Multisignature (multisig)

An arrangement in which spending or other actions require valid signatures from a minimum number of designated keys (m-of-n, e.g., 2-of-3). Used by businesses, custodians and bridges. A multisig structure does not by itself prove that control is shared: all keys, or the signing process, may in practice be controlled by a single person or entity. Conversely, threshold or aggregated signature schemes can distribute signing authority while producing a single on-chain signature. Attribution must therefore establish who actually controls the keys and signing process, rather than infer either shared or sole control from the transaction structure alone.