Enhancement of anonymous authentication scheme in wireless sensor network

User authentication scheme with anonymity is one of important issues for wireless sensor network. In this paper, we improve Wu et al.´s scheme providing anonymity and overcome Zeng et al.´s attack. We demonstrate that our enhancement scheme not only provides the same performance as Wu et al.´s scheme, but also provides better security properties by achieving anonymity. Proposed scheme can adapt wireless sensor network to provide users anonymity.