@misc{cryptoeprint:2005:255,
author = {Jintai Ding and Jason E. Gower},
title = {Inoculating Multivariate Schemes Against Differential Attacks},
howpublished = {Cryptology ePrint Archive, Report 2005/255},
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.