Abstract: An embedded data code comprises periodic tiles having occlusions. In one embodiment, each tile is comprised of glyphs encoding a first code system. The occlusions are comprised of information, such as glyphs encoding a second code system, graphics, or text. The occlusions may occur periodically in each tile. A reading device may be used to capture an image of a portion of the substrate that includes a tile. A processor then analyzes the image to determine the tile code pattern and decode the tiled code.

Abstract: A substrate, such as a document of value, carries a design feature (F), which includes an array of repeating patterns with the patterns exhibiting discrete differences in one or more visual characteristics, for example, shape, color or optical responses, according to a predetermined pattern. The differences are, preferably, indiscernible to the unaided eye, but can be discriminated by an optical reading machine. In an alternatively preferred embodiment, the visual characteristics of each pattern represent 8- or 16-bit information.

Abstract: A self-verifying security document, such as a banknote, comprises a flexible sheet formed from a plastics substrate bearing indicia. The sheet has a window of transparent plastics material that includes self-verification means for verifying a security device provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window into register with the security device. The self-verification means may be an optical lens for reading an area of microprinting. In another embodiment, the self-verification means may be an optical filter for viewing an area printed with metameric inks. In other embodiments, the self-verification means and the security device may be polarizing windows or Moire inducing patterns.

Abstract: This invention relates generally to a method and apparatus, as implemented by a software program on a computer system, for digitally producing counterfeit-deterring scrambled or coded indicia images, typically in a printed form. This method and system are capable of combining a source image with a latent image so the scrambled latent image is visible only when viewed through a special decoder lens. The digital processing allows different latent images to be encoded according to different parameters. Additionally, latent images might be encoded into single component colors of an original visible image, at various angles from each other. A second embodiment teaches a method of forming an optical surface having diffraction properties that vary over the optical surface in accordance with a security graphic image that includes an encoded recognizable indicium formed as a parallax panoramagram image through a lenticular line screen.

Abstract: The system and method of the present invention forms an item specific pattern on a plain or holographic metallized film or hot stamp foil, including an embossed substrate with or without holograms. An ink jet printhead includes a plurality of ink jet channels and respective ink jets that receive one of etchant or etchant-resistant mask material for ejecting etchant or etchant-resistant mask material through the respective ink jets onto a metallized surface of the metallized film or hot stamp foil. A controller individually and digitally controls the ejection of etchant or etchant-resistant mask material in a programmed manner for ink jet printing on the metallized surface a unique pattern of etchant or etchant-resistant mask. Etchant etches the metallized surface into an item specific pattern by the ink jet printed etchant or subsequently applied etchant that exposes the metallized surface devoid of the etchant-resistant mask.

Abstract: The invention relates to an apparatus and method for enhancing the security of selected information associated with a negotiable document, such as the monetary value of a cheque. In the invention, one or more security features are printed or applied onto the cheque. One such security feature is an encrypted control code. The preferred embodiment employs a secret key cryptographic scheme to encrypt the monetary value and thereby generate a first control code which is printed on the check. When the check is presented for payment, a validator, such as bank or cheque clearing house, employs a verification system having a copy of the encryption key to read the monetary value from the cheque and re-encrypt it according to said scheme to generate a second control code. The cheque is not honored if the first and second control codes are not identical. Another security feature is a security image, composed, for instance, from a foreground image of the monetary value superimposed over a background motif image.

Abstract: A self-verifying security document, such as a banknote, comprises a flexible sheet formed from a plastics substrate bearing indicia. The sheet has a window of transparent plastics material which includes self-verification means for verifying a security device provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window into register with the security device. The self-verification means may be an optical lens for reading an area of microprinting. In another embodiment, the self-verification means may be an optical filter for viewing an area printed with metameric inks. In other embodiments, the self-verification means and the security device may be polarizing windows or Moire inducing patterns.

Abstract: Preprinted forms are used in a general purpose printing device to allow for the subsequent verification of the authenticity of a printed document such as a ticket for transportation services. In operation, the user accesses the seller of the goods/services and during an information exchange with the seller the user inputs at least a portion of the preprinted data from the form. The seller then uses this information to formulate a printable control indicia which is then printed on the form at the user's location. When the form is subsequently presented to the seller, for example when the user attempts to board an aircraft using the form he/she printed, the preprinted portion of the form is used to obtain a decipher key which in turn is used to decipher the control indicia. Inability to decode the control indicia indicates that the printed material on the form may not be authentic.

