@misc{cryptoeprint:2006:202,
author = {Ryuichi Harasawa, Yutaka Sueyoshi, and Aichi Kudo},
title = {Ate pairing for $y^{2}=x^{5}-\alpha x$ in characteristic five},
howpublished = {Cryptology ePrint Archive, Report 2006/202},
year = {2006},
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.