| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an information recording/reproducing device which can efficiently manage key information for decoding a plurality of divided encrypted information by suppressing increase in data volume when dividing the encrypted information. <P>SOLUTION: The information recording/reproducing device is used for encrypting and recording content data, and for decrypting and reproducing the content data and is provided with a key information holding body for holding key information 1 necessary for decoding the content data and a division management means for performing the division of the content data and the storage of division management information 4 for managing the divided content data into the key information holding body. The key information 1 includes management information 2 for managing the content data before being divided, and the key information holding body is composed of the key information 1 for the content data before being divided and a division information parameter field 4 for storing the division management information 4 on which the management information 2 in the key information 1 is overwritten. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