Abstract: A document is printed with graphical symbols which encode information but are not human readable; the graphical symbols are formed into some or all of a visible element and the shapes of the external borders of several graphical symbols differ from each other in order to achieve a desired appearance for the element. Typically, one or both of the linear dimensions of a graphical symbol can be altered for the appropriate aesthetic effect. Prior art graphical symbols (e.g. glyphs etc.) are generally fixed in shape and hence cannot be modified for aesthetic effect. Instead, they have generally been large and obtrusive blocks which considerably mar the appearance of a printed document. This negative impact on appearance has been one of the major causes inhabiting the uptake of graphical symbol technology for encoding information.

Abstract: A counterfeit-resistant document comprises a substrate and a nano-pattern of nano-structures disposed on the substrate, wherein the nano-pattern is configured for forming a latent message (e.g., a warning or alert message) that appears on a copy of the document. The nano-pattern forms one of a foreground and a background of the latent message; and another pattern, e.g., a conventional pattern or another nano-pattern, forms the other of the foreground and background of the latent message. The nano-pattern and the other pattern are configured, such that the foreground and background exhibit substantially similar visual densities on an original of the document, and exhibit substantially different visual densities on the copied document. This can be accomplished by forming the nano-pattern with nano-structures (e.g.

Abstract: A fluorescent or luminous composition, comprising a multilayered film-coated powder having at least two coating films on a base particle, and a fluorescent or luminous substance; the composition, wherein at least one layer of the coating films contains the fluorescent or luminous substance; a genuine/counterfeit discrimination object, in which the fluorescent or luminous composition; and a genuine/counterfeit discrimination method, comprising recognizing fluorescence or luminescence by irradiating, with a light, the genuine/counterfeit discrimination object.

Abstract: A multi-layer, pressure sensitive label having a print receiving layer, a sealant layer, a silicone layer, a varnish layer and an adhesive layer, whereby the pressure sensitive label is separable from a substrate between the silicone and a varnish layer leaving a transparent surface allowing the viewing or reading of any underlying text, message or indicia on the substrate.

Abstract: Disclosed is a printing system in which unauthorized copying and reproduction are prevented by making it easy to identify the source which created or manipulated image data to be reproduced and outputted. In accordance with this printing system, image data is entered from a personal computer that generates the image data, attribute information concerning the personal computer and a printer for forming an image is acquired, identification information which specifies the personal computer and the printer is generated based upon the attribute information, this identification information is added to the image data, and an image is printed using the image data to which the identification information has been added.

Abstract: Disclosed is a method for counterfeit-proof of documents bearing a picture. The picture is transferred into a digital image file or present as a digital image file into which a binary form secret image present is incorporated. The digital image file is divided into cells of a number equaling a number of pixels of the secret image. A parameter function allocates a binary output value to each cell on the basis of parameter values, which describe each image point, in such a manner that the bivalent output value of all the cells yields a bivalent position matrix, by the parameter values of the image points of the individual cells being modified with the aid of an optimizing process in such a manner that, first, the changes made to the image file of the picture of the document result in no visually perceivable changes and, second, the result of applying the parameter function to the individual cells yields a bivalent position matrix which corresponds to the binary values of the secret image.

Abstract: In a method and system for identifying one or more objects, a two-dimensional, optically readable pattern and an identification code are generated. The pattern and the identification code are paired in one-to-one correspondence by means of a predetermined algorithm and are arbitrary. A two-dimensional representation of the pattern is provided on the object or on a pattern support connected thereto. The identification code is stored together with associated identification information. In order to identify the object, the representation of the pattern thereof is optically scanned and the associated identification code determined, by means of which the identification information can be determined.

Abstract: The invention relates to an apparatus and method for enhancing the security of selected information associated with a negotiable document, such as the monetary value of a cheque. In the invention, one or more security features are printed or applied onto the cheque. One such security feature is an encrypted control code. The preferred embodiment employs a secret key cryptographic scheme to encrypt the monetary value and thereby generate a first control code which is printed on the cheque. When the cheque is presented for payment, a validator, such as bank or cheque clearing house, employs a verification system having a copy of the encryption key to read the monetary value from the cheque and re-encrypt it according to said scheme to generate a second control code. The cheque is not honored if the first and second control codes are not identical. Another security feature is a security image, composed, for instance, from a foreground image of the monetary value superimposed over a background motif image.

