@misc{cryptoeprint:2009:169,
author = {Hu Yupu and Gao Juntao and Liu Qing},
title = {Floating Fault analysis of Trivium under Weaker Assumptions},
howpublished = {Cryptology ePrint Archive, Report 2009/169},
year = {2009},
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.