| 摘要 |
<P>PROBLEM TO BE SOLVED: To allow contents to be reproduced continually during grace periods set on respective contents, after a license has passed the expiration date. <P>SOLUTION: The grace period of each content, a digital signature for data, into which a license ID and grace period information are coupled, and a server certificate for verifying the digital signature are described in a reproduction control metafile 41 for reproduction control of content. Verification of the server certification and verification of the digital signature are performed. If the verifications are successful, an AV player 15 obtains a license; permision is obtained for reproducing the content, until time equal to the expiration date described in the license plus the grace period described in the reproduction control metafile 41; and then the reproduction of the content is terminated, if the grace period has passed. <P>COPYRIGHT: (C)2010,JPO&INPIT |
