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SYSTEM AND METHOD FOR PRODUCTION
AND AUTHENTICATION OF ORIGINAL
DOCUMENTS
FIELD OF THE INVENTION 5
The present invention relates to the field of counterfeit resistant documents, and more particularly to systems and methods employing database techniques to verify authenticity. 10
BACKGROUND OF THE INVENTION
The problem of counterfeiting is long established. Since it was recognized that a document itself could represent 15 value, a motivation has existed for forgery. Two types of methods evolved for preventing counterfeiting: counterfeit resistant features, such as signatures, special printing, special document recording medium recording stock, magnetic and/or electrical features, and the like; and legal sanctions 20 for an otherwise easy copying process. For example, most cultures provide heavy sanctions for counterfeiting of currency, typically much harsher than private document counterfeiting.
The issues of authentication and counterfeit deterrence 25 can be important in many contexts. Bills of currency, stock and bond certificates, credit cards, passports, bills of lading, as well as many other legal documents (e.g., deeds, wills, etc.) All must be reliably authentic to be useful. Authentication and avoidance of counterfeiting can also be important 30 in many less obvious contexts. For example, improved verification/counterfeiting prevention mechanisms would be very useful in, for example, verifying the contents of shipping containers, quickly identifying individuals with particular health or criminal histories, etc. Counterfeit products 35 are, by definition, unauthorized copies of a product, its packaging, labeling, and/or its logo(s). Attractive targets for counterfeiters are items with significant brand equity or symbolic value, where the cost of production is below the market value. 40
In the commercial manufacturing world, it is not uncommon for counterfeit or otherwise unauthorized goods to be manufactured, distributed, and sold in direct competition with authentic goods. Counterfeiting has reached epidemic proportions worldwide, especially in the area of consumer 45 goods including goods made from fabric, plastic, leather, metal, or combinations thereof such as clothing, handbags and wallets, perfumes, and other consumer goods. Electronics and software products are also particular targets of counterfeiters, who appropriate the value of trademarks or 50 copyrights without license. Since costs savings based on decreased incremental cost of production (exclusive of license fees) is not a necessary element in the counterfeiting scheme, the counterfeit articles may be of apparently high quality and closely resemble authentic articles. Indeed, 55 counterfeit articles can so closely resemble genuine goods that consumers readily confuse the counterfeit articles with the authentic articles. In other circumstances, the manufacturer segments the world market for different sales and distribution practices, so that the "counterfeit" goods may be 60 essentially identical to authorized goods. Further, in many instances, a manufacturer produces goods under license from an intellectual property owner, and thus sales outside the terms of the license agreement are also "counterfeit".
A wide variety of attempts have been made to limit the 65 likelihood of counterfeiting. For example, some have tried to assure the authenticity of items by putting coded or uncoded
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markings thereon (e.g., an artist's signature on his or her painting). Unfortunately, as soon as the code is broken— e.g., a counterfeiter learns to duplicate a signature, this method becomes worthless for authentication purposes. In the context of paper products (e.g., currency), counterfeiting-prevention methods have also used two-dimensional authentication mechanisms—e.g., watermarks or special threads incorporated within the paper used to make the currency. These mechanisms are clearly helpful, but they can also be overcome. For example, counterfeiters routinely bleach a one dollar bill (in such a way that the colored threads which mark the special currency paper are not damaged) and then imprint the markings of a one-hundred dollar bill thereon. Thus, the mere release of physical security materials into the market forms one limitation on their unfettered use.
Other authentication methods have utilized mechanisms that provide three dimensions of data. For example, the holograms provided on many credit cards provide more variables (i.e., relative to two-dimensional threads or watermarks) which may be precalibrated, and thereafter, used to verify the authenticity of an item. Nevertheless, since holograms have a pre-set, or deterministic, pattern they may also be duplicated and counterfeit products made. Further, since the holograms are invariant, they are subject to pilferage before application to goods, or translocation from authorized to unauthorized goods in the marketplace. Authentication mechanisms, which utilize deterministic patterns, are inherently vulnerable to counterfeiting since the counterfeiter, in essence, has a "fixed" target to shoot at. High security schemes, such as military codes, have encryption keys that change frequently. This method, however, assists prospectively in securing valuable time-sensitive information, and does not prevent subsequent decryption of a previously transmitted message. At the other end of the spectrum, a random element-based authentication mechanism would provide an incessantly "moving" and nonrepeating target that would be practically impossible to undetectably duplicate, without knowledge of the encoding scheme.
