Abstract:
A system for detecting fraudulent documents comprises a barcode reader and a sensor arrangement. The output from the barcode reader and the sensor arrangement are used in conjunction to increase the accuracy of determining if a document is fraudulent.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a system and method for detecting fraudulent documents. More particularly, but not exclusively, it relates to a method and system for detecting fraudulent documents comprising a barcode and further security features. 
       BACKGROUND TO THE INVENTION 
       [0002]    A large number of documents, such as passports and airline tickets, now encode data in the form of a barcode. Further security features are often added to such documents in order to increase the security, such as watermarks, the owner&#39;s photograph and written details of the document&#39;s rightful owner. 
         [0003]    Highly skilled forgers can produce documents that look exceptionally similar to genuine documents and which cannot be readily detected by security personnel who have only a limited amount of time in order to verify the authenticity of the information presented to them in a document. 
       SUMMARY OF THE INVENTION 
       [0004]    According to a first aspect of the present invention there is provided a method of detecting a fraudulent document comprising the steps of: 
         [0000]    i) reading content stored in a coded form on the document using a reader;
 
ii) determining a characteristic of further content of the document using a sensor arrangement; and
 
iii) verifying the characteristic of the further content at a processor.
 
         [0005]    Step (i) may comprise reading a barcode using a barcode reader. Step (i) may comprise reading coded data from an RFID tag, typically a near-field communications (NFC) tag, using an RFID tag reader. Step (iii) may comprise comparing the coded content to an entry in a reference database. 
         [0006]    Step (ii) may comprise determining spacing between at least two defined fields printed on the document. Step (iii) may comprise comparing the spacing between said defined fields to a reference spacing. The likelihood of a forger replicating exactly the distance between fields within a document is small, the more inter-field distances that are measured the higher the likelihood of detecting a fraudulent document. 
         [0007]    Step (ii) may comprise determining the content of text printed on the document. Step (ii) may comprise determining the content of said text using optical character recognition. The coded information and the text may be printed on opposite sides of the document. Step (iii) may comprise verifying that the content of the text matches at least part of the content of the coded information. In many instances of fraudulent documents the textual information does not match the coded information, typically in the form of a barcode, present on the document. Thus, a comparison of the content of the textual and coded information yields an indicator of whether a document is fraudulent or not. 
         [0008]    Step (ii) may comprise determining the content of an image printed on the document. Step (iii) may comprise comparing the content of said image to a reference image. Step (iii) may comprise cross-referencing an entry in a database corresponding to the image to at least part of the coded information read in Step (i). The image may comprise a photograph, typically of the document owner. Similarly to textual content, an image imprinted on a fraudulent will often not correspond to the content of the coded information stored on the document. 
         [0009]    Step (ii) may comprise capturing a plurality of images of the printed image, each captured image being captured when the document is illuminated by a different one of a plurality of light sources. Step (iii) may comprise comparing the content of said image to a reference image. At least two of the plurality of light sources may be aligned differently with respect to the document. At least two of the plurality of light sources may operate at different wavelengths. The image may comprise a watermark. The term watermark is used herein to encompass holographic as well as classical watermarking technology, such that the watermark may be embedded in a plastic laminate of the document or embedded in the print media forming the document. The illumination of certain types of image embedded in a document, in particular a watermark, from differing light sources will produce differing contrast and possibly colour variations within an image of the watermark. Variations the inclination of the light sources with respect to the document and/or wavelength of the light emitted by the light sources enhance these effects. 
         [0010]    Step (ii) may comprise determining whether a projection is present on a surface of the document. Step (ii) may comprise illuminating the surface of a document at an acute angle with respect to a surface of the document, typically 30° or less. Step (ii) may comprise measuring the intensity of scattered light from the surface at a predefined angle with respect to the surface. Step (ii) may comprise measuring the intensity of laser speckle. Step (iii) may comprise comparing the intensity of said scattered light to a reference. The scattering of light from a surface of the document will be increased where a projection, typically formed by the insertion of a photograph under a plastic laminate, or the pasting on of a photograph, in the production of a fraudulent document, is present. The detection of the increased light scattering, compared to a reference flat surface, would indicate that a document is fraudulent. 
