Research On Access Technology For Secure Data Based On Group Signature

The access technique for secure data based on group signature, is one that takes group signature as authentication scheme, and can achieve user's accessing data in the anonymous mode, and authenticating user's valid identity.Based on ACJT group signature scheme introduced by Ateniese et al, this paper introduces the general means and security of access technique of group signature. In the face of the disadvantage of ACJT scheme about leaking cryptic keys, this paper mainly discusses and advances the countermeasure for leaking cryptic keys. With these countermeasures, ACJT scheme is improved. Then combining the scheme of time-dependent hierarchical keys, a system model is formed, which is more secure and efficient, and can realize anonymous authentication.The provided countermeasures in this paper are member revocation scheme based on revocation list and key updating scheme for forward security. The combination of these two schemes ensures that, the identity of registered group member can be revoked efficiently, and when finding a member's group signature key is leaked, with the leaked key, attacker can't produce valid group signature.By theoretic analysis and experimentations in the stimulant network, it is proved that, in the improved ACJT group signature scheme, the added methods of revocation of group members and forward security of keys are feasible and effective, and compared with old system's anonymous authentication, the authentication efficiency in new secure system for data access based on ACJT scheme and hierarchical keys is more efficient.