@misc{cryptoeprint:2007:439,
author = {Nam-Su Jho and Myung-Hwan Kim and Do Won Hong and Byung-Gil Lee},
title = {Multiparty Key Agreement Using Bilinear Map},
howpublished = {Cryptology ePrint Archive, Report 2007/439},
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.