, example.primary_input, proof, ans);
+
+    leave_block("Call to run_r1cs_ppzksnark");
+
+    return ans;
+}
+
+} // libsnark
+
+#endif // RUN_R1CS_PPZKSNARK_TCC_
diff --git a/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark.cpp b/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark.cpp
new file mode 100644 (file)
index 0000000..5c54150
--- /dev/null
@@ -0,0 +1,71 @@
+/** @file
+ *****************************************************************************
+ Profiling program that exercises the ppzkSNARK (first generator, then prover,
+ then verifier) on a synthetic R1CS instance.
+
+ The command
+
+     $ src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark 1000 10 Fr
+
+ exercises the ppzkSNARK (first generator, then prover, then verifier) on an R1CS instance with 1000 equations and an input consisting of 10 field elements.
+
+ (If you get the error `zmInit ERR:can't protect`, see the discussion [above](#elliptic-curve-choices).)
+
+ The command
+
+     $ src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/profiling/profile_r1cs_ppzksnark 1000 10 bytes
+
+ does the same but now the input consists of 10 bytes.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#include <cassert>
+#include <cstdio>
+
+#include "common/default_types/r1cs_ppzksnark_pp.hpp"
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+#include "relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp"
+#include "zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.hpp"
+
+using namespace libsnark;
+
+int main(int argc, const char * argv[])
+{
+    default_r1cs_ppzksnark_pp::init_public_params();
+    start_profiling();
+
+    if (argc == 2 && strcmp(argv[1], "-v") == 0)
+    {
+        print_compilation_info();
+        return 0;
+    }
+
+    if (argc != 3 && argc != 4)
+    {
+        printf("usage: %s num_constraints input_size [Fr|bytes]\n", argv[0]);
+        return 1;
+    }
+    const int num_constraints = atoi(argv[1]);
+    int input_size = atoi(argv[2]);
+    if (argc == 4)
+    {
+        assert(strcmp(argv[3], "Fr") == 0 || strcmp(argv[3], "bytes") == 0);
+        if (strcmp(argv[3], "bytes") == 0)
+        {
+            input_size = div_ceil(8 * input_size, Fr<default_ec_pp>::capacity());
+        }
+    }
+
+    enter_block("Generate R1CS example");
+    r1cs_example<Fr<default_r1cs_ppzksnark_pp> > example = generate_r1cs_example_with_field_input<Fr<default_r1cs_ppzksnark_pp> >(num_constraints, input_size);
+    leave_block("Generate R1CS example");
+
+    print_header("(enter) Profile R1CS ppzkSNARK");
+    const bool test_serialization = true;
+    run_r1cs_ppzksnark<default_r1cs_ppzksnark_pp>(example, test_serialization);
+    print_header("(leave) Profile R1CS ppzkSNARK");
+}
diff --git a/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp b/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp
new file mode 100644 (file)
index 0000000..a068b09
--- /dev/null
@@ -0,0 +1,479 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of interfaces for a ppzkSNARK for R1CS.
+
+ This includes:
+ - class for proving key
+ - class for verification key
+ - class for processed verification key
+ - class for key pair (proving key & verification key)
+ - class for proof
+ - generator algorithm
+ - prover algorithm
+ - verifier algorithm (with strong or weak input consistency)
+ - online verifier algorithm (with strong or weak input consistency)
+
+ The implementation instantiates (a modification of) the protocol of \[PGHR13],
+ by following extending, and optimizing the approach described in \[BCTV14].
+
+
+ Acronyms:
+
+ - R1CS = "Rank-1 Constraint Systems"
+ - ppzkSNARK = "PreProcessing Zero-Knowledge Succinct Non-interactive ARgument of Knowledge"
+
+ References:
+
+ \[BCTV14]:
+ "Succinct Non-Interactive Zero Knowledge for a von Neumann Architecture",
+ Eli Ben-Sasson, Alessandro Chiesa, Eran Tromer, Madars Virza,
+ USENIX Security 2014,
+ <http://eprint.iacr.org/2013/879>
+
+ \[PGHR13]:
+ "Pinocchio: Nearly practical verifiable computation",
+ Bryan Parno, Craig Gentry, Jon Howell, Mariana Raykova,
+ IEEE S&P 2013,
+ <https://eprint.iacr.org/2013/279>
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_PPZKSNARK_HPP_
+#define R1CS_PPZKSNARK_HPP_
+
+#include <memory>
+
+#include "algebra/curves/public_params.hpp"
+#include "common/data_structures/accumulation_vector.hpp"
+#include "algebra/knowledge_commitment/knowledge_commitment.hpp"
+#include "relations/constraint_satisfaction_problems/r1cs/r1cs.hpp"
+#include "zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark_params.hpp"
+
+namespace libsnark {
+
+/******************************** Proving key ********************************/
+
+template<typename ppT>
+class r1cs_ppzksnark_proving_key;
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_proving_key<ppT> &pk);
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_proving_key<ppT> &pk);
+
+/**
+ * A proving key for the R1CS ppzkSNARK.
+ */
+template<typename ppT>
+class r1cs_ppzksnark_proving_key {
+public:
+    knowledge_commitment_vector<G1<ppT>, G1<ppT> > A_query;
+    knowledge_commitment_vector<G2<ppT>, G1<ppT> > B_query;
+    knowledge_commitment_vector<G1<ppT>, G1<ppT> > C_query;
+    G1_vector<ppT> H_query;
+    G1_vector<ppT> K_query;
+
+    r1cs_ppzksnark_proving_key() {};
+    r1cs_ppzksnark_proving_key<ppT>& operator=(const r1cs_ppzksnark_proving_key<ppT> &other) = default;
+    r1cs_ppzksnark_proving_key(const r1cs_ppzksnark_proving_key<ppT> &other) = default;
+    r1cs_ppzksnark_proving_key(r1cs_ppzksnark_proving_key<ppT> &&other) = default;
+    r1cs_ppzksnark_proving_key(knowledge_commitment_vector<G1<ppT>, G1<ppT> > &&A_query,
+                               knowledge_commitment_vector<G2<ppT>, G1<ppT> > &&B_query,
+                               knowledge_commitment_vector<G1<ppT>, G1<ppT> > &&C_query,
+                               G1_vector<ppT> &&H_query,
+                               G1_vector<ppT> &&K_query) :
+        A_query(std::move(A_query)),
+        B_query(std::move(B_query)),
+        C_query(std::move(C_query)),
+        H_query(std::move(H_query)),
+        K_query(std::move(K_query))
+    {};
+
+    size_t G1_size() const
+    {
+        return 2*(A_query.domain_size() + C_query.domain_size()) + B_query.domain_size() + H_query.size() + K_query.size();
+    }
+
+    size_t G2_size() const
+    {
+        return B_query.domain_size();
+    }
+
+    size_t G1_sparse_size() const
+    {
+        return 2*(A_query.size() + C_query.size()) + B_query.size() + H_query.size() + K_query.size();
+    }
+
+    size_t G2_sparse_size() const
+    {
+        return B_query.size();
+    }
+
+    size_t size_in_bits() const
+    {
+        return A_query.size_in_bits() + B_query.size_in_bits() + C_query.size_in_bits() + libsnark::size_in_bits(H_query) + libsnark::size_in_bits(K_query);
+    }
+
+    void print_size() const
+    {
+        print_indent(); printf("* G1 elements in PK: %zu\n", this->G1_size());
+        print_indent(); printf("* Non-zero G1 elements in PK: %zu\n", this->G1_sparse_size());
+        print_indent(); printf("* G2 elements in PK: %zu\n", this->G2_size());
+        print_indent(); printf("* Non-zero G2 elements in PK: %zu\n", this->G2_sparse_size());
+        print_indent(); printf("* PK size in bits: %zu\n", this->size_in_bits());
+    }
+
+    bool operator==(const r1cs_ppzksnark_proving_key<ppT> &other) const;
+    friend std::ostream& operator<< <ppT>(std::ostream &out, const r1cs_ppzksnark_proving_key<ppT> &pk);
+    friend std::istream& operator>> <ppT>(std::istream &in, r1cs_ppzksnark_proving_key<ppT> &pk);
+};
+
+
+/******************************* Verification key ****************************/
+
+template<typename ppT>
+class r1cs_ppzksnark_verification_key;
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_verification_key<ppT> &vk);
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_verification_key<ppT> &vk);
+
+/**
+ * A verification key for the R1CS ppzkSNARK.
