Enhancement of Two-Factor User Authentication in Wireless Sensor Networks

Wireless sensor networks are widely used for applications such as environmental monitoring, airport safety, health care, etc. For user authentication, in 2009, Das proposed a two-factor user authentication scheme in wireless sensor networks. They claimed that this scheme provided efficiency, strong security, and user anonymity property. However, we find that Das's scheme is still vulnerable to masquerade attack and cannot achieve user anonymity. This paper will propose an improvement to remedy the weakness of Das's scheme.