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EP-3953911-B1 - DOCUMENT AUTHENTICATION BY DETERMINATION OF SURFACE APPEARANCE USING CONTROLLED ILLUMINATION

EP3953911B1EP 3953911 B1EP3953911 B1EP 3953911B1EP-3953911-B1

Inventors

  • BUD, ANDREW
  • NEWELL, ANDREW
  • BIRD, Gemma

Dates

Publication Date
20260506
Application Date
20200408

Claims (14)

  1. A method of determining whether a document is genuine, the method comprising: illuminating the document (110) with a controlled illumination source (106) which is in a fixed spatial relationship with a camera (104); changing the distance between the camera and a centroid of the document; wherein the illumination is modulated in intensity and/or in color during the process, the method comprising using the camera to capture imagery of the document in a first position and in a second position while changing the distance between the camera and the centroid of the document wherein the distance change includes a change in a distance between the camera and a centroid of the document along an axis perpendicular to the plane of the document; analyzing the captured imagery to obtain information about changes in appearance of a surface of the document resulting from: changes in illumination incident on the document caused by changing a position of the controlled illumination source with respect to the document; and changes in a position of the camera with respect to the document caused by the changing of the distance between the centroid of the document and the camera; characterised in analyzing the information about surface reflectivity of the document to determine a likelihood that the captured imagery was captured from a genuine document.
  2. The method of claim 1, wherein the distance between the camera and the centroid of the document is changed by moving one of the camera and the document along a linear trajectory.
  3. The method of claim 2, wherein an angle between the linear trajectory and a plane of the document is less than 90 degrees.
  4. The method of claim 1, wherein the distance between the camera and the centroid of the document is changed by moving one of the camera and the document along a curved trajectory.
  5. The method of claim 1, wherein: the camera and the controlled illumination source are components of a mobile device; the distance between the camera and a centroid of the document is changed by a user of the mobile device; and the user of the mobile device is instructed to move the device while keeping an image of the document displayed on a screen of the device within a specified region on the screen.
  6. The method of claim 5 further comprising using the mobile device to displace the image of the document displayed on the screen of the device such that the user of the mobile device causes the mobile device to move in a desired trajectory corresponding to a trajectory in which the user of the mobile device keeps the image of the document displayed on the screen of the device within the specified region on the screen.
  7. The method of claim 1 wherein the captured imagery includes imagery of a photograph within the document, and the step of analyzing the information about changes in appearance of the surface of the document includes analyzing changes in reflections from the photograph to determine a likelihood that the captured imagery of the photograph was captured from a photograph that is not an altered photograph or a replacement photograph.
  8. The method of claim 1 wherein the captured imagery includes imagery of a region adjacent to a photograph appearing within the document, and the step of analyzing the information about changes in appearance of the surface of the document includes analyzing changes in reflections from the region adjacent to the photograph to determine a likelihood that the region adjacent to the photograph was affected by at least one of alteration of the photograph and replacement of the photograph.
  9. The method of claim 1 wherein the controlled source of illumination comprises a display screen.
  10. The method of claim 9, wherein the display screen displays a pattern.
  11. The method of claim 9, wherein the display screen displays a changing pattern that is controlled by at least one of a device spatially proximate to the document and a remote server in data communication with a device spatially proximate to the document which device houses the display screen.
  12. A method of determining whether a document is genuine, the method comprising: illuminating the document (110) with a controlled illumination source (106) which is in a fixed spatial relationship with a camera (104); while changing a spatial arrangement of at least one of an intensity and a color of the controlled source of illumination, capturing imagery of the document; analyzing the captured imagery to obtain information about an appearance of the document, wherein the analysis includes analyzing reflections of illumination from the controlled source of illumination; and using the information about the surface reflectivity of the document to determine a likelihood that the reflections of illumination were received from a genuine document.
  13. The method of claim 12, wherein the controlled source of illumination is a display screen controlled by a device spatially proximate to the document.
  14. The method of claim 12, wherein the controlled source of illumination is a display screen controlled by signals received from a remote server in data communication with a device housing the display screen that is spatially proximate to the document.

Description

The verification of the true identity of a natural person is becoming essential in an increasing range of contexts. Anti-money laundering regulations require that large transactions, privileged operations and the opening of financial services accounts be attributed to persons whose identities have been adequately established. Security concerns require that persons travelling or entering sensitive installations should not conceal their true identities, so that their past records may first be scrutinized. The most generally accepted source of evidence of the true identity of a person is that issued by governments. In order to issue passports or national identity cards, governments require trusted documentation, adequate corroboration and, if necessary, investigation. In countries where national identity cards do not exist, such as the United States, the Real ID act places reliance on the driving license, and a substantial obligation of due diligence is placed on the Motor Vehicle or Driver administrative bodies that issue driving licenses. Thus, the physical possession of a government-issued identity document (ID) such as a passport, identity card or high-trust driving license is generally considered a trustworthy corroboration of the identity asserted by an individual. In a number of countries, digital identities are being created with the aspiration of being used instead of physical documents. In the European Union, the eIDAS Regulations permit the use of compliant digital identities throughout the member states. Normally, to establish an eIDAS digital identity in the first place, a person must present themselves together with their government issued identity document. The trust vested by the relying party in such a document depends on the document itself being genuine and un-falsified. For this reason, governments have for centuries invested in increasingly sophisticated methods of printing and laminating such documents, in a race to keep ahead of the increasing sophistication of forgers. In the last decade electronic means have been added, with the insertion of microchips into documents complying with the ICAO 9303 standard. Such micro-chips contain the information printed in the document, plus a digital certificate signed by the issuing authority. Under current cryptographic practice, such certificates are considered impossible to forge and hence represent the best possible guarantee of the authenticity of the information contained in the chip, which is readable contactlessly using NFC technology. However, there are many circumstances in which such a chip is absent, or the means to read it are unavailable. For this reason, physical means to confirm authenticity remain important. There are three main measures employed. The first is security printing, which embeds layers of pattern in the printed document. Imperfect copies are exposed by distortions, errors or erasures in such patterns. The second is spectrographic response, which determines the way the document responds to illumination by ultra-violet light. The third method is to embed or emboss a holographic element in the document, whose reflective properties, in terms of color, directionality and intensity and combinations thereof are highly characteristic. Typical examples are holograms embedded in credit cards, and holographic embossing in the surface of driving licenses. Normally, such embossing includes or covers the identity photograph found on practically all identity documents. There is an increasing requirement to check the identity of an individual remotely and automatically. In-person identity checks require space in an accessible location and consume employee time. Above all, they are inconvenient for the user, who must travel to the checking location and invest appreciable amounts of time in the process. They are increasingly reluctant to do so, as the process confers no direct value in return for the investment of their time. Organizations able to permit users to prove their identity remotely, preferably on their now-ubiquitous smartphones, gain an immediate competitive advantage. Early methods of remote identity checking required users to engage in a live video call with an agent, who would interview the person to ensure they were genuinely present humans, then examine the document via the video link, to establish its authenticity. This method, still widely mandated in the financial services regulations of many countries, has a number of drawbacks; it is very costly, requiring an employee to talk with the person for some minutes. It is also ineffective in security terms, as it is difficult for an employee to determine if the document has been forged or modified based just on the imagery available from a video call. The fine details embedded in security printing are not visible, and the correctness of the holograms cannot be adequately assessed. US 2018/0091672 A1 discloses authentication using a mobile phone to capture images of a securi