EP3746992B1 - Method for checking the authenticity and/or integrity of a security document having a printed security feature, security feature and arrangement for verification - Google Patents

Description

The present invention relates to a method for checking the authenticity and/or integrity of a security document with a printed security feature. Furthermore, the invention relates to the printed security feature for the security document and an arrangement for verifying the security document with the security feature.

From the WO 2013/034471 A1 a device for mobile recognition of a document having a wavelength conversion property is known. The device comprises a light generating device, an image recording device and a processor.

In the WO 2012/083469 A1 describes a method and a device for the authentication of documents marked with photochromic systems. The method for checking the authenticity of a security feature provides that a first and a second image of the security feature are recorded. The appearance of the security feature changes in the visible range when stimulated by a flash of light. The first picture is taken without, the second picture with using a mobile phone flash function. Furthermore, an authentication check can be carried out by the cell phone with the aid of a suitable data processing program.

From the DE 10 2015 219 393 A1 a method for identifying an object is known. An identification feature with a plurality of identification elements is arranged on or on the object. A first identification feature becomes visually recognizable by irradiating the identification elements with light in a wavelength range of 380 nm to 790 nm.

From the WO 2013/034603 A1 a method for verifying a security document with a security feature in the form of at least one pigment-like fluorescent printing element is known.

According to the U.S. 2004/0169847 A1 Articles are marked with a unique sequence consisting of patterns for authentication using an article marking method. The patterns can be photoluminescence patterns, for example.

The WO 2017/103119 A1 FIG. 1 shows a security element comprising a first pattern of discrete elements of a first material and a second pattern of discrete elements of a second material. A third pattern generated from the superimposition of the first pattern with the second pattern can be detected by an image acquisition unit, the first and/or the second pattern being excited to luminescence. The third pattern showing an image is compared to a reference image.

In general, numerous different types of security features are used in a wide variety of applications. Only a few of these are suitable as security features for security documents, for example banknotes, certificates, ID cards, identification cards and the like. In this subset of security features Few designs to date are suitable for trustworthy and difficult to manipulate verification with widely available simple devices and devices. For example, complex emission properties can be integrated into printable phosphors, but their authenticity can only be examined with expensive and complicated test devices, which can only be found in a few places, e.g. B. be held in central banks. In particular, there is a lack of simple arrangements that are available to virtually every end user for checking security features and thus allowing the integrity and authenticity of security documents to be checked.

Based on the prior art, one object of the present invention is to provide a method which enables the verification of a security document with a printed security feature. A further object is to provide a security feature which can be printed on a security document or is produced using known printing methods during the production of the security document and subsequently allows verification of the security document. Verification should also be possible on the go, for example with a smartphone, using widely available devices. The security feature should be able to be applied to a large number of security documents or objects. A further object of the present invention is to provide an arrangement for verifying the security document with this security feature.

According to the invention, the object is achieved by a method for verification or for authenticity and/or integrity testing for a security document with a security feature according to appended claim 1 and by a printed security feature and an arrangement for verifying the security document with a security feature according to the appended independent claims 7 and 11.

The method according to the invention is used for authenticity and/or integrity testing or verification testing of a security document with a security feature according to claim 1 printed on it.

In the light of the present invention, the term “printed substance” is to be understood broadly, in the sense of a material with or in which information can be reproduced. In the simplest case, it is a printing ink with pigments and/or phosphors. In the context of the present invention, the term “visually non-visible” or “visually imperceptible” means that the corresponding information or radiation or pattern cannot be detected by the user's naked eye.

In a first method step, the security feature applied to the security document is irradiated with electromagnetic radiation of a predetermined wavelength using an illumination unit of the mobile terminal device. The security feature, in particular the first printing substance, is excited to luminescence by the irradiation. For this purpose, the first printing substance is configured in such a way that, when excited with an excitation radiation such as that emitted by the lighting unit, it shows an invisible emission in a wavelength range that can be detected by an image acquisition unit of the mobile terminal device and preferably can also be displayed in a display unit of the mobile terminal device.

In a further method step, emission values of the security feature are recorded using the image recording unit of the mobile terminal device. A number of individual images of the security feature that is excited are generated at time-defined intervals. The individual images contain the visually non-visible radiation of the first printing substance and an image of the pattern formed by the second printing substance. The individual images can be stored in a memory or, after appropriate processing (visualization of the invisible pattern), displayed on the display unit.

In a subsequent method step, the captured individual images are evaluated using a data processing unit and used to check the authenticity and/or integrity used. For verification, the individual images are compared with stored reference images or the recorded emission values with stored reference values. The reference images are selected according to the time-defined recording intervals of the individual images. The reference images can in particular be formed by the patterns imaged with the second printing substance.

