To detect data falsification in a routing path in an image forming device for synthesizing an additional image (watermark or the like) with an original image.
Synthetic data in which examination data stored in an ROM 104 instead of an original image and examination data stored in an ROM 107 instead of additional image are synthesized are obtained with prescribed timing and its hash value is calculated. Then, the hash value and normal hash value prepared in advance are compared by an examining means 112. Thus, falsification in the routing path of the image data can be detected. When falsification is detected, fraudulent copying and fraudulent use of secret documents and the like can be protected by executing function restriction processing for prohibiting printing of falsification notification and the synthetic image.
MIYOSHI NOBUKAZU
YOSHIDA YOSHIHARU
KIKUCHI MASAHIKO
SUZUKI NOBUAKI
TAKAHASHI KENICHI
YAMAZAKI HIDEKI
| JP2003198834A | 2003-07-11 | |||
| JP2007036985A | 2007-02-08 | |||
| JPH07203196A | 1995-08-04 | |||
| JP2003204429A | 2003-07-18 |
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