Cryptology ePrint Archive: BibTeX Citation of Report 2004/049

@misc{cryptoeprint:2004:049,
    author = {Christophe Clavier},
    title = {Side Channel Analysis for Reverse Engineering (SCARE) - An Improved Attack Against a Secret A3/A8 GSM Algorithm},
    howpublished = {Cryptology ePrint Archive, Report 2004/049},
    year = {2004},
    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.