Abstract: Universally available preprinted forms are used in a general purpose printing device to allow for the subsequent verification of the authenticity of a printed document such as a ticket, stamp, check, or money order. In operation, the user accesses the seller of the goods/services and during an information exchange with the seller there is inputted at least a portion of the preprinted data from the form. The seller then uses this information to formulate a printable control indicia which is then printed on the form at the user's location. When the form is subsequently presented to the seller, for example when the user uses the form he/she printed, the preprinted portion of the form is used to obtain a decipher key which in turn is used to decipher the control indica. If desired, a special security marking may be associated with the form for additional security. Inability to decode the control indicia indicates that the printed material on the form may not be authentic.

Abstract: A self-verifying security document, such as a banknote, comprises a flexible sheet formed from a plastics substrate bearing indicia. The sheet has a window of transparent plastics material which includes self-verification means for verifying a security device provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window into register with the security device. The self-verification means may be an optical lens for reading an area of microprinting. In another embodiment, the self-verification means may be an optical filter for viewing an area printed with metameric inks. In other embodiments, the self-verification means and the security device may be polarizing windows or Moire inducing patterns.

Abstract: An organizational tool for use by individuals in providing a portable container holding consolidated personal medical and health information from both traditional and non-traditional sources on a plurality of sheets having specialized formats for the recording of such information including healthcare directives, personal information, medications, treatments and test results.

Abstract: The invention relates to a multilayer label comprising at least one authenticity feature (5), which authenticity feature (5) consists of at least two parts (51, 52) positioned on different layers (1, 2) of the label. The authenticity feature (5) can be a barcode which can consist of at least two parts (51, 52) positioned on different layers (1, 2) of the label. The barcode can have m lines of which n lines are arranged on one layer (1) of the label and m-n lines are arranged on another layer (2) of the label, where m>n>0. The label can have a lower layer (2) and an upper layer (1), with the lower layer (2) having a greater surface area than the at least one layer (1) positioned on top of it. The upper side and/or lower side of at least one of the layers (1, 2) can be coated with an adhesive at least in sections and/or at least in points.

Abstract: Disclosed are methods and systems for authenticating a unique article utilizing a generated unique data signature. The unique data signature is generated by encrypting a received data set representative of a unique identification number fixed to a substantially unforgeable document. The unique data signature is fixed to the unique article or to an optionally generated ownership certificate or the like. The unforgeable document is retained, possibly as the ownership certificate, or the like, or as a part thereof, to thereby authenticate the unique article.

Abstract: A plastic film comprising a plastic resin having imprinted on one of its surfaces a microtyped marking is disclosed. The film, optionally in the form of a laminate with a film of polymeric material, paper or metal foil is useful as packaging material.

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet bas a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarising windows (31, 32) or Moire inducing patterns (41, 42).

Abstract: The invention relates to a method for marking solid, liquid or gaseous substances, whereby the substance to be marked is provided with at least one synthetically produced nucleic acid sequence. Said nucleic acid sequence contains a first sequence section constructed with the 5′ terminal end, a second sequence comprised of at least two bases and connected to said nucleic acid sequence, and a third sequence section constructed with the 3′ terminal end and connected to the said nucleic acid sequence. In order to simplify the identification of the marking, the invention provides that a first primer group is used with a first primer section corresponding to the first sequence section and a second primer group is used with a third primer section corresponding to the third sequence section.

Abstract: The invention relates to an apparatus and method for enhancing the security of selected information associated with a negotiable document, such as the monetary value of a cheque. In the invention, one or more security features are printed or applied onto the cheque. One such security feature is an encrypted control code. The preferred embodiment employs a secret key cryptographic scheme to encrypt the monetary value and thereby generate a first control code which is printed on tile cheque. When the cheque is presented for payment, a validator, such as bank or cheque cle aring house, employs a verification system having a copy of the encryption key to read the monetary value from the cheque and re-encrypt it according to said scheme to generate a second control code. The cheque is not honoured if the first and second control codes are not identical. Another security feature is a security image, composed, for instance, from a foreground image of the monetary value superimposed over a background motif image.

Abstract: A credit card with driver's license for providing credit to an individual, information regarding the individual and proof of registration to operate a motor vehicle on a single form of identification. The credit card with driver's license includes a semi rigid thin piece of material having a face side, a photograph of the individual positioned on the face side, additional identifying information positioned on the face side and a magnetic strip storing information providing access to credit of the individual and personal information regarding the individual upon reading of said magnetic strip by a credit card terminal. The credit card with driver's license is registered with a department of motor vehicles in a state in which the owner resides and credit is provided by either an independent financial institution or the state government issuing the driver's license.