+ */
+template<typename ppT>
+class r1cs_ppzksnark_verification_key {
+public:
+    G2<ppT> alphaA_g2;
+    G1<ppT> alphaB_g1;
+    G2<ppT> alphaC_g2;
+    G2<ppT> gamma_g2;
+    G1<ppT> gamma_beta_g1;
+    G2<ppT> gamma_beta_g2;
+    G2<ppT> rC_Z_g2;
+
+    accumulation_vector<G1<ppT> > encoded_IC_query;
+
+    r1cs_ppzksnark_verification_key() = default;
+    r1cs_ppzksnark_verification_key(const G2<ppT> &alphaA_g2,
+                                    const G1<ppT> &alphaB_g1,
+                                    const G2<ppT> &alphaC_g2,
+                                    const G2<ppT> &gamma_g2,
+                                    const G1<ppT> &gamma_beta_g1,
+                                    const G2<ppT> &gamma_beta_g2,
+                                    const G2<ppT> &rC_Z_g2,
+                                    const accumulation_vector<G1<ppT> > &eIC) :
+        alphaA_g2(alphaA_g2),
+        alphaB_g1(alphaB_g1),
+        alphaC_g2(alphaC_g2),
+        gamma_g2(gamma_g2),
+        gamma_beta_g1(gamma_beta_g1),
+        gamma_beta_g2(gamma_beta_g2),
+        rC_Z_g2(rC_Z_g2),
+        encoded_IC_query(eIC)
+    {};
+
+    size_t G1_size() const
+    {
+        return 2 + encoded_IC_query.size();
+    }
+
+    size_t G2_size() const
+    {
+        return 5;
+    }
+
+    size_t size_in_bits() const
+    {
+        return (2 * G1<ppT>::size_in_bits() + encoded_IC_query.size_in_bits() + 5 * G2<ppT>::size_in_bits());
+    }
+
+    void print_size() const
+    {
+        print_indent(); printf("* G1 elements in VK: %zu\n", this->G1_size());
+        print_indent(); printf("* G2 elements in VK: %zu\n", this->G2_size());
+        print_indent(); printf("* VK size in bits: %zu\n", this->size_in_bits());
+    }
+
+    bool operator==(const r1cs_ppzksnark_verification_key<ppT> &other) const;
+    friend std::ostream& operator<< <ppT>(std::ostream &out, const r1cs_ppzksnark_verification_key<ppT> &vk);
+    friend std::istream& operator>> <ppT>(std::istream &in, r1cs_ppzksnark_verification_key<ppT> &vk);
+
+    static r1cs_ppzksnark_verification_key<ppT> dummy_verification_key(const size_t input_size);
+};
+
+
+/************************ Processed verification key *************************/
+
+template<typename ppT>
+class r1cs_ppzksnark_processed_verification_key;
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_processed_verification_key<ppT> &pvk);
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_processed_verification_key<ppT> &pvk);
+
+/**
+ * A processed verification key for the R1CS ppzkSNARK.
+ *
+ * Compared to a (non-processed) verification key, a processed verification key
+ * contains a small constant amount of additional pre-computed information that
+ * enables a faster verification time.
+ */
+template<typename ppT>
+class r1cs_ppzksnark_processed_verification_key {
+public:
+    G2_precomp<ppT> pp_G2_one_precomp;
+    G2_precomp<ppT> vk_alphaA_g2_precomp;
+    G1_precomp<ppT> vk_alphaB_g1_precomp;
+    G2_precomp<ppT> vk_alphaC_g2_precomp;
+    G2_precomp<ppT> vk_rC_Z_g2_precomp;
+    G2_precomp<ppT> vk_gamma_g2_precomp;
+    G1_precomp<ppT> vk_gamma_beta_g1_precomp;
+    G2_precomp<ppT> vk_gamma_beta_g2_precomp;
+
+    accumulation_vector<G1<ppT> > encoded_IC_query;
+
+    bool operator==(const r1cs_ppzksnark_processed_verification_key &other) const;
+    friend std::ostream& operator<< <ppT>(std::ostream &out, const r1cs_ppzksnark_processed_verification_key<ppT> &pvk);
+    friend std::istream& operator>> <ppT>(std::istream &in, r1cs_ppzksnark_processed_verification_key<ppT> &pvk);
+};
+
+
+/********************************** Key pair *********************************/
+
+/**
+ * A key pair for the R1CS ppzkSNARK, which consists of a proving key and a verification key.
+ */
+template<typename ppT>
+class r1cs_ppzksnark_keypair {
+public:
+    r1cs_ppzksnark_proving_key<ppT> pk;
+    r1cs_ppzksnark_verification_key<ppT> vk;
+
+    r1cs_ppzksnark_keypair() = default;
+    r1cs_ppzksnark_keypair(const r1cs_ppzksnark_keypair<ppT> &other) = default;
+    r1cs_ppzksnark_keypair(r1cs_ppzksnark_proving_key<ppT> &&pk,
+                           r1cs_ppzksnark_verification_key<ppT> &&vk) :
+        pk(std::move(pk)),
+        vk(std::move(vk))
+    {}
+
+    r1cs_ppzksnark_keypair(r1cs_ppzksnark_keypair<ppT> &&other) = default;
+};
+
+
+/*********************************** Proof ***********************************/
+
+template<typename ppT>
+class r1cs_ppzksnark_proof;
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_proof<ppT> &proof);
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_proof<ppT> &proof);
+
+/**
+ * A proof for the R1CS ppzkSNARK.
+ *
+ * While the proof has a structure, externally one merely opaquely produces,
+ * seralizes/deserializes, and verifies proofs. We only expose some information
+ * about the structure for statistics purposes.
+ */
+template<typename ppT>
+class r1cs_ppzksnark_proof {
+public:
+    knowledge_commitment<G1<ppT>, G1<ppT> > g_A;
+    knowledge_commitment<G2<ppT>, G1<ppT> > g_B;
+    knowledge_commitment<G1<ppT>, G1<ppT> > g_C;
+    G1<ppT> g_H;
+    G1<ppT> g_K;
+
+    r1cs_ppzksnark_proof()
+    {
+        // invalid proof with valid curve points
+        this->g_A.g = G1<ppT> ::one();
+        this->g_A.h = G1<ppT>::one();
+        this->g_B.g = G2<ppT> ::one();
+        this->g_B.h = G1<ppT>::one();
+        this->g_C.g = G1<ppT> ::one();
+        this->g_C.h = G1<ppT>::one();
+        this->g_H = G1<ppT>::one();
+        this->g_K = G1<ppT>::one();
+    }
+    r1cs_ppzksnark_proof(knowledge_commitment<G1<ppT>, G1<ppT> > &&g_A,
+                         knowledge_commitment<G2<ppT>, G1<ppT> > &&g_B,
+                         knowledge_commitment<G1<ppT>, G1<ppT> > &&g_C,
+                         G1<ppT> &&g_H,
+                         G1<ppT> &&g_K) :
+        g_A(std::move(g_A)),
+        g_B(std::move(g_B)),
+        g_C(std::move(g_C)),
+        g_H(std::move(g_H)),
+        g_K(std::move(g_K))
+    {};
+
+    size_t G1_size() const
+    {
+        return 7;
+    }
+
+    size_t G2_size() const
+    {
+        return 1;
+    }
+
+    size_t size_in_bits() const
+    {
+        return G1_size() * G1<ppT>::size_in_bits() + G2_size() * G2<ppT>::size_in_bits();
+    }
+
+    void print_size() const
+    {
+        print_indent(); printf("* G1 elements in proof: %zu\n", this->G1_size());
+        print_indent(); printf("* G2 elements in proof: %zu\n", this->G2_size());
+        print_indent(); printf("* Proof size in bits: %zu\n", this->size_in_bits());
+    }
+
+    bool is_well_formed() const
+    {
+        return (g_A.g.is_well_formed() && g_A.h.is_well_formed() &&
+                g_B.g.is_well_formed() && g_B.h.is_well_formed() &&
+                g_C.g.is_well_formed() && g_C.h.is_well_formed() &&
+                g_H.is_well_formed() &&
+                g_K.is_well_formed());
+    }
+
+    bool operator==(const r1cs_ppzksnark_proof<ppT> &other) const;
+    friend std::ostream& operator<< <ppT>(std::ostream &out, const r1cs_ppzksnark_proof<ppT> &proof);
+    friend std::istream& operator>> <ppT>(std::istream &in, r1cs_ppzksnark_proof<ppT> &proof);
+};
+
+
+/***************************** Main algorithms *******************************/
+
+/**
+ * A generator algorithm for the R1CS ppzkSNARK.
