@misc{cryptoeprint:2008:391,
author = {Tao Xie FanBao Liu DengGuo Feng},
title = {Could The 1-MSB Input Difference Be The Fastest Collision Attack For MD5 ?},
howpublished = {Cryptology ePrint Archive, Report 2008/391},
year = {2008},
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.