Gregory G. Rose Philip Hawkes Michael Paddon Cameron McDonald Miriam Wiggers de Vries Design and Primitive Specification for Shannon. 2007 Symmetric Cryptography http://drops.dagstuhl.de/opus/volltexte/2007/1019 conf/dagstuhl/2007P7021 db/conf/dagstuhl/P7021.html#RoseHPMV07