Finally, although existing authentication mechanisms provide adequate protection against counterfeiting in some contexts, increasingly powerful tools are available to decode encrypted messages, making more secure schemes necessary for long-term protection. For example, in conjunction with its monitoring and surveillance activities, governments routinely seek to break or circumvent encryption codes. The technologies employed are then quickly adopted by the private sector, and indeed government regulations seek to maintain weak encryption standards, facilitating codebreaking. In addition to computers, current counterfeiters have access to extremely powerful tools for undermining physical copy-protection schemes—e.g., color photocopying equipment, reverse engineering of semiconductor chips, etc. These factors have combined to continually provoke strong demand for new methods and mechanisms for authenticating items, especially methods and mechanisms that are less vulnerable to counterfeiting and/or employ new copy-protection mechanisms.
More recently, techniques have evolved for authentication of digital information, for example based on cryptological techniques. However, these techniques do not serve to verify the authenticity of a particular copy of the information. In fact, modern digital content protection schemes do seek to prevent digital copying of content; however, these rely on secure hardware for storage of the digital content, and a
breach of hardware security measures results in copyable content with no distinction between an original and a copy thereof.
A number of modern systems implement challenge-response authentication, which provide enhanced security for 5 encryption keys and encrypted content. See, for example, U.S. Pat. No. 6,028,937 (Tatebayashi et al.), U.S. Pat. No. 6,026,167 (Aziz), U.S. Pat. No. 6,009,171 (Ciacelli et al.) (Content Scrambling System, or "CSS"), U.S. Pat. No. 5,991,399 (Graunke et al.), U.S. Pat. No. 5,948,136 (Smy- 10 ers) (IEEE 1394-1995), and U.S. Pat. No. 5,915,018 (Aucsmith), expressly incorporated herein by reference, and Jim Wright and Jeff Robillard (Philsar Semiconductor), "Adding Security to Portable Designs", Portable Design, March 2000, pp. 16-20. 15
The present invention therefore addresses instances where the issue is not merely whether the information is authentic, but rather whether the information is authentic (and unaltered), and the copy itself an original. Obviously, known 2Q techniques may be used to authenticate the content of a document, for example, by providing self-authenticating digital signatures, remote database authentication, trusted intermediary techniques, and the like. Likewise, numerous techniques are available for providing self-authenticating 25 features for the physical medium, for example, security threads, inks, papers and watermarks, printing techniques (e.g., intaglio printing, microlithography), fluorescent inks and/or fibers, steganographic patterns, magnetic and/or electrical/electronic patterns, and the like. 30
In fact, database techniques are known for authenticating objects associated with documents (labels or certificates), in which the document is both self-authenticating and may further reference a remote database with authentication information for the document or associated object. These 35 techniques, however, are not intended to primarily secure the document itself, and thus the techniques fail to particularly address document content security and authentication, as well as models for commercial exploitation thereof.
It is known that the color of an object can be represented 40 by three values, and that the color may be used for identification and authentication. For example, the color of an object can be represented by red, green and blue values, an intensity value and color difference values, by a CIE value, or by what are known as "tristimulus values" or numerous 45 other orthogonal combinations. For most tristimulus systems, the three values are orthogonal; i.e., any combination of two elements in the set cannot be included in the third element. One such method of quantifying the color of an object is to illuminate an object with broad band "white" 50 light and measure the intensity of the reflected light after it has been passed through narrow band filters. Typically three filters (such as red, green and blue) are used to provide tristimulus light values representative of the color of the surface. Yet another method is to illuminate an object with 55 three monochromatic light sources or narrow band light sources (such as red, green and blue) one at a time and then measure the intensity of the reflected light with a single light sensor. The three measurements are then converted to a tristimulus value representative of the color of the surface. 60 Such color measurement techniques can be utilized to produce equivalent tristimulus values representative of the color of the surface. Generally, it does not matter if a "white" light source is used with a plurality of color sensors (or a continuum in the case of a spectrophotometer), or if a 65 plurality of colored light sources are utilized with a single light sensor.
