| 摘要 |
<p>PROBLEM TO BE SOLVED: To effectively check alteration of the data which are recorded on a recording medium. SOLUTION: The MAC value that is generated for every file belonging to a directory 122A and the ICV (D-ICV) that is generated from MAC value of all files belonging to the directory 122A are stored in a sequence page 121A. Then the sequence pages 121A, 121B... which are produced for all directories 122A, 122B... included in a disk and the ICV generated from the D-ICV stored in all sequence pages 121A, 121B... are stored in a sequence block 114. As the MAC value is closed for every directory and managed via the pages 121A, 121B..., the alteration of data can be checked for every directory.</p> |
