A multi-signature wallet (multi-sig) is a smart contract or scheme that requires m signatures out of n designated signers to authorize a transaction. The most widely used implementation on EVM chains is Safe (formerly Gnosis Safe).
Multi-sigs are the standard for protocol treasuries, DAO funds, and admin keys on serious DeFi protocols. They eliminate single-signer compromise as a sufficient condition for theft, an attacker has to compromise the threshold number of signers simultaneously.
Common configurations:
- 2-of-3 for small teams or personal high-value wallets.
- 3-of-5 or 4-of-7 for protocol admin or operational treasuries.
- 5-of-9 or larger for DAO treasuries with distributed governance.
Multi-sig is not magic. It fails when signers reuse devices, when the same person controls multiple "signer" keys, when the social attack surface is wide (signers who don't know each other and can be impersonated), and when signers approve transactions without simulating what they actually do.