@misc{cryptoeprint:2009:161,
author = {Yuichi Komano and Hideo Shimizu and Shinichi Kawamura},
title = {Built-in Determined Sub-key Correlation Power Analysis},
howpublished = {Cryptology ePrint Archive, Report 2009/161},
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.