A New Lightweight User Authentication and Key Agreement Scheme for WSN

The Internet of Things (IoT) is one of the most up-to-date and newest technologies that allows remote control of heterogeneous networks and has a good outlook for industrial applications. Wireless sensor networks (or in brief WSNs) have a key role on the Internet of industrial objects. Due to the limited resources of the sensor nodes, designing a balanced authentication scheme to provide security in reasonable performance in wireless sensor networks is a major challenge in these applications. So far, several security schemes have been presented in this context, but unfortunately, none of these schemes have provided desired security in reasonable cost. In 2017, Khemissa et al. proposed a security protocol for mutual authentication between sensor node and user in WSNs, however, in this paper we show that this protocol is not safe enough in the confrontation of desynchronization, user impersonation and gateway impersonation attacks. The proposed attacks succeed with the probability of one and to be realized only require an execution of the protocol. Given merits of the Khemissa et al.'s protocol, we also improved their protocol in such a way that provides suitable level of security, and also we prove its security using two formal ways, i.e. BAN logic and also the Scyther tool. We also argue informally about the improved protocol's security.