Abstract:
A method and system is disclosed for printing an authenticatable image having an embedded image into a receiver having a discernible physical characteristic, such that the printed image can be used to authenticate the receiver which includes scanning the receiver to produce information related to the discernible physical characteristic of the receiver, and providing a carrier which includes information related to the scanned receiver discernible physical characteristic. The method also includes combining the carrier with an input image to form the authenticatable image having the embedded image, and printing the authenticatable image having the embedded image onto the receiver.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a divisional application of U.S. Ser. No. 09/930,696 filed Aug. 15, 2001 entitled AUTHENTIC DOCUMENT AND METHOD OF MAKING by David L. Patton et al. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates generally to the field of authenticating documents and in particular creating a print medium with an identifying physical anomaly.  
       BACKGROUND OF THE INVENTION  
       [0003]     An article from the Hardcopy Observer, “Pitney Postage Plan Wins Approval, Escher Tries New Approach”, January 2000 announces a technology that enhances the security of postage documents by forming a signature of the paper fiber over a localized region and then printing this signature elsewhere on the envelope in the form of wavy lines.  
         [0004]     Since the image obtained from scanning paper fiber is random, it is very likely that no two envelopes ever have or ever will possess the same fiber structure. Therefore, every envelope may be considered to have a unique identifier and may be used to uniquely identify every letter. The technique requires that the fiber signature be printed and encoded as a series of wavy lines elsewhere on the envelope. How the fiber signature is distilled from the fibrous region is not disclosed. A significant advantage of this system is that it is unlikely that a counterfeiter would discover the process needed to duplicate this process. Simply copying the envelope is not sufficient because modern copiers do not copy the fibrous structure. The copier resolution is simply not high enough. By providing an information channel directly related to the unique aspects of the paper itself, the ability to counterfeit is minimized.  
         [0005]     However, the technique described above has a significant shortcoming. The requirement is that the fibrous signature is used as the unique identifier. The fibrous signature relies on the construction of the paper base of the envelope. Other medium such as photographic paper, thermal transfer, and inkjet all have different surface characteristics. In some cases these media do not have a paper base or a paper base that is close to the surface where the fiber structure is available for scanning. These media generally have a receiver layer constructed using a polymeric material. The polymeric materials used to form the receiving layer cover the paper base obscuring the fibers. The fibers themselves are susceptible to damage from outside elements such as water, abrasion, etc. In addition the technique does not provide a separate record in the form of a digital file of the scan of the envelope&#39;s fiber or link that file back to the envelope.  
         [0006]     Verification Technologies, Inc. discloses on their Website at http://www.netventure.com/vti/isis/main.htm a method for identifying valuable objects by capturing a unique series of microphotographs and a log of how they are collected. The microphotographs are then used to verify the authenticity of the objects.  
         [0007]     In each of the cases cited the feature being scanned or photographed already exists as a part of the object. The features are not purposely created during the time of manufacture for the sole purpose of proving authenticity. Nor is any attempt made to artificially create the mark or produce a mark that is physically robust.  
         [0008]     It is an object of the present invention to provide a high-resolution scan of the physical indicia identifier creating a unique digital representation of the physical indicia identifier.  
         [0009]     It is a further object of the present invention to provide a cryptographically secure method for invisibly hiding (or embedding) a message derived using a texturally derived signature from the anomaly. In the case of printed image on the media, the need for a visible representation of the data to authenticate an image is eliminated.  
         [0010]     It is another object of the present invention to provide a unique physical indicia identifier by embossing, etching or printing a pattern on the front or back surface of a media.  
         [0011]     It is a further object of the present invention to provide a high-resolution scan of the physical indicia identifier creating a unique digital representation of the physical indicia identifier.  
       SUMMARY OF THE INVENTION  
       [0012]     In accordance with one aspect of the present invention there is provided a method for making media on which is used for making an authenticable original document, comprising the steps of: 
        providing a predetermined amount of media;     forming a three dimensional physical indicia identifier on the predetermined amount of media.        
