FIELD: copy protection technologies.
SUBSTANCE: method includes detection step including detection of first water-mark inserted into digital information, which contains first signal generated on basis of first rule, as well as insertion step, including insertion of second water-mark, which contains second signal, generated on basis of second rule and having structure different from structure of first signal, into digital information, in case if first water-mark is detected at detection step. Device has detection device meant for detecting said first water-mark inserted into digital information, and insertion device meant for inserting said second water-mark into digital information, in case if detection device detects first water-mark.
EFFECT: higher effectiveness, higher productiveness.
6 cl, 11 dwg
