The basic elliptic curve digital signature algorithm(ECDSA) is improved and then a new multi-signature scheme based on the elliptic curve cryptosystem is presented.It can allow multiple users to sign the same document orderly and finally to form a group signature.Furthermore,a new signature verification scheme is proposed,which can prevent members of the fraud effectively.The signer can find false signature through the verification operation.At the same time,according to the failure information the signatur...