| 摘要 |
<p>The identifiers of both the media and contents in different categories are listed in a revocation list, and version information is set. The list is set up in a memory interface, and consequently it is continuously used even when a medium is loaded and when the content is reproduced. The version of the revocation list held by a device is checked when the content is read. If the version of the held revocation list is older, the read of the content is stopped. By conducting collation with the medium identifier when the medium is loaded, and by conducting collation with the content identifier when the content is used, false contents and false media are excluded.</p> |
