| 摘要 |
<p>A content key, an authentication key, program data along with an effective key block (EKB) are transmitted by an encryption key structure of a tree structure. The EKB has a structure in which a device constituting a tree leaf holds a leaf key and a limited node key. A specific effective key block (EKB) is generated and distributed to a group specified by a specific node, thus limiting an updateable device. A device not belonging to a group cannot be decoded, ensuring the distribution security of the key and so forth. Keys or data is distributed by an encryption key structure of tree structure, thereby providing an information processing system and method capable of efficiently and safely distributing data.</p> |
