36 releases (stable)
new 3.0.0-pre7 | Nov 21, 2024 |
---|---|
3.0.0-pre0 | Sep 30, 2024 |
2.5.7 | Mar 26, 2024 |
2.5.0 | Dec 22, 2023 |
1.2.0 | Mar 30, 2023 |
#104 in Cryptography
1,979 downloads per month
Used in 4 crates
660KB
4K
SLoC
BLS Signature Scheme
The blissful crate provides a production ready BLS signature implementation.
Security Notes
This crate has received one security audit from Kudelski Security, with no significant findings. The audit report can be found here. We'd like to thank LIT Protocol for sponsoring this audit.
All operations are constant time unless explicity noted.
Documentation
BLS signatures offer the smallest known signature size as well as other benefits like one round threshold signing and signature aggregation.
BLS signatures rely on pairing-friendly curves which have two fields for points. This library provides keys and signatures for both fields.
For example, most signatures occur in the G1 group requiring public keys in G2 so these are simply named Signature
and PublicKey
.
The variant type swaps the fields and thus is name SignatureVt
and PublicKeyVt
. Signature proofs of knowledge are supported using
the proof_of_knowledge
method on Signatures
which allow a signature holder to prove knowledge of a signature without revealing it.
The signed message is still disclosed. Given this is useful mainly for Signatures, it is not provided directly for multi-signatures or
aggregated signatures.
This library supports threshold signatures in the form of PartialSignature
generated from SecretKeyShare
instead of a SecretKey
.
PartialSignature
s can be combined to make a full Signature
assuming there are sufficient above the threshold. SecretKeyShare
s can
be generated using shamir secret sharing from crates like vsss-rs or using distributed key generation methods like
gennaro-dkg.
Multi-signatures are signatures that have been aggregated that were signed over the same message. This allowed for signature compression and very fast verification assuming rogue key attacks have been taken into account using Proofs of Possession. For now this library only provides the proof of possession scheme as this is the most widely used.
Aggregated signatures are signatures that have been aggregated that were signed over different messages. While verification isn't much faster for this, it's still allows for signature compression.
Examples
Key operations
From random entropy source
let sk = SecretKey::<Bls12381G1Impl>::random(rand_core::OsRng);
let pk = PublicKey::from(&sk);
let pop = ProofOfPossession::new(&sk).expect("a proof of possession");
assert_eq!(pop.verify(pk).unwrap_u8(), 1u8);
From seed
let sk = SecretKey::<Bls12381G1Impl>::hash(b"seed phrase");
let pk = PublicKey::from(&sk);
Split a key into key shares
let shares = sk.split::<rand_core::OsRng, 3, 5>(rand_core::OsRng);
Restore a key from shares
let sk = SecretKey::<Bls12381G1Impl>::combine::<3, 5>(&shares);
Signature operations
Create a signature
let sig = Signature::new(&sk, b"00000000-0000-0000-0000-000000000000").expect("a valid signature");
Verify a signature
assert_eq!(sig.verify(pk, b"00000000-0000-0000-0000-000000000000").unwrap_u8(), 1u8);
License
Licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
References
Dependencies
~5–7MB
~125K SLoC