| 摘要 |
<p>Message Authentication Code (MAC) values formed with respect to each file belonging to a directory (122A) and Integrity Check Values (ICVs,D-ICVs) formed on the basis of the MAC values of all files belonging to the directory (122A) are stored into a sequence page (121A). Sequence pages (121A,121B,...) formed respectively with respect to all of the directories (122A,122B,...) on a disk and the ICVs formed on the basis of the D-ICVs stored in all of the sequence pages (121A,121B,...) are stored into a sequence block (114). Since the MAC values are closed and managed every directory by the sequence pages (121A,121B,...), a data alteration check can be executed every directory. An alteration check of data recorded on a recording medium can be efficiently performed. <IMAGE></p> |
