A remote authentication scheme preserving user anonymity

Many smart card-based remote authentication schemes have been proposed, due to its convenience and secure computation of the smart card. However, these schemes didn´t protect the users´ identities while authenticating the users, even though user anonymity is an important issue in many e-commerce applications. In 2004, Das et al. proposed a remote authentication scheme to authenticate users while preserving the users´ anonymity. Their scheme adopted dynamic identification to achieve this function. This article points out Das et al.´s scheme fails to protect the user´s anonymity, and propose a new scheme to conquer the weakness.