摘要 |
A method and apparatus for copyright protection for various recording media such as Digital Video Discs (DVDs) uses a combination of a Video Finger Print Signal and an Authenticating Signature to permit the player to handle either copy-protected or non-copy-protected media, in a manner that is difficult to compromise. Both a Video Finger Print Signal and an Authenticating Signature are recorded on the media only when copy-protection is required. The nature of this Authenticating Signature is such that it will not be transferred to illicit copies made on CD recorders. When either an original protected or an original non-protected disk is played, the presence or absence of the Authenticating Signature causes the player to correctly play the program video. All original DVDs therefore play normally. When a copy of a non-protected CD is played, the absence of the Video Print Signal also causes the player to correcly playback the video signal data. However, when a copy of a protected CD is played, the absence of the Authenticating Signature causes the player to prohibit the disk from playing normally.
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