@misc{cryptoeprint:2009:354,
author = {ZHAO Xin-jie and WANG Tao and ZHENG Yuan-yuan},
title = {Cache Timing Attacks on Camellia Block Cipher},
howpublished = {Cryptology ePrint Archive, Report 2009/354},
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.