Recently, Hsu and Chuang proposed an efficient user identification scheme with key preserving user anonymity for distributed computer networks. Their protocol addressed an identity disclosure attack on the Yang et al. and Mangipudi-Katti schemes. Unfortunately, Hsu and Chuang’s new scheme posed vulnerability that the service provider could compute the private key of the user and imitate the user to send the service request to other service provider. In this paper, we analyzed Hsu-Chuang scheme and presented the vulnerability. We further secured their protocol by proposing a novel protocol that overcomes the above limitation while achieving the same security features. Besides, we made a demonstration of the correctness of our new scheme and analyzed the security properties. After compared Hsu-Chuang scheme and the new scheme, we also illustrated an example to illustrate the application of our improved protocol.