Information-signal playback system, information-signal reading apparatus, information-signal processing apparatus, information-signal playback method, information-signal reading method and information-signal processing apparatus

An 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 an information-signal processing apparatus, the encrypted media type information, the media type information, and the encrypted video signal;
• wherein the information-signal processing apparatus comprises:
• 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.

An information-signal reading method comprising:

• 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;
• encrypting the media type information to create encrypted media type information;
• supplying, to an information-signal processing apparatus, the encrypted media type information, the media type information, and the encrypted video signal, wherein the information-signal processing apparatus performs the steps of:
• decrypting the encrypted media type information and the encrypted video signal;
• determining the copy control information from the decrypted video signal;
• comparing the decrypted media type information with the media type information to determine whether the media type information has been altered;
• and
• 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.