一个智能卡加密的好文章，详细记述了一个加强的智能卡加密算法的实现-Abstract – Hwang and Li proposed the first remote user

authentication scheme using smart cards to solve the

problems of Lamport scheme. Unfortunately, Hwang and Li’s

scheme has some security weaknesses. First, Chan- Chang,

Shen- Lin- Hwang and then Chang-Hwang pointed out some

attacks on Hwang – Li’s scheme. This paper presents a new

remote user authentication scheme with forward secrecy,

which provides forward secrecy to the long term secret key of

the authentication server. This scheme is also secure against

Chan – Cheng and all the extended attacks1.