         [0011]    According to a second aspect of the present invention there is provided a fraudulent document detection system comprising: 
         [0000]    a reader device arranged to read content stored in a coded form on the document;
 
a sensor arrangement arranged to determine a characteristic of further content of the document; and
 
a processor arranged to receive the coded content and the further content and to verify the characteristic of the further content.
 
         [0012]    The reader device may comprise a barcode reader. The reader may comprise an RFID tag reader, typically a near-field communications (NFC) tag reader. The processor may be arranged to compare the coded content to an entry in a reference database in order to verify the coded content. 
         [0013]    The sensor arrangement may be arranged to determine spacing between at least two defined fields printed on the document. The processor may be arranged to compare the spacing between said defined fields to a reference spacing. 
         [0014]    The sensor arrangement may be arranged to determine the content of text printed on the document. The processor may be arranged to determine the content of said text using optical character recognition (OCR). The coded information and the text may be printed on opposite sides of the document. The processor may be arranged to verify that the content of the text matches at least part of the content of the coded information. 
         [0015]    The sensor arrangement may be arranged to determine the content of an image printed on the document. The processor may be arranged to compare the content of said image to a reference image. The processor may be arranged to cross-reference an entry in a database corresponding to the image to at least part of the coded information. The image may comprise a photograph, typically of the document owner. 
         [0016]    The sensor arrangement may be arranged to capture a plurality of images of the printed image, each captured image being captured when the document is illuminated by a different one of a plurality of light sources. The processor may be arranged to compare the content of said image to a reference image. At least two of the plurality of light sources may be aligned differently with respect to the document. At least two of the plurality of light sources may operate at different wavelengths. The image may comprise a watermark. 
         [0017]    The sensor arrangement may be arranged to determine whether a projection is present on a surface of the document. A light source may be arranged to illuminate the surface of a document at an acute angle with respect to a surface of the document, typically 30° or less. The sensor arrangement may be arranged to measure the intensity of scattered light from the surface at a predefined angle with respect to the surface. The sensor arrangement may be arranged to measure the intensity of laser speckle. The processor may be arranged to compare the intensity of said scattered light to a reference. 
         [0018]    The sensor arrangement may comprise a plurality of sensors, each of which is arranged to determine a different characteristic of the document. Non-limiting examples of sensors include: photosensors, camera, laser speckle detectors. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a schematic representation of a first embodiment of a fraudulent document detection system according to an aspect of the present invention; and 
           [0020]      FIG. 2  is a flowchart detailing the steps of a method of detecting a fraudulent document. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0021]    Referring now to  FIG. 1 , a first embodiment of a fraudulent document detection system  100  comprises a barcode reader  102 , a sensor arrangement  104 , light sources  106   a - d , a transparent platen  107  and a processing unit  108 . 
         [0022]    The barcode reader  102  comprises a light source  110  and a light sensitive array  112 . In some embodiments the light source  110  is a laser light source, typically a laser diode light source and the array  112  is a linear or two dimensional array. In at least one alternative embodiment, the light source  110  is a polychromatic light source and the array  112  is camera, typically a charge coupled device (CCD) or CMOS array, arranged to capture an image of a barcode passing before the reader  102 . A signal indicative of information contained within a scanned barcode is output from the array  112  to the processing unit  108 . 
         [0023]    The sensor arrangement  104  comprises a number of sensors  114 ,  116 ,  118 ,  120 . Typically the sensors  114 ,  116 ,  118 ,  120  comprise a camera  114 , a scatter photo-sensor  116  and a linear contrast sensor  118  and an OCR reader  120 . Typically, the camera  114  is a CCD or CMOS array. 
         [0024]    Three of light sources  106   a - c  are inclined at different angles with respect to the platen  107 , with the light source  106   c  being inclined at a grazing angle, typically less than 30°, often 20° or less with respect to the platen  107 . In some embodiments the light source  106   c  may be a laser light source and the scatter photo-sensor  116  may be a laser speckle detector. The fourth light source  106   d  emits light at a different wavelength to the other light sources  106   a - c.    
