With The Analysis And Improvement Of A Fault Threshold Signature Scheme

Threshold signature is the promotion of group signature. Introducing secret sharing into group signature scheme can form threshold signature scheme.In threshold signature, only the authorized subset of the groups can represent the entire group to sign; the identity of the signature members can be discovered once there is a dissension. Therefore, a safe essential requirement of threshold signature is unforgeability, that is, an authorized subset should not pose as another to sign.This paper studies the threshold signature scheme with fault—tolerance from two aspects:analysis the security of existing scheme and improve it. Main content as follows:Firstly, this paper introduces theory which is related with group signature and secret sharing. As introducing secret sharing into group signature scheme can form threshold signature scheme, this paper introduces the basic knowledge of threshold signature.Secondly, we studied the threshold signature scheme with fault—tolerance by Zhang Xinglan, and analyzed the security of the scheme. We find that dishonest internal participants can forge the signature of the other participants and also can direct authorized signature subsets of counterfeit. We pointed out the threshold signature scheme with no non-forgeability. It is not safe and unable to be applied in practice.Finally, based on the threshold signature scheme with fault—tolerance by Zhang Xinglan, we improved the scheme and put forward two safety threshold signature scheme with fault-tolerance.