A digital mark is derived or created for placement on a document to identify, authenticate, or verify the document's origins. Private information is received and digitized. The digitized private information is scrambled in response to the document's contents. The scrambled private information is formed into a mark. The mark is placed on or in the document, apart from the document's information.
A method (and system) for generating an output file from a source file where benign modifications to a content of the output file still render the output file authentic, includes constructing an index vector from the source file, quantizing the source file, generating an authentication mark from the quantized source file and the index vector, generating an authentication tag by appending the index vector to the authentication mark, and generating the output file by appending the authentication tag to the source file.
A device for hiding information in a text comprises a mechanicanism for providing the text, means for linguistically analyzing the text to produce text components, for determining a plurality of formulation alternatives for the text by varying the order of the text components and, optionally, in addition by using synonyms for text components, determining every formulation alternative is grammatically correct for the text and has essentially the same meaning as the text. Certain partial information is allocated to every sequence and/or to every synonym or to every paraphrase.
The watermark grid signal and the watermark payload signal are separately applied to an image. The process is particularly useful in situations where variable data such as serial numbers (or other image specific data) is being embedded in a series of images. In such situations the grid signal can be uniform over an entire sequence of images and only the payload signal need be changed before being printed on each image. The time, computational and labor intensive processes can be applied to the task of embedding the grid signal in the image to insure that visual artifacts are not created. After the image has been changed to embed the grid signal, the payload data can be inserted into at least a selected part of the image. Since the payload signal is less likely to create visual artifacts than the uniform grid signal, less effort need be used to avoid creating visual artifacts due to the payload signal. The relatively random nature of the payload data can be relied upon to avoid creating significant visual artifacts. The same bifurcated process can be used to apply digital watermarks to other media such as sound recordings where potential artifacts are in the nature of sound anomalies rather that visual artifacts.
The present invention relates generally to validating and providing physical objects. In one implementation, a physical object includes a first digital watermark carried thereon. The first digital watermark includes a first plural-bit message representing at least a reduced-bit representation of a biometric corresponding to an authorized bearer of the physical object. The physical object further includes semantic information carried thereon. At least a portion of the semantic information corresponds to the authorized bearer of the physical object. In another implementation, an apparatus is provided to validate physical objects. In some cases the objects include identification documents.
A steganographic embedder associates data with a media signal by encoding the data, a link to the data, or a combination of both into the media signal. The embedder may be located in an media signal capture device or an external process or device.
