DATA MAINTENANCE SYSTEM, DATA MAINTENANCE METHOD, DATA MAINTENANCE PROGRAM, DATA REGISTRATION DEVICE, AND DATA VERIFICATION DEVICE

Abstract

A data registration device (200) processes original data stored in a data source, and registers the processed data. A data verification device (300) calculates, as a reference digest value, a digest value of reference combined data generated on the basis of a digest value of the original data and a digest value of the processed data. The data verification device then: calculates a digest value of the registered processed data as a provisional digest value; acquires, as a provisional digest value, a digest value stored in the data source; calculates, as a verification digest value, a digest value of verification combined data generated on the basis of the provisional digest value of the original data and the provisional digest value of the processed data; and compares the verification digest value with the reference digest value.