A New Dynamic ID-Based Remote User Authentication Scheme with Forward Secrecy

Forward secrecy is one of the important properties of remote user authentication schemes to limit the effects of eventual failure of the entire system when the long-term private keys of one or more parties are compromised. Recently, Tsai et al. showed that Wang et al.’s dynamic ID-based remote user authentication scheme fails to achieve user anonymity and is vulnerable to user impersonation attack, and proposed an enhanced version to overcome all the identified flaws. In this paper, however, we will point out that, Tsai et al.’s scheme still suffers from the denial of service attack and cannot provide forward secrecy. To remedy these security flaws, we propose an enhanced authentication scheme, which covers all the identified weaknesses of Tsai et al.’s scheme and is more suitable for mobile application scenarios where resource constrained and security concerned.