MPC Wallet

An MPC wallet uses multi-party computation to split a private key into shares held by different parties or devices, which jointly produce a signature without any of them ever assembling the full key. To the blockchain the result looks like an ordinary single-signature transaction, so it works on any chain and costs no extra gas, unlike on-chain multisig. Custodians and many keyless consumer wallets use MPC to remove the single point of failure of one stored key and to allow shares to be refreshed. Trust assumptions still matter: you rely on the vendor's implementation, its share-recovery process and its availability, and a flawed protocol or the compromise of enough shares can still expose funds.