 
         [0015]     In another aspect of the present invention there is provided a media that is used for making an authenticable original document, the media having a three dimensional physical indicia identifier formed thereon, the media being made of a material such that when the three dimensional physical indicia is digitally scanned a unique digital file is produced.  
         [0016]     These and other aspects, objects, features, and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings in which:  
         [0018]      FIG. 1  is a schematic of a sheet of media having pre-formed physical indicia identifier made in accordance with the present invention;  
         [0019]      FIG. 2  is a schematic diagram illustrating how a sheet of media having pre-formed physical indicia identifier is made in accordance with the present invention;  
         [0020]      FIG. 3  is a schematic diagram illustrating a second embodiment of how a sheet of media having pre-formed physical indicia identifier is made in accordance with the present invention;  
         [0021]      FIG. 4  is a partial view of  FIGS. 2 and 3  illustrating how a sheet of media having pre-formed physical indicia identifier is made in accordance with the present invention;  
         [0022]      FIG. 5  is a flow chart illustrating the operation of the overall system made in accordance with the present invention;  
         [0023]      FIG. 6  is a schematic diagram of a system made in accordance with the present invention;  
         [0024]      FIG. 7  is a flow chart of the operation of the system of  FIG. 6 .  
         [0025]      FIG. 8  is a completed document made using the sheet of  FIG. 1 ;  
         [0026]      FIG. 9A  is a flow chart illustrating one method on how the document of  FIG. 8  is verified; and  
         [0027]      FIG. 9B  is a flow chart illustrating another method on how the document of  FIG. 8  is verified. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     The invention utilizes aspects of data embedding. The science of data embedding is also referred to as data hiding, information hiding, data embedding, watermarking, and steganography. A data embedding technique is disclosed in Honsinger, et al., U.S. Pat. No. 6,044,156, which is incorporated herein by reference.  
         [0029]     Referring to  FIG. 1 , there is illustrated a sheet  10  for making a document in accordance with the present invention. Sheet  10  may be a print medium such as photosensitive, ink-jet, or thermal transfer media uniquely fingerprinted with a physical indicia identifier  15 . The physical indicia identifier  15  is a unique physical feature formed in the front or back surface or an integral part of the structure of the sheet  10 . For example, the physical indicia identifier  15  can be but is not limited to an embossed, etched or engraved indicia or a discernable physical characteristic on the front and/or back surface of the sheet  10  and not duplicatable using known visual copying techniques. The physical indicia identifier  15  may or may not be visible to the unaided eye. Sheet  10  is also printed with a unique identification number  20 . The identification number  20  may be a human and/or machine-readable code, for example an alphanumeric or a bar code.  
         [0030]     Referring now to  FIG. 2 , there is illustrated a schematic diagram of an apparatus for making the sheet  10  of media  41  having the physical indicia identifier  15  and identification number  20 . It is well known to those in the art of manufacturing resin-coated media that a resin such as polyurethane or polyethylene is heated to above the glass transition point then applied to a base  40  such as paper or plastic via a hopper  42 . After the resin has been applied to the base, the base is run through a set of chilled rollers  44  where the resin is evenly spread over the surface of the base  40  and hardened. The resulting base  40  can be used to manufacture media  41  in the form of thermal, photosensitive paper or inkjet paper. The type of media  41  being manufactured can determine whether the physical indicia identifier  15  is formed on the front or back surface. For example if the media  41  is of the thermal type having a resin overcoat, the physical indicia identifier  15  may be formed on the top surface. If the media  41  is photosensitive paper where an emulsion is coated on a resin coated base, the physical indicia identifier  15  may be formed on the back surface. If the media  41  is inkjet paper, which may or may not have a resin coating, the embossing may be used to form the physical indicia identifier  15  on either the back or front surface. In the case where the media  41  is manufactured in a roll  46  to roll  47  process as shown in  FIG. 2 , the base  40 , after the resin has been coated, passes through a set of physical indicia identifier forming rollers  48 . Referring to  FIG. 4 , there is illustrated an enlarged partial view of  FIGS. 2 and 3 . The rollers  48  contain heating elements  50  similar to the heating elements used in thermal heat heads such as those used in a KODAK ds 8650 PS Color Printer. As the media  41  passes between the rollers&#39; heating elements  50  the heat from the heating elements  50  form a specified three-dimensional pattern of the physical indicia identifier  15 . A logic control unit, such as computer  45  controls the heating elements to provide successively different physical indicias. This allows the forming of a unique physical indicia identifier  15  for each sheet. After the physical indicia identifier  15  is formed in the surface of the resin coating a high-resolution scan is made via a scanner  52  and/or  54 . In addition, an identification number  20  is printed on either the front or back surface of the media  41  via a printer  56  or a printer  58  located on the roller  48  and/or roller  49  respectively. In the embodiment illustrated, the high resolution-scan is on the order of 1200 dots/inch. The results of the high resolution-scan are stored in memory, for example in memory of computer  45  or on a memory storage device such as on a CD  25  (shown in  FIG. 6 ) via a computer  45  along with the identification number  20 . The method used for obtaining the high-resolution scan will be explained later. While in the particular embodiment illustrated the results of the scan is stored on a CD, it may be stored in any desired memory storage device or location. For example, but not limited to a computer disc, memory stick, memory card, or an internet accessible URL address such as a web site.  
