Security of Dynamic ID-Based Remote User Authentication Scheme

Recently, Wang et al. proposed a new dynamic ID-based remote user authentication scheme which is an improvement of Das et al.´s scheme. They claimed their scheme is efficient and secure. After thorough analyses, we find Wang et al.´s scheme suffers from masquerade attacks because an attacker can choose an identity at will and be authenticated by the remote server successfully. In this paper, we will demonstrate how to mount masquerade attacks on Wang et al.´s proposed scheme.