| 摘要 |
PROBLEM TO BE SOLVED: To inhibit the unauthorized use of contents even when identification information of a revocation list is altered or is not updated rightly. SOLUTION: Identification information 3, 4 for identifying a specific optical disk or an optical disk device, version information of the identification information 3, 4, and information indicating update date are recorded in an optical disk 1. Identification information 8, 9 for identifying a specific optical disk or an optical disk device, version information of the identification information 8, 9 and information indicating update date are recorded in a storage device 7 of an optical disk device 6. The optical disk device 6 judges justice of the identification information 3, 4 recorded in the optical disk 1 and identification information 8, 9 recorded in the storage device 7 based on version information and update date, only when it is judged the justice exists, recording/reproducing of data using the optical disk 1 are permitted. COPYRIGHT: (C)2008,JPO&INPIT |
