Multisig Wallet

Multisig wallets implement an M-of-N authorization scheme: M signatures from a set of N keys are required to execute any transaction. A 2-of-3 multisig means any 2 of 3 designated keys must sign, protecting against loss of a single key (you can still transact with 2 of 3) while also protecting against theft of a single key (an attacker with 1 key cannot steal funds). Common configurations: 2-of-3 for personal use, 3-of-5 for small organizations, 5-of-9 for large DAOs.

The security advantages are dramatic. Most single-key wallets that have been drained were compromised through a single vulnerability: phishing got the seed phrase, a malicious app got the private key, or a hardware failure destroyed the only key copy. With a 2-of-3 multisig where keys are held on different devices in different locations, no single compromise is catastrophic. Gnosis Safe (now just 'Safe') is the dominant Ethereum multisig infrastructure, holding hundreds of billions in assets for DAOs, DeFi protocols, and institutions. Coinbase, Binance, and virtually every major crypto institution use some form of multisig for their cold storage.

For retail users, multisig complexity has historically been a barrier. Setting up a 2-of-3 Safe on Ethereum with hardware wallet keys requires technical familiarity, and every transaction requires signing on multiple devices — inconvenient but worthwhile for large holdings. Tools like Safe{Wallet} (app.safe.global) have made the UI much more approachable. A simpler alternative for retail is hardware wallet + passphrase (BIP39 passphrase adds a 25th word to your seed, effectively creating two wallets from one device). For holdings above $50,000–$100,000, multisig or equivalently secure setups are increasingly considered mandatory.