Abstract: Digital watermarking of audio, image, video or multimedia data is achieved by inserting the watermark into the perceptually significant components of a decomposition of the data in a manner so as to be visually imperceptible. In a preferred method, a frequency spectral image of the data, preferably a Fourier transform of the data, is obtained. A watermark is inserted into perceptually significant components of the frequency spectral image. The resultant watermarked spectral image is subjected to an inverse transform to produce watermarked data. The watermark is extracted from watermarked data by first comparing the watermarked data with the original data to obtain an extracted watermark. Then, the original watermark, original data and the extracted watermark are compared to generate a watermark which is analyzed for authenticity of the watermark.

Abstract: A security document is provided comprising: a security image area on the face of the document and a printed security image within the security image area. At least a portion of the security image area is divided into a plurality of image element cells, such that the image element cells define an array of image element cells across the security image area. Each of the image element cells is divided into a plurality of pixels, such that each image element cell defines a cell pixel array. At least a portion of the security image area is divided into a plurality of complementary image element cells, such that the complementary image element cells define an array of complementary image element cells across the security image area. Each of the complementary image element cells is divided into a plurality of pixels, such that each complementary image element cell defines a cell pixel array. The printed security image comprises image elements and complementary image elements.

Abstract: The configuration procedure for an access code and for a security code is provided, comprising: providing references retaining element file that records the base checkerboard-like substrate, checkerboard-like substrates and the color substrates as a graphical image with a hierarchical layered structure arranged on the base substrate, assigning the digital elements to both the x- and the y-axes of the base substrate, assigning the digital elements assigned to the references retaining element on the base substrate perpendicular to the selected two retaining element to the selected two retaining element of the checkerboard-like substrate, configuring code based on the assigned digital elements and the prescribed priority order of the first and areal codes and at the time of the code configuration, recording the location of the retaining element, coaxially rotating the checkerboard-like substrates and color substrates with respect to base checkerboard-like substrate, whereby a new code is configured based on the

Abstract: A method is described to combine together at least two continuous tone digital images into a combined digital image. When viewed in the standard manner, the combined image appears to be the first of the two images. The second image cannot be seen. When the bits within each pixel of the combined image are reversed, i.e. the least significant bit (LAB) is exchanged with the most significant bit (MB), and the resultant image is viewed, then the second image is seen. In this way, one image can be hidden inside the noise bits of another image. The method is applied to color images by treating each color separation independently. The encoding of one image into the other, while maintaining good image quality is accomplished using two simultaneous error diffusion calculations to determine the single output value for each pixel.

Abstract: A security device comprises a substrate (1) having a viewing region (3) which is provided on one side with first indicia (7) and on the other side with second indicia (9) overlying the first indicia. The substrate carries an obscuring material (10) aligned with the second indicia (9) so as to prevent at least the second indicia from being viewed from the one side of the substrate under reflected radiation. The substrate is sufficiently transparent while the obscuring material permits the passage of sufficient transmitted radiation to allow the second indicia (9) to be viewed from the one side of the substrate under transmission conditions.

Abstract: An intelligent agent and its client communicate using a selector known by both parties to generate and interpret messages and thereby effectively disguise confidential information transmitted in the messages from third parties. Moreover, a neural network is used to implement the decision logic and/or the message disguising functions of an agent such that the logic employed in such functions is not readily reverse compiled or scanned by third parties.

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet has a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarising windows (31, 32) or Moire inducing patterns (41, 42).

Abstract: A programmable hologram generator comprises a layered structure of a pixelated VLSI chip, a reflective ferroelectric liquid crystal that is physically disposed on the VLSI chip, and a photorefractive crystal that is physically disposed on the liquid crystal. The VLSI chip is controlled by a computer wherein holograms are digitally stored. The reflective state of the individual pixel areas of the liquid crystal are controlled or selected by this computer control of the VLSI chip. A desired hologram is written into the photorefractive crystal by a reference beam that illuminates the photorefractive crystal, and by an illumination beam that is reflected from the selected pixels of the liquid crystal and thereafter interferes with the reference beam. The hologram that is written into the photorefractive crystal is a function of the control of the reflective state of the pixels of the liquid crystal, as this reflective state is in turn controlled by the pixels of the VLSI chip.

