Abstract: A process for scrambling and unscrambling the image part of a sampled MAC ne video signal excluding the synchronization signal begins by dividing at two dividing points the MAC luminance signal and the chrominance signal to form two pairs of segments that are adjacent in each pair. For both transmission and reception each one of two dividing points between the two segments is synchronously defined in a pseudo-random manner to form a pair slightly overlapping in the neighborhood of the pertinent dividing point. The segments are processed in each pair as a whole in order to scramble prior to transmission and again to unscramble upon reception so as to restore the initial video signal.

Abstract: A process for scrambling and unscrambling video signals during transmission begins with a sampled line of video signals. The line is divided into adjacent segments, each of which has at least two samples. The dividing point between the two segments is defined in a pseudo-random manner, synchronously in the transmission and the reception. One of the segments is transmitted in a reversed manner. Upon reception, it is returned into its original direction.