A reproduction method and apparatus for reproducing video data and/or audio data from a recordable medium having video data and/or audio data recorded thereon. The video data and/or audio data is generated by superimposing information concerning an attribute of a video signal and/or an audio signal on a signal of digitized video data and/or a signal of digitized audio data. Information concerning a copyright superimposed on the video data and/or audio data is reproduced from the medium, and a type of the medium is identified. Reproduction is stopped in response to a determination that the medium is illegally produced, the determination being based on a combination of the information concerning a copyright which is reproduced and the type of the medium identified.