Security bound enhancement of remote user authentication using smart card

Distribution of resources and services via open network has becoming latest trend in information technology. This is provided by many service provider servers. In open network, hackers can easily obtain the communication data. Therefore, open networks and servers demand the security to protect data and information. Hence, network security is most important requirement in distributed system. In this security system, authentication is considered as the fundamental and essential method. Recently many remote user authentication schemes are proposed. In 2012, WANG Ding et al. proposed a remote user authentication scheme, in which the author stated that the scheme provides protection against offline password guessing, impersonation and other known key attacks. By cryptanalysis we have identified that, WANG Ding et al.'s scheme does not provide user anonymity, once the smart card is stolen. This scheme is also susceptible to offline password guessing attack, server masquerading attack, stolen smart card attack and insider attack. Further, this scheme still has problem with proper perfect forward secrecy and user revocation. In order to fix these security weaknesses, an enhanced authentication scheme is proposed and analysed using the formal verification tool for measuring the robustness. From the observation of computational efficiency of the proposed scheme, we conclude that the scheme is more robust and easy to implement practically.