Selective encryption of the MC EZBC bitstream for DRM scenarios

Universal Multimedia Access (UMA) calls for solutions where content is created once and subsequently adapted to given requirements. With regard to UMA and scalability, which is required often due to a wide variety of end clients, the best suited codecs are wavelet based (like the MC-EZBC) due to their inherent high number of scaling options. However, we do not only want to adapt the content to given requirements but we want to do so in a secure way. Through DRM we can ensure that the actual content is safe and copyright is observed. However, traditional encryption removes the option of scalability in the encrypted domain which is opposed to what we want to achieve for UMA. The solution is selective encryption where only a part of the content is encrypted, enough to ensure safety but at the same time little enough to keep scalability intact. Towards this goal we discuss various methods of applying encryption to the bitstream produced by the MC-EZBC in order to keep scalability intact in the encrypted domain while also keeping security intact with regard to various DRM scenarios.