Multimedia Security and Copyright Protection

A distributed multimedia system involves three components: the owner or the creator of the multimedia data, the user or the customer of the multimedia data, and in the middle, the network to deliver the multimedia data. This thesis is an effort to identify some of the open security problems related to these three components and to provide solutions to these problems. In particular, we have designed and implemented the Encryption Algorithm, which utilizes the statistical behavior of MPEG compressed video. The statistical analysis of MPEG compressed video streams shows that the plain-text of compressed video has its own unique properties and is very different from text and other data types. This statistical analysis triggered our development of an efficient and secure algorithm for MPEG video streams. We introduced a watermark construction algorithm which applies a standard encryption function, such as DES, to the original multimedia data, and we have proved that this scheme is non-invertible and is successful against the ``multiple claims of ownership'''' attack. We derived non-invertible watermarking methods which apply to image, video and audio streams. The watermark is embedded directly to the MPEG encoded bit streams to avoid the expensive three-step (``decoding-watermarking-encoding'''') process. We identified the customer''s right problem and have designed two protocols to solve this problem. We discussed security issues within multicast environment and provided simple, efficient, and secure multicast protocols with copyright protection for the multimedia data.