Tamper Evident Certificates
U.S. Pat. Nos. 5,913,543 and 5,370,763 (Curiel), expressly incorporated herein by reference, relates to a tamper evident and counterfeit resisting document, for example a temporary vehicle registration which may be made of paper or paperboard. The document has a zone for inserting information and a pattern within said zone for resisting counterfeiting. A transparent tape which preferably has a silicone resin coating which contains a wax is adhesively secured over information contained within the zone. In other embodiments, an alteration resistant article contains variable data and includes an outer film having an upper surface and a lower surface with an adhesive secured to the lower surface. A hologram for receiving at least a portion of the variable data on the upper surface is secured to the outer film lower surface and, in one embodiment, the hologram has portions which have release properties and portions which have greater adhesive bonding properties than the release containing portions. These respective portions may be established by providing a release material on certain portions of the upper surface of the hologram and providing adhesive enhancing materials on other portions of the hologram upper surface. The hologram may be embossed and have a metallized upper surface. A plurality of relatively small hologram particles may be provided in the outer layer and/or the adhesive layer. The hologram is secured to a substrate which, in one embodiment, has an upper surface printed with pattern means which are printed to a lesser depth than the variable data. In another embodiment, the hologram is provided as a unit with the outer film and overlies the variable data. This system therefore provides physical techniques for document authentication and preventing content alteration.
U.S. Pat. No. 5,601,683 (Martin, Feb. 11, 1997), incorporated herein by reference, provides a photocopy resistant document, having a background pattern or logo which is printed with solvent-sensitive, dye based ink. The presence of this photocopy-resistant background pattern or logo limits copying.
U.S. Pat. No. 5,949,042 (Dietz, II, et al., Sep. 7, 1999), expressly incorporated herein by reference, provides a gaming ticket validation system and method.
Artificial Watermarks
U.S. Pat. No. 5,928,471 (Howland, et al. Jul. 27, 1999), expressly incorporated herein by reference, relates to improved security features for paper, and in particular to a method of making paper and transparentising selected areas of paper to provide enhanced security features. The invention thus provides a method of making paper comprising the step of depositing fibers onto a support surface to form a porous absorbent sheet, applying a transparentising resin to at least portion of said porous sheet and subsequently impregnating the porous sheet with a sizing resin.
The following patents, expressly incorporated herein by reference, provide enhanced security features for use with finished paper and for non-currency and non-security papers. EP-A2-0203499 discloses a method of applying a pseudo watermark to paper. This method comprises the preparation of a paper containing thermally sensitive material, the presence of which renders the translucency of the paper variable by temperature change. When heat is subsequently applied to a part of the surface of the paper, a region of the paper becomes semi-translucent. U.S. Pat. No. 2,021, 141 (Boyer, November 1935) discloses a method of apply5
ing pseudo watermarks to paper, by applying a resinous composition to finished paper which permeates the paper and causes it to become more transparent, or translucent, than the surrounding area. GB-A-1489084 describes a method of producing a simulated watermark in a sheet of 5 paper. The sheet is impregnated in the desired watermark pattern with a transparentising composition which, when submitted to ultra violet radiation, polymerizes to form a simulated watermark. U.S. Pat. No. 5,118,526 (Allen, et al., Jun. 2, 1992) describes a method of producing simulated 10 watermarks by applying heat, in the desired watermark pattern, onto a thin solid matrix of waxy material placed in contact with a sheet of paper. This results in an impression of a durable translucent watermark. U.S. Pat. No. 4,513,056 15 (Vernois, et al., Apr. 23, 1985) relates to a process for rendering paper either wholly or partially transparent by impregnation in a special bath of a transparentization resin and subsequent heat cross-linking of the resin. EP-A10388090 describes a method of combining a see-through or 20 print-through feature with a region of paper which has a substantially uniform transparency which is more transparent than the majority of the remainder of the sheet. JP 61-41397 discloses a method for making paper transparent and a method for its manufacture for see-through window 25 envelopes. The method utilises the effect of causing ink cross-linked by ultra-violet rays to permeate paper thus causing that part of the paper to become transparent.
Copy Resistant Printing Techniques 30
U.S. Pat. No. 5,946,103 (Curry, Aug. 31, 1999), expressly incorporated herein by reference, relates to halftone patterns for trusted printing. Predetermined machine and/or human readable information is embedded in at least one serpentine pattern that is printed on each original document, so that any 35 given instance of such a document can be later verified or refuted as being the original by determining whether this information can be recovered from the document or not. The method for verifying the originality of printed documents, said comprises providing at least one trusted printer for 40 printing original documents, embedding predetermined information in each of the original documents in at least one halftone pattern that is composed of halftone cells, each of the cells containing a fill pattern which is symmetric about a central axis of the cell, with the information being repre- 45 sented by the angular orientations of the respective axis of symmetry of at least some of the cells; and classifying the documents as original documents only if said predetermined information can be recovered therefrom. Thus, the technique relies on information which can be readily printed but not 50 readily photocopied.
