Abstract:
An identification document authenticator and method of operating the same is disclosed. Specifically, the authenticator is equipped with a light source that illuminates an identification document. Authentic identification documents may comprise one or more diffractive elements that, when illuminated, generate a unique image. The image is then viewable via a viewer provided on the authenticator.

Description:
FIELD OF THE DISCLOSURE 
       [0001]    The present disclosure is generally directed toward document authentication and specifically directed toward optical-based authentication mechanisms. 
       BACKGROUND 
       [0002]    The use of identification documents and other credentials is pervasive. Credentials are used on a daily basis for a number of different purposes. Credentials are most commonly used to prove identity, to verify age, to access an asset (e.g., secure area, financial account, computing resource, etc.), to evidence driving privileges, to cash a check, and so on. Airplane passengers are required to show a credential during check in, and sometimes at security screening and prior to boarding their flight. We also live in an ever-evolving cashless society where credentials are used to make payments, access an automated teller machine (ATM), debit an account, or make a payment, etc. Many industries require that their employees carry photo identification credentials on the job and to access various locations on a job site. 
         [0003]    While many different types of security features have been developed to enhance the security associated with credentials, few have been as useful and difficult to copy as holographic features. Most credential holographic security features are attached to the credential base during the manufacturing process. If the credential is in part an optical recording medium, then it is possible to record the hologram directly into the medium. A practical implementation of this concept presents a large number of technical and price hurdles especially if the medium is not tailored for holographic recording. A complex optical system is required to record a quality hologram. The plastics industry is working with companies specializing in holography to develop an optical medium suitable for both holographic data storage and personalized holograms visible in natural light. 
         [0004]    For security holograms, the optical recording requirement can be eliminated by creating a computer generated hologram on the master of formatted medium information (the photo mask). This becomes practical if the lithographic process has sub-micron resolution and the formatted medium has good diffraction characteristics (a contoured surface). The resulting security hologram is more secure than the attached holograms currently employed on bank cards. In the latter case, a counterfeited label can be attached to a bank card. To counterfeit a hologram which is a part of the credential optical medium format, on the other hand, the whole medium must be counterfeited. 
       SUMMARY 
       [0005]    It is, therefore, one aspect of the present disclosure to provide a credential with one or more security features, such as diffractive security holograms. It is also an aspect of the present disclosure to provide an authenticator that enables easy and convenient authentication of such credentials. 
         [0006]    In some embodiments, an authentic credential is provided with one or more diffractive security features. One example of a diffractive security feature is a feature that is a formatted digitally-mastered hologram created by a software program. The diffractive security feature can be located at one or more positions on a credential. The diffractive security feature may comprise a plurality of diffractive elements (e.g., independent images). In some embodiments, the diffractive element may have a maximum vertical and/or horizontal dimension of about 3 mm. The shape of the diffractive element, however, has no impact on the holographic produced provided that the light source used to recreate the image is largely confined to the area within the boundary. 
         [0007]    In some embodiments, a diffractive element provided on an authentic credential generates an image when it is illuminated with a light source, such as a collimated laser beam. The diffractive element, when illuminated, generates a unique image that is easily identified visually. The diffracted light behaves as if it is emanating from the pinhole of a pinhole camera. This means that the image can be generated by placing a flat screen in the path of the reflected light. There is no focal plane so the size of the image can be changed simply by moving the screen towards or away from the credential. Also, the image can be magnified in one axis only by tilting the screen away from the orientation normal to the reflected beam. 
         [0008]    For the purposes of this disclosure, credentials are broadly defined and may include, for example, credit cards, bank cards, phone cards, passports, driver&#39;s licenses, network access cards, employee badges, debit cards, security cards, visas, immigration documentation, national ID cards, citizenship cards, social security cards, security badges, certificates, identification cards or documents, voter registration cards, police ID cards, border crossing cards, legal instruments or documentation, security clearance badges and cards, gun permits, gift certificates or cards, labels or product packaging, membership cards or badges, etc. Also, the terms “document,” “credential,” “card,” and “documentation” are used interchangeably throughout this document. Credentials are also sometimes interchangeably referred to as “security documents,” “ID documents,” “identification documents,” “security credentials,” “photo-IDs,” and “photo ID documents”. 
         [0009]    It is also an aspect of the present disclosure to provide a system for verifying the authenticity of a credential as described herein. Specifically, an authentication system is disclosed which includes a light source configured to illuminate a credential with emitted light and a viewer configured to facilitate viewing of light reflected by the credential. In some embodiments, the viewer may include a viewing window and a viewing screen. If the illuminated credential is an authentic credential (e.g., a credential having a diffractive security feature), then an image may be displayed in the viewer. If the illuminated credential is not an authentic credential, then no image may be displayed in the viewer. 
