LAYERED SECURITY IN DIGITAL WATERMARKING

摘要

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. Biometric information may also be embedded in a machine readable code in the object or indexed via the machine readable code. This biometric information is used to generate biometric templates, and facilitate or enhance biometric comparison for one to one or one to many verification.