Cryptology ePrint Archive: BibTeX Citation of Report 2001/068

@misc{cryptoeprint:2001:068,
    author = {J.Nakahara Jr and P.S.L.M.Barreto and B.Preneel and J.Vandewalle and H.Y.Kim},
    title = {SQUARE Attacks on Reduced-Round PES and IDEA Block Ciphers},
    howpublished = {Cryptology ePrint Archive, Report 2001/068},
    year = {2001},
    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.