An enhancement is provided for a copy protection method that discourages
copying (e.g., by video taping) of video signals. The enhancement adds
negative amplitude pulses to the video signal at a location in the
horizontal blanking interval "back porch" after the color burst. This
enhances jitter when the copy protected signal is recorded on a VCR
(video cassette recorder) and the recording is replayed, thereby making
the recorded signal not suitable for viewing.