In an image reading apparatus, a user ID is input as login information pertaining to the user who implemented reading of the original document. The user ID is embedded in the image data created from the original document data as an electronic watermark, and the image data is sent to a PC. The PC that receives the image data reads the user ID from the image data. If the user ID read from the image data matches a user ID entered by a user who issued a printing command, the PC issues a print command regarding the image data. Otherwise, printing is prohibited. Through this processing, printing of the image data is permitted only for the user who implemented reading of the image data.