Time dependency: an efficient biometric-based authentication for secure communication in wireless healthcare sensor networks

Healthcare systems promise a significant impact in the field of quality of life. However, security is one of the hottest topics that must be guaranteed in these systems. One of the effective ways to provide security is through cryptographic protocols. The keys generated by these protocols must be disposable and time-dependent to resist replay attacks. In this paper, we show that not only secret keys must be time-dependent, but also the existence of a time-independent variable in authentication protocols can compromise users' privacy. Recently, an elliptic curve cryptography-based authentication protocol with time-independent variables has been proposed for wireless healthcare sensor networks. This paper intends to secure the previous protocol. We simulate our proposed scheme using AVISPA, a well-known formal method to validate security protocols, and the result shows that our proposed protocol is provably safe. Besides, we prove that our protocol preserves mutual authentication property using the widely-used BAN logic, and low complexity makes our protocol suitable for practical applications. We show that users can securely agree on a shared key within 387μ s with a 256-byte overhead.