+ *
+ * Given a R1CS constraint system CS, this algorithm produces proving and verification keys for CS.
+ */
+template<typename ppT>
+r1cs_ppzksnark_keypair<ppT> r1cs_ppzksnark_generator(const r1cs_ppzksnark_constraint_system<ppT> &cs);
+
+template<typename ppT>
+r1cs_ppzksnark_keypair<ppT> r1cs_ppzksnark_generator(
+    const r1cs_ppzksnark_constraint_system<ppT> &cs,
+    const Fr<ppT>& t,
+    const Fr<ppT>& alphaA,
+    const Fr<ppT>& alphaB,
+    const Fr<ppT>& alphaC,
+    const Fr<ppT>& rA,
+    const Fr<ppT>& rB,
+    const Fr<ppT>& beta,
+    const Fr<ppT>& gamma
+);
+
+/**
+ * A prover algorithm for the R1CS ppzkSNARK.
+ *
+ * Given a R1CS primary input X and a R1CS auxiliary input Y, this algorithm
+ * produces a proof (of knowledge) that attests to the following statement:
+ *               ``there exists Y such that CS(X,Y)=0''.
+ * Above, CS is the R1CS constraint system that was given as input to the generator algorithm.
+ */
+template<typename ppT>
+r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover(const r1cs_ppzksnark_proving_key<ppT> &pk,
+                                                const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                                const r1cs_ppzksnark_auxiliary_input<ppT> &auxiliary_input);
+
+/*
+ Below are four variants of verifier algorithm for the R1CS ppzkSNARK.
+
+ These are the four cases that arise from the following two choices:
+
+ (1) The verifier accepts a (non-processed) verification key or, instead, a processed verification key.
+     In the latter case, we call the algorithm an "online verifier".
+
+ (2) The verifier checks for "weak" input consistency or, instead, "strong" input consistency.
+     Strong input consistency requires that |primary_input| = CS.num_inputs, whereas
+     weak input consistency requires that |primary_input| <= CS.num_inputs (and
+     the primary input is implicitly padded with zeros up to length CS.num_inputs).
+ */
+
+/**
+ * A verifier algorithm for the R1CS ppzkSNARK that:
+ * (1) accepts a non-processed verification key, and
+ * (2) has weak input consistency.
+ */
+template<typename ppT>
+bool r1cs_ppzksnark_verifier_weak_IC(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                                     const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                     const r1cs_ppzksnark_proof<ppT> &proof);
+
+/**
+ * A verifier algorithm for the R1CS ppzkSNARK that:
+ * (1) accepts a non-processed verification key, and
+ * (2) has strong input consistency.
+ */
+template<typename ppT>
+bool r1cs_ppzksnark_verifier_strong_IC(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                                       const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                       const r1cs_ppzksnark_proof<ppT> &proof);
+
+/**
+ * Convert a (non-processed) verification key into a processed verification key.
+ */
+template<typename ppT>
+r1cs_ppzksnark_processed_verification_key<ppT> r1cs_ppzksnark_verifier_process_vk(const r1cs_ppzksnark_verification_key<ppT> &vk);
+
+/**
+ * A verifier algorithm for the R1CS ppzkSNARK that:
+ * (1) accepts a processed verification key, and
+ * (2) has weak input consistency.
+ */
+template<typename ppT>
+bool r1cs_ppzksnark_online_verifier_weak_IC(const r1cs_ppzksnark_processed_verification_key<ppT> &pvk,
+                                            const r1cs_ppzksnark_primary_input<ppT> &input,
+                                            const r1cs_ppzksnark_proof<ppT> &proof);
+
+/**
+ * A verifier algorithm for the R1CS ppzkSNARK that:
+ * (1) accepts a processed verification key, and
+ * (2) has strong input consistency.
+ */
+template<typename ppT>
+bool r1cs_ppzksnark_online_verifier_strong_IC(const r1cs_ppzksnark_processed_verification_key<ppT> &pvk,
+                                              const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                              const r1cs_ppzksnark_proof<ppT> &proof);
+
+/****************************** Miscellaneous ********************************/
+
+/**
+ * For debugging purposes (of r1cs_ppzksnark_r1cs_ppzksnark_verifier_gadget):
+ *
+ * A verifier algorithm for the R1CS ppzkSNARK that:
+ * (1) accepts a non-processed verification key,
+ * (2) has weak input consistency, and
+ * (3) uses affine coordinates for elliptic-curve computations.
+ */
+template<typename ppT>
+bool r1cs_ppzksnark_affine_verifier_weak_IC(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                                            const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                            const r1cs_ppzksnark_proof<ppT> &proof);
+
+
+} // libsnark
+
+#include "zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc"
+
+#endif // R1CS_PPZKSNARK_HPP_
diff --git a/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc b/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc
new file mode 100644 (file)
index 0000000..aeb2bbb
--- /dev/null
@@ -0,0 +1,762 @@
+/** @file
+*****************************************************************************
+
+Implementation of interfaces for a ppzkSNARK for R1CS.
+
+See r1cs_ppzksnark.hpp .
+
+*****************************************************************************
+* @author     This file is part of libsnark, developed by SCIPR Lab
+*             and contributors (see AUTHORS).
+* @copyright  MIT license (see LICENSE file)
+*****************************************************************************/
+
+#ifndef R1CS_PPZKSNARK_TCC_
+#define R1CS_PPZKSNARK_TCC_
+
+#include <algorithm>
+#include <cassert>
+#include <functional>
+#include <iostream>
+#include <sstream>
+
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+#include "algebra/scalar_multiplication/multiexp.hpp"
+#include "algebra/scalar_multiplication/kc_multiexp.hpp"
+#include "reductions/r1cs_to_qap/r1cs_to_qap.hpp"
+
+namespace libsnark {
+
+template<typename ppT>
+bool r1cs_ppzksnark_proving_key<ppT>::operator==(const r1cs_ppzksnark_proving_key<ppT> &other) const
+{
+    return (this->A_query == other.A_query &&
+            this->B_query == other.B_query &&
+            this->C_query == other.C_query &&
+            this->H_query == other.H_query &&
+            this->K_query == other.K_query);
+}
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_proving_key<ppT> &pk)
+{
+    out << pk.A_query;
+    out << pk.B_query;
+    out << pk.C_query;
+    out << pk.H_query;
+    out << pk.K_query;
+
+    return out;
+}
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_proving_key<ppT> &pk)
+{
+    in >> pk.A_query;
+    in >> pk.B_query;
+    in >> pk.C_query;
+    in >> pk.H_query;
+    in >> pk.K_query;
+
+    return in;
+}
+
+template<typename ppT>
+bool r1cs_ppzksnark_verification_key<ppT>::operator==(const r1cs_ppzksnark_verification_key<ppT> &other) const
+{
+    return (this->alphaA_g2 == other.alphaA_g2 &&
