Cryptology ePrint Archive: BibTeX Citation of Report 2011/391

@misc{cryptoeprint:2011:391,
    author = {Amir Moradi and Markus Kasper and Christof Paar},
    title = {On the Portability of Side-Channel Attacks – An Analysis of the Xilinx Virtex 4, Virtex 5, and Spartan 6 Bitstream Encryption Mechanism},
    howpublished = {Cryptology ePrint Archive, Report 2011/391},
    year = {2011},
    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.