A scrambling technique for protecting video images recorded on tape
W.R. Hale, Christopher S. Johnson · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1991
This paper reports that some of the present unattended video surveillance systems record short sequences of video images or scenes on tape. Each of these scenes consist of short bursts of 6 to 8 video frames. The Video Scrambling System can be inserted in the input to the video recorder to scramble the video image prior to recording. The video tape will then contain a series of scrambled scenes each of which has been scrambled differently. The video tape with the scrambled images must now be played back through the Video Scrambling System to descramble the images for viewing. The images cannot be unscrambled without the proper codes having been inserted into the equipment. An attempt to insert false images into the tape can be easily detected since the equipment will not descramble an image that has not been properly scrambled. The equipment will demonstrate the scrambling and unsrambling technique and how the resulting images look when descrambled.