Abstract: A method for controlling keys used in the verification of encoded information generated by a transaction evidencing device and printed on a document comprises the steps of generating a plurality of random verifier master keys to obtain a set of verifier master keys consisting of a fixed number of keys; generating at least one pointer by applying a psuedorandom algorithm to data unique to the transaction evidencing device; calculating a plurality of verifier token keys to obtain a verifier token key set corresponding to the set of verifier master keys; encrypting the verifier token key set with a privacy key; and distributing the set verifier token keys and the privacy key to verifiers. The token keys are a function of the verifier master keys and a code valid for a limited time. The pointer algorithm is an appropriate symmetric key cryptographic algorithm and the code is function of a date dependent parameter. The master keys are distributed to postal and vendor data centers.

Abstract: A label for a container which is at least partially translucent, an image bearing portion located on part of the label with the image bearing portion including an image which is in a visually incoherent form, and a viewing member located on another part of the label for rendering the image in a visually coherent form when the image is viewed through the viewing member. The image or message provided on said image bearing portion can be optically encoded so as not to be intelligible except when viewed through the viewing member, such as a decoding window. Encoding/decoding techniques which can be utilized include, but are not limited to, lenticular indicia and hologram indicia, both of which are decoded by using techniques "matched" to the encoding technique. The label may be integrally formed on, for example, a box-type container.

Abstract: A watermarking procedure wherein each of a set of copies of the work has a slightly-modified form of a "baseline" watermark that is placed within a critical region of the data. The slight variations in the watermarks, however, are not perceptually visible and do not interfere with the work. If multiple persons collude to attempt to create an "illicit" copy of the work (i.e., a copy without a watermark), however, at least one of the modified watermarks is present in the copy, thereby identifying both the illicit copy and the copier.

Abstract: Digital watermarking of audio, image, video or multimedia data is achieved by inserting the watermark into the perceptually significant components of a decomposition of the data in a manner so as to be visually imperceptible. In a preferred method, a frequency spectral image of the data, preferably a Fourier transform of the data, is obtained. A watermark is inserted into perceptually significant components of the frequency spectral image. The resultant watermarked spectral image is subjected to an inverse transform to produce watermarked data. The watermark is extracted from watermarked data by first comparing the watermarked data with the original data to obtain an extracted watermark. Then, the original watermark, original data and the extracted watermark are compared to generate a watermark which is analyzed for authenticity of the watermark.

Abstract: A system quickly verifies that the content of an image has not been changed since an earlier time when the content of that image was stamped. The system consists of a stamping process that embeds stamping information into a source image and produces a verification key, and a verification process that extracts stamping information from a stamped source image based on the verification key. Furthermore, the verification process produces an image itself, from which the verification can be readily judged visually or by use of a computer or other display device. In the verification process, the changes in an image can be detected and localized. The image stamping process further includes an error diffussion process so that the effects of combining the stamping information with the original image are not readily perceptable. An image is safeguarded against malicious manipulations and the proprietary rights are protected by maintaining the integrity of the image content.

Abstract: The present invention relates to a method for producing security paper which includes a security feature. The method comprises forming paper in a wet state, which paper incorporates on or more security features, applying to the paper a sizing agent, thereafter applying to one or both sides of the sized paper a coating comprising an unpigmented polyurethane. The unpigmented polyurethane may optionally comprise a functional additive provided that the presence of the functional additive does not increase the opacity of the paper by more than 1%. After the polyurethane has been applied the paper is dried. The coating composition provides a film, when cast on a glass surface, having a Konig hardness of from 15 to 130 seconds.

Abstract: A composite including a polymeric film having a first generally planar major surface and an opposite second major surface defined by a multiplicity of elongate parallel contiguous ridge portions. The ridge portions each have a generally triangular cross section and elongate obscured and transmitting second major surface portions intersecting at the apex of the ridge with the obscured second major surface portion being on the side of the ridge generally facing a first end of the sheet and the transmitting second major surface portions being on the side of the ridge portions adjacent a second end of the sheet.

Abstract: A product, such as a credit card, passport, or bank note, is secured against forgery or fraud by the provision of a unique pattern of overlying individual fibers which are embedded in a transparent base material, and such that the fibers form differing geometrical configurations which are optically scannable through a surface of the transparent base material. The product is thus made unique and impossible to forge, and its authenticity may be verified by initially scanning the geometrical configurations, with the scanned information being converted into digital data which may be compressed and encrypted, and then stored in a permanent memory. Following the distribution of the product, an inspector may scan the product and compare the obtained data with the stored data to thereby verify the authenticity of the product.

