@misc{cryptoeprint:2007:034,
author = {Li An-Ping},
title = {A New Type of Cipher: DICING_CSB},
howpublished = {Cryptology ePrint Archive, Report 2007/034},
year = {2007},
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.