Enhancement of Timestamp-based User Authentication Scheme with Smart Card

User authentication is an important technology to guarantee that only the legal users can access resources from the remote server. The advantages of smart cards are storage and computation abilities. Recently, there are many remote user authentication protocols with smart card have been proposed to improve security, efficiency, and functionality extensively by many scholars. This article finds that Awasthi et al.’s scheme may suffer impersonate attack, and do not allow changing password freely for the user. Finally, we proposed an improved timestamp-based user authentication scheme. The modified method is more efficient and secure than Awasthi et al.’s scheme.