@misc{cryptoeprint:2004:310,
author = {Yevgeniy Dodis and Aleksandr Yampolskiy},
title = {A Verifiable Random Function With Short Proofs and Keys},
howpublished = {Cryptology ePrint Archive, Report 2004/310},
year = {2004},
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.