Abstract: A new proxy blind signature scheme is proposed.Based on this, all possible parameters to be chosen in signature equations are considered and a general method to construct proxy blind signature based on ElGamal's signature is obtained.From the view of computational complexity, the comparisons between these schemes show which one is better than others.The security of these schemes is also discussed and shown that they have good properties as unforgeability, distinguish-ability, non-repudiation and revocability etc.

Key words: digital signature, blind signature, proxy blind signature, proxy signature