         [0031]      FIG. 3  illustrates a schematic diagram of an apparatus made in accordance with the present invention wherein the media  41  is cut into a plurality of cut sheets  43  each having a physical indicia identifier  15  and identification number  20  as previously discussed. Like numerals in  FIG. 3  indicate like parts and operation as previously discussed with respect to  FIG. 2 . The media  41  is fed from the roll  46  via a set of drive rollers  55  and  57  through the set of rollers  48  and  49 . These rollers  48  and  49  contain either heating elements  50  or embossers (not shown). As the media  41  passes between the roller  48  and  49  the embossing roller form the specified pattern of the physical indicia identifier  15 . As each unique physical indicia identifier  15  is formed in the surface of the media  41  the high-resolution scan is made via the scanner  52  or  54  and the identification number  20  is printed on either the front or back surface of the media  41  via printer  56  or a printer  58 . After the physical indicia identifier  15  has been formed and the identification number  20  printed on the media  41 , the media  41  is cut into sheets  10  via a cutter assembly  60 . Each sheet  10  having its&#39; own distinct physical indicia identifier  15 , identification number  20 , which is associated with a unique scan of the identifier  15 . Typically this is accomplished by a computer associating the scanned digital file with the identification number  20  and storing this information in a memory device.  
         [0032]     Referring to  FIG. 5 , a flow chart illustrates a method for making an original document using sheet  10  in accordance with the present invention. A sheet  10  is provided at step  100 . The identification number  20  is printed on sheet  10  and the physical indicia identifier  15  is formed on the sheet  10  at steps  110  and  120  respectively. A high-resolution scan of the physical indicia identifier  15  is made and a digital file of the high-resolution scan is created at step  130 . The digital file of the high-resolution scan is linked to the sheet  10  via the printed identification number  20  at step  140 . The high-resolution scan provides a unique digital file with respect to physical indicia identifier  15 . The digital file of the high-resolution scan of the physical indicia identifier  15  is stored in memory such as written to a CD  25  (shown in  FIG. 6 ) at step  150  and is associated with the unique identifier number  20 . A digital file that is to be later printed on the sheet  10  is created at step  160 . In the particular embodiment illustrated, the digital file is a text file  165 , however, the digital file may be an image file or mixture of text and image files. For the purposes of the present invention a text file shall mean a text file, an image file, or a combination of text and image files. If the text file  165  is large, it may be distilled at step  170  to a smaller representation called a distilled digital text file  175  using hash algorithms. These algorithms are utilized widely in computer systems. An example of a known hash algorithm is the Secure Hash Algorithm (SHA) of National Institute of Standards and Technology (NIST). With this algorithm it is possible to distill a large data set to 160 bits, rendering the probability of any two documents having the same hash value astronomically small. Modern watermarking technologies can easily hide this amount of data.  
