  In this paper, we will study Lee, Kim and Yoo, a verifier password typed key
agreement scheme and demonstrate that the scheme is not secure. Then, the
authors will propose an enhanced verifier typed key agreement scheme relied on
Lee, Kim and Yoo scheme and demonstrate that the propose scheme resists against
password guessing attack and stolen verifier attack. The authors are claimed
that the proposed scheme is more secure and efficient compare with Lee, Kim and
Yoo.
