Security Enhanced Anonymous Multiserver Authenticated Key Agreement Scheme Using Smart Cards and Biometrics

Algorithm 2

No perfect forward secrecy on Chuang and Chen’s scheme.

(i) got and in previous public channel.

(ii) knew one of user’s long-term secret:

 ⇒ has and

 ⇒

 ⇒

 ⇒

(iii) can compute all of previous session key .