mcl

A portable and fast pairing-based cryptography library.

Abstract

mcl is a library for pairing-based cryptography, which supports the optimal Ate pairing over BN curves and BLS12-381 curves.

News

• support BN_P256 (hash-to-curve is not yet standard way.)
• the performance of {G1,G2}::mulVec(z, xVec, yVec, n) has improved for n >= 256. (about 2x speed up for n = 512).
  • But it changes the type of xVec from const G* to G* because xVec may be normalized when computing.
  • fix mul(G, G, F) for F = Fp at v1.61
• add set DST functions for hashMapToGi
• add F::invVec, G::normalizeVec
• improve SECP256K1 for x64
• add G1::mulVecMT, G2::mulVecMT (enabled by MCL_USE_OMP=1)
• improve mulMod of SECP256K1 for wasm
• fix FpToG1(P, u, v) and Fp2ToG2(P, u, v) when u == v (This bug does not affect mapToG1 and mapToG2).
• add millerLoopVecMT (enabled if built with MCL_USE_OMP=1)
• support s390x(systemz)
• improve M1 mac performance
• set default MCL_MAX_BIT_SIZE=512 so disable to support NICT_P521.
• improve performance
• support M1 mac
• dst for mapToG1 has changed to BLS_SIG_BLS12381G1_XMD:SHA-256_SSWU_RO_POP_.
• mclBn_eth* functions are removed.
• mcl::bn::mapToG1(G1& out, const Fp& v) supports BLS12_MAP_FP_TO_G1 in EIP 2537.
• mcl::bn::hashAndMapToG1(G1& out, const void *msg, size_t msgSize) supports (hash-to-curve-09 BLS12381G1_XMD:SHA-256_SSWU_RO_)
• MCL_MAP_TO_MODE_HASH_TO_CURVE_07 is added for hash-to-curve-draft-07.

Support architecture

• x86-64 Windows + Visual Studio 2015 (or later)
• x86, x86-64 Linux + gcc/clang
• x86-64, M1 macOS
• ARM / ARM64 Linux
• WebAssembly : see mcl-wasm
• Android : see mcl-android
• iPhone
• s390x(systemz)
  • install llvm and clang, and make UPDATE_ASM=1 once.
• (maybe any platform to be supported by LLVM)

Support curves

• BN curve ; p(z) = 36z^4 + 36z^3 + 24z^2 + 6z + 1.
  • BN254 ; a BN curve over the 254-bit prime p(z) where z = -(2^62 + 2^55 + 1).
  • BN_SNARK1 ; a BN curve over a 254-bit prime p such that n := p + 1 - t has high 2-adicity.
  • BN381_1 ; a BN curve over the 381-bit prime p(z) where z = -(2^94 + 2^76 + 2^72 + 1).
  • BN462 ; a BN curve over the 462-bit prime p(z) where z = 2^114 + 2^101 - 2^14 - 1.
• BLS12_381 ; a BLS12-381 curve

BLS signature

See bls if you want mcl for BLS-signature.

C-API

See api.md and FAQ for serialization and hash-to-curve.

How to build on Linux and macOS

x86-64/ARM/ARM64 Linux, macOS and mingw64 are supported.

GMP is necessary only to build test programs.

• sudo apt install libgmp-dev on Ubuntu
• brew install gmp on macOS

How to build with Makefile

For x86-64 Linux and macOS,

git clone https://github.com/herumi/mcl
cd mcl
make -j4

clang++ is required except for x86-64 on Linux and Windows.

make -j4 CXX=clang++

• lib/libmcl.* ; core library
• lib/libmclbn384_256.* ; library to use C-API of BLS12-381 pairing

How to build with CMake

For x86-64 Linux and macOS.

mkdir build
cd build
cmake ..
make

For the other platform, clang++ is required.

mkdir build
cd build
cmake .. -DCMAKE_CXX_COMPILER=clang++
make

For Visual Studio,

mkdir build
cd build
cmake .. -A x64
msbuild mcl.sln /p:Configuration=Release /m

options

see cmake .. -LA.

tests

make test binaries in ./bin.

cmake .. -DBUILD_TESTING=ON
make -j4

How to make from src/{base,bint}{32,64}.ll

clang (clang-cl on Windows) is necessary to build files with a suffix ll.

