New efficient user identification and key distribution scheme providing enhanced security

Apart from user identification and key distribution, it is very useful for the login process to achieve user anonymity. Recently, Wu and Hsu proposed an efficient user identification scheme with key distribution while preserving user anonymity by extending an earlier work of Lee and Chang. We however find out that the Wu and Hsu scheme has a serious weakness, which can be exploited by the service provider to learn the secret token of the user who requests services from the service provider. We further propose a scheme to overcome this limitation while attaining the same set of objectives as the previous works. Performance analyses have shown that efficiency in terms of both computation and communication is not sacrificed in our scheme.