         [0033]     Using the distilled digital text file  175  and an algorithm on CD  25  a message image  185  is created at step  180 . Briefly, the message image  185  is obtained taking the distilled image and scrambling it into a predetermined pattern/template. An example of obtaining this message image is described in greater detail in U.S. Pat. No. 6,044,156 both of which are incorporated herein by reference. The message image  185  is combined with the high-resolution scan file of the physical indicia identifier  15  at step  190 . One method of combining is convolving. An example of convolving is described in U.S. Pat. No. 6,925,192 issued Aug. 2, 2005 to Chris W. Honsinger and David L. Patton. From Fourier theory, spatial convolution of two functions in the frequency domain is the same as adding together the functions phases while multiplying their respective Fourier amplitudes. Therefore, the effects of combining the message with a carrier, such as by the described convolution technique, distributes the message energy in accordance with the phase of the carrier and to modulate the amplitude spectrum of the message with the amplitude spectrum of the carrier. If the message image were a single delta function and the carrier of random phase and of uniform Fourier magnitude, the effect of convolving with the carrier would be to distribute the delta function over space. The Fourier magnitude would maintain its shape because the carrier is of uniform amplitude spectrum. If the amplitude of the convolved delta function is lowered in the space domain, the convolution may be viewed as a way to redistribute energy over space in an invisible way. The effect of convolving an arbitrary message with a random phase carrier is to spatially disperse the message energy over the image. In this sense, the convolution is a dispersive process. The message image  185  combined or convolved with the high resolution scan file of the physical indicia identifier  15  creates a dispersed message  195  at step  190  and the dispersed message  195  along with the text  36  is printed on the sheet  10  at step  200 . Due to the convolution step only the text  36  will be seen and the dispersed message  195  will not be seen by the unaided eye.  
         [0034]     Referring now to  FIG. 6 , the sheet  10  containing the physical indicia identifier  15  and identification number  20  is placed into a printer  22  such as an inkjet or thermal printer. A compact disc (CD)  25  containing the digital file of the high-resolution scan of the physical indicia identifier  15  is placed into a computer  30 . The digital file of the high-resolution scan of the physical indicia identifier  15  has previously been associated to the sheet  10  via the identification number  20 . The high-resolution scan of the physical indicia identifier  15  can also exist on a remote server located at a service provider and be accessed via a communication network such as the Internet  33 . The high-resolution scan of the physical indicia identifier  15  can also exist in any type of memory such as a floppy disk, DVD, hard drive, portal hard drive, etc. and delivered to the computer  30  by any appropriate means.  
         [0035]     Now referring to  FIG. 7 , there is illustrated a flow chart showing how a user creates an original document  34  shown in  FIGS. 6 and 8  made in accordance with the present invention. The user places the sheet  10  into the printer  22  and the CD  25  into the computer  30  at step  220 . A software program in the computer  30 , typically obtained from the CD  25 , asks the user for the identification number(s)  20  for the sheet(s)  10  at step  230 . The user enters the identification number  20  via a keyboard  32  (shown in  FIG. 6 ) at step  240 . If there is more than one sheet required for printing the document, the correct identification number  20  for each sheet placed into the printer and the additional sheets are entered into the computer in the order they will be printed. Using a word processor such as Microsoft Word or Claris Works, the user creates the text file, which is to be printed on the sheet  10  at step  250 . The software using the physical indicia identifier high-resolution scan file  15  and the digital text file creates the dispersed message at step  260  which was previously described in greater detail with respect to steps  160 ,  170 ,  180  &amp;  190  of  FIG. 5 . The digital text file  165  with the dispersed message  195  intermixed therein is printed on the selected sheet(s) at step  270  creating only one original document  34  at step  280  as shown in  FIGS. 6 and 8  that cannot be counterfeited using standard duplicating methods.  
         [0036]     Now referring to  FIG. 8 , there is illustrated the completed document  34  made in accordance with the present invention. The completed document  34  comprises the physical indicia identifier  15 , the identification number  20 , the text  36 , and the dispersed message  195 , which is not normally visible as it is intermixed with the text  36 .  
