Patent ID: 7548887

Claim:
An information-signal playback system comprising an information-signal reading apparatus and an information-signal processing apparatus: the information-signal reading apparatus comprising: readout means for reading out media type information from a recording medium and an encrypted video signal comprising copy control information, the media type information indicating a type for the recording medium; encryption means for encrypting the media type information to create encrypted media type information; and output means for supplying, to the information-signal processing apparatus, the encrypted media type information, the media type information, and the encrypted video signal; and the information-signal processing apparatus comprising: decryption means for decrypting the encrypted media type information and the encrypted video signal received from the information-signal reading apparatus; determining means for determining the copy control information from the decrypted video signal; comparing means for comparing the decrypted media type information with the media type information, and determining whether the media type information has been altered; and control means for controlling output of the video signal based on the media type information, the decrypted media type information, the determination of whether the media type information has been altered, and the copy control information.