In a further procedural step, the result of the verification is output. A positive result of the authenticity and/or integrity check is output if the captured individual images match the reference images stored in the data processing unit or if the emission values match the reference values.

While only one image is compared with a reference in previously known verification methods, it is a particular advantage of the present invention that a plurality of individual images of the security feature that is activated is recorded at defined time intervals by means of the image acquisition unit of the terminal device. The individual images recorded in this way or data derived from them can then be compared with stored reference data according to the recording intervals defined in terms of time.

In a preferred method step, the captured individual images are checked with the stored reference images at defined positions of the images. For example, three points are selected at specific positions in the image area of a single image and the corresponding pixels at the specific positions of the reference image are compared with these. The images, especially their positions, defined and determined point positions and the measured luminescence as well as the luminescence stored as a reference are compared.

The reference values are preferably stored in a digital memory, which can be part of the mobile terminal device, or in an intelligent database on a remote server.

The individual images of the excited security feature on the security document are recorded at intervals of less than 100 milliseconds (ms). The individual images of the security feature excited on the security document are preferably recorded at time intervals of microseconds (ps). The decay times of the emission of the first printing substance and the time intervals between the individual images are suitably chosen in order to be able to record the emission in the individual images.

Preferably, the captured individual images are checked against the reference images by the data processing unit using a data processing program. The data processing program preferably includes an algorithm for executing the steps of the method according to the invention. The algorithm is preferably designed to evaluate cryptographic data or other non-cognitively detectable data that is encoded, for example, as the non-visible or the visible pattern. The data processing unit is preferably part of the mobile terminal device.

The image acquisition unit is preferably a photo sensor or an image sensor. The image acquisition unit particularly preferably comprises a plurality of photo sensors, in particular one Camera, which is also sensitive to non-visible radiation and converts this into electrical image signals.

The lighting unit for irradiating the security document is preferably one or more LEDs that generate white light. The white light can be implemented as part of a flashlight function of the mobile device. In particular, the light generated contains radiation in the frequency range that is required for the excitation of the first printing substance so that it is excited to emit non-visible emissions.

The visually non-visible and the visually visible pattern of the first and the second printing substance are preferably arranged in one and the same area on the security document. For example, the non-visible pattern can be attached directly to a portrait of a person in a passport. Checking the non-visible pattern would then immediately reveal tampering if the portrait was altered or exchanged, as this inevitably leads to damage to the non-visible pattern.

The security document is preferably checked online using the mobile terminal device, which transmits data to a server and receives it from it. Alternatively, the security document is preferably checked offline using the mobile terminal device, d. H. the complete verification is carried out by the mobile device and the result is displayed by it.

The method can be used to verify the security feature with defined patterns and materials.

One advantage of the method according to the invention is that the security document can be checked on the move using any mobile terminal device that is equipped with a flashlight function with a white LED or LED emitting white light and the corresponding data processing unit. This makes it possible, in particular, to check the security features integrated there by taking pictures of physical security documents using a conventional mobile device (smartphone, tablet, wearables), which has been configured by software (app) for the application, and to use the result of the check directly in digital applications. For example, the authenticity of a person can be confirmed within an online purchase process by photographing an ID card and simultaneously verifying the authenticity of this ID card. The method is also advantageous because it can be used both online and offline. Another benefit is that verification is quick and easy.

The security document can also be checked using other data processing systems with image acquisition units, e.g. As desktop monitors, service terminals or the like.

The printed security feature according to the invention can be applied to a security document, in particular can be printed during the production of the security document. The security feature consists of a visually invisible pattern and a visually visible pattern. The visually invisible pattern is formed by a first printing substance. The first printing substance can be excited to luminescence by electromagnetic radiation of a predetermined wavelength, so that the first printing substance has a emits non-visible radiation that is not visible to the human eye, but can nevertheless be captured by an image acquisition unit of a mobile device and converted into electrical image signals. The visually visible pattern is formed by a second printing substance. The first printing substance is selected so that when it is stimulated by electromagnetic radiation, in particular illuminated by the flashlight of the mobile device, invisible radiation is emitted from the first printing substance, which can be detected or read by the image acquisition unit of the mobile terminal.

The printed security feature, which can be applied to a security document, serves to verify the security document, with the authenticity and/or integrity being checked. Authenticity is the authenticity and integrity of an object. The security document with a printed security feature can be checked using the method described above. What has been described above applies to all embodiments. The details of the security feature according to the invention described below can also be used for the method described above.

In one embodiment, the second printing substance can also be excited to luminescence, in which case the two printing substances particularly preferably have two different emission spectra and/or decay times. The decay times are preferably in the millisecond range. The printing substances are selected in such a way that the decay times are in the range of the serial or single image recording times of the mobile terminal device. Preferably, the decay times are chosen so that after excitation of the first particle with the flash light conventional smartphones at least two consecutive images can be taken by the camera of the smartphone, in which sufficiently strong emissions of the first particles can be recorded.

