Efficient frequency domain video scrambling for content access control

Multimedia data security is very important for multimedia commerce on the Internet such as video-on-demand and real-time video multicast. Traditional cryptographic algorithms for data security are often not fast enough to process the vast amount of data generated by the multimedia applications to meet the real-time constraints. This paper presents a joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors. The new approach is very simple to implement, yet provides considerable level of security, has minimum adverse impact on the compression efficiency, and allows transparency, transcodability, and other content processing functionalities without accessing the cryptographic key.