METHOD FOR VERIFYING THE AUTHENTICITY OF A MULTI-PART SECURITY FEATURE OF A VALUE OR SECURITY PRODUCT

Description

[0001] The invention relates to a method for authenticity verification of a security feature of a value or security product formed from a plurality of feature parts and thereby having at least two optically activatable states, using a mobile terminal having at least one light source and at least one image sensor.

[0002] Valuable or security documents can be, for example, an identity document, a check card, a non-personalised authorization card such as a ticket or a means of payment, or a valuable or security element intended for product security.

[0003] For example, it is known from the prior art to integrate holograms as security features into security documents or valuable documents. Security features or security elements are entities that have at least one characteristic that makes unauthorized duplication, imitation, and / or counterfeiting of an object in which the security element is integrated difficult. Holograms are used as security features in passports or identity cards, for example. However, they are also used in banknotes, driver's licenses, visas, other security tokens, labels or tickets, credit cards, bank cards, phone cards, and similar devices.

[0004] Volume holograms represent a special group of holograms. In a volume hologram, a diffractive structure of the hologram is stored within the volume of the holographic recording material. Holographic exposure films, usually provided on rolls, are typically used as recording materials for volume holograms in valuable and / or security documents. These exposure films are suitable for storing interference structures whose characteristic dimensions are in the range of the wavelength of the light used to record or reconstruct the hologram.

[0005] In a contact copying process, the holographic exposure film is placed in front of a master in which diffractive structures are formed that are to be "transferred" into the holographic exposure film. The diffractive structures of the master are thus copied into the holographic film in this process. For this purpose, coherent light is irradiated onto the master through the holographic film, which is placed in close proximity to the master or in contact with the master. The diffractive structures in the master diffract the light in such a way that the diffracted light is reflected back into the holographic film. There, it interferes with the coherent light used to illuminate the master. An interference structure is thus formed in the holographic film, which is determined by the light diffracted by the master.If the holographic film is developed and reconstructed, the reconstruction resembles the one observed when the master is illuminated. A hologram, also known as a Denisyuk hologram, is stored in the holographic film. It is understood that the incident light must have a suitable wavelength (or wavelengths) and a suitable direction (or directions) of incidence so that diffraction at the diffraction structure occurs in the desired manner.

[0006] For security or valuable documents, for example, the use of holographic features formed from volume holograms is suitable, as they are particularly suitable for verification when viewed perpendicularly, for example, to the exposed and developed holographic film. The reconstruction light is preferably irradiated at an acute angle, for example, at 45 degrees to the vertical. The angle between the direction of incidence of the reconstruction light and the direction of reflection of the light diffracted by the generated volume hologram, which reconstructs the hologram's information, is essentially determined during master production.

[0007] DE 10 2007 052 ​​952 A1 describes a security document comprising two adjacent volume reflection holograms, a first volume reflection hologram consisting of a more strongly scattering layer and a second volume reflection hologram consisting of a less scattering layer. For both layers, the intensity of the reconstruction increases the closer one approaches the angle of exposure. This security document has proven itself in practice and offers adequate protection against product counterfeiting.

[0008] DE 10 2015 116 708 A1 describes a method for verifying a document in which a smartphone with an image camera captures two angle-dependent security features from two different positions. The smartphone's illumination is used to stimulate the two security features. The camera then captures the two security features from two different angles.

[0009] US 2006 / 0 022 059 A1 describes a holographic security feature with two different optical states, as well as a mobile handheld device for reading the security feature. The holographic security feature exhibits a different reconstruction depending on the direction of irradiation.

[0010] DE 10 2018 217 560 A1 describes a security document with a security element that has several diffraction structures that can be optically detected at different angles of incidence and reconstruction.

[0011] DE 10 2017 120 536 A1 describes a method for producing a hologram, as well as a security element and a security document. This document essentially deals with holograms distributed across multiple virtual hologram planes, so that different representations of the hologram can be seen on the security document at different viewing angles.

[0012] There is a need to be able to reliably read security features including holograms or optically variable features by machine even when no stationary reading device is available.

[0013] It is therefore the object of the present invention to provide a method for authenticity verification of a security feature of a value or security product formed from a plurality of feature parts and thus having at least two different optically activatable states, which method also enables mobile use and thereby permits reliable machine testing of a security feature consisting of a plurality of parts.

[0014] This object is achieved by a method having the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

[0015] The method according to the invention comprises the following steps: Illuminating the security feature with the at least one light source of the mobile terminal at a first angle and checking whether this has caused a first optically active state of the security feature and detected by the image