+            this->alphaB_g1 == other.alphaB_g1 &&
+            this->alphaC_g2 == other.alphaC_g2 &&
+            this->gamma_g2 == other.gamma_g2 &&
+            this->gamma_beta_g1 == other.gamma_beta_g1 &&
+            this->gamma_beta_g2 == other.gamma_beta_g2 &&
+            this->rC_Z_g2 == other.rC_Z_g2 &&
+            this->encoded_IC_query == other.encoded_IC_query);
+}
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_verification_key<ppT> &vk)
+{
+    out << vk.alphaA_g2 << OUTPUT_NEWLINE;
+    out << vk.alphaB_g1 << OUTPUT_NEWLINE;
+    out << vk.alphaC_g2 << OUTPUT_NEWLINE;
+    out << vk.gamma_g2 << OUTPUT_NEWLINE;
+    out << vk.gamma_beta_g1 << OUTPUT_NEWLINE;
+    out << vk.gamma_beta_g2 << OUTPUT_NEWLINE;
+    out << vk.rC_Z_g2 << OUTPUT_NEWLINE;
+    out << vk.encoded_IC_query << OUTPUT_NEWLINE;
+
+    return out;
+}
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_verification_key<ppT> &vk)
+{
+    in >> vk.alphaA_g2;
+    consume_OUTPUT_NEWLINE(in);
+    in >> vk.alphaB_g1;
+    consume_OUTPUT_NEWLINE(in);
+    in >> vk.alphaC_g2;
+    consume_OUTPUT_NEWLINE(in);
+    in >> vk.gamma_g2;
+    consume_OUTPUT_NEWLINE(in);
+    in >> vk.gamma_beta_g1;
+    consume_OUTPUT_NEWLINE(in);
+    in >> vk.gamma_beta_g2;
+    consume_OUTPUT_NEWLINE(in);
+    in >> vk.rC_Z_g2;
+    consume_OUTPUT_NEWLINE(in);
+    in >> vk.encoded_IC_query;
+    consume_OUTPUT_NEWLINE(in);
+
+    return in;
+}
+
+template<typename ppT>
+bool r1cs_ppzksnark_processed_verification_key<ppT>::operator==(const r1cs_ppzksnark_processed_verification_key<ppT> &other) const
+{
+    return (this->pp_G2_one_precomp == other.pp_G2_one_precomp &&
+            this->vk_alphaA_g2_precomp == other.vk_alphaA_g2_precomp &&
+            this->vk_alphaB_g1_precomp == other.vk_alphaB_g1_precomp &&
+            this->vk_alphaC_g2_precomp == other.vk_alphaC_g2_precomp &&
+            this->vk_rC_Z_g2_precomp == other.vk_rC_Z_g2_precomp &&
+            this->vk_gamma_g2_precomp == other.vk_gamma_g2_precomp &&
+            this->vk_gamma_beta_g1_precomp == other.vk_gamma_beta_g1_precomp &&
+            this->vk_gamma_beta_g2_precomp == other.vk_gamma_beta_g2_precomp &&
+            this->encoded_IC_query == other.encoded_IC_query);
+}
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_processed_verification_key<ppT> &pvk)
+{
+    out << pvk.pp_G2_one_precomp << OUTPUT_NEWLINE;
+    out << pvk.vk_alphaA_g2_precomp << OUTPUT_NEWLINE;
+    out << pvk.vk_alphaB_g1_precomp << OUTPUT_NEWLINE;
+    out << pvk.vk_alphaC_g2_precomp << OUTPUT_NEWLINE;
+    out << pvk.vk_rC_Z_g2_precomp << OUTPUT_NEWLINE;
+    out << pvk.vk_gamma_g2_precomp << OUTPUT_NEWLINE;
+    out << pvk.vk_gamma_beta_g1_precomp << OUTPUT_NEWLINE;
+    out << pvk.vk_gamma_beta_g2_precomp << OUTPUT_NEWLINE;
+    out << pvk.encoded_IC_query << OUTPUT_NEWLINE;
+
+    return out;
+}
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_processed_verification_key<ppT> &pvk)
+{
+    in >> pvk.pp_G2_one_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.vk_alphaA_g2_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.vk_alphaB_g1_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.vk_alphaC_g2_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.vk_rC_Z_g2_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.vk_gamma_g2_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.vk_gamma_beta_g1_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.vk_gamma_beta_g2_precomp;
+    consume_OUTPUT_NEWLINE(in);
+    in >> pvk.encoded_IC_query;
+    consume_OUTPUT_NEWLINE(in);
+
+    return in;
+}
+
+template<typename ppT>
+bool r1cs_ppzksnark_proof<ppT>::operator==(const r1cs_ppzksnark_proof<ppT> &other) const
+{
+    return (this->g_A == other.g_A &&
+            this->g_B == other.g_B &&
+            this->g_C == other.g_C &&
+            this->g_H == other.g_H &&
+            this->g_K == other.g_K);
+}
+
+template<typename ppT>
+std::ostream& operator<<(std::ostream &out, const r1cs_ppzksnark_proof<ppT> &proof)
+{
+    out << proof.g_A << OUTPUT_NEWLINE;
+    out << proof.g_B << OUTPUT_NEWLINE;
+    out << proof.g_C << OUTPUT_NEWLINE;
+    out << proof.g_H << OUTPUT_NEWLINE;
+    out << proof.g_K << OUTPUT_NEWLINE;
+
+    return out;
+}
+
+template<typename ppT>
+std::istream& operator>>(std::istream &in, r1cs_ppzksnark_proof<ppT> &proof)
+{
+    in >> proof.g_A;
+    consume_OUTPUT_NEWLINE(in);
+    in >> proof.g_B;
+    consume_OUTPUT_NEWLINE(in);
+    in >> proof.g_C;
+    consume_OUTPUT_NEWLINE(in);
+    in >> proof.g_H;
+    consume_OUTPUT_NEWLINE(in);
+    in >> proof.g_K;
+    consume_OUTPUT_NEWLINE(in);
+
+    return in;
+}
+
+template<typename ppT>
+r1cs_ppzksnark_verification_key<ppT> r1cs_ppzksnark_verification_key<ppT>::dummy_verification_key(const size_t input_size)
+{
+    r1cs_ppzksnark_verification_key<ppT> result;
+    result.alphaA_g2 = Fr<ppT>::random_element() * G2<ppT>::one();
+    result.alphaB_g1 = Fr<ppT>::random_element() * G1<ppT>::one();
+    result.alphaC_g2 = Fr<ppT>::random_element() * G2<ppT>::one();
+    result.gamma_g2 = Fr<ppT>::random_element() * G2<ppT>::one();
+    result.gamma_beta_g1 = Fr<ppT>::random_element() * G1<ppT>::one();
+    result.gamma_beta_g2 = Fr<ppT>::random_element() * G2<ppT>::one();
+    result.rC_Z_g2 = Fr<ppT>::random_element() * G2<ppT>::one();
+
+    G1<ppT> base = Fr<ppT>::random_element() * G1<ppT>::one();
+    G1_vector<ppT> v;
+    for (size_t i = 0; i < input_size; ++i)
+    {
+        v.emplace_back(Fr<ppT>::random_element() * G1<ppT>::one());
+    }
+
+    result.encoded_IC_query = accumulation_vector<G1<ppT> >(std::move(base), std::move(v));
+
+    return result;
+}
+
+template <typename ppT>
+r1cs_ppzksnark_keypair<ppT> r1cs_ppzksnark_generator(const r1cs_ppzksnark_constraint_system<ppT> &cs)
+{
+    /* draw random element at which the QAP is evaluated */
+    const  Fr<ppT> t = Fr<ppT>::random_element();
+
+    const  Fr<ppT> alphaA = Fr<ppT>::random_element(),
+        alphaB = Fr<ppT>::random_element(),
+        alphaC = Fr<ppT>::random_element(),
+        rA = Fr<ppT>::random_element(),
+        rB = Fr<ppT>::random_element(),
+        beta = Fr<ppT>::random_element(),
+        gamma = Fr<ppT>::random_element();
+
+    return r1cs_ppzksnark_generator<ppT>(cs, t, alphaA, alphaB, alphaC, rA, rB, beta, gamma);
+}
+
+template <typename ppT>
+r1cs_ppzksnark_keypair<ppT> r1cs_ppzksnark_generator(
+    const r1cs_ppzksnark_constraint_system<ppT> &cs,
+    const Fr<ppT>& t,
+    const Fr<ppT>& alphaA,
+    const Fr<ppT>& alphaB,
+    const Fr<ppT>& alphaC,
+    const Fr<ppT>& rA,
+    const Fr<ppT>& rB,
+    const Fr<ppT>& beta,
+    const Fr<ppT>& gamma
+)
+{
+    enter_block("Call to r1cs_ppzksnark_generator");
+
+    /* make the B_query "lighter" if possible */
+    r1cs_ppzksnark_constraint_system<ppT> cs_copy(cs);
+    cs_copy.swap_AB_if_beneficial();
+
+    qap_instance_evaluation<Fr<ppT> > qap_inst = r1cs_to_qap_instance_map_with_evaluation(cs_copy, t);
