| 摘要 |
PURPOSE: To prevent an electronic document from being forged by detecting the approval date of a certificate or warrant, issued in the form of an electronic document, being altered. CONSTITUTION: A seal impression generating means 60 composes a seal impression of a seal impression fixed from part on a seal impression fixed from storage means 40 and a seal impression variable part on a seal impression display pattern storage means 50 for an electronic document on an electronic document storage means 40 or a newly generated electronic document, and an approval means 90 approves the accounts by putting the seal impression on the electronic document, and outputs if on a recording medium on an electronic document output means 75. At this time, one of display patterns of plural dates determined according to the approval data is selected to generate image information on the approval data. To certify this electronic document, the image information on the approval date is read out and it is judged whether it matches with a predicted date display pattern. |
