This book documents the contribution made by the author to the development of a DRM system specification providing all users of a Digital Media Value Chain with an open, standard, interoperable and reconfigurable solution enabling a broad variety of business models to be implemented. These range from simply informing what other users can do on content (e.g. the Creative Commons approach), to a full-fledged DRM system enforcing protection. The system described in this book may allow to monetize the value contributed by each player to the value chain, reducing the costs associated to online micro-payments for digital media and guaranteeing privacy of personal data and transaction information. To achieve this goal, a number of existing standard technologies have been integrated, adapted or extended, a number of missing key technologies have been developed, proposed and converted to ISO standards.