I. Introduction
In the last few years, wireless body area network (WBAN) has been playing a vital role in modernizing healthcare delivery in modern medical systems [1]. As a network of limited power miniature devices situated on the bodies of patients to remotely keep track of their health for instantaneous medical diagnosis, WBAN appears to be a double-edged sword: it enables interesting user-oriented applications such as emergency medical systems while making the unauthorized access of the patients’ sensitive data possible because of the openness of its wireless channels [1]. As a result, authentication and data privacy are essential in WBAN.