A perfect dynamic-id and biometric based remote user authentication scheme under multi-server environments using smart cards

In modern era, remote user can access the multiple-services from anywhere in the world at any time through Internet. So, to provide the legitimacy among the users, various remote user authentication schemes have been designed. Recently, Chuang and Chang has proposed a scheme under multi-server architecture based on three security factors namely, smart card, password and biometric and claimed that, their scheme can resist several kind of attacks and can be successful to provide more security properties than that of existing schemes. In this paper, we have reviewed their schemes and proved that Chuang and Chang's scheme cannot resist server spoofing or user impersonate attack, password guessing attack and also fails to achieve forward key secrecy. To overcome their weaknesses and fulfill such important security requirements, we have proposed an improved remote user authentication scheme under multi-server environment.