Efficient frequency domain selective scrambling of digital video

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/systems for data security are often not fast enough to process the vast amount of data generated by multimedia applications to meet 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 levels of security and different levels of transparency, and has a very limited adverse impact on compression efficiency and no adverse impact on error resiliency. Furthermore, it allows transcodability/scalability, and other content processing functionalities without having to access the cryptographic key and perform decryption and reencryption.