@misc{cryptoeprint:2012:034,
author = {Boris Köpf and Laurent Mauborgne and Martin Ochoa},
title = {Automatic Quantification of Cache Side-Channels},
howpublished = {Cryptology ePrint Archive, Report 2012/034},
year = {2012},
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.