An Improved Efficient Remote User Authentication Scheme in Multi-server Environment using Smart Card

In a single server environment, one server is responsible for providing services to all the authorized remote users. However, the problem arises if a user wishes to access several network services. To overcome this weakness, various multi-server authentication schemes have been proposed. In 2012, Taygi et al. [1] proposed a scheme for multi-server environment. But it is found that their proposed scheme is insecure against user impersonation attack, server masquerading attack, collaboration attack between a valid user and a server, smart card stolen attack, password guessing attack and password change attack. Then we propose an improved scheme can overcome possible attacks and also provides better computational cost as well as communication cost than related schemes published earlier.