12 KiB
mcl
A portable and fast pairing-based cryptography library.
Abstract
mcl is a library for pairing-based cryptography. The current version supports the optimal Ate pairing over BN curves and BLS12-381 curves.
Support architecture
- x86-64 Windows + Visual Studio
- x86, x86-64 Linux + gcc/clang
- ARM Linux
- ARM64 Linux
- (maybe any platform to be supported by LLVM)
- WebAssembly
Support curves
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
Benchmark
A 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
software | x64 | x86 | arm | arm64(msec) |
---|---|---|---|---|
ate-pairing | 0.21 | - | - | - |
mcl | 0.31 | 1.6 | 22.6 | 3.9 |
TEPLA | 1.76 | 3.7 | 37 | 17.9 |
RELIC PRIME=254 | 0.30 | 3.5 | 36 | - |
MIRACL ake12bnx | 4.2 | - | 78 | - |
NEONabe | - | - | 16 | - |
- compile option for RELIC
cmake -DARITH=x64-asm-254 -DFP_PRIME=254 -DFPX_METHD="INTEG;INTEG;LAZYR" -DPP_METHD="LAZYR;OATEP"
Higher-bit BN curve benchmark by mcl
For JavaScript(WebAssembly), see ID based encryption demo.
paramter | x64 | Firefox on x64 | Safari on iPhone7 |
---|---|---|---|
BN254 | 0.29 | 2.48 | 4.78 |
BN381_1 | 0.95 | 7.91 | 11.74 |
BN462 | 2.16 | 14.73 | 22.77 |
- 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.
Installation Requirements
- GMP and OpenSSL
apt install libgmp-dev libssl-dev
Create a working directory (e.g., work) and clone the following repositories.
mkdir work
cd work
git clone git://github.com/herumi/mcl
git clone git://github.com/herumi/cybozulib
git clone git://github.com/herumi/xbyak ; for only x86/x64
git clone git://github.com/herumi/cybozulib_ext ; for only Windows
- Cybozulib_ext is a prerequisite for running OpenSSL and GMP on VC (Visual C++).
Build and test on x86-64 Linux, macOS, ARM and ARM64 Linux
To make lib/libmcl.a and test it:
cod work/mcl
make test
To benchmark a pairing:
bin/bn_test.exe
To make sample programs:
make sample
if you want to change compiler options for optimization, then set CFLAGS_OPT_USER
.
make CLFAGS_OPT_USER="-O2"
Build for 32-bit Linux
Build openssl and gmp for 32-bit mode and install <lib32>
make ARCH=x86 CFLAGS_USER="-I <lib32>/include" LDFLAGS_USER="-L <lib32>/lib -Wl,-rpath,<lib32>/lib"
Build for 64-bit Windows
- make library
mklib.bat
- make exe binary of sample\pairing.cpp
mk sample\pairing.cpp
bin/bn_test.exe
open mcl.sln and build or if you have msbuild.exe
msbuild /p:Configuration=Release
Build with cmake
For Linux,
mkdir build
cd build
cmake ..
make
For Visual Studio,
mkdir build
cd build
cmake .. -A x64
msbuild mcl.sln /p:Configuration=Release /m
Build for wasm(WebAssembly)
mcl supports emcc (Emscripten) and test/bn_test.cpp
runs on browers such as Firefox, Chrome and Edge(enable extended JavaScript at about:config).
Type
emcc -O3 -I ./include/ -I ../cybozulib/include/ src/fp.cpp test/bn_test.cpp -DNDEBUG -s WASM=1 -o t.html
emrun --no_browser --port 8080 --no_emrun_detect .
and open http://<address>:8080/t.html
.
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
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
Libraries
- libmcl.a ; static C++ library of mcl
- libmcl_dy.so ; shared C++ library of mcl
- libbn256.a ; static C library for
mcl/bn256f.h
- libbn256_dy.so ; shared C library
If you want to remove '_dyof so files, then
makeSHARE_BASENAME_SUF=`.
How to initialize pairing library
Call mcl::bn256::initPairing
before calling any operations.
