@misc{cryptoeprint:2012:679,
author = {Yehuda Lindell and Kobbi Nissim and Claudio Orlandi},
title = {Hiding the Input-Size in Secure Two-Party Computation},
howpublished = {Cryptology ePrint Archive, Report 2012/679},
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.