Digital Video Scrambling Using Motion Vector and Slice Relocation

As digitalized content rapidly proliferates in networked systems, content security necessarily arises as one of the most important issues. Many developers have studied techniques for allowing only authorized persons to access content. Recently, video scrambling techniques, one type of the authorizing tools, have been introduced. However, they change the original video data, which often increases the bit rate of the source data. To overcome this problem, we propose a scrambling technique which deliberately distorts the original video sequences in a reversible way by arbitrarily relocating the differential motion vectors and MB (macroblock) starting positions in a slice. This method can be applied to most common video coding techniques such as MPEG-1/2/4, and H.264.