David Arditti Côme Berbain Olivier Billet Henri Gilbert Jacques Patarin QUAD: Overview and Recent Developments. 2007 Symmetric Cryptography http://drops.dagstuhl.de/opus/volltexte/2007/1015 conf/dagstuhl/2007P7021 db/conf/dagstuhl/P7021.html#ArdittiBBGP07