Multisignature (Multisig)

Definition

Multisignature is a spending arrangement that requires authorization from more than one cryptographic key. A common Bitcoin example is a two-of-three setup, in which any two designated keys can jointly authorize a transaction. The keys may be held by different people, devices, or locations, reducing dependence on one secret or one operator. Multisig is different from making several copies of the same private key or splitting a recovery phrase into informal pieces. It creates a defined authorization policy that the spending mechanism enforces. The arrangement can improve resilience, but it also increases coordination and backup complexity. Losing too many keys can make funds inaccessible, and recovery may require wallet configuration information in addition to individual secrets. Standardized partially signed transaction formats can help separate participants review and sign the same payment without first combining their private keys in one place.