         [0010]    A method of verifying the authenticity of a credential is also provided. Specifically, the method includes illuminating a credential with light and analyzing the light that is reflected by the credential. Based on the analysis of the reflected light, the credential can be verified as authentic if an image is observed. Failure to observe an image in the reflected light may signify that the credential is not an authentic credential. 
         [0011]    The present invention will be further understood from the drawings and the following detailed description. Although this description sets forth specific details, it is understood that certain embodiments of the invention may be practiced without these specific details. It is also understood that in some instances, well-known circuits, components and techniques have not been shown in detail in order to avoid obscuring the understanding of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present disclosure is described in conjunction with the appended figures: 
           [0013]      FIG. 1  is a perspective view of an authentication system in accordance with embodiments of the present disclosure; 
           [0014]      FIG. 2  is a perspective view of an authenticator sub-assembly in accordance with embodiments of the present disclosure; 
           [0015]      FIG. 3  is a perspective view of a simplified authentication system in accordance with embodiments of the present disclosure; 
           [0016]      FIG. 4  is a plan view of a credential in accordance with embodiments of the present disclosure; 
           [0017]      FIG. 5  is a schematic view of a series of images in motion in accordance with embodiments of the present disclosure; and 
           [0018]      FIG. 6  is a flow diagram depicting an authentication method in accordance with embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the described embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims. 
         [0020]    Referring initially to  FIG. 1 , an authentication system  104  will be described in accordance with embodiments of the present disclosure. Specifically, an authentication system  104  is depicted as comprising an authenticator housing  112  having a slot  116  configured to receive a credential  108  therein. The authenticator housing  112  may further include a viewer  120 , which corresponds to a feature on the authenticator housing  112  that facilitates the viewing of light that is reflected off the credential  108  as it is slid through the slot  116 . 
         [0021]    In some embodiments, the authenticator housing  112  may be made of a light-weight but sturdy material. Examples of suitable materials for the authenticator housing  112  include, without limitation, plastic, ceramic, glass, metal, alloys, and combinations thereof. The authenticator housing  112  may be designed for simple hand-held use or it may be configured to be secured to an object such as a table, wall, or the like. 
         [0022]    The viewer  120  may include one or more optical features that enhance viewing of images on a surface. For example, the viewer  120  may comprise one or more of a prism, lens, mirror, diffraction grating, or the like to enhance the viewing of light that is reflected off the credential  108 . Alternatively, the viewer  120  may be a simple piece of plastic or glass that fills a hole in the authenticator housing  112 . In such an embodiment, the viewer  120  is simply a viewing window to a viewing surface or screen contained within the authenticator housing  112 . 
         [0023]    With reference now to  FIG. 2 , additional details of components contained within the authenticator housing  112  will be described in accordance with embodiments of the present disclosure. Specifically, an authenticator sub-assembly  204  is depicted that includes a support  208 , a switch assembly  212 , a light source  224  incorporated into a light module  228 , and a viewing screen  240  positioned on a circuit board  248 . The authenticator housing  112  may be secured to the support  208  with one or more connectors  248 . The connectors, while depicted as comprising a nut-and-bolt system may be achieved with any known type of fastening or securing mechanism. 
         [0024]    In some embodiments, the switch assembly  212  comprises various components to detect that a credential  108  has been inserted in the slot  116  and in response thereto, to activate other components of the authenticator sub-assembly  204 . In particular, the switch assembly  212  may comprise a credential guide that is co-located in the slot  116 . The credential guide may receive and hold the credential  108  is a particular position as it is slid through the slot  116 . 
         [0025]    The switch assembly  212  may also comprise a switch  216  and a switch actuator  220 . The switch  216  and/or switch actuator  220  may include any collection of mechanical, electrical, or electromechanical devices that detect the presence of the credential  108  in the slot  116  and activate the light source  224  to illuminate the credential  108  while in the slot  116 . In the depicted embodiment, the switch  216  comprises one or more electrical contacts that are connected when the actuator  220  is moved by the credential  108 . The connection of the contacts at the switch  216  may cause one or more other circuits in the authenticator sub-assembly (e.g., an illumination circuit residing on the circuit board  248 ) to become closed and operational. This, in turn, causes the light source  224  to become activated and illuminate the credential  108 . Although the actuator  220  is depicted as comprising a ball, spring, and lever arrangement, those of skill in the art will appreciate that any type of known switch-activation arrangement may be employed. As an example, the actuator  220  may be optically-based and may have an optical proximity sensor (e.g., photodiode, photosensor, etc.) that detects the presence of the credential  108  in the slot  116 . Thereafter, the sensor may send an electrical signal to the switch  216 , thereby causing the switch  216  to activate the light source  224 . 