It is understandable that the printing substances mentioned can each be composed of several different particle subtypes. For example, it can be particularly advantageous to set the resulting emission properties by means of a random, inhomogeneous mixture of a plurality of printing substances and then to store these properties specifically for the security document. This allows unique properties to be set for individual security documents or for groups of security documents.

In one embodiment, the visually non-visible pattern is in the form of a machine-readable code. In an alternative embodiment, the visually visible pattern is in the form of a machine-readable code (binary data). The visually non-visible pattern and the visually visible pattern are particularly preferably designed as a machine-readable code. The machine-readable code is particularly preferably a cryptographic code which, for example, has the form of a barcode, QR code or the like.

The security feature preferably consists of the visually non-visible pattern and the visually visible pattern, which together form a further pattern which can preferably be displayed by the display unit of the mobile device. In order to confirm the authenticity of the security feature, the user of the mobile device can, for example, have both patterns displayed in one image on the display unit, so that the composite further pattern becomes recognizable.

The security feature can preferably be applied to a security document to be checked or to a comparable object (eg label) to be checked. Alternatively, the security feature can preferably be introduced on a security document to be checked or in an object to be checked.

The security feature can be read, for example, by a smartphone.

Security processes can preferably be processed by evaluating the security feature, in particular its pattern or code. An object, a process or a user can be identified on the basis of the pattern or code. Information or encrypted secrets (e.g. data keys) can also be read out in the security feature and used in the further process. This process can be used to further verify integrity. For example, decrypted information is compared with data from the security document. For example, a name or ID number can be stored again as a QR code, so that an "offline check" can also be carried out without access to a remote server. Furthermore, the decrypted information can also be compared with data in an external database ("online check").

The security feature can be used for multi-factor authentication. For example, it can be applied to a photo of a passport, with the photo, the decay time of the first printed substance after luminescence excitation of the security feature and the pattern formed by the security feature being checked.

Another advantage of the security feature is that items on which it is printed can be assigned to a common group or distinguished from one another. Furthermore, the authenticity or authenticity can be checked. It is also advantageous that information, for example serial numbers, can be transmitted through the applied pattern.

The arrangement according to the invention serves to check the authenticity and/or integrity or the verification check of a security document. The arrangement includes a security feature and a mobile terminal. The security feature is printed on the security document. The security feature corresponds to the security feature described above with all embodiments. The mobile terminal includes a lighting unit and an image capturing unit. The lighting unit is designed to emit electromagnetic radiation. The image capturing unit is used to capture radiation, in particular non-visible radiation, which is emitted by a non-visible pattern of the security feature after excitation has taken place. Furthermore, the image acquisition unit is used for radiation detection of a visually visible pattern. The non-visible pattern is formed by a first printing substance that can be excited to luminescence by means of electromagnetic radiation. The visually visible pattern is formed by a second printing substance.

The security document on which the security feature is applied can be, for example, a bank note, a token, a passport or an identity card. Further uses of the security feature on e.g. B. the following items are possible: value and security documents, stamps, banknotes, ID cards, vehicle registration documents, bank cards, concert tickets, Train tickets, food packaging, clothing, spare parts, labels or medicine packaging. A person skilled in the art is aware of numerous other possible uses of security features, which should not be excluded here.

The security feature can also be used to identify and assign objects, for example in warehouses, or to protect products.

One of the following devices, for example, can be used to apply the printable security feature, with a defined pattern preferably being applied: printing machine, stamp or spray device.

The lighting unit is preferably an LED. The lighting unit is particularly preferably an LED for generating white light, known as a white LED, which is regularly integrated in mobile terminals. White LEDs are known to use a blue LED in combination with a conversion phosphor.

The mobile terminal is preferably a smartphone. Alternatively, the mobile end device is preferably a tablet PC with a camera. Furthermore, the mobile terminal can be a smartwatch. In an alternative embodiment, the mobile terminal is part of a smart home system.

The lighting unit is preferably a camera of the mobile terminal device with a flash light function. The flashlight function has the usual lighting times.

The image capture unit is preferably a camera of the mobile terminal device for capturing individual or serial images or videos. The image capture unit has the default capture time and capture intervals.

Further details, advantages and developments of the invention result from the following description of a preferred embodiment of the invention, with reference to the drawing.

The single FIGURE shows a method step of the method according to the invention for checking the authenticity and/or integrity of a security document 01 with a printed security feature 02. The security document 01 is an identification document with a feature 03, such as bibliographic data or a photo of the ID card owner. The security feature 02 has a code or a pattern 04 . The pattern 04 consists of a first printing substance (not shown) and a second printing substance (not shown). The pattern 04 is arranged on the feature, for example the photo, so that multi-factor authentication can take place. The first printing substance can be excited to luminesce by electromagnetic radiation of a predetermined wavelength and forms a visually invisible pattern. The second printing substance forms a visually visible pattern.

