@misc{cryptoeprint:2014:400,
author = {Peeter Laud and Jan Willemson},
title = {Composable Oblivious Extended Permutations},
howpublished = {Cryptology ePrint Archive, Report 2014/400},
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.