Forensic marking using a common customization function

#The present invention relates generally to systems, methods and apparatus for providing forensic markings for media content. Forensic marking is the practice of creating individual copies of information content that are substantially identical for most practical purposes, but that can in fact be distinguished from one another in order to ascertain information about their chain-of-custody subsequent to their distribution. For example, intentionally introduced errors in logarithmic tables were used in previous centuries to prove that certain publications of those tables had been copied from a particular source without authorization from the table's creator. In the modern era, forensic marking is widely viewed as an important technique for protection of valuable media information content such as movies, music, programming, documents, and other digital information content such as software and data files and has convincingly demonstrated its commercial efficacy. Forensic marking is typically intended to assist in locating a point in the chain-of-custody where an unauthorized use of the content occurred.

#A wide range of schemes have been proposed for introducing identifiable marks into content and for subsequently identifying their presence. The broad class of techniques commonly known as “watermarking”, wherein auxiliary data is imperceptibly embedded into the content, are most commonly associated with this task, however a range of different approaches are possible. An exemplary methodology that does not incorporate watermarking is to simultaneously capture one or more scenes in a film production by employing two cameras at different locations and using these similar recordings as alternately selectable versions of content for the purpose of distinguishing copies. Another approach that can be employed with video content is to superimpose a figure or graphic onto the image that is either brief and unnoticeable (such as the “cap coding” dots that are reported to be employed in commercial film production) or that is innocuous (such as superimposing an additional face in a crowd or changing the color of a chair).

#Various forensic marking schemes offering differing performance and capabilities with respect to: the types of content to which they are applicable (e.g., video, audio, textual, images, executable program instructions, data, etc.); the degree of transparency or interference of the marking with respect to primary intended purpose of the content; the payload capacity of the marking (e.g., number of uniquely marked copies that can be generated and the amount of the marked content necessary to identify the mark); the effort required to apply or identify the mark (e.g., the computational complexity of insertion or detection of the forensic mark); the recoverability of the mark following incidental use and modification of the content (“robustness”); or the resistance of the mark to attempts to interfere with its use (“security”) through forgery, modification, eavesdropping, and erasure.

#The present invention will hereinafter be described in conjunction with the appended drawing figures, wherein like reference numerals denote like elements, and:

#FIG. 1 illustrates a general block diagram overview of the forensic marking system in accordance with an example embodiment of the invention;

#FIG. 2 shows a block diagram describing elements of the common customization function of FIG. 1 in accordance with an example embodiment of the invention;

#The ensuing detailed description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing detailed description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an embodiment of the invention. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.

#FIG. 1 illustrates a high-level block diagram of the forensic marking technique of the present invention. The original content 100 is pre-processed by a pre-processing function 104, optionally in combination with alternate content elements 102, to obtain a multiplicity of tributaries 106 and associated customization information 108. The tributaries 106 and customization information 108 are utilized by a common customization function 114 to produce distinctly marked content 118 that carries any of a multiplicity of identifiable mark messages 116. The original content 100 and alternate content elements 102 may be any type of data, signal, or information; however typical embodiments will for practical reasons be limited in applicability to a limited set of data or information types. The tributaries 106 and customization information 108 are represented in a well-defined format that permits independent validation of its compliance with various protocol requirements by a validation function 110, if desired, prior to its application to the common customization function 114. The relationship between the pre-processing function 104, validation function 110 (when present), and common customization function 114 is illustrated in FIG. 1.

#It should be appreciated that while FIG. 1 and the other figures may accurately represent the physical relationships between various components for an example apparatus of the present invention, it is understood that these figures may also illustrate conceptual or logical relationships between various elements of the invention. For example, boxes may correspond to functions, which may be either discretely implemented or integrated with other functions, and arrows may correspond to the flow of information, either by value or by reference. Other relationships, functions, and data paths may also be present in the device which are not shown in the figures including, for example, connectivity to external information sources for control or recording of device activities and access to content-specific information such as encryption and decryption keys.