The advent of consumer digital media products has vastly increased the concerns of copyright-dependent organizations within the music and movie industries. The increase usage of personal computers as household appliances has made it convenient for consumers to convert media originally in a physical/analog form into a digital form. This combined with the Internet and popular file sharing tools, has made unauthorized distribution of copies of copyrighted digital media much easier. The Digital Rights Management (DRM) field was thus spawned to prevent unauthorized access to digital content. The DRM solutions exist as either proprietary products owned by companies or as open standards. Most of the implemented DRM solutions suffer mainly from interoperability issue. This could kill the competition in the market through locking the users to certain products only. In this book, a new DRM system is proposed which overcomes the interoperability issue which exists in today's DRM products. This new DRM system is called Digital Rights Unit System (DRUS).