Security enhanced user authentication scheme for wireless sensor network

Authentication and privacy are the two imperative security requirements by every wireless networks. Only recently, Vaidya, Rodrigues and Park proposed two low-cost authentication schemes with user privacy for wireless sensor networks (WSNs). However, this paper shows Vaidya et al.'s schemes cannot provide privacy in the presence of an adversary as they claim. Also, Vaidya et al.'s schemes are vulnerable to offline password guessing attack. To overcome these weaknesses, this paper improves their profound authentication schemes. The security of the improved scheme is analysed which reveals that the improved scheme can overcome such weaknesses. The performance of the improved scheme is the same as Vaidya et al.'s schemes with the same simplicity as well as being still suitable for WSNs.