#include <mcl/bn256.hpp>
mcl::bn::CurveParam cp = mcl::BN254; // or mcl::BN_SNARK1
mcl::bn256::initPairing(cp);
mcl::bn256::G1 P(...);
mcl::bn256::G2 Q(...);
mcl::bn256::Fp12 e;
mcl::bn256::pairing(e, P, Q);
- (BN254) a BN curve over the 254-bit prime p = 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 with
mcl/bn384.hpp
. - BN462 with
mcl/bn512.hpp
.
See test/bn_test.cpp.
Default constructor of Fp, Ec, etc.
A default constructor does not initialize the instance. Set a valid value before reffering it.
Definition of groups
The curve equation for a BN curve is:
E/Fp: y^2 = x^3 + b .
- the cyclic group G1 is instantiated as E(Fp)[n] where n := p + 1 - t;
- the cyclic group G2 is instantiated as the inverse image of E'(Fp^2)[n] under a twisting isomorphism phi from E' to E; and
- the pairing e: G1 x G2 -> Fp12 is the optimal ate pairing.
The field Fp12 is constructed via the following tower:
- Fp2 = Fp[u] / (u^2 + 1)
- Fp6 = Fp2[v] / (v^3 - Xi) where Xi = u + 1
- Fp12 = Fp6[w] / (w^2 - v)
- GT = { x in Fp12 | x^r = 1 }
Arithmetic operations
G1 and G2 is additive group and has the following operations:
- T::add(T& z, const T& x, const T& y); // z = x + y
- T::sub(T& z, const T& x, const T& y); // z = x - y
- T::neg(T& y, const T& x); // y = -x
- T::mul(T& z, const T& x, const INT& y); // z = y times scalar multiplication of x
Remark: &z == &x or &y are allowed. INT means integer type such as Fr, int and mpz_class.
T::mul
uses GLV method then G2::mul
returns wrong value if x is not in G2.
Use T::mulGeneric(T& z, const T& x, const INT& y)
for x in phi^-1(E'(Fp^2)) - G2.
Fp, Fp2, Fp6 and Fp12 have the following operations:
- T::add(T& z, const T& x, const T& y); // z = x + y
- T::sub(T& z, const T& x, const T& y); // z = x - y
- T::mul(T& z, const T& x, const T& y); // z = x * y
- T::div(T& z, const T& x, const T& y); // z = x / y
- T::neg(T& y, const T& x); // y = -x
- T::inv(T& y, const T& x); // y = 1/x
- T::pow(T& z, const T& x, const INT& y); // z = x^y
- Fp12::unitaryInv(T& y, const T& x); // y = conjugate of x
Remark: Fp12::mul
uses GLV method then returns wrong value if x is not in GT.
Use Fp12::mulGeneric
for x in Fp12 - GT.
Map To points
- mapToG1(G1& P, const Fp& x);
- mapToG2(G2& P, const Fp2& x);
These functions maps x into Gi according to [Faster hashing to G2].
String format of G1 and G2
G1 and G2 have three elements of Fp (x, y, z) for Jacobi coordinate. normalize() method normalizes it to affine coordinate (x, y, 1) or (0, 0, 0).
getStr() method gets
0
; infinity1 <x> <y>
; not compressed format2 <x>
; compressed format for even y3 <x>
; compressed format for odd y
Verify an element in G2
G2::isValid()
checks that the element is in the curve of G2 and the order of it is r.
G2::set()
, G2::setStr
and operator<<
also check the order.
If you check it out of the library, then you can stop the verification by calling G2::setOrder(0)
.
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
Java API
See java.md
License
modified new BSD License http://opensource.org/licenses/BSD-3-Clause
The original source of the followings are https://github.com/aistcrypt/Lifted-ElGamal . These files are licensed by BSD-3-Clause and are used for only tests.
include/mcl/elgamal.hpp
include/mcl/window_method.hpp
test/elgamal_test.cpp
test/window_method_test.cpp
sample/vote.cpp
This library contains mie and 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, (preprint)
- Skew Frobenius Map and Efficient Scalar Multiplication for Pairing–Based Cryptography, Y. Sakemi, Y. Nogami, K. Okeya, Y. Morikawa, CANS 2008.
Author
光成滋生 MITSUNARI Shigeo(herumi@nifty.com)