Scalable encryption for multimedia content access control

Traditional cryptography systems treat every portion of a message (a video, an image, or an audio) equally and encrypt the entire message as a whole. As a result, those security systems often have only two states: access authorization and access denial. To facilitate multi-level access control with interoperability, scalable security mechanism is needed. Further, the availability of varying network bandwidth and diverse receiver device capabilities demand scalable and flexible approaches that are capable of adapting to changing network conditions as well as device capabilities. In this paper, we describe a multimedia encryption scheme that supports scalability. One desirable feature of the proposed scheme is its simplicity and flexibility in supporting scalable content access control.