@misc{cryptoeprint:2012:189,
author = {Steve Kremer and Robert Künnemann and Graham Steel},
title = {Universally Composable Key-Management},
howpublished = {Cryptology ePrint Archive, Report 2012/189},
year = {2012},
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.