@misc{cryptoeprint:2011:325,
author = {Aram Jivanyan and Gurgen Khachatryan},
title = {New Receipt-Free E-Voting Scheme and Self-Proving Mix Net as New Paradigm},
howpublished = {Cryptology ePrint Archive, Report 2011/325},
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.