+
+    print_indent(); printf("* QAP number of variables: %zu\n", qap_inst.num_variables());
+    print_indent(); printf("* QAP pre degree: %zu\n", cs_copy.constraints.size());
+    print_indent(); printf("* QAP degree: %zu\n", qap_inst.degree());
+    print_indent(); printf("* QAP number of input variables: %zu\n", qap_inst.num_inputs());
+
+    enter_block("Compute query densities");
+    size_t non_zero_At = 0, non_zero_Bt = 0, non_zero_Ct = 0, non_zero_Ht = 0;
+    for (size_t i = 0; i < qap_inst.num_variables()+1; ++i)
+    {
+        if (!qap_inst.At[i].is_zero())
+        {
+            ++non_zero_At;
+        }
+        if (!qap_inst.Bt[i].is_zero())
+        {
+            ++non_zero_Bt;
+        }
+        if (!qap_inst.Ct[i].is_zero())
+        {
+            ++non_zero_Ct;
+        }
+    }
+    for (size_t i = 0; i < qap_inst.degree()+1; ++i)
+    {
+        if (!qap_inst.Ht[i].is_zero())
+        {
+            ++non_zero_Ht;
+        }
+    }
+    leave_block("Compute query densities");
+
+    Fr_vector<ppT> At = std::move(qap_inst.At); // qap_inst.At is now in unspecified state, but we do not use it later
+    Fr_vector<ppT> Bt = std::move(qap_inst.Bt); // qap_inst.Bt is now in unspecified state, but we do not use it later
+    Fr_vector<ppT> Ct = std::move(qap_inst.Ct); // qap_inst.Ct is now in unspecified state, but we do not use it later
+    Fr_vector<ppT> Ht = std::move(qap_inst.Ht); // qap_inst.Ht is now in unspecified state, but we do not use it later
+
+    /* append Zt to At,Bt,Ct with */
+    At.emplace_back(qap_inst.Zt);
+    Bt.emplace_back(qap_inst.Zt);
+    Ct.emplace_back(qap_inst.Zt);
+
+    const Fr<ppT>      rC = rA * rB;
+
+    // consrtuct the same-coefficient-check query (must happen before zeroing out the prefix of At)
+    Fr_vector<ppT> Kt;
+    Kt.reserve(qap_inst.num_variables()+4);
+    for (size_t i = 0; i < qap_inst.num_variables()+1; ++i)
+    {
+        Kt.emplace_back( beta * (rA * At[i] + rB * Bt[i] + rC * Ct[i] ) );
+    }
+    Kt.emplace_back(beta * rA * qap_inst.Zt);
+    Kt.emplace_back(beta * rB * qap_inst.Zt);
+    Kt.emplace_back(beta * rC * qap_inst.Zt);
+
+    /* zero out prefix of At and stick it into IC coefficients */
+    Fr_vector<ppT> IC_coefficients;
+    IC_coefficients.reserve(qap_inst.num_inputs() + 1);
+    for (size_t i = 0; i < qap_inst.num_inputs() + 1; ++i)
+    {
+        IC_coefficients.emplace_back(At[i]);
+        assert(!IC_coefficients[i].is_zero());
+        At[i] = Fr<ppT>::zero();
+    }
+
+    const size_t g1_exp_count = 2*(non_zero_At - qap_inst.num_inputs() + non_zero_Ct) + non_zero_Bt + non_zero_Ht + Kt.size();
+    const size_t g2_exp_count = non_zero_Bt;
+
+    size_t g1_window = get_exp_window_size<G1<ppT> >(g1_exp_count);
+    size_t g2_window = get_exp_window_size<G2<ppT> >(g2_exp_count);
+    print_indent(); printf("* G1 window: %zu\n", g1_window);
+    print_indent(); printf("* G2 window: %zu\n", g2_window);
+
+#ifdef MULTICORE
+    const size_t chunks = omp_get_max_threads(); // to override, set OMP_NUM_THREADS env var or call omp_set_num_threads()
+#else
+    const size_t chunks = 1;
+#endif
+
+    enter_block("Generating G1 multiexp table");
+    window_table<G1<ppT> > g1_table = get_window_table(Fr<ppT>::size_in_bits(), g1_window, G1<ppT>::one());
+    leave_block("Generating G1 multiexp table");
+
+    enter_block("Generating G2 multiexp table");
+    window_table<G2<ppT> > g2_table = get_window_table(Fr<ppT>::size_in_bits(), g2_window, G2<ppT>::one());
+    leave_block("Generating G2 multiexp table");
+
+    enter_block("Generate R1CS proving key");
+
+    enter_block("Generate knowledge commitments");
+    enter_block("Compute the A-query", false);
+    knowledge_commitment_vector<G1<ppT>, G1<ppT> > A_query = kc_batch_exp(Fr<ppT>::size_in_bits(), g1_window, g1_window, g1_table, g1_table, rA, rA*alphaA, At, chunks);
+    leave_block("Compute the A-query", false);
+
+    enter_block("Compute the B-query", false);
+    knowledge_commitment_vector<G2<ppT>, G1<ppT> > B_query = kc_batch_exp(Fr<ppT>::size_in_bits(), g2_window, g1_window, g2_table, g1_table, rB, rB*alphaB, Bt, chunks);
+    leave_block("Compute the B-query", false);
+
+    enter_block("Compute the C-query", false);
+    knowledge_commitment_vector<G1<ppT>, G1<ppT> > C_query = kc_batch_exp(Fr<ppT>::size_in_bits(), g1_window, g1_window, g1_table, g1_table, rC, rC*alphaC, Ct, chunks);
+    leave_block("Compute the C-query", false);
+
+    enter_block("Compute the H-query", false);
+    G1_vector<ppT> H_query = batch_exp(Fr<ppT>::size_in_bits(), g1_window, g1_table, Ht);
+    leave_block("Compute the H-query", false);
+
+    enter_block("Compute the K-query", false);
+    G1_vector<ppT> K_query = batch_exp(Fr<ppT>::size_in_bits(), g1_window, g1_table, Kt);
+#ifdef USE_MIXED_ADDITION
+    batch_to_special<G1<ppT> >(K_query);
+#endif
+    leave_block("Compute the K-query", false);
+
+    leave_block("Generate knowledge commitments");
+
+    leave_block("Generate R1CS proving key");
+
+    enter_block("Generate R1CS verification key");
+    G2<ppT> alphaA_g2 = alphaA * G2<ppT>::one();
+    G1<ppT> alphaB_g1 = alphaB * G1<ppT>::one();
+    G2<ppT> alphaC_g2 = alphaC * G2<ppT>::one();
+    G2<ppT> gamma_g2 = gamma * G2<ppT>::one();
+    G1<ppT> gamma_beta_g1 = (gamma * beta) * G1<ppT>::one();
+    G2<ppT> gamma_beta_g2 = (gamma * beta) * G2<ppT>::one();
+    G2<ppT> rC_Z_g2 = (rC * qap_inst.Zt) * G2<ppT>::one();
+
+    enter_block("Encode IC query for R1CS verification key");
+    G1<ppT> encoded_IC_base = (rA * IC_coefficients[0]) * G1<ppT>::one();
+    Fr_vector<ppT> multiplied_IC_coefficients;
+    multiplied_IC_coefficients.reserve(qap_inst.num_inputs());
+    for (size_t i = 1; i < qap_inst.num_inputs() + 1; ++i)
+    {
+        multiplied_IC_coefficients.emplace_back(rA * IC_coefficients[i]);
+    }
+    G1_vector<ppT> encoded_IC_values = batch_exp(Fr<ppT>::size_in_bits(), g1_window, g1_table, multiplied_IC_coefficients);
+
+    leave_block("Encode IC query for R1CS verification key");
+    leave_block("Generate R1CS verification key");
+
+    leave_block("Call to r1cs_ppzksnark_generator");
+
+    accumulation_vector<G1<ppT> > encoded_IC_query(std::move(encoded_IC_base), std::move(encoded_IC_values));
+
+    r1cs_ppzksnark_verification_key<ppT> vk = r1cs_ppzksnark_verification_key<ppT>(alphaA_g2,
+                                                                                   alphaB_g1,
+                                                                                   alphaC_g2,
+                                                                                   gamma_g2,
+                                                                                   gamma_beta_g1,
+                                                                                   gamma_beta_g2,