         [0037]     Now referring to  FIG. 9A , there is illustrated a flow chart of one method on how a document is verified in accordance with the present invention. A digital scan of the physical indicia identifier  15  is made at step  285 . The identification number is used to find the previously scanned information of the physical indicia identifier  15  on CD  25  at step  290 . This stored information is compared with the information obtained by scanning of the physical indicia identifier  15  on document at step  295 . If the scanned information regarding the physical indicia identifier  15  is the same as the stored information the document is verified at decision block  296  as being an original at step  297 , otherwise the scanned document cannot be verified at step  298 .  
         [0038]     Referring to  FIG. 9B  there is illustrated a flow chart of another method on how a document is verified in accordance with the present invention. In this method two different techniques are used to derive the same common data such that the common data obtained by the two different techniques must correspond in order to verify that the document is an original. A digital scan of the document  34  is made at step  300  and using appropriate algorithms on CD  25 , the physical indicia identifier  15 , the text  36 , and the dispersed message  195  are obtained. The physical indicia identifier  15  is located and the dispersed message  195  is obtained at step  310 . By using the data embedding and extraction algorithm described in detail below, the physical indicia identifier  15  is processed in the Fourier domain to maintain phase and flatten the Fourier magnitude. This result is inverse Fourier transformed to obtain a carrier, which is then correlated with the dispersed message  195  as found by step  190  previously discussed in  FIG. 5 . The physical indicia identifier  15  is correlated with the dispersed message  195 , and the message image  185  is recovered at step  330 . Now, the message image  185  recovered at step  330  should correspond to the candidate message image  410  (text file) that is to be validated.  
         [0039]     To obtain the candidate message image  410 , the text file  405  is extracted at step  340  from the scan done at step  300 . An optical character-recognition (OCR) algorithm extracts the digital file  405  of the text at step  340 . It is understood that OCR is one example of a text recognition algorithm and there are many others that can be used. Using the same hash algorithm, text file  405  is distilled at step  350 . This distilled text is used to create a message image as discussed with respect to  FIG. 5  to form a candidate message image  410  at step  360 . A decision of validity is made at decision block  370  by comparing the value of the candidate message image  410  obtained at step  360  with the message image  185  recovered at step  330 . If the candidate message image  410  is the same as the recovered message image  185  recovered at step  330 , the document is validated at step  390 . Otherwise the document is not validated at step  380 . As can be seen in this method two distinct techniques are used to obtain a common data. In one method the common data is obtained starting from the beginning of the method of  FIG. 5 . In the second method using the scanned document and starting at the end of method of  FIG. 5  and working backwards, the common data is obtained. In the embodiment illustrated the common data is the message image, however, the common data could have been the distilled text file. In such case after step  330 , the distilled text file could have been obtained using the appropriate algorithm. This could have been compared with the data obtained at step  350 . All that is important is that the common data is obtained using one method starting from the beginning and compared with the common data is starting from the other end of the process.  
         [0040]     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.  
       Parts List  
       [0000]    
       
           10  sheet  
           15  physical indicia identifier  
           20  identification number  
           22  printer  
           25  CD  
           30  computer  
           32  keyboard  
           33  Internet  
           34  document  
           36  text  
           40  base  
           41  media  
           42  hopper  
           43  cut sheets  
           44  chilled roller  
           45  computer  
           46  roll  
           47  roll  
           48  indicia identifier forming rollers  
           49  indicia identifier forming rollers  
           50  heating elements  
           52  scanner  
           54  scanner  
           55  drive roller  
           56  printer  
           57  drive roller  
           58  printer  
           60  cutter assembly  
           100  step  
           110  step  
           120  step  
           130  step  
           140  step  
           150  step  
           160  step  
           165  digital text file  
           170  step  
           175  distilled digital text file  
           180  step  
           185  message image  
           190  step  
           195  dispersed message  
           200  step  
           220  step  
           230  step  
           240  step  
           250  step  
           260  step  
           270  step  
           280  step  
           285  step  
           290  step  
           295  step  
           296  decision block  
           297  step  
           298  step  
           300  step  
           310  step  
           320  step  
           330  step  
           340  step  
           350  step  
           360  step  
           370  decision block  
           380  step  
           390  step  
           405  digital text file  
           410  candidate message image