         [0026]    As can be seen in  FIG. 2 , the switch assembly  212  may include various structures that fix or support the relative positions of the components of the switch assembly  212 . In some embodiments, the structure may include scaffolding that is made of plastic that has been molded or otherwise manufactured. The scaffolding of the switch assembly  212  may be fastened, glued, or otherwise attached to the support  208 , thereby fixing the position of the switch assembly  212  relative to other components of the authenticator sub-assembly  204 . 
         [0027]    The light module  228  may also be supported by a mounting bracket  236  that is fastened, glued, or otherwise attached to the support  208 . In particular, the light module  228  may be connected to the mounting bracket  236  and the mounting bracket  236  may also provide a mounting location for a power source  232 . In some embodiments, the light module  228  is directed toward the switch assembly  212  and particularly the slot  116 . This enables the light source  224  to emit light toward the credential  108  when the credential  108  is located in the slot  116 . 
         [0028]    In some embodiments, when the switch  216  is activated by movement of the actuator  220 , power is provided from the power source  232  to the light source  224 . The power may be provided directly from the power source  232  to the light source  224 , or it may be passed through one or more circuits and/or circuit elements residing on the circuit board  248 . 
         [0029]    The circuit board  248 , in some embodiments, comprises one or more potentiometers that enable either the automated or manual adjustment of power provided to from the power source  232  to the light source  224 . In embodiments where the power source  232  corresponds to a self-contained power source such as a battery, collection of batteries, or the like having a finite voltage supply, circuitry on the circuit board  248  may comprise a voltage or current regulator. The voltage or current regulator on the circuit board  248  may maintain constant optical power at the light source  224 , even as voltage of the power source  232  decreases with loss of charge. 
         [0030]    In embodiments where the power source  232  corresponds to a power converter (e.g., A/C to D/C power converter), the circuit board  248  may comprise one or more circuit elements that condition the power either before or after it has been converted to DC power before the power is provided to the light source  224 . Alternatively, the need for additional power regulation circuitry on the circuit board  248  may become obsolete. 
         [0031]    Although not depicted, it has been described that components of the switch assembly  212 , the circuit board  248 , the power source  232 , and the light source  224  may operate in cooperation with one another. This means that the above-noted parts of the sub-assembly  204  may be electrically connected to one another via one or more of wires, conductive traces, and the like. Where conductive traces are used, the conductive traces may be established on the upper surface of the support  208 . 
         [0032]    The light source  224  may correspond to any type of known light source or collection of light sources. In particular, the light source  224  may correspond to any type of light source that is capable of producing collimated light as an output. Non-limiting examples of suitable light sources  224  include a laser and collimating lens, a laser diode, or any other device capable of producing coherent light. The light source  224  may be fastened or otherwise secured to a mounting portion of the light module  228 , which accurately positions the light source  224  relative to the credential  108 . 
         [0033]    The mounting portion is attached to the mounting bracket  236  at any number of locations. In some embodiments, the mount location determines the viewer version and which types of credentials  108  are capable of being authenticated by the authenticator sub-assembly  204 . More specifically, the light source  224  may be mounted at any number of different vertical positions, where each different vertical position results in a different portion of the credential  108  being illuminated. As one non-limiting example, the light source  224  may be mounted at about 26.8 mm from the bottom of the slot  116 . As another non-limiting example, the light source  224  may be mounted at about 18.5 mm from the bottom of the slot  116 . Thus, the authenticator housing  112  can be configured to authenticate credentials of different types having security features at different locations. 
         [0034]    Similar to the mounting bracket  236  and switch assembly  212 , the circuit board  248  may also be secured or otherwise fastened to the support  208 . In addition to providing a mounting surface and traces between circuitry components for operating the light source  224 , the circuit board  248  may also provide a flat surface for a screen  240  or the like. In particular, the screen  240  may correspond to either a reflective surface or a single-colored surface  240  that facilitates easy viewing of reflected light through the viewer  120 . The screen  240 , in some embodiments, may be constructed from a plastic material or high-quality photo paper and may have either a white or black color. If the screen  240  is reflective, the screen  240  may be either (1) a plastic material coated in a reflective material or (2) entirely manufactured from a reflective material. The screen  240  can be mounted to the circuit board  248  or it may be integrated therein. 
