Data management security against leakage or loss of personal information is achieved by setting a division range for dividing personal information into identification information that enables a specific individual to be identified and attribute information that does not by itself enable a specific individual to be identified. A CPU performs first division of personal information into identification information and attribute information in accordance with the division range specified by the user, performs second division of identification information that has undergone first division into a plurality of fragments for which data processing is possible, and furthermore generates linkage key information for restoring the divided identification information, attribute information, and plurality of fragments to the original personal information, and executes data storage processing that stores the identification information, attribute information, and plurality of fragments in an external storage apparatus and linkage key information in a nonvolatile auxiliary storage apparatus.