@misc{cryptoeprint:2014:481,
author = {Eduarda S.V. Freire and Julia Hesse and Dennis Hofheinz},
title = {Universally Composable Non-Interactive Key Exchange},
howpublished = {Cryptology ePrint Archive, Report 2014/481},
year = {2014},
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.