@misc{cryptoeprint:2009:569,
author = {Rosario Gennaro and Jonathan Katz and Hugo Krawczyk and Tal Rabin},
title = {Secure Network Coding Over the Integers},
howpublished = {Cryptology ePrint Archive, Report 2009/569},
year = {2009},
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.