Security improvements of dynamic ID-based remote user authentication scheme with session key agreement

Password-based authentication schemes have been widely adopted to protect resources from unauthorized access. In 2010, Khan et al. proposed an efficient and secure dynamic ID-based authentication scheme to overcome the weaknesses of Wang et al.´s scheme. In this paper, we show that Khan et al.´s scheme is vulnerable to password guessing attack, forgery attack, and does not provide user anonymity. Also, we propose the improved scheme to overcome the security drawbacks of Khan et al.´s scheme and to provide user anonymity and session key agreement, even if the secret values stored in the smart card is revealed. As a result, the improved scheme is relatively more secure than the related scheme in terms of security.