Cryptology ePrint Archive: BibTeX Citation of Report 2002/003

@misc{cryptoeprint:2002:003,
    author = {Jorge Nakahara Jr and  Bart Preneel and Joos Vandewalle},
    title = {Square Attacks on Reduced-Round Variants of the Skipjack Block Cipher},
    howpublished = {Cryptology ePrint Archive, Report 2002/003},
    year = {2002},
    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.