         [0035]    In addition to supporting the screen  240 , the circuit board  248  may also comprise a port  244  that enables the authentication system  104  to communicate with external devices. In some embodiments, the port  244  may correspond to a Universal Serial Bus (USB) port. Alternatively, or in addition, the port  244  may provide a mechanism for feeding or charging the power source  232 . Even more specifically, the circuit board  248  may provide a battery charger which draws power from the port  244  whenever it is connected to a host device such as a computer. Where the port  244  corresponds to a USB port, the USB signal lines may not be connected so the host device does not ‘see’ the components of the authenticator sub-assembly  204  but does provide 5 volt power. 
         [0036]    The circuit board  248  may also comprise a micro-controller which monitors the power source  232  voltage when the switch  216  is activated. If the voltage falls below a predetermined level, the processor flashes an LED on the circuit board  248  to warn the user that the power source  232  (e.g., battery) needs to be discharged. In some embodiments, the screen  240  may comprise a small hole located above or below the image area (e.g., an area where reflected light will be viewable through the viewer  120 ) that allows light from the low-voltage LED to pass through the screen  240  and be viewed through the viewer  120 . 
         [0037]    The power source  232  itself may also be provided with an internal circuit which disconnects the power source  232  from the circuit board  248  and light source  224  when its output voltage drops below a safe operating level. This prevents a deep discharge from damaging the power source  232 . 
         [0038]    With reference now to  FIG. 3 , optical properties of the authenticator sub-assembly  204  will be described in connection with a simplified authentication system  304 . Specifically, the simplified authentication system  304  is incorporated in or part of the authenticator sub-assembly  204 . The simplified authentication system  304  shows the minimal components that enable an optical-based authentication of credentials  108 . Specifically, the light module  228  comprises the light source  224  that emits a first beam of light, which may be referred to as emitted light  308 . The emitted light  308  travels toward the credential  108  while the credential  108  is in the slot  116  and hits the credential  108 . 
         [0039]    The emitted light  308  then reflects off the credential and the reflected light  312  travels toward the screen  240 . If the credential  108  is authentic and comprises one or more security features as described herein, then the reflected light  312  will display one or more predetermined images on the screen  240 . The images displayed on the on the screen  240  are then viewable by a user through the viewer  120 . If the credential  108  is not authentic, then no image will be created by the reflected light  312  and displayed on the screen  240 . 
         [0040]    With reference now to  FIGS. 4 and 5 , additional details of an authentic credential  108  will be described in accordance with at least some embodiments of the present disclosure. More specifically, the credential  108  may be provided with a data region  404  and one or more security features  408 . While the security feature  408  is depicted as being separate from the data region  404 , it may be possible to combine the data region  404  and security feature  408  into a single region on the credential  108 . In particular, the security feature  408  may be incorporated into the data region  404  and vice versa. 
         [0041]    The security feature  408 , in some embodiments, may comprise a plurality of diffractive elements  412   a - g , where each diffractive element is separate and distinct from the other diffractive elements. Each diffractive element may also be referred to as an image. The difference from one diffractive element  412  to the next is that lines  416  in successive diffractive elements are rotated by a predetermined amount. The rotation of the lines  416  from one diffractive element (e.g., the first diffractive element  412   a ) to the next diffractive element (e.g., the second diffractive element  412   b ) creates a subtle difference from image to image, which allows the eye to see movement in the image displayed on the screen  240  by the reflected light  312 . In some embodiments, as the credential  108  is moved through the slot  116  (e.g., in the direction of arrows depicted in  FIG. 5 ), the emitted light  308  incrementally reflects off a different image (series of lines  116 ) and the user is able to view a moving image in the viewer  120 . If the credential  108  is not authentic and does not comprise the security feature  408  as-disclosed, then images and specifically moving images will not be viewable through the viewer  120 . The diffractive images (only lines) that go across the width of the card are only part of a primary image that is viewable with the eyes, making it discrete due to the subtle differences (line rotation) from image to image. Each set of line alignment will reflect back a shade to the eye and noise to the reader which is viewed as a line. Since the lines rotate about 10 degrees from one image to the next image, when you slide the card from one edge to the other, the viewer will display a single line that spins like a wheel. 
         [0042]    Although the security feature  408  is depicted as having a repeating series of seven diffractive elements  412   a - g , those of ordinary skill in the art will appreciate that the security feature  408  may comprise a greater or lesser number of diffractive elements without departing from the scope of the present disclosure. Furthermore, the security feature  408  may comprise only a single set of diffractive elements  412 . Further still, the credential  108  may comprise more than one security feature  408 . 
