A Conditional Privacy-Preserving Efficient Authentication Scheme With Revocability for Wireless Body Area Networks

Smart healthcare leverages Internet of Things (IoT), wireless communication and cloud computing technologies in the medical industry to enable healthcare professionals and patients to deliver remote medical services, conduct intelligent monitoring and analyze diseases without being constrained by time and location. Wireless Body Area Network (WBAN), extensively utilized in this sector, is a wireless network composed of wearable or embedded devices placed in different parts of the human body to monitor and record human health signals continuously. However, a contradiction exists between identity authentication and privacy protection in WBANs, which necessitates addressing the challenge of balancing anonymity and traceability. The open wireless environment makes WBANs vulnerable to various attacks and security threats, while sensor nodes in these networks face limitations such as restricted computing power. This paper addresses practical concerns in WBANs including identity authentication and dynamic user management, and develops an effective privacy-preserving authentication scheme that incorporates revocability and conditional privacy protection. A novel revocable certificateless short signature algorithm is designed that not only has high execution efficiency but also utilizes the binary tree structure to achieve keys update and user revocation, ensuring high execution efficiency while addressing the issue of high key management complexity in traditional schemes. This scheme uses pseudonyms instead of real identity information in authentication request messages for anonymity, and tracks malicious users based on the (t, k) secret sharing mechanism. The papers security analysis shows that the scheme is unforgeable under the random oracle model (ROM) and can resist typical security threats meeting various security requirements. Compared with other related schemes, this scheme has higher communication and computational efficiency and is more suitable for WBAN environments.