A multi-signature (multi-sig) wallet is a cryptocurrency wallet that requires multiple private key signatures to authorise a transaction, rather than just one. Think of it as a safe that requires two or more keys held by different people to open — no single person can unilaterally move the funds. Multi-sig is one of the most important security tools in crypto, widely used by exchanges, DAOs, institutional custodians, and sophisticated individuals who want to eliminate single points of failure in their asset protection setup.
Multi-sig configurations are written as M-of-N: 2-of-3 — any 2 of 3 designated key holders must sign (most common; one key can be lost without losing access); 3-of-5 — any 3 of 5 must sign (used by large treasuries for resilience); 2-of-2 — both keys required (maximum security, zero redundancy). Use cases: Exchange security — major exchanges use multi-sig for cold wallets so no single employee can steal funds; DAO treasuries — Gnosis Safe is the industry standard multi-sig for DAO fund management; Business wallets — corporate crypto accounts requiring multiple executive approvals; and Personal security — keeping keys in different physical locations. The trade-off is operational complexity — every transaction requires coordination between key holders. On Ethereum and EVM chains, Gnosis Safe is the most widely used multi-sig implementation.
Example: A DeFi protocol’s treasury holds $50M in a 3-of-5 Gnosis Safe multi-sig, with keys distributed among 5 core team members across 3 countries. Hacking requires simultaneously compromising 3 independent, geographically separated key holders — effectively impossible.
Learn more: Gnosis Safe — What is Multi-Sig?
