Lightweight anonymous and mutual authentication scheme for wireless body area networks

Wireless body area networks (WBANs) represent an important technology for e-health systems. They provide enhanced efficiency, more flexibility, and important cost savings for patients, healthcare providers, and medical professionals in home, as well as hospital settings. Mutual authentication with anonymity and session unlinkability belongs to an important class of authentication schemes for WBANs. Among the security schemes of this class, the scheme presented in Li et al. (2017) is seen as the lightest in terms of resource consumption. However, several recent papers reported that the scheme exhibits some problems with session unlinkability and forward secrecy of session keys. In this paper, we first present a security analysis of the Li et al. scheme and then propose a new security enhancement that ensures both session unlinkability and forward secrecy. Through a deep analysis, we show that the proposed scheme exhibits high robustness against well-known security attacks and prove its safety using the Automated Validation of Internet Security Protocols and Applications (AVISPA) tool while assuring mutual authentication with BAN-logic. In terms of complexity, the proposed scheme exhibits a lower XOR and random number generation costs observed in Li et al. and other proposed schemes. Consequently, we have considered such costs in the proposed scheme and we shifted the costly random number generation function from the sensor node to the hub in order to enhance computation performance, energy consumption, and communication. Finally, we evaluated the proposed scheme using Castalia framework and demonstrated its high efficiency.