+                                                                                   rC_Z_g2,
+                                                                                   encoded_IC_query);
+    r1cs_ppzksnark_proving_key<ppT> pk = r1cs_ppzksnark_proving_key<ppT>(std::move(A_query),
+                                                                         std::move(B_query),
+                                                                         std::move(C_query),
+                                                                         std::move(H_query),
+                                                                         std::move(K_query));
+
+    pk.print_size();
+    vk.print_size();
+
+    return r1cs_ppzksnark_keypair<ppT>(std::move(pk), std::move(vk));
+}
+
+template <typename ppT>
+r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover(const r1cs_ppzksnark_proving_key<ppT> &pk,
+                                                const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                                const r1cs_ppzksnark_auxiliary_input<ppT> &auxiliary_input,
+                                                const r1cs_ppzksnark_constraint_system<ppT> &constraint_system)
+{
+    enter_block("Call to r1cs_ppzksnark_prover");
+
+#ifdef DEBUG
+    assert(constraint_system.is_satisfied(primary_input, auxiliary_input));
+#endif
+
+    const Fr<ppT> d1 = Fr<ppT>::random_element(),
+        d2 = Fr<ppT>::random_element(),
+        d3 = Fr<ppT>::random_element();
+
+    enter_block("Compute the polynomial H");
+    const qap_witness<Fr<ppT> > qap_wit = r1cs_to_qap_witness_map(constraint_system, primary_input, auxiliary_input, d1, d2, d3);
+    leave_block("Compute the polynomial H");
+
+#ifdef DEBUG
+    const Fr<ppT> t = Fr<ppT>::random_element();
+    qap_instance_evaluation<Fr<ppT> > qap_inst = r1cs_to_qap_instance_map_with_evaluation(constraint_system, t);
+    assert(qap_inst.is_satisfied(qap_wit));
+#endif
+
+    knowledge_commitment<G1<ppT>, G1<ppT> > g_A = pk.A_query[0] + qap_wit.d1*pk.A_query[qap_wit.num_variables()+1];
+    knowledge_commitment<G2<ppT>, G1<ppT> > g_B = pk.B_query[0] + qap_wit.d2*pk.B_query[qap_wit.num_variables()+1];
+    knowledge_commitment<G1<ppT>, G1<ppT> > g_C = pk.C_query[0] + qap_wit.d3*pk.C_query[qap_wit.num_variables()+1];
+
+    G1<ppT> g_H = G1<ppT>::zero();
+    G1<ppT> g_K = (pk.K_query[0] +
+                   qap_wit.d1*pk.K_query[qap_wit.num_variables()+1] +
+                   qap_wit.d2*pk.K_query[qap_wit.num_variables()+2] +
+                   qap_wit.d3*pk.K_query[qap_wit.num_variables()+3]);
+
+#ifdef DEBUG
+    for (size_t i = 0; i < qap_wit.num_inputs() + 1; ++i)
+    {
+        assert(pk.A_query[i].g == G1<ppT>::zero());
+    }
+    assert(pk.A_query.domain_size() == qap_wit.num_variables()+2);
+    assert(pk.B_query.domain_size() == qap_wit.num_variables()+2);
+    assert(pk.C_query.domain_size() == qap_wit.num_variables()+2);
+    assert(pk.H_query.size() == qap_wit.degree()+1);
+    assert(pk.K_query.size() == qap_wit.num_variables()+4);
+#endif
+
+#ifdef MULTICORE
+    const size_t chunks = omp_get_max_threads(); // to override, set OMP_NUM_THREADS env var or call omp_set_num_threads()
+#else
+    const size_t chunks = 1;
+#endif
+
+    enter_block("Compute the proof");
+
+    enter_block("Compute answer to A-query", false);
+    g_A = g_A + kc_multi_exp_with_mixed_addition<G1<ppT>, G1<ppT>, Fr<ppT> >(pk.A_query,
+                                                                             1, 1+qap_wit.num_variables(),
+                                                                             qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
+                                                                             chunks, true);
+    leave_block("Compute answer to A-query", false);
+
+    enter_block("Compute answer to B-query", false);
+    g_B = g_B + kc_multi_exp_with_mixed_addition<G2<ppT>, G1<ppT>, Fr<ppT> >(pk.B_query,
+                                                                             1, 1+qap_wit.num_variables(),
+                                                                             qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
+                                                                             chunks, true);
+    leave_block("Compute answer to B-query", false);
+
+    enter_block("Compute answer to C-query", false);
+    g_C = g_C + kc_multi_exp_with_mixed_addition<G1<ppT>, G1<ppT>, Fr<ppT> >(pk.C_query,
+                                                                             1, 1+qap_wit.num_variables(),
+                                                                             qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
+                                                                             chunks, true);
+    leave_block("Compute answer to C-query", false);
+
+    enter_block("Compute answer to H-query", false);
+    g_H = g_H + multi_exp<G1<ppT>, Fr<ppT> >(pk.H_query.begin(), pk.H_query.begin()+qap_wit.degree()+1,
+                                             qap_wit.coefficients_for_H.begin(), qap_wit.coefficients_for_H.begin()+qap_wit.degree()+1,
+                                             chunks, true);
+    leave_block("Compute answer to H-query", false);
+
+    enter_block("Compute answer to K-query", false);
+    g_K = g_K + multi_exp_with_mixed_addition<G1<ppT>, Fr<ppT> >(pk.K_query.begin()+1, pk.K_query.begin()+1+qap_wit.num_variables(),
+                                                                 qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
+                                                                 chunks, true);
+    leave_block("Compute answer to K-query", false);
+
+    leave_block("Compute the proof");
+
+    leave_block("Call to r1cs_ppzksnark_prover");
+
+    r1cs_ppzksnark_proof<ppT> proof = r1cs_ppzksnark_proof<ppT>(std::move(g_A), std::move(g_B), std::move(g_C), std::move(g_H), std::move(g_K));
+    //proof.print_size();
+
+    return proof;
+}
+
+template <typename ppT>
+r1cs_ppzksnark_processed_verification_key<ppT> r1cs_ppzksnark_verifier_process_vk(const r1cs_ppzksnark_verification_key<ppT> &vk)
+{
+    enter_block("Call to r1cs_ppzksnark_verifier_process_vk");
+
+    r1cs_ppzksnark_processed_verification_key<ppT> pvk;
+    pvk.pp_G2_one_precomp        = ppT::precompute_G2(G2<ppT>::one());
+    pvk.vk_alphaA_g2_precomp     = ppT::precompute_G2(vk.alphaA_g2);
+    pvk.vk_alphaB_g1_precomp     = ppT::precompute_G1(vk.alphaB_g1);
+    pvk.vk_alphaC_g2_precomp     = ppT::precompute_G2(vk.alphaC_g2);
+    pvk.vk_rC_Z_g2_precomp       = ppT::precompute_G2(vk.rC_Z_g2);
+    pvk.vk_gamma_g2_precomp      = ppT::precompute_G2(vk.gamma_g2);
+    pvk.vk_gamma_beta_g1_precomp = ppT::precompute_G1(vk.gamma_beta_g1);
+    pvk.vk_gamma_beta_g2_precomp = ppT::precompute_G2(vk.gamma_beta_g2);
+
+    pvk.encoded_IC_query = vk.encoded_IC_query;
+