• BIT = 64 (if 64-bit CPU) else 32
• src/base${BIT}.ll is necessary if MCL_USE_LLVM is defined.
  • This code is used if xbyak is not used.
• src/bint${BIT}.ll is necessary if MCL_BINT_ASM=1.
  • src/bint-x64-{amd64,win}.asm is used instead if MCL_BINT_ASM_X64=1.
  • It is faster than src/bint64.ll because it uses mulx/adox/adcx.

These files may be going to be unified in the future.

How to test of BLS12-381 pairing

# C
make bin/bn_c384_256_test.exe && bin/bn_c384_256_test.exe

# C++
make bin/bls12_test.exe && bin/bls12_test.exe

How to profile on Linux

Use perf

make MCL_USE_PROF=1 bin/bls12_test.exe
env MCL_PROF=1 bin/bls12_test.exe

Use Intel VTune profiler

Supporse VTune is installed in /opt/intel/vtune_amplifier/.

make MCL_USE_PROF=2 bin/bls12_test.exe
env MCL_PROF=2 bin/bls12_test.exe

How to build on 32-bit x86 Linux

Build GMP for 32-bit mode.

sudo apt install g++-multilib
sudo apt install clang-14
cd <GMP dir>
env ABI=32 ./configure --enable-cxx --prefix=<install dir>
make -j install
cd <mcl dir>
make ARCH=x86 LLVM_VER=-14 GMP_DIR=<install dir>

How to build on 64-bit Windows with Visual Studio

Python3 is necessary. Open a console window, and

git clone https://github.com/herumi/mcl
cd mcl

# How to build libmcl.a for arm on Linux

make ARCH=armv7l lib/libmcl.a LLVM_VER=-12 CLANG_TARGET="-target armv7" CXX=g++-12 PRE=arm-linux-gnueabi-

# static library
mklib
mk -s test\bls12_test.cpp && bin\bls12_test.exe

# dynamic library
mklib dll
mk -d test\bls12_test.cpp && bin\bls12_test.exe

(not maintenanced) Open mcl.sln and build or if you have msbuild.exe

msbuild /p:Configuration=Release

C# test

cd mcl
mklib dll
cd ffi/cs
dotnet build mcl.sln
cd ../../bin
../ffi/cs/test/bin/Debug/netcoreapp3.1/test.exe

How to build for wasm(WebAssembly)

mcl supports emcc (Emscripten) and test/bn_test.cpp runs on browers such as Firefox, Chrome and Edge.

• IBE on browser
• SHE on browser
• BLS signature on brower

The timing of a pairing on BN254 is 2.8msec on 64-bit Firefox with Skylake 3.4GHz.

Node.js

• mcl-wasm pairing library
• bls-wasm BLS signature library
• she-wasm 2 Level Homomorphic Encryption library

Benchmark

The latest benchmark(2018/11/7)

Intel Core i7-6700 3.4GHz(Skylake), Ubuntu 18.04.1 LTS

Intel Core i7-7700 3.6GHz(Kaby Lake), Ubuntu 18.04.1 LTS on Windows 10 Vmware

• now investigating the reason why gcc is slower than clang.

Higher-bit BN curve benchmark

For JavaScript(WebAssembly), see ID based encryption demo.

• x64 : 'Kaby Lake Core i7-7700(3.6GHz)'.
• Firefox : 64-bit version 58.
• iPhone7 : iOS 11.2.1.
• BN254 is by test/bn_test.cpp.
• BN381_1 and BN462 are by test/bn512_test.cpp.
• All the timings are given in ms(milliseconds).

