Glossary
BLS Signature
A pairing-based signature scheme that aggregates many signatures into one short signature — used by Ethereum's beacon chain for validator attestations.
BLS (Boneh–Lynn–Shacham) signatures use pairing-based cryptography to produce extremely compact aggregate signatures: thousands of individual signatures combine into a single 96-byte signature that verifies in one step.
Ethereum's beacon chain uses BLS for validator attestations, which is what makes its supermajority finality scheme practical with hundreds of thousands of validators. The trade-off is performance — pairing checks are heavier than ECDSA verification — and trust assumptions that differ from secp256k1.