@misc{cryptoeprint:2013:562,
author = {Binglong Chen and Chang-An~Zhao},
title = {Self-pairings on supersingular elliptic curves with embedding degree $three$},
howpublished = {Cryptology ePrint Archive, Report 2013/562},
year = {2013},
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.