@misc{cryptoeprint:2004:265,
author = {Yongge Wang and Bei-Tseng Chu },
title = {sSCADA: Securing SCADA Infrastructure Communications},
howpublished = {Cryptology ePrint Archive, Report 2004/265},
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.