Schnorr Signatures
bch · scaling
A digital signature scheme with linear properties that can improve verification, multi-signature design, and privacy.
Schnorr signatures are a digital signature scheme developed by Claus Schnorr. Like ECDSA, they prove that a private key authorized a message, but their linear mathematical structure makes them easier to aggregate and batch-verify in carefully designed protocols.
The main benefit is linearity: multiple keys or signatures can be combined in protocols such as MuSig, making some multi-party spends look like ordinary single-signature spends. This can reduce on-chain data and improve privacy, but only when wallets and contracts use compatible aggregation protocols.
Bitcoin Cash enabled Schnorr signatures for transaction signing in its May 2019 network upgrade. Bitcoin later introduced Schnorr signatures as part of Taproot in 2021. The exact features available differ by chain and script system.
Schnorr signatures still require secure nonce generation and careful implementation. Reusing or leaking signing nonces can expose private keys, and aggregation schemes need protections against rogue-key attacks.
Related terms
Public Key
→Cryptographic data used to verify signatures made by the corresponding private key.
cryptography · technical
Private Key
→Secret cryptographic material used to produce signatures or other authorization proofs.
cryptography · security · wallet
Signature
→A cryptographic proof that a message was authorized by the holder of a private key.
cryptography
Taproot
→A Bitcoin upgrade that enables more private and efficient spending using Schnorr signatures and script path commitments.
btc · upgrade
Privacy
→The ability to transact without revealing sensitive information about identity, balances, or counterparties.
security · principle