@misc{cryptoeprint:2009:312,
author = {Huseyin Hisil and Kenneth Koon-Ho Wong and Gary Carter and Ed Dawson},
title = {Jacobi Quartic Curves Revisited},
howpublished = {Cryptology ePrint Archive, Report 2009/312},
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.