         [0043]    The security feature  408  and specifically the independent diffractive elements  412   a - g  of the security feature  408  may be created by any number of processes. As one non-limiting example, the security feature  408  is produced with the application of a high resolution black and white silver halide photographic film. The film is imaged using high resolution contact masks with spot sizes down to about 2.5 microns. The film is imaged with visible light but the film is sensitized in the near UV. The film silver halide grain size is submicron and the film is capable of resolving images close to 1 micron. The film has high contrast so that exposed and processed areas of the film have maximum optical diffraction and the unexposed areas have high transparency. 
         [0044]    The film is then contact printed using masks created from photomask masters. A chrome on quartz glass master plate is written with electron beams, sputtering or evaporating away the chrome where the beam contacts the plate. The process is similar to that used to create the masters for chip manufacturing. The areas sputtered away transmit light and the areas with chrome block the light completely. 
         [0045]    Master film is created by replicating the plate with high resolution high contrast photographic film. The film process is reversed so that the film is representative of the initial master. The chromed areas of the photomask master have high optical density on the master film and look black. The quartz glass areas where the chrome has been removed being low optical density on the film replica and are transparent. 
         [0046]    From this master film the media film is imaged using contact printing. The areas exposed are not reversed in this case but are developed normally to create dark images where the light contacts the film. After the initial development of the dark images the remaining silver is not washed out as it would in normal black and white photographic film processing, but migrated to the surface of the film using a special process. Once the silver halide is at the surface of the film, the halides are converted to silver to form a reflective silver surface. The remaining halides in the film are then developed and fixed in the film. The final media film looks like a reflective silver with dark near black printing on it. 
         [0047]    For this media to function for the life of the credential the silver surface should be protected. The silver at the surface of the film will oxidize within hours of being exposed in the air. The media is therefore handled without air contact and then encapsulated in polymer resin to protect the media from air and water. 
         [0048]    Although embodiments of the present disclosure discussed the use of linear lines  416  to be printed in each diffractive element  412  and the lines  416  in successive diffractive elements are to be rotated by a predetermined amount, it should be appreciated that features other than lines may be used. Specifically, the series of images may have non-linear lines, shapes, curves, etc. that result in any type of animation or depiction of multiple images as the credential  108  is moved though the slot  116  and different diffractive elements  412  are illuminated. 
         [0049]    With reference now to  FIG. 6 , an authentication method will be described in accordance with at least some embodiments of the present disclosure. The method begins when a credential is presented to the authentication system  104  (step  604 ). This step may involve placing the credential  108  into the slot  116  of the authentication system  104  such that the actuator  220  is moved, thereby activating the switch  216 . 
         [0050]    When the credential  108  is presented to the authentication system  104 , the method continues by illuminating the credential  108  with emitted light  308  (step  608 ) and moving the credential  108  within the slot  116  such that different parts of the security feature  408 , if present, are illuminated (step  612 ). 
         [0051]    The light which reflects off the credential  108  as the credential  108  moves is then analyzed (step  616 ). Analysis of the reflected light  312  may involve observing the reflected light  312  through the viewer  120  to determine whether the reflected light  312  displays one or more images. Alternatively, or in addition, analysis of the reflected light  312  may involve determining whether the reflected light  312  or an image produced thereby is moving on the screen  240 . 
         [0052]    Based on an analysis of the reflected light  312 , the authenticity (or lack thereof) is determined (step  620 ). In particular, if the reflected light  312  produced one or more images or created some other indication that the emitted light  308  was reflected by a security feature  408 , then the credential  108  can be confirmed as authentic. If, however, the reflected light  312  fails to produce any indication that it was reflected by a security feature  408  or a similar component, then the credential may be considered not authentic or may require further authenticity testing. 
         [0053]    In the foregoing description, for the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods and steps thereof may be performed in a different order than that described. It should also be appreciated that the methods described above may be performed by hardware components or may be embodied in sequences of machine-executable instructions, which may be used to cause a machine, such as a general-purpose or special-purpose processor or logic circuits programmed with the instructions to perform the methods. In other words, the methods described herein can be performed by a human (manually) or a machine (automatically). In an automated implementation, the machine-executable instructions may be stored on one or more machine readable mediums, such as CD-ROMs or other type of optical disks, floppy diskettes, ROMs, RAMs, EPROMs, EEPROMs, SIMs, SAMs, magnetic or optical cards, flash memory, or other types of machine-readable mediums suitable for storing electronic instructions. Alternatively, the methods may be performed by a combination of hardware and software. 
         [0054]    Specific details were given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
         [0055]    Also, it is noted that the embodiments were described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. 
         [0056]    Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as storage medium. A processor(s) may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. 
         [0057]    While illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.