A digital differential steganographic system and method includes a master key that is generated from an unmarked media, a mark-point reservoir created from the unmarked media and containing a set of viable candidate mark points for the unmarked media, and a mark-point applicator to insert data into the...http://www.google.fr/patents/US8107668?utm_source=gb-gplus-shareBrevet US8107668 - Digital differential watermark and method
