Secure Threshold Group Signature Scheme

Threshold signature is an important digital signature.Up to now,many threshold signature schemes are proposed.But none of them is secure.There are some weaknesses in these schemes: when the number of malicious shareholders is more than the threshold,they can obtain the secret of the group with high probability,then they can forge group signature.A secure threshold group signature scheme is set up in this paper based on the analysis of previous schemes.This scheme has more efficient performance when compared with the previous schemes.Especially, an attractive property of this scheme is that it overcomes the weakness of previous schemes.Finally,the security of the new scheme is analyzed and discussed.