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
The problems of cryptography and secrecy systems furnish an interesting application of communication theory. In this paper a theory of secrecy systems is developed. The approach is on a theoretical level and is intended to complement the treatment f
