| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a configuration capable of performing management by units of contents stored in an information recording medium, preventing unauthorized utilization of the contents. <P>SOLUTION: A content to be stored in the information recording medium is partitioned by units and encryption, based on a unit key generated for each unit, is performed. An embedded key is generated, on the basis of various kinds of key generation information, and a unit key corresponding to each unit is generated, causing a record seed, corresponding to each unit, to act on the embedded key. Furthermore, a block key is generated based on the unit key and a block seed by blocks, to be set for every three sectors for example, and encryption by block units is performed. When a content is decoded, agreement of its key generation information, record seed, and block seed stored in a disk becomes the condition for decoding, and unauthorized utilization of the content can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
