Cryptanalysis and Improvement of a Robust Smart Card Authentication Scheme for Multi-server Architecture
A multi-server authentication scheme enables a remote user to access the services provided by multiple servers after registering with the registration center. Recently, Pippal et al. (Wirel Pers Commun 2013, doi:10.?1007/?s11277-013-1039-6) introduced a robust smart card authentication scheme for multi-server architecture. They also illustrated that their scheme could be free from potential network attacks, and validated the scheme by using BAN logic. In this paper, by presenting concrete attacks, we demonstrate that Pippal et al.s scheme can not withstand off-line password guessing attacks, impersonation attacks and privileged insider attacks. Furthermore, to overcome these attacks, we propose an improved authentication scheme for multi-server architecture using smart card and password. Security and efficiency analysis indicates that our scheme not only actually achieves intended security goals (e.g., two-factor authentication, perfect forward secrecy etc.), but also is efficient enough to be implemented for practical applications.
smart card authentication scheme multi-server off-line password guessing attacks impersonation attacks