The other benchmark results are bench.txt.

An old benchmark of a BN curve BN254(2016/12/25).

• x64, x86 ; Inte Core i7-6700 3.4GHz(Skylake) upto 4GHz on Ubuntu 16.04.
  • sudo cpufreq-set -g performance
• arm ; 900MHz quad-core ARM Cortex-A7 on Raspberry Pi2, Linux 4.4.11-v7+
• arm64 ; 1.2GHz ARM Cortex-A53 HiKey

• compile option for RELIC

cmake -DARITH=x64-asm-254 -DFP_PRIME=254 -DFPX_METHD="INTEG;INTEG;LAZYR" -DPP_METHD="LAZYR;OATEP"

SELinux

mcl uses Xbyak JIT engine if it is available on x64 architecture, otherwise mcl uses a little slower functions generated by LLVM. The default mode enables SELinux security policy on CentOS, then JIT is disabled.

% sudo setenforce 1
% getenforce
Enforcing
% bin/bn_test.exe
JIT 0
pairing   1.496Mclk
finalExp 581.081Kclk

% sudo setenforce 0
% getenforce
Permissive
% bin/bn_test.exe
JIT 1
pairing   1.394Mclk
finalExp 546.259Kclk

How to make asm files (optional)

The asm files generated by this way are already put in src/asm, then it is not necessary to do this.

Install LLVM.

make MCL_USE_LLVM=1 LLVM_VER=<llvm-version> UPDATE_ASM=1

For example, specify -3.8 for <llvm-version> if opt-3.8 and llc-3.8 are installed.

If you want to use Fp with 1024-bit prime on x86-64, then

make MCL_USE_LLVM=1 LLVM_VER=<llvm-version> UPDATE_ASM=1 MCL_MAX_BIT_SIZE=1024

API for Two level homomorphic encryption

• Efficient Two-level Homomorphic Encryption in Prime-order Bilinear Groups and A Fast Implementation in WebAssembly, N. Attrapadung, G. Hanaoka, S. Mitsunari, Y. Sakai, K. Shimizu, and T. Teruya. ASIACCS 2018
• she-api
• she-api(Japanese)

Java API

See java.md

License

modified new BSD License http://opensource.org/licenses/BSD-3-Clause

This library contains some part of the followings software licensed by BSD-3-Clause.

• xbyak
• cybozulib
• Lifted-ElGamal

References

• ate-pairing
• Faster Explicit Formulas for Computing Pairings over Ordinary Curves, D.F. Aranha, K. Karabina, P. Longa, C.H. Gebotys, J. Lopez, EUROCRYPTO 2011, (preprint)
• High-Speed Software Implementation of the Optimal Ate Pairing over Barreto-Naehrig Curves, Jean-Luc Beuchat, Jorge Enrique González Díaz, Shigeo Mitsunari, Eiji Okamoto, Francisco Rodríguez-Henríquez, Tadanori Teruya, Pairing 2010, (preprint)
• Faster hashing to G2,Laura Fuentes-Castañeda, Edward Knapp, Francisco Rodríguez-Henríquez, SAC 2011, (PDF)
• Skew Frobenius Map and Efficient Scalar Multiplication for Pairing–Based Cryptography, Y. Sakemi, Y. Nogami, K. Okeya, Y. Morikawa, CANS 2008.

compatilibity

• mclBnGT_inv returns a - b w, a conjugate of x for x = a + b w in Fp12 = Fp6[w]
  • use mclBnGT_invGeneric if x is not in GT
• mclBn_setETHserialization(true) (de)serialize acoording to ETH2.0 serialization of BLS12-381 when BLS12-381 is used.
• (Break backward compatibility) libmcl_dy.a is renamed to libmcl.a
  • The option SHARE_BASENAME_SUF is removed
• 2nd argument of mclBn_init is changed from maxUnitSize to compiledTimeVar, which must be MCLBN_COMPILED_TIME_VAR.
• break backward compatibility of mapToGi for BLS12. A map-to-function for BN is used. If MCL_USE_OLD_MAPTO_FOR_BLS12 is defined, then the old function is used, but this will be removed in the future.

