@misc{cryptoeprint:2008:085,
author = {Chang-An Zhao and Fangguo Zhang and Jiwu Huang},
title = {All Pairings Are in a Group},
howpublished = {Cryptology ePrint Archive, Report 2008/085},
year = {2008},
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.