The digital data water marking system which utilizes new watermark insertion method and method of detection

摘要

(57) Abstract As for water marking system, 1st consecutive parameter for inserting the watermark (v, h), private key K _PRI, and 2nd consecutive parameter for detecting the watermark (|H (f)|) Public key K _PUB is used. It is impossible, to inform the private key, by the information regarding the public key, elimination or modification of the watermark is impossible. Insertion of the watermark is executed it is done with the filter which possesses impulse response h false noise signal serial by adding to the data which (v) filtering the watermark is done. Detection of the watermark is executed by (f) due to is done searching, whether it includes the noise which filtering the frequency response H to which the said data is beforehand set through the data which is received. This invention is application to the copy protection.