| 摘要 |
An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is produced so as to include a plurality of sub-trees that are grouped in accordance with categories and managed by category entities. An EKB is produced so as to include data produced by selecting a path in the key tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path, and the resultant EKB is provided to a device. When a requester issues a request for production of an EKB is issued, the requester may produce a root key or may request a key distribution center to produce a root key. When the key distribution center produces an EKB, the key distribution center requests a category entity to produce a sub-EKB. Thus, the EKB can be produced and managed in a highly efficient manner. |
