FIELD: physics.
SUBSTANCE: device has a printing unit for creating documents by printing an embedded image, which prohibits or permits copying depending on the selection of a user who then enters a password. When copying two documents, the copying of one of which is prohibited, a user password entry screen is not displayed and the printing unit does not print images obtained by reading both documents. When copying a document, the copying of which is permitted, a user password entry screen is displayed and the printing unit prints the image obtained by reading the second document only if the password entered by the user matches the password entered when the second document was created by the printing unit. When copying two documents, one of which was created separately from the other by printing another embedded image, which was formed when the user was allowed to copy and then entered a password, a user password entry screen is not displayed, and the printing unit does not print images obtained by reading said documents.
EFFECT: preventing unauthorised copying of a secure document by a malicious user.
3 cl, 7 dwg
