In 2007, Liao-Wang proposed a dynamic ID-based remote user authentication scheme for multi-server environment using smart cards.However, Hsiang-Shih demonstrated that Liao-Wang's scheme has security flaws.Moreover, Hsiang-Shih proposed an improvement scheme which resolves the security flaws of Liao-Wang scheme.In this paper, we propose an enhanced remote user authentication scheme which maintains the merits of Hsiang-Shih's scheme.Performance evaluation demonstrated the efficiency of the proposed scheme over related works.Security analysis proved that the proposed scheme is secure against known attacks.