New cryptanalysis paradigm on a nonce-based mutual authentication scheme

In 2005, Lee, Kim, and Yoo proposed a nonce-based mu-tual authentication scheme using smart cards. However, this paper demonstrates that Lee-Kim-Yoo's scheme is vulnerable to an impersonation attack that the attacker without knowing the remote user's any secret can mas-querade as him by obtaining the valid authentication mes-sage from any normal session between the remote user and the system. Our purpose is to emphasize that it is danger-ous that the remote user and the system separately imple-ment their authentication operations without any logical relation to achieve the mutual authentication. Further-more, we suggest that the tool of matching conversations would be useful as a sanity check to find this kind of the security breach.