A new proxy blind multi-signature scheme based on the intractability of the elliptic curve discrete logarithm problem is proposed.Some methods of attack to the discrete logarithm problem are discussed.The scheme can avoid the cheating from the signers efficiently.The signatory can validate the last signature to discover fake signature

at the same time all members can deal with the emergency according to the error message in time

it also can validate the validity of signatorys public key avoid the cheating by inner users.The scheme takes full advantage of elliptic curve cryptosystem

such as shorter private key

higher signature efficiency and reduces the cost of communication

so it is security and practical.