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US 2003/0223584 A1Published application
Layered security in digital watermarking
AssigneeDigimarc Corporation
InventorsBrett Alan Bradley, Brett T. Hannigan, John Kennedy Barr
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AssigneeDigimarc Corporation
InventorsBrett Alan Bradley, Brett T. Hannigan, John Kennedy Barr
Estimating the term…
A media object authentication system uses layers of security features based on digital watermarks embedded in media objects. The system generates a first digital watermark with a message payload carrying data about the object, such as a hash of text data printed on the object. The first digital watermark is combined with a content signature derived from features of the media object, such as frequency domain attributes, edge attributes, or other filtered version of the media signal (e.g., image photo on a secure document) on the media object. This combination forms a new digital watermark signal that is embedded in the host media object. To verify the object, the digital watermark payload is extracted and compared with the data about the object. The combined digital watermark and content signature is also evaluated to authenticate the media signal on the media object.
A method for creating a media object for authentication, comprising:
A method of authenticating a media object using a digital watermark embedded in the media object, the method comprising:
The method of claim 21 wherein the hash is derived from text data printed on the printed object.
A method of authenticating a media object using a digital watermark embedded in the media object, the method comprising:
Dependencies are inferred from the claim text.