@misc{cryptoeprint:2008:082,
author = {Roberto Araujo and Peter Y. A. Ryan},
title = {Improving the Farnel, Threeballot, and Randell-Ryan Voting Schemes},
howpublished = {Cryptology ePrint Archive, Report 2008/082},
year = {2008},
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.