Security Weaknesses of Xxxxx et al Sample Clauses

Security Weaknesses of Xxxxx et al s Scheme‌ In this section, we analyze the security weaknesses of Xxxxx et al.’s scheme [14]. Xxxxx et al. cryptanalyzed Xxx et al.’s scheme [13] and improved it by providing enhanced security properties. They claimed that their protocol could withstand various attacks. However, we show that their protocol is vulnerable to off-line password guessing attacks and does not provide perfect forward secrecy. We also show that their protocol cannot satisfy accurate password change. The capabilities of an adversary A [25] throughout this paper are as follows: • An adversary A can be either a user or a sensor node, but not a gateway node [26]. • An adversary A has total control over the public communication channel. Thus, the adversary can intercept, insert, delete or modify any message transmitted via a public channel. • An adversary A may steal a user’s smart card and extract the information stored in it by means of analyzing the power consumption [27]. • An adversary A can easily guess low-entropy passwords in an off-line manner, but the guessing of two secret parameters is computationally infeasible in polynomial time [28].