@misc{cryptoeprint:2005:182,
author = {Chih-I Wang, Chun-I Fan, and D. J. Guan},
title = {Cryptanalysis on Chang-Yang-Hwang Protected Password Change Protocol},
howpublished = {Cryptology ePrint Archive, Report 2005/182},
year = {2005},
note = {\url{http://eprint.iacr.org/}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.