BLS threshold signature
An implementation of BLS threshold signature
Installation Requirements
Create a working directory (e.g., work) and clone the following repositories.
mkdir work
cd work
git clone git://github.com/herumi/xbyak.git
git clone git://github.com/herumi/cybozulib.git
git clone git://github.com/herumi/mcl.git
git clone git://github.com/herumi/bls.git
git clone git://github.com/herumi/cybozulib_ext ; for only Windows
Build and test for Linux
Specifiy UNIT=4 or 6 always to make. Default UNIT is 6. To make lib/libbls.a and test, run
cd bls
make test UNIT=4
To make sample programs, run
make sample_test
Build and test for Windows
cd mcl
mklib
cd ..\bls
mklib
mk test\bls_test.cpp
bls_test.exe
API
Basic API
BLS signature
e : G2 x G1 -> Fp12 ; optimal ate pairing over BN curve
Q in G2 ; fixed global parameter
H : {str} -> G1
s in Fr: secret key
sQ in G2; public key
s H(m) in G1; signature of m
verify ; e(sQ, H(m)) = e(Q, s H(m))
void bls::init();
Initialize this library. Call this once to use the other api.
void SecretKey::init();
Initialize the instance of SecretKey. s
is a random number.
void SecretKey::getPublicKey(PublicKey& pub) const;
Get public key sQ
for the secret key s
.
void SecretKey::sign(Sign& sign, const std::string& m) const;
Make sign s H(m)
from message m.
bool Sign::verify(const PublicKey& pub, const std::string& m) const;
Verify sign with pub and m and return true if it is valid.
e(sQ, H(m)) == e(Q, s H(m))
Secret Sharing API
void SecretKey::getMasterSecretKey(SecretKeyVec& msk, size_t k) const;
Prepare k-out-of-n secret sharing for the secret key.
msk[0]
is the original secret key s
and msk[i]
for i > 0 are random secret key.
void SecretKey::set(const SecretKeyVec& msk, const Id& id);
Make secret key f(id) from msk and id where f(x) = msk[0] + msk[1] x + ... + msk[k-1] x^{k-1}.
You can make a public key f(id)Q
from each secret key f(id) for id != 0 and sign a message.
void Sign::recover(const SignVec& signVec, const IdVec& idVec);
Collect k pair of sign f(id) H(m)
and id
for a message m and recover the original signature s H(m)
for the secret key s
.
PoP (Proof of Possesion)
void SecretKey::getPop(Sign& pop) const;
Sign pub and make a pop s H(sQ)
bool Sign::verify(const PublicKey& pub) const;
Verify a public key by pop.
Go
make run_go
License
modified new BSD License http://opensource.org/licenses/BSD-3-Clause
Author
MITSUNARI Shigeo(herumi@nifty.com)