To perform scramble and descramble processing with a simple and inexpensive configuration and also to eliminate image deterioration after descramble by switching video signal lines according to time lapse in every period corresponding to one horizontal scanning section of an analog component video signal or every period corresponding to the period obtained by multiplying one horizontal scanning section prescribed times.

An analog component video signal consists of a Y signal (luminance signal) and two color-difference signals R-Y and B-Y and the signals R-Y and B-Y are switched over the timing of a signal switching section 1H. Here, the switching of the signals R-Y and B-Y is performed at timing in a horizontal synchronous section. Thus, it is possible to obtain a scrambled analog component video signal. Descramble similarly performs switching about the signals R-Y and B-Y in the section 1H at the timing of the horizontal synchronous section in accordance with these scramble results.