An enhanced smart card based remote user password authentication scheme

Smart card based password authentication is one of the simplest and efficient authentication mechanisms to ensure secure communication in insecure network environments. Recently, Chen et al. have pointed out the weaknesses of some password authentication schemes and proposed a robust smart card based remote user password authentication scheme to improve the security. As per their claims, their scheme is efficient and can ensure forward secrecy of the session key. However, we find that Chen et al.'s scheme cannot really ensure forward secrecy, and it cannot detect the wrong password in login phase. Besides, the password change phase of Chen et al.'s scheme is unfriendly and inefficient since the user has to communicate with the server to update his/her password. In this paper, we propose a modified smart card based remote user password authentication scheme to overcome the aforementioned weaknesses. The analysis shows that our proposed scheme is user friendly and more secure than other related schemes.