Abstract: This invention relates generally to a method and apparatus, as implemented by a software program on a computer system, for digitally producing counterfeit-deterring scrambled or coded indicia images, typically in a printed form. This method and system are capable of combining a source image with a latent image so the scrambled latent image is visible only when viewed through a special decoder lens. The digital processing allows different latent images to be encoded according to different parameters. Additionally, latent images might be encoded into single component colors of an original visible image, at various angles from each other.

Abstract: Multiple validations of printed documents incorporating image information and authorizing data on a printed document assist in the printed document validation process. This technique requires the authorized document holder to have an image identification accompany the application or production of the document. Image information is converted to a storable image that is used in one of a plurality of validating schemes that assures that the presenter of the printed document is not a substitute. Such schemes included visual comparison of the printed document presenter and extracted image information and validation that the data has not been altered. Non-reversible encryption of the data, as it is read from the document at the document presentation site is used to formulate encoded authorization data that is then compared against like encoded authorized document holder data stored at a centrally located data base.

Abstract: A watermarking procedure wherein each of a set of copies of the work has a slightly-modified form of a "baseline" watermark that is placed within a critical region of the data. The slight variations in the watermarks, however, are not perceptually visible and do not interfere with the work. If multiple persons collude to attempt to create an "illicit" copy of the work (i.e., a copy without a watermark), however, at least one of the modified watermarks is present in the copy, thereby identifying both the illicit copy and the copier.

Abstract: A method and device for protecting visual information against unauthorized access and modification using a printed cryptographic watermark includes printing a first array of shapes on a first sheet of material to be protected and printing a second array of shapes on a second sheet of material, which is transparent so as to form a developer for developing a watermark encoded in a combination of the first and second arrays of shapes. The watermark is encoded by preparing each array using black and white pixels. Each pixel, which may be a square, rectangle, circle, hexagon or other shape, is split into first and second collections of subpixels, the first collection of subpixels appearing in the first array of shapes and the second collection of subpixels appearing in the second array of shapes.

Abstract: A facsimile security system includes a base sheet capable of having confidential information thereon and a cover sheet with imprinting thereon for obscuring the confidential information on the base sheet. The imprinting comprises lines in a repeated pattern over the cover sheet and the lines are separated by spaces without imprinting which spaces extend across the cover sheet or in an elongated direction of the cover sheet. The spaces may extend in a diagonal direction on the cover sheet or the spaces may extend only partially across the cover sheet in a repeated pattern. The cover sheet is preprinted in a preferred form of the invention.

Abstract: The invention disclosed here is a method of encoding serial numbers indicating "confidentiality" or "proprietary information" on printed documents. A group of marks in the form of small-sized dots or equivalent markings are repetitively printed across the face of the document. The placement and location of the markings defines a readable binary serial number. Intermixing the markings with the printed matter on the document makes it difficult or impossible to remove the serial number created by the markings, and they will remain on the document after repeated photocopies of it are made.

Abstract: A system for the encryption of documents is described. A document, which may contain not only text, but also handwriting, pictures, charts, or other graphic images, is converted into a bitmap. This bitmap is encrypted and printed, preferably in a widely-spaced format for ease of subsequent processing, as an encrypted document. The encrypted document may then be copied or sent via facsimile machine as any other printed document, but without disclosing its contents to individuals other than the intended recipient. The encrypted document, or a replica thereof, is then scanned into a decryption device, which converts it into an encrypted bitmap, decrypts the encrypted bitmap, and displays or prints the decrypted document. Bitmap compression may optionally be used to reduce the size of the encrypted document.

Abstract: A security device for use on identification cards, monetary documents, and the like using a reference pattern and a message pattern each having the appearance of a random pattern of dots. The reference pattern is a dense pattern of randomly positioned dots, and the message pattern is a modulated version of the reference pattern in which the dots of the reference pattern are slightly repositioned by an amount depending on the grey value or color value of a message image at each dot location. The message image is decrypted and becomes visible with a range of grey values when it is viewed through a film transparency of the reference pattern. The dot pattern may be printed, embossed or recorded as a photograph or a hologram. Decryption of the message image may be accomplished by viewing through a contact mask, superposition of images of the message pattern and reference pattern, by viewing the message pattern through a mask positioned at a real image of the reference pattern, or like means.