Analysis and Enhancement of Biometric-Based Multi-Server Authentication Scheme Using Chebyshev Chaotic Map

Earlier authentication protocols used to ask a user to register with all the servers with whom he/she wanted to access the services. Nowadays, an efficient way is provided by multi-server authentication techniques which remove the burden of individual registration and ask a user to register only with one registration center and access services provided by different servers. So far, many multi-server authentication protocols have been given in the literature. But most of them are having drawbacks. Recently, Chatterjee et al. gave a multi-server authentication protocol that used Chebyshev chaotic map approach for providing authentication. This paper analyzes the abovementioned protocol and found that it suffers from eavesdropping and user impersonation attacks. Besides that, there are flaws in registration, login and authentication phases of the protocol. Thereafter, we propose the modifications in the protocol without increase in the computation cost in order to make it more robust and secure.