Image data registration method and apparatus and image data verification method and apparatus

摘要

A character recognition process is executed for image data written with text information, and a digital signature is given to the character recognition results and image data. The digital signature is given to data coupling both digest values of the character recognition results and image data. The digital signature is verified, a character recognition process is executed for the image data, and further a digest value of the character recognition results is calculated and compared with the digest value of the stored character recognition results. The location where both the digest values are incoincident is identified as an alteration position.