@misc{cryptoeprint:2011:122,
author = {Kristj{\'a}n Valur J{\'o}nsson and Gunnar Kreitz and Misbah Uddin},
title = {Secure Multi-Party Sorting and Applications},
howpublished = {Cryptology ePrint Archive, Report 2011/122},
year = {2011},
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.