Orr Dunkelman Sebastiaan Indesteege Nathan Keller A Differential-Linear Attack on 12-Round Serpent. 308-321 2008 INDOCRYPT http://dx.doi.org/10.1007/978-3-540-89754-5_24 conf/indocrypt/2008 db/conf/indocrypt/indocrypt2008.html#DunkelmanIK08