Date Added: Jul 2013
Remote user authentication scheme with key agreement is a very practical mechanism to verify a remote user and then provide secure communication. Furthermore, many network environments have been becoming multi-server based due to the rapid growth of computer networks. Therefore, more and more researches have been focused on proposing smart card based remote authentication scheme with session key agreement for multi-server environment. Recently, Tsaur, Li and Lee proposed such a novel scheme which adopts a self-verified timestamp technique to help the smart card based authentication scheme not only effectively achieve password-authenticated key agreement but also avoid the difficulty of implementing clock synchronization in multi-server environments.