An Improved Certificateless Mutual Authentication and Key Agreement Protocol for Cloud-Assisted Wireless Body Area Networks

This paper is based on the work published by Cheng et al. in the journal Mobile Networks and Applications. Cheng et al. proposed a certificateless authentication and key agreement scheme for secure cloud-assisted wireless body area networks. In this paper, we firstly cryptanalyzed Cheng’s scheme in term of various security issues and its errorneous protocol design. We shows that their scheme has various security vulnerabilities such as impersonation attacks, lack of mutual authentication, and so on. Moreover, their claim regarding the certificateless scheme is also doubtful. In addition, there are many problems in the design of their scheme such as the private keys are being shared, incorrect definition of hashes etc. Secondly, we focus on introducing an improved version of certificateless mutual authentication and key agreement protocol with resilience over security against key generator centers as well as existing attackers to mitigate the aforesaid concerns. In addition, we propose a provable security model for the security proofs which proves the robustness of the proposed scheme using the random oracle model. We also done the informal security analysis for the proposed work. It can be easily seen that the proposed protocol provides resistance against attacks like; impersonation, man-in-the-middle, known key secrecy, etc.