A Forward-secure Anonymity Signature Scheme Based on Ring Signature Idea

A new forward-secure anonymous signature scheme based on the difficulty of quadratic root modulo composite and factorization problem and the idea of ring signature is proposed in this paper.This scheme has the following advantages:the group manager can only revoke the identity of the signer with the receiver's cooperation;The signer can choose his anonymous scope he wants;Even the attacker obtained the current secret key of some user illegally,he still could not forge the signature of the past time period.