A Designated Verifier Group Signature Scheme Based on Ring Signature Idea

A threshold group signature scheme is proposed combining the idea of ring signature.This solves the problem that the threshold group manager has the absolute power in revoking the signer's identity,and the unconditional anonymity of ring signature provides chances for the criminals.Comparing to the existing ones,this scheme has following advantages:(1) The right of the group manager is restricted,he can only revoke the identity of the signer with the receiver's co-operation.(2) The threshold value is conveniently changeable.(3) It is easy to add or delete one or more the group members,and the scheme's parameters are changed little.