@misc{cryptoeprint:2008:292,
author = {Sorina Ionica and Antoine Joux },
title = {Another approach to pairing computation in Edwards coordinates},
howpublished = {Cryptology ePrint Archive, Report 2008/292},
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.