Patent ID: 7861311

Claim:
An apparatus in a file system including a File Allocation Table (FAT) area, a directory entry area, and a data area, the FAT area, the directory entry area, and the data area being separate and non-overlapping, the apparatus managing a hidden area by setting a portion of the data area as the hidden area and controlling an access to the set hidden area, the apparatus comprising: a processor; a hidden area generation unit, which under control of the processor, sets the portion of the data area as the hidden area and records meta data for the set hidden area in a cluster of the data area and cluster identification information for identifying a hidden area in clusters of the data area, wherein cluster numbers of the clusters are recorded in the meta data; a hidden area release unit which moves a directory entry of a root directory of the hidden area into the directory entry area and returns the cluster recorded with the meta data and the clusters recorded with the cluster identification information to release the set hidden area; and an access control unit which controls the access to the hidden area in a state where the hidden area is set.