| 摘要 |
In a method for preventing unauthorized use of a recording medium having intentionally implanted error information, first, information is read and the error information is compared with a key code. It is then concluded that the recording medium is a true recording medium (lawfully produced medium). A true recording medium with implanted error information (Master Data) contains error information that can be corrected by the Error Correction circuit of the optical disc apparatus. When Master Data is copied by a recorder, Master Data is copied through the Error Correction circuit. Master Data is corrected by the Error Correction circuit of the recorder to create Copy Data. Thus Copy Data contains the same data of the Master Data but without the original error information of the Master Data. By detecting a lack of the error information, it is then concluded that the Copy Data is not a lawfully produced medium. Alternatively, a predetermined sequence or placement of error data in Master Data can be detected and used to determine if a copy is a lawfully produced medium. |