In the illustrated method step, the security feature 02 is excited to luminescence by means of a smartphone 06 by activating the flash light function of a camera (not shown) and emitting electromagnetic radiation. The flashlight function emits electromagnetic radiation 07.

In further method steps not shown, several individual images are recorded using the smartphone camera and compared with stored reference images by means of a data processing unit of the smartphone 06. The comparison takes place using the images, defined points on the images and using the luminescence characteristics of the excited first printing substance.

The properties and parameters of phosphor particles and their emissions are known to the person skilled in the art, so that a detailed description of these test steps is dispensed with.

Reference List

01

security document

02

security feature

03

Photo of ID card holder

04

Pattern

05

-

06

smartphone

07

electromagnetic radiation

Claims (13)

1. A method for checking the authenticity and/or integrity of a security document having a printed security feature, the security feature having a first printing substance, which is excitable to luminescence and in this case, following the end of the excitation, emits a visually non-perceptible radiation within a decay time, which radiation can be captured by means of an image capture unit of a terminal device, and the security feature having a second printing substance, comprising the following steps:

   - irradiating the security feature applied on the security document using an electromagnetic radiation of predetermined wavelength, by means of an illumination unit of the terminal device;

   - taking a plurality of individual images of the excited security feature at temporally defined intervals by means of the image capture unit of the terminal device, the individual images depicting the emitted visually non-perceptible radiation of the first printing substance and an image of the second printing substance, and the individual images being captured at intervals of less than 100 milliseconds;

   - examining the detected individual images or data derived therefrom by means of a data processing unit, the individual images or derived data being compared with stored reference data according to the temporally defined taking intervals; and

   - outputting a result of the authenticity and/or integrity check of the captured individual images using the reference images.
2. The method according to Claim 1, characterized in that the examination of the captured individual images using reference images takes place at defined positions of the images.
3. The method according to Claim 1 or 2, characterized in that emission values, particularly emission spectrum and/or radiation intensities at certain times within the decay time, are determined by the terminal device from the individual images taken of the excited security feature.
4. The method according to one of Claims 1 to 3, characterized in that the individual images are stored in a storage device or, following automatic image processing, are displayed on a display unit.
5. The method according to one of Claims 1 to 4, characterized in that the data processing unit is a constituent of a mobile terminal device, and in that the image capture unit comprises a photosensor, an image sensor or a camera.
6. The method according to one of Claims 1 to 5, characterized in that the first printing substance is printed as an invisible pattern and the second printing substance is printed as a visible pattern in a common area on the security document.
7. A security feature for a security document, a visually invisible pattern being formed by a first printing substance, which is excitable to luminescence using an electromagnetic radiation of a predetermined wavelength, and a visually visible pattern being formed by a second printing substance; and the first printing substance, which is excitable to luminescence, upon excitation by the electromagnetic radiation, emitting a visually non-perceptible radiation following the end of the excitation within a decay time, which visually non-perceptible radiation can be captured by an image capture unit, the temporal emission of the first printing substance being chosen such that the temporal emission can be captured in individual images, the individual images being captured at intervals smaller than 100 milliseconds.
8. The security feature according to Claim 7, characterized in that the second printing substance is also excitable to luminescence and the first and the second printing substances have different decay times and/or emit in different spectral ranges.
9. The security feature according to Claim 7 or 8, characterized in that the visually invisible pattern and/or the visually visible pattern are designed as a machine-readable code, particularly as a non-cognitively-comprehensible code.
10. The security feature according to one of Claims 7 to 9, characterized in that the security feature can be applied on the security document to be checked or introduced into the same.
11. An arrangement for checking the authenticity and/or integrity of a security document, comprising:

    - a security feature according to one of Claims 7 to 10, which is applied to the security document; and

    - a mobile terminal device having an illumination unit, which is designed for emitting an electromagnetic radiation; having an image capture unit, which is used for capturing a visually non-perceptible radiation of a visually invisible pattern and a visually visible pattern, the invisible pattern being formed by a first printing substance, which is excitable to luminescence by means of an electromagnetic radiation, and the visually visible pattern being formed by a second printing substance, the image capture unit being designed to capture the radiation in temporal intervals smaller than one second; and having a data processing unit for examining the authenticity and/or integrity of the security document on the basis of the radiation captured by the image capture unit.
12. The arrangement according to Claim 11, characterized in that the mobile terminal device is a smartphone, a tablet PC or a constituent of a smart home system.
13. The arrangement according to Claim 11 or 12,
    characterized in that the security feature is applied on the security document by means of a printing machine, a stamp or a spray device.

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