Blockchain-Aided Authenticated Key Agreement With Message-Dependent Traceability for WBANs

Abstract

As a significant building block in the intelligent healthcare system, wireless body area networks (WBANs) collect users’ real-time biomedical data, enabling application providers to provide wide medical services. Due to the open environment and wireless transmission of WBANs, the sensitive biomedical data suffers from various security threats. Although authenticated key agreement (AKA) is a promising technology to deal with these threats, the existing AKA protocols encounter deficiencies in security, privacy, and practicality. Therefore, in this paper, we propose a blockchain-aided authenticated key agreement protocol with message-dependent traceability (BAKA-MT) for WBANs. In the proposed BAKA-MT, the user device can establish one or more different session keys with application providers to guarantee security of the transmitted biomedical data. Meanwhile, the manager is able to monitor network status by revealing the real identity of malicious entities that release illegal messages. Conversely, the identity privacy of honest entities transmitting legitimate data is still protected. In addition, blockchain with smart contract is adopted in BAKA-MT to ensure mutual authentication between communication entities and revoke malicious entities. Finally, the rigorous security proof and performance evaluation demonstrate that BAKA-MT is secure and practical.