@misc{cryptoeprint:2003:184,
    author = {Nicolas T. Courtois and Guilhem Castagnos and Louis Goubin},
    title = {What do DES S-boxes Say to Each Other ?},
    howpublished = {Cryptology ePrint Archive, Report 2003/184},
    year = {2003},
    url = {http://eprint.iacr.org/2003/184},
}