Cryptanalysis on Efficient Two-factor User Authentication Scheme with Unlinkability for Wireless Sensor Networks

To provide secure authentication for wireless sensor networks (WSNs), recently Jiang et al. proposed an efficient two-factor user authentication scheme with unlinkability. They argued that the scheme provides resilience of privileged insider attack, stolen-verifier attack, password guessing attack, weak stolen smart card attack, replay attack, forgery attack, identity guessing attack and tracking attack. Unfortunately, this paper provides cryptanalysis on Jiang et al.’s scheme focused on denial of service attacks on gateway node and user, respectively, and password guessing attack with the assumption on stolen smart card attack feasibility. Furthermore, this paper provides simple directions of the counterpart’s solutions on them.