         [0025]    The processing unit  108  comprises a processor  122 , and a data storage device  124 , typically a magnetic hard disc. 
         [0026]    In use, a document  126 , such as a passport or driving licence, bearing a barcode  128  is placed on the platen  107 , typically the platen  107  has a raised edge such that the document  126  locates positively in a defined orientation on the platen  107 . The barcode reader  102  reads the barcode  128  from the document  126  and passes data corresponding to the barcode  128  to the processor  122  which decodes the barcode  128 . In some instances the barcode  128  is a PDF 417 barcode, which may be encrypted. 
         [0027]    The scatter photo-sensor  116  is aimed at a target are of the platen  107  where a feature of the document  126  to be scanned that is known to be tampered with is found, for example a photograph on a driver&#39;s licence or a passport. The light source  106   c  is activated by the processor  122  and the scatter photo-sensor  116  measures the level of light scattered from the target area. A signal corresponding to the scattered light level passes from the photo-sensor  116  to the processor  122  where it is compared to a signal threshold. If the level of light scattered from the target area exceeds the threshold the processor  122  flags the document as being possibly fraudulent. 
         [0028]    The linear contrast sensor  118  is located such that it runs along a line where defined fields  130   a,b,c  printed in the document  126  to be scanned are located. Non-limiting examples of such fields are name, age, address etc. Any one, or combination of the light sources  106   a - d  are activated by the processor  122 . The contrast sensor  118  senses where light is reflected from the document  126  and where it adsorbed, i.e. where there is ink printed on the document and where there is not. A signal corresponding to the distances between printed areas of the document is output to the processor  122 . The processor  122  compares the signal output from the contrast sensor  118  to a reference signal and if the two do not match the processor  122  flags the document  126  as being possibly fraudulent. 
         [0029]    The camera  114  is arranged to capture an image of either the whole of the document  126  or pre-defined areas of the document  126 . In one mode, the camera  114  is aimed at a target area of the platen  107  where an image  132 , typically a photograph of the document&#39;s bearer, is printed or attached to the document  126 . The processor  122  instructs the camera  114  to capture the image  132 . Data corresponding to the image  132  passes from the camera  114  to the processor  122 . In some instances the processor  122  accesses a database  134  of images stored on the data storage device  124  and compares the data of the image  132  to an entry in the database  134 , the database entry having been identified from the scanning of the barcode  128 . If the data of the image  132  does not correspond to that of the database entry the processor  122  flags the document  126  as being possibly fraudulent. 
         [0030]    In an alternative embodiment, processor  122  connects to a remote database and verifies the image data against and entry in the remote database as described hereinbefore. 
         [0031]    The camera  114  can also be used to check for, and authenticate, watermarks  136  in the document  126 . The processor  122  instructs each of the light sources  106   a - d  to illuminate the platen  107 , and consequently the document  126 , sequentially. The camera  114  captures a series of images of the document  126  synchronously with the illumination of the document  126  by the light sources  106   a - d . The illumination of the watermark  136  within the document  126  by the light sources  106   a - c  at differing angles of incidence produces differing contrast and possibly colour variations between the series of the image of the watermark  136 . The use of a different wavelength of the light emitted by the fourth light sources  106   d  produces a further difference in the colour refracted from holographic watermarks embedded in laminations and will enhance contrast effects associated with watermarks embedded in the printed media of the document  126 . The camera  114  passes the series of images to the processor  122  where the images are compared to reference images in a manner substantially as described hereinbefore with reference to the document bearer&#39;s photograph. The processor  122  can be arranged to flag the document  126  as fraudulent if an expected reflection from a watermark is not viewed in a single image in a series, if contrast levels associated with a watermark are not correct between images in a series, or if refracted colour patterns are not correct in a single image, or between images in a series. 
