BLS Signatures vs Schnorr Signatures

Aggregate multiple signatures into one: A single 96-byte BLS signature can represent signatures from thousands of validators. This is critical for Ethereum's Beacon Chain consensus, reducing block verification overhead from O(n) to O(1).

No communication rounds needed: Signers can create partial signatures independently. This enables simple Distributed Validator Technology (DVT) setups (e.g., Obol, SSV Network) and trustless staking pools without complex coordination protocols.

Widely audited cryptography: Based on well-understood ECDSA foundations. Bitcoin's Taproot upgrade uses Schnorr (BIP 340), proving its security in a $1T+ asset environment. Libraries are mature and optimized.

Supports complex signing logic: Enables MuSig for multi-signatures and adaptor signatures for Layer 2 protocols (Lightning Network). Its linearity allows for elegant smart contract integrations where signature logic must be verified on-chain.

Higher computational cost: Pairing operations are slower than elliptic curve point additions. Requires careful curve selection (e.g., BLS12-381) and more complex library implementations, increasing audit surface and integration time.

Requires signing rounds: Protocols like MuSig2 need 2-3 communication rounds between signers to produce a single aggregate signature. This adds latency and complexity for real-time dApp signatures compared to non-interactive BLS.

Non-interactive aggregation: Thousands of signatures can be combined into a single, constant-sized (96-byte) signature. This is critical for Ethereum's Beacon Chain consensus (1000s of validators) and Layer-2 rollups like zkSync to compress proof data.

Linear property enables secure, non-interactive multi-signatures (MuSig) with well-understood security assumptions. The core algorithm is simpler than pairing-based BLS, leading to widespread adoption in Bitcoin (Taproot) and Litecoin.

Standard Schnorr signatures (64 bytes) are smaller than individual BLS signatures (96-128 bytes). This reduces on-chain footprint for applications where per-signature cost matters, like Bitcoin transaction batching or Lightning Network channel updates.

Advanced multi-signature schemes like MuSig2 require signers to exchange nonces in multiple rounds. This adds latency and coordination overhead compared to BLS's non-interactive aggregation, making it less ideal for large, asynchronous validator sets.

Key limitation: Relies on pairing-friendly elliptic curves (e.g., BLS12-381), making verification computationally intensive (~5-10x slower than ECDSA). This matters for high-throughput L1s or applications requiring fast single-signature verification, as it can become a bottleneck.

Key limitation: Multi-signature schemes like MuSig2 require signers to exchange nonces in multiple communication rounds. This matters for decentralized validator sets or stateless environments where non-interactivity is critical, adding latency and complexity to signing ceremonies.

Ideal for Proof-of-Stake blockchains (e.g., Ethereum, Dfinity, Chia) and zk-SNARK proving systems. Its ability to aggregate thousands of validator signatures into a constant-sized proof is unmatched for scaling consensus and reducing block witness size.

Optimal for Bitcoin L2s, Lightning Network, and multi-sig wallets (e.g., Taproot). Offers superior privacy (indistinguishable from single sig), batch verification speed, and leverages the battle-tested Bitcoin cryptographic stack for maximum security and developer familiarity.