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Trusted Authority Assisted Three-Factor Authentication and Key Agreement Protocol for the Implantable Medical System

The application of implantable medical devices (IMDs), which solves the problems of geographical distance limitation and real-time health monitoring that plague patients and doctors, has caused great repercussions in the medical community. Despite the great potential of wide application, it also brings some security and privacy issues, such as the leakage of health data and unauthorized access to IMDs. Although a number of authentication and key agreement (AKA) schemes have been developed, we find that some subtle attacks still remain to be addressed. Then we propose an improved AKA scheme which achieves strong security features including user anonymity and known key security. It is formally proved to be secure under the Real-or-Random model. Moreover, a comprehensive security analysis shows that our scheme can resist various attacks and satisfy the desired requirements. Finally, the performance analysis shows the superiority of our protocol which is suitable for the implantable medical system.