FAQ

How do I set the hash value to Fr?

The behavior of setHashOf function may be a little different from what you want.

• https://github.com/herumi/mcl/blob/master/api.md#hash-and-mapto-functions
• https://github.com/herumi/mcl/blob/master/api.md#set-buf0bufsize-1-to-x-with-masking-according-to-the-following-way

Please use the following code:

template<class F>
void setHash(F& x, const void *msg, size_t msgSize)
{
    uint8_t md[32];
    mcl::fp::sha256(md, sizeof(md), msg, msgSize);
    x.setBigEndianMod(md, sizeof(md));
    // or x.setLittleEndianMod(md, sizeof(md));
}

History

• 2022/Apr/10 v1.60 improve {G1,G2}::mulVec
• 2022/Mar/25 v1.59 add set DST functions for hashMapToGi
• 2022/Mar/24 add F::invVec, G::normalizeVec
• 2022/Mar/08 v1.58 improve SECP256K1 for x64
• 2022/Feb/13 v1.57 add mulVecMT
• 2021/Aug/26 v1.52 improve {G1,G2}::isValidOrder() for BLS12-381
• 2021/May/04 v1.50 support s390x(systemz)
• 2021/Apr/21 v1.41 fix inner function of mapToGi for large dst (not affect hashAndMapToGi)
• 2021/May/24 v1.40 fix sigsegv in valgrind
• 2021/Jan/28 v1.31 fix : call setOrder in init for isValidOrder
• 2021/Jan/28 v1.30 a little optimization of Fp operations
• 2020/Nov/14 v1.28 support M1 mac
• 2020/Jun/07 v1.22 remove old hash-to-curve functions
• 2020/Jun/04 v1.21 mapToG1 and hashAndMapToG1 are compatible to irtf/eip-2537
• 2020/May/13 v1.09 support draft-irtf-cfrg-hash-to-curve-07
• 2020/Mar/26 v1.07 change DST for hash-to-curve-06
• 2020/Mar/15 v1.06 support hash-to-curve-06
• 2020/Jan/31 v1.05 mclBn_ethMsgToFp2 has changed to append zero byte at the end of msg
• 2020/Jan/25 v1.04 add new hash functions
• 2019/Dec/05 v1.03 disable to check the order in setStr
• 2019/Sep/30 v1.00 add some functions to bn.h ; api.md.
• 2019/Sep/22 v0.99 add mclBnG1_mulVec, etc.
• 2019/Sep/08 v0.98 bugfix Ec::add(P, Q, R) when P == R
• 2019/Aug/14 v0.97 add some C api functions
• 2019/Jul/26 v0.96 improved scalar multiplication
• 2019/Jun/03 v0.95 fix a parser of 0b10 with base = 16
• 2019/Apr/29 v0.94 mclBn_setETHserialization supports ETH2.0 serialization of BLS12-381
• 2019/Apr/24 v0.93 support ios
• 2019/Mar/22 v0.92 shortcut for Ec::mul(Px, P, x) if P = 0
• 2019/Mar/21 python binding of she256 for Linux/Mac/Windows
• 2019/Mar/14 v0.91 modp supports mcl-wasm
• 2019/Mar/12 v0.90 fix Vint::setArray(x) for x == this
• 2019/Mar/07 add mclBnFr_setLittleEndianMod, mclBnFp_setLittleEndianMod
• 2019/Feb/20 LagrangeInterpolation sets out = yVec[0] if k = 1
• 2019/Jan/31 add mclBnFp_mapToG1, mclBnFp2_mapToG2
• 2019/Jan/31 fix crash on x64-CPU without AVX (thanks to mortdeus)

Author

MITSUNARI Shigeo([email protected])

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