A note on a user friendly remote authentication scheme with smart cards
In this letter, we indicate that a proposed user-friendly remote authentication scheme with smart card is insecure. The authentication scheme suffers from the replay attack. An adversity can eavesdrop valid authentication information from the communicating data, modify it, and impersonate the legitimate user to login the remote system. We also present a modified scheme to overcome this vulnerability and improve the robustness. In the modified scheme, the replay attack cannot work successfully. To crack the password from the communicating message is infeasible. Even if the password is compromised, the attacker still cannot pass the authentication and gain the authority of the legitimate user.
remote authentication smart card cryptography