Cryptology ePrint Archive: BibTeX Citation of Report 2008/166

@misc{cryptoeprint:2008:166,
    author = {Nicolas T. Courtois and Karsten Nohl and Sean O'Neil},
    title = {Algebraic Attacks on the Crypto-1 Stream Cipher in MiFare Classic and Oyster Cards},
    howpublished = {Cryptology ePrint Archive, Report 2008/166},
    year = {2008},
    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.