@misc{cryptoeprint:2011:248,
author = {Fanbao Liu and Yi Liu and Tao Xie and Yumeng Feng},
title = {Fast Password Recovery Attack: Application to APOP },
howpublished = {Cryptology ePrint Archive, Report 2011/248},
year = {2011},
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.