An efficient three-party password-based key agreement protocol using extended chaotic maps

Three-party password-based key agreement protocols allow two users to authenticate each other via a public channel and establish a session key with the aid of a trusted server.Recently,Farash et al.[Farash M S,Attari M A 2014 "An efficient and provably secure three-party password-based authenticated key exchange protocol based on Chebyshev chaotic maps",Nonlinear Dynamics 77(7):399–411] proposed a three-party key agreement protocol by using the extended chaotic maps.They claimed that their protocol could achieve strong security.In the present paper,we analyze Farash et al.’s protocol and point out that this protocol is vulnerable to off-line password guessing attack and suffers communication burden.To handle the issue,we propose an efficient three-party password-based key agreement protocol using extended chaotic maps,which uses neither symmetric cryptosystems nor the server’s public key.Compared with the relevant schemes,our protocol provides better performance in terms of computation and communication.Therefore,it is suitable for practical applications.