py_ecc

Warning

This library contains some experimental code and has not been audited.

BLS Signatures

py_ecc implements the IETF BLS draft standard v4 as per the inter-blockchain standardization agreement. The BLS standards specify different ciphersuites which each have different functionality to accommodate various use cases. The following ciphersuites are available from this library:

G2Basic also known as BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_NUL_
G2MessageAugmentation also known as BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_AUG_
G2ProofOfPossession also known as BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_POP_

Basic Usage

from py_ecc.bls import G2ProofOfPossession as bls_pop

private_key = 5566
public_key = bls_pop.SkToPk(private_key)

message = b'\xab' * 32  # The message to be signed

# Signing
signature = bls_pop.Sign(private_key, message)

# Verifying
assert bls_pop.Verify(public_key, message, signature)

Aggregating Signatures

private_keys = [3, 14, 159]
public_keys = [bls_pop.SkToPk(key) for key in private_keys]
signatures = [bls_pop.Sign(key, message) for key in private_keys]

# Aggregating
agg_sig = bls_pop.Aggregate(signatures)

# Verifying signatures over the same message.
# Note this is only safe if Proofs of Possession have been verified for each of the public keys beforehand.
# See the BLS standards for why this is the case.
assert bls_pop.FastAggregateVerify(public_keys, message, agg_sig)

Multiple Aggregation

messages = [b'\xaa' * 42, b'\xbb' * 32, b'\xcc' * 64]
signatures = [bls_pop.Sign(key, message) for key, message in zip(private_keys, messages)]
agg_sig = bls_pop.Aggregate(signatures)

# Verify aggregate signature with different messages
assert bls_pop.AggregateVerify(public_keys, messages, agg_sig)

py_ecc package