@misc{cryptoeprint:2003:030,
author = {Ronald Cramer and Serge Fehr and Yuval Ishai and Eyal Kushilevitz},
title = {Efficient Multi-Party Computation over Rings},
howpublished = {Cryptology ePrint Archive, Report 2003/030},
year = {2003},
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.