Analysis and Improvement of a Mutual Authentication Scheme for Wireless Body Area Networks

An increase in aging population and the consequent chronic diseases pose not only serious effects to the economy but also a heavy burden to the medical system. Wireless body area networks (WBANs) provide a simple and low-cost strategy for health monitoring and telemedicine of the elderly. Many authentication schemes based on WBAN have been presented to address the sensitivity and privacy of collected data and the open characteristic of wireless networks. Wu et al. recently presented an efficient anonymous authentication scheme for WBANs, in which a one-side bilinear pairing methodology was applied to reduce the burden on the WBAN client side. However, we demonstrate that their scheme suffers from client impersonation attacks and that the adversary can easily forge a legal client to access the network service. In this paper, we analyze the limitations of Wu et al.'s scheme and design a novel mutual authentication scheme for WBANs that adopt asymmetric bilinear pairing to enhance security. Results of security and performance analyses reveal that the new scheme offers more effective security, better performance, and higher efficiency than Wu et al.'s scheme. We also provide a formal security proof of the protocol by using BAN authentication logic.