Cryptanalysis of Hsiang-Shih’s Authentication Scheme for Multi-Server Architecture

Kuo-Hui YEH
Nai-Wei LO
Yingjiu LI, Singapore Management University


From user point of view, password-based remote user authentication technique is one of the most convenient and easy-to-use mechanisms to provide necessary security on system access. As the number of computer crimes in modern cyberspace has increased dramatically, the robustness of password-based authentication schemes has been investigated by industries and organizations in recent years. In this paper, a well-designed password-based authentication protocol for multi-server communication environment, introduced by Hsiang and Shih, is evaluated. Our security analysis indicates that their scheme is insecure against session key disclosure, server spoofing attack, and replay attack and behavior denial