摘要 |
PROBLEM TO BE SOLVED: To manage authentication information according to a time change and the number of accesses.SOLUTION: A user block UB0 stores prescribed regulations for changing data series such as a method for changing the data series, and a method for restoring a block number to be changed and the changed data series in the data series, according to a time course and the number of accesses. A user block UB1 stores the original data series, and a user block UB2 stores the changed data series. In the original data series, data of a block defined by the user block UB0 are changed and then restores the changed data to the original data series. |