@misc{cryptoeprint:2007:479,
author = {J. Wu and D.R. Stinson},
title = {An Efficient Identification Protocol and the Knowledge-of-Exponent Assumption},
howpublished = {Cryptology ePrint Archive, Report 2007/479},
year = {2007},
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.