+    leave_block("Call to r1cs_ppzksnark_verifier_process_vk");
+
+    return pvk;
+}
+
+template <typename ppT>
+bool r1cs_ppzksnark_online_verifier_weak_IC(const r1cs_ppzksnark_processed_verification_key<ppT> &pvk,
+                                            const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                            const r1cs_ppzksnark_proof<ppT> &proof)
+{
+    assert(pvk.encoded_IC_query.domain_size() >= primary_input.size());
+
+    const accumulation_vector<G1<ppT> > accumulated_IC = pvk.encoded_IC_query.template accumulate_chunk<Fr<ppT> >(primary_input.begin(), primary_input.end(), 0);
+    const G1<ppT> &acc = accumulated_IC.first;
+
+    if (!proof.is_well_formed())
+    {
+        return false;
+    }
+
+    G1_precomp<ppT> proof_g_A_g_precomp      = ppT::precompute_G1(proof.g_A.g);
+    G1_precomp<ppT> proof_g_A_h_precomp = ppT::precompute_G1(proof.g_A.h);
+    Fqk<ppT> kc_A_1 = ppT::miller_loop(proof_g_A_g_precomp,      pvk.vk_alphaA_g2_precomp);
+    Fqk<ppT> kc_A_2 = ppT::miller_loop(proof_g_A_h_precomp, pvk.pp_G2_one_precomp);
+    GT<ppT> kc_A = ppT::final_exponentiation(kc_A_1 * kc_A_2.unitary_inverse());
+    if (kc_A != GT<ppT>::one())
+    {
+        return false;
+    }
+
+    G2_precomp<ppT> proof_g_B_g_precomp      = ppT::precompute_G2(proof.g_B.g);
+    G1_precomp<ppT> proof_g_B_h_precomp = ppT::precompute_G1(proof.g_B.h);
+    Fqk<ppT> kc_B_1 = ppT::miller_loop(pvk.vk_alphaB_g1_precomp, proof_g_B_g_precomp);
+    Fqk<ppT> kc_B_2 = ppT::miller_loop(proof_g_B_h_precomp,    pvk.pp_G2_one_precomp);
+    GT<ppT> kc_B = ppT::final_exponentiation(kc_B_1 * kc_B_2.unitary_inverse());
+    if (kc_B != GT<ppT>::one())
+    {
+        return false;
+    }
+
+    G1_precomp<ppT> proof_g_C_g_precomp      = ppT::precompute_G1(proof.g_C.g);
+    G1_precomp<ppT> proof_g_C_h_precomp = ppT::precompute_G1(proof.g_C.h);
+    Fqk<ppT> kc_C_1 = ppT::miller_loop(proof_g_C_g_precomp,      pvk.vk_alphaC_g2_precomp);
+    Fqk<ppT> kc_C_2 = ppT::miller_loop(proof_g_C_h_precomp, pvk.pp_G2_one_precomp);
+    GT<ppT> kc_C = ppT::final_exponentiation(kc_C_1 * kc_C_2.unitary_inverse());
+    if (kc_C != GT<ppT>::one())
+    {
+        return false;
+    }
+
+    // check that g^((A+acc)*B)=g^(H*\Prod(t-\sigma)+C)
+    // equivalently, via pairings, that e(g^(A+acc), g^B) = e(g^H, g^Z) + e(g^C, g^1)
+    G1_precomp<ppT> proof_g_A_g_acc_precomp = ppT::precompute_G1(proof.g_A.g + acc);
+    G1_precomp<ppT> proof_g_H_precomp       = ppT::precompute_G1(proof.g_H);
+    Fqk<ppT> QAP_1  = ppT::miller_loop(proof_g_A_g_acc_precomp,  proof_g_B_g_precomp);
+    Fqk<ppT> QAP_23  = ppT::double_miller_loop(proof_g_H_precomp, pvk.vk_rC_Z_g2_precomp, proof_g_C_g_precomp, pvk.pp_G2_one_precomp);
+    GT<ppT> QAP = ppT::final_exponentiation(QAP_1 * QAP_23.unitary_inverse());
+    if (QAP != GT<ppT>::one())
+    {
+        return false;
+    }
+
+    G1_precomp<ppT> proof_g_K_precomp = ppT::precompute_G1(proof.g_K);
+    G1_precomp<ppT> proof_g_A_g_acc_C_precomp = ppT::precompute_G1((proof.g_A.g + acc) + proof.g_C.g);
+    Fqk<ppT> K_1 = ppT::miller_loop(proof_g_K_precomp, pvk.vk_gamma_g2_precomp);
+    Fqk<ppT> K_23 = ppT::double_miller_loop(proof_g_A_g_acc_C_precomp, pvk.vk_gamma_beta_g2_precomp, pvk.vk_gamma_beta_g1_precomp, proof_g_B_g_precomp);
+    GT<ppT> K = ppT::final_exponentiation(K_1 * K_23.unitary_inverse());
+    if (K != GT<ppT>::one())
+    {
+        return false;
+    }
+
+    return true;
+}
+
+template<typename ppT>
+bool r1cs_ppzksnark_verifier_weak_IC(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                                     const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                     const r1cs_ppzksnark_proof<ppT> &proof)
+{
+    enter_block("Call to r1cs_ppzksnark_verifier_weak_IC");
+    r1cs_ppzksnark_processed_verification_key<ppT> pvk = r1cs_ppzksnark_verifier_process_vk<ppT>(vk);
+    bool result = r1cs_ppzksnark_online_verifier_weak_IC<ppT>(pvk, primary_input, proof);
+    leave_block("Call to r1cs_ppzksnark_verifier_weak_IC");
+    return result;
+}
+
+template<typename ppT>
+bool r1cs_ppzksnark_online_verifier_strong_IC(const r1cs_ppzksnark_processed_verification_key<ppT> &pvk,
+                                              const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                              const r1cs_ppzksnark_proof<ppT> &proof)
+{
+    bool result = true;
+    enter_block("Call to r1cs_ppzksnark_online_verifier_strong_IC");
+
+    if (pvk.encoded_IC_query.domain_size() != primary_input.size())
+    {
+        print_indent(); printf("Input length differs from expected (got %zu, expected %zu).\n", primary_input.size(), pvk.encoded_IC_query.domain_size());
+        result = false;
+    }
+    else
+    {
+        result = r1cs_ppzksnark_online_verifier_weak_IC(pvk, primary_input, proof);
+    }
+
+    leave_block("Call to r1cs_ppzksnark_online_verifier_strong_IC");
+    return result;
+}
+
+template<typename ppT>
+bool r1cs_ppzksnark_verifier_strong_IC(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                                       const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                       const r1cs_ppzksnark_proof<ppT> &proof)
+{
+    enter_block("Call to r1cs_ppzksnark_verifier_strong_IC");
+    r1cs_ppzksnark_processed_verification_key<ppT> pvk = r1cs_ppzksnark_verifier_process_vk<ppT>(vk);
+    bool result = r1cs_ppzksnark_online_verifier_strong_IC<ppT>(pvk, primary_input, proof);
+    leave_block("Call to r1cs_ppzksnark_verifier_strong_IC");
+    return result;
+}
+
+template<typename ppT>
+bool r1cs_ppzksnark_affine_verifier_weak_IC(const r1cs_ppzksnark_verification_key<ppT> &vk,
+                                            const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                            const r1cs_ppzksnark_proof<ppT> &proof)
+{
+    enter_block("Call to r1cs_ppzksnark_affine_verifier_weak_IC");
+    assert(vk.encoded_IC_query.domain_size() >= primary_input.size());
+
+    affine_ate_G2_precomp<ppT> pvk_pp_G2_one_precomp        = ppT::affine_ate_precompute_G2(G2<ppT>::one());
+    affine_ate_G2_precomp<ppT> pvk_vk_alphaA_g2_precomp     = ppT::affine_ate_precompute_G2(vk.alphaA_g2);
+    affine_ate_G1_precomp<ppT> pvk_vk_alphaB_g1_precomp     = ppT::affine_ate_precompute_G1(vk.alphaB_g1);
+    affine_ate_G2_precomp<ppT> pvk_vk_alphaC_g2_precomp     = ppT::affine_ate_precompute_G2(vk.alphaC_g2);
+    affine_ate_G2_precomp<ppT> pvk_vk_rC_Z_g2_precomp       = ppT::affine_ate_precompute_G2(vk.rC_Z_g2);
+    affine_ate_G2_precomp<ppT> pvk_vk_gamma_g2_precomp      = ppT::affine_ate_precompute_G2(vk.gamma_g2);
+    affine_ate_G1_precomp<ppT> pvk_vk_gamma_beta_g1_precomp = ppT::affine_ate_precompute_G1(vk.gamma_beta_g1);
+    affine_ate_G2_precomp<ppT> pvk_vk_gamma_beta_g2_precomp = ppT::affine_ate_precompute_G2(vk.gamma_beta_g2);
+
+    enter_block("Compute input-dependent part of A");
