A method for protecting a DVD video includes deriving a distinct version of the video data from sequential distinct data objects contained in a content database. Each data object has at least one member and selected data objects have at least two members that produce discernibly different analog output...http://www.google.de/patents/US7062046?utm_source=gb-gplus-sharePatent US7062046 - Method and system for tracing an analog copy of a digital work to a unique digital copy and a particular digital player
