Presentations «Previous Next»

Video Scrambling By Segmenting Video Information Lines

Ron D. Katznelson, M/A-COM Linkabit Corp.
Gordon K. Walker, M/A-COM Linkabit Corp.
Paul Moroney, M/A-COM Linkabit Corp.

Abstract

A system for scrambling a video signal having a plurality of horizontal lines, each of which includes a video information portion and a non-video information portion. The scrambling system includes a memory; means for storing the video information portion of each video signal line in the memory; and means for forming scrambled horizontal lines by retrieving each of a plurality of said stored video information lines in a plurality of segments preceded by a non-video segment and separated by non-video segment(s). The retrieval means include means for varying the respective durations of the retrieved video information segments in individual scrambled horizontal lines in accordance with an encryption keystream; and means for varying the total duration of the non-video segments for individual scrambled horizontal lines in accordance with a predetermined timing pattern. A complementary descrambling system also is disclosed.

Suggested Citation

Ron D. Katznelson, Gordon K. Walker, and Paul Moroney. "Video Scrambling By Segmenting Video Information Lines" U.S. Pat. No. 4,736,420.. Apr. 1988.