Anonymous Shared Certificate Entity Authentication Protocol

Currently most existing entity authentication protocols can not guarantee anonymity against compromised verifier in semi-honest model. To solve the question, this paper puts forward a shared certificate entity authentication model, by which some qualities for anonymous entity authentication in semi-honest situation are suggested reasonably. On basis of our proposed model, this paper designs two anonymous entity authentication protocols including an anonymous shared certificate bi-entity authentication protocol and an anonymous shared certificate multi-entity authentication protocol. In proposed protocols it is only single certificate that is used to verify identity correctly and anonymously for legitimate users who has different identity secret. Any compromised verifier has capability to verify correctly whether the user identity is legitimate or not, but it is difficult for it to judge which legitimate user has been verified and distinguish who the verifying user is in particular, therefore attacker does not learn any useful information from legitimate user by spying upon the information of public channel or compromising the certificate. So the security requirements of anonymous entity authentication are achieved successfully, meanwhile the proposed model is more feasibly and effective than zero knowledge protocol in practical applications.