Self-clocking glyph codes have been developed for embedding machine readable digital data in images of various descriptions. See, for example, Bloomberg et al. (United States patent application, filed May 10, 1994 under 55 Ser. No. 08/240,798) for Self-Clocking Glyph Codes and U.S. Pat. No. 5,453,605 (Hecht et al, Sep. 26, 1995) for Global Addressability for Self-Clocking Glyph Codes. To integrate these glyph codes into line art images, the data typically are embedded in small, similarly sized, spatially 60 formatted, elliptical or slash-like marks or "glyphs" which are slanted to the left or right in generally orthogonal orientations to encode binary zeros ("0's") or ones ("l's"), respectively. Customarily, these glyphs are written on a spatially periodic, two-dimensional lattice of centers at a 65 density that enables up to about 500 bytes of data per square inch to be stored on a document. These glyph codes are well
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suited for incorporating digital data channels into textual and other types of line art images.
U.S. Pat. No. 5,193,853 (Wicker, Mar. 16, 1993), and U.S. Pat. No. 5,018,767 (Wicker, May 28, 1991), incorporated herein by reference, provide anticounterfeiting methods wherein a marked image has a minute dot or line pitch which varies from normal scanning resolution of typical copying devices, making such mechanical copying detectable.
U.S. Pat. No. 5,315,112, (Tow, May 24, 1994) for Methods and Means for Embedding Machine Readable Digital Data in Halftone Images, describes the use of "circularly asymmetric" halftone dots for incorporating self-clocking glyph codes into halftone images, and defines a workable approach if the data is confined to the midtone regions of the image in accordance with a known or identifiable spatial formatting rule. High sensitivity, however, is required to recover the embedded data with acceptable reliability from the darker or lighter regions of the image.
U.S. Pat. No. 5,706,099, (Curry, Jan. 6, 1998) for Method and Apparatus for Generating Serpentine Halftone Images, expressly incorporated herein by reference, provides circular serpentine halftone cell structures, e.g., Truchet tiles, for embedding data in images. These serpentine halftone cells have a high degree of rotational tone invariance. The arcuate fill patterns may be rotated 45 degrees with respect to the halftone cell boundaries to produce another rotationally distinguishable pair of halftone structures. These structures have been called Manhattans and also are sometimes referred to as ortho-serpentines.
As described in more detail in U.S. Pat. No. 5,696,604, (Curry, Dec. 9, 1997) for Analytic Halftone Dot Construction for a Hyperacuity Printer U.S. Pat. No. 5,410,414 (Curry, Apr. 25, 1995) for Halftoning in a Hyperacuity Printer, and U.S. Pat. No. 5,710,636 (Curry, Jan. 20, 1998) for Method and Apparatus for Generating Halftone Images Having Human Readable Patterns Formed Therein, which are hereby incorporated by reference, halftone patterns may be generated somewhat differently from the traditional way that halftones are generated. The goal is to more precisely control the way the edges of the halftone fill pattern or "shape" evolves as it grows from highlight to shadow. More particularly, in traditional digital halftoning, turning on an appropriate number of bits in a threshold array generates the desired tone. The array holds a sequence of threshold values that may spiral outward from a central location as the threshold values ascend. Bits corresponding to those locations in the halftone cell "turn on" if the incoming data intensity is equal to or greater than the threshold value for that bit location. This method generates halftone dots that grow asymmetrically, as one threshold after another is traversed through a range of intensity values from, say, 0 to 255. For serpentine patterns, however, it is desired to grow the halftone fill pattern at all positions on its perimeter simultaneously to maintain better control of the shape. Therefore, a two step process typically is employed for generating the halftone fill patterns. First, an analytical shape function is defined which grows according to a predetermined evolution from the smallest shape for highlight regions, through midtones, and finally to full coverage of the halftone cell. In this step, shape information is maintained with "infinite precision" with analytic functions. Second, as the area of the shape gets larger, the fill pattern or shape is rendered as if it were a segment of text or line art with a corresponding shape. The result is more control over the shape and the tone evolution of the halftone because they are defined with analytic functions. Nevertheless, it is
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