| 摘要 |
It is an object of the present invention to provide a technique for managing, in a file system that stores past images of a data file, access right to the past images. A computer according to the present invention includes a past access control list in which access right of a user to past images and a period in which the access right is applied are described and validates accessibility to the past images using the past access control list (see FIG. 5). |
