@misc{cryptoeprint:2010:423,
author = {LI Yun-qiang and Wang Ai-lan},
title = {Near Collisions for the Compress Function of Hamsi-256 Found by Genetic Algorithm},
howpublished = {Cryptology ePrint Archive, Report 2010/423},
year = {2010},
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.