+    const accumulation_vector<G1<ppT> > accumulated_IC = vk.encoded_IC_query.template accumulate_chunk<Fr<ppT> >(primary_input.begin(), primary_input.end(), 0);
+    assert(accumulated_IC.is_fully_accumulated());
+    const G1<ppT> &acc = accumulated_IC.first;
+    leave_block("Compute input-dependent part of A");
+
+    bool result = true;
+    enter_block("Check knowledge commitment for A is valid");
+    affine_ate_G1_precomp<ppT> proof_g_A_g_precomp = ppT::affine_ate_precompute_G1(proof.g_A.g);
+    affine_ate_G1_precomp<ppT> proof_g_A_h_precomp = ppT::affine_ate_precompute_G1(proof.g_A.h);
+    Fqk<ppT> kc_A_miller = ppT::affine_ate_e_over_e_miller_loop(proof_g_A_g_precomp, pvk_vk_alphaA_g2_precomp, proof_g_A_h_precomp, pvk_pp_G2_one_precomp);
+    GT<ppT> kc_A = ppT::final_exponentiation(kc_A_miller);
+
+    if (kc_A != GT<ppT>::one())
+    {
+        print_indent(); printf("Knowledge commitment for A query incorrect.\n");
+        result = false;
+    }
+    leave_block("Check knowledge commitment for A is valid");
+
+    enter_block("Check knowledge commitment for B is valid");
+    affine_ate_G2_precomp<ppT> proof_g_B_g_precomp = ppT::affine_ate_precompute_G2(proof.g_B.g);
+    affine_ate_G1_precomp<ppT> proof_g_B_h_precomp = ppT::affine_ate_precompute_G1(proof.g_B.h);
+    Fqk<ppT> kc_B_miller = ppT::affine_ate_e_over_e_miller_loop(pvk_vk_alphaB_g1_precomp, proof_g_B_g_precomp, proof_g_B_h_precomp,    pvk_pp_G2_one_precomp);
+    GT<ppT> kc_B = ppT::final_exponentiation(kc_B_miller);
+    if (kc_B != GT<ppT>::one())
+    {
+        print_indent(); printf("Knowledge commitment for B query incorrect.\n");
+        result = false;
+    }
+    leave_block("Check knowledge commitment for B is valid");
+
+    enter_block("Check knowledge commitment for C is valid");
+    affine_ate_G1_precomp<ppT> proof_g_C_g_precomp = ppT::affine_ate_precompute_G1(proof.g_C.g);
+    affine_ate_G1_precomp<ppT> proof_g_C_h_precomp = ppT::affine_ate_precompute_G1(proof.g_C.h);
+    Fqk<ppT> kc_C_miller = ppT::affine_ate_e_over_e_miller_loop(proof_g_C_g_precomp, pvk_vk_alphaC_g2_precomp, proof_g_C_h_precomp, pvk_pp_G2_one_precomp);
+    GT<ppT> kc_C = ppT::final_exponentiation(kc_C_miller);
+    if (kc_C != GT<ppT>::one())
+    {
+        print_indent(); printf("Knowledge commitment for C query incorrect.\n");
+        result = false;
+    }
+    leave_block("Check knowledge commitment for C is valid");
+
+    enter_block("Check QAP divisibility");
+    affine_ate_G1_precomp<ppT> proof_g_A_g_acc_precomp = ppT::affine_ate_precompute_G1(proof.g_A.g + acc);
+    affine_ate_G1_precomp<ppT> proof_g_H_precomp       = ppT::affine_ate_precompute_G1(proof.g_H);
+    Fqk<ppT> QAP_miller  = ppT::affine_ate_e_times_e_over_e_miller_loop(proof_g_H_precomp, pvk_vk_rC_Z_g2_precomp, proof_g_C_g_precomp, pvk_pp_G2_one_precomp, proof_g_A_g_acc_precomp,  proof_g_B_g_precomp);
+    GT<ppT> QAP = ppT::final_exponentiation(QAP_miller);
+    if (QAP != GT<ppT>::one())
+    {
+        print_indent(); printf("QAP divisibility check failed.\n");
+        result = false;
+    }
+    leave_block("Check QAP divisibility");
+
+    enter_block("Check same coefficients were used");
+    affine_ate_G1_precomp<ppT> proof_g_K_precomp = ppT::affine_ate_precompute_G1(proof.g_K);
+    affine_ate_G1_precomp<ppT> proof_g_A_g_acc_C_precomp = ppT::affine_ate_precompute_G1((proof.g_A.g + acc) + proof.g_C.g);
+    Fqk<ppT> K_miller = ppT::affine_ate_e_times_e_over_e_miller_loop(proof_g_A_g_acc_C_precomp, pvk_vk_gamma_beta_g2_precomp, pvk_vk_gamma_beta_g1_precomp, proof_g_B_g_precomp, proof_g_K_precomp, pvk_vk_gamma_g2_precomp);
+    GT<ppT> K = ppT::final_exponentiation(K_miller);
+    if (K != GT<ppT>::one())
+    {
+        print_indent(); printf("Same-coefficient check failed.\n");
+        result = false;
+    }
+    leave_block("Check same coefficients were used");
+
+    leave_block("Call to r1cs_ppzksnark_affine_verifier_weak_IC");
+
+    return result;
+}
+
+} // libsnark
+#endif // R1CS_PPZKSNARK_TCC_
diff --git a/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark_params.hpp b/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark_params.hpp
new file mode 100644 (file)
index 0000000..4054b8e
--- /dev/null
@@ -0,0 +1,34 @@
+/** @file
+ *****************************************************************************
+
+ Declaration of public-parameter selector for the R1CS ppzkSNARK.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+
+#ifndef R1CS_PPZKSNARK_PARAMS_HPP_
+#define R1CS_PPZKSNARK_PARAMS_HPP_
+
+#include "relations/constraint_satisfaction_problems/r1cs/r1cs.hpp"
+
+namespace libsnark {
+
+/**
+ * Below are various template aliases (used for convenience).
+ */
+
+template<typename ppT>
+using r1cs_ppzksnark_constraint_system = r1cs_constraint_system<Fr<ppT> >;
+
+template<typename ppT>
+using r1cs_ppzksnark_primary_input = r1cs_primary_input<Fr<ppT> >;
+
+template<typename ppT>
+using r1cs_ppzksnark_auxiliary_input = r1cs_auxiliary_input<Fr<ppT> >;
+
+} // libsnark
+
+#endif // R1CS_PPZKSNARK_PARAMS_HPP_
diff --git a/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/tests/test_r1cs_ppzksnark.cpp b/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/tests/test_r1cs_ppzksnark.cpp
new file mode 100644 (file)
index 0000000..6f8b575
--- /dev/null
@@ -0,0 +1,42 @@
+/** @file
+ *****************************************************************************
+ Test program that exercises the ppzkSNARK (first generator, then
+ prover, then verifier) on a synthetic R1CS instance.
+
+ *****************************************************************************
+ * @author     This file is part of libsnark, developed by SCIPR Lab
+ *             and contributors (see AUTHORS).
+ * @copyright  MIT license (see LICENSE file)
+ *****************************************************************************/
+#include <cassert>
+#include <cstdio>
+
+#include "common/default_types/r1cs_ppzksnark_pp.hpp"
+#include "common/profiling.hpp"
+#include "common/utils.hpp"
+#include "relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp"
+#include "zk_proof_systems/ppzksnark/r1cs_ppzksnark/examples/run_r1cs_ppzksnark.hpp"
+
+using namespace libsnark;
+
+template<typename ppT>
+void test_r1cs_ppzksnark(size_t num_constraints,
+                         size_t input_size)
+{
+    print_header("(enter) Test R1CS ppzkSNARK");
+
+    const bool test_serialization = true;
+    r1cs_example<Fr<ppT> > example = generate_r1cs_example_with_binary_input<Fr<ppT> >(num_constraints, input_size);
+    const bool bit = run_r1cs_ppzksnark<ppT>(example, test_serialization);
+    assert(bit);
+
+    print_header("(leave) Test R1CS ppzkSNARK");
+}
+
+int main()
+{
+    default_r1cs_ppzksnark_pp::init_public_params();
+    start_profiling();
+
+    test_r1cs_ppzksnark<default_r1cs_ppzksnark_pp>(1000, 100);
+}
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