@misc{cryptoeprint:2010:458,
author = {Masahiro Yagisawa },
title = {Key Agreement Protocols Using Multivariate Equations on Non-commutative Ring},
howpublished = {Cryptology ePrint Archive, Report 2010/458},
year = {2010},
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.