Cryptanalysis and Enhancement of an Anonymous Self-Certified Key Exchange Protocol

Authentication protocols with anonymity have gained much popularity recently which allows users to access any public network without compromising their identity. Several key exchange protocols have been proposed in the literature using either public key infrastructure or identity-based cryptosystem. However, the former suffers from heavy computation cost and latter fails to prevent key escrow problem. Recently, Islam et al. have proposed a self-certified authenticated key agreement protocol based on ECC which removes the above limitations. However, through careful analysis, we found that their scheme lack anonymity and vulnerable to trace the attack, clogging attack, and fails to prevent the replay attack. To overcome these weaknesses, we propose an anonymous self-certified authenticated key exchange protocol by including the required security features. The scheme is formally proved using Automated Validation of Internet Security protocols and Applications software. Also, the formal authentication proofs using Burrows–Abadi–Needham logic ensures successful authentication. Furthermore, the performance analysis demonstrates that the proposed scheme accomplishes less computational cost and is applicable to a client–server architecture.