         [0032]    In some embodiments the camera  114  can be arranged to operate as the OCR sensor  120 . However, the invention will be described with reference to the OCR sensor  120  being a discrete unit. The OCR sensor  120  captures an image of the document  126  through the platen  107  and passes the image to the processor  122 . The processor  122  parses the data into text strings. The processor  122  establishes fields, such as name, address date of birth etc., and their contents from a template stored at the data storage device  124 . Once established the contents of the fields are cross-referenced with the data extracted from the barcode  128  by the processor  122 . If the data extracted from the fields by OCR do not correspond to those extracted from the barcode  128  the processor  122  flags the document  126  as potentially fraudulent. It will be appreciated that only a single field need be used to establish that a document is potentially fraudulent. 
         [0033]    The processor  122  issues a warning to a user of the system that the document  126  appears fraudulent upon a pre-determined threshold criteria being met. The threshold criteria can be that any one, or combination of the conditions detailed above that indicate a possibly fraudulent document are reached. For sensitive issues such as border security controls, access to restricted area or firearms purchases only a single condition may have to be met. The processor  122  issues the warning to the user via a screen, not shown, an audio signal such as a beep or message, or via an alert issued to an electronic device of the user, such as a pager, mobile telephone or personal digital assistance. Alternatively, or additionally, the meeting of the pre-determined threshold criteria in an access control scenario can result in a door or entry port not being opened, or an area locked down. 
         [0034]    It will be appreciated that although shown with a sensor arrangement comprising a plurality of sensor the present invention is operable with any one or combination of the sensors detailed hereinbefore operating as the sensor arrangement. 
         [0035]    It will be appreciated that although shown with a document in which the barcode and other features are on a single side of the document they may be on opposite sides of the document, or some features may be on one side and some features may be on the other side of the document. In this instance the barcode reader and sensors are mounted appropriately to read their respective features. 
         [0036]    In an alternative embodiment, not shown, a RFID tag reader replaces the barcode reader and the document has an RFID tag embedded in, or mounted upon, it, which holds data corresponding to that encoded in the barcode of the present embodiment. 
         [0037]    Referring now to  FIG. 2 , a method of detecting a fraudulent document comprises reading coded content from a document using a reader, typically either a barcode reader or an RFID tag reader (Step  200 ). A sensor, or number of sensors determine at least one additional characteristic of further content of the document (Step  202 ). A processor verifies both the coded and the further content as either valid or not, possibly by cross-referencing them (Step  204 ). 
         [0038]    It will be appreciated that although described with reference to a barcode scanner the present invention is applicable to any suitable self-service terminal (SST) or network of SSTs where document authentication may be applied. Examples of suitable SSTs include, but are not limited to, an automated teller machine (ATM), an information kiosk, an electronic funds transfer (EFT) terminal a financial services centre, a bill payment kiosk, a lottery kiosk, a postal services machine, a check-in and/or check-out terminal such as those used in the retail, hotel, car rental, gaming, healthcare, and airline industries, or the like. 
         [0039]    As described herein the SST comprises one or more modules each of which is operable to perform at least one specific function. Typically, the module implements its function either in response to a customer action and/or a command received from a PC core (which is also a module) of the SST. Non-limiting examples of modules include: display, journal printer, operator panel, encrypting keypad, PC core, etc. 
         [0040]    Typically, each module comprises a processor to enable the module to perform its function, and a communications facility to enable the module to communicate with the controller, but in some instances this may not be essential. 
         [0041]    Each module comprises one or more devices that contributes to the execution of the module&#39;s respective function. Typically, each device comprises a replaceable part within the module. Non-limiting examples of devices include: for the display module, a display panel, a display panel housing, and the like. 
         [0042]    Each device comprises one or more components configured to enable the device to contribute to the execution of the module&#39;s function. 
         [0043]    It will also be appreciated that the steps of the methods described herein may be carried out in order suitable to effect the present invention, or simultaneously where appropriate. The methods described herein may be performed by software in machine readable form on a tangible storage medium or as a propagating signal. 
         [0044]    Various modifications may be made to the above described embodiment without departing from the spirit and the scope of the invention.