Nicolas Courtois Blandine Debraize Specific S-Box Criteria in Algebraic Attacks on Block Ciphers with Several Known Plaintexts. 100-113 2007 WEWoRC http://dx.doi.org/10.1007/978-3-540-88353-1_9 conf/weworc/2007 db/conf/weworc/weworc2007.html#CourtoisD07