@misc{cryptoeprint:2012:643,
author = {Amos Beimel and Eran Omri and Ilan Orlov},
title = {Protocols for Multiparty Coin Toss With Dishonest Majority},
howpublished = {Cryptology ePrint Archive, Report 2012/643},
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.