Image scanning device with time authentication requesting function

摘要

When executing an e-document scan, an image scanning device MFP1 scans a document and stores scanned data. After resetting a timer, the image scanning device calculates a hash value of the scanned data, and transmits the calculated hash value to a TSA (8 in Figure 1) to request the TSA to issue a timestamp. When receiving a timestamp from the TSA, the image scanning device stores the scanned data and the timestamp in an e-document folder in storage unit 22. When failing to receive a timestamp within a prescribed period of time after requesting the timestamp, the image scanning device adds a comment to the scanned data indicating that the timestamp failed to be received, and prints out on printing unit 17 the scanned data with the comment.