Design of a Secure Authentication and Key Agreement Scheme Preserving User Privacy Usable in Telecare Medicine Information Systems

摘要: Authentication and key agreement schemes play a very important role in enhancing the level of security telecare medicine information systems (TMISs). Recently, Amin Biswas demonstrated that authentication scheme proposed by Giri et al. is vulnerable to off-line password guessing attacks privileged insider also does not provide user anonymity. They an improved scheme, claiming it resists various attacks. However, this paper demonstrates Biswas's defenseless against replay perfect forward secrecy. This shows al.'s only suffers from weaknesses pointed out Biswas, but Moreover, proposes novel overcome mentioned weaknesses. Security performance analyses show overcomes weaknesses, more efficient than previous schemes.