ID-Based Certificateless Electronic Cash on Smart Card against Identity Theft and Financial Card Fraud

A three-factor authentication combines biometrics information with user password and smart card to provide security-enhanced user authentication. An's scheme provides more improved user authentication than Das's scheme. But An's scheme is not secure against denial of service attack in login phase, forgery attack. Li et al. pointed out them and proposed three-factor remote user authentication scheme with key agreement for multimedia system. However, Li et al's scheme still has some security problem. In this paper, we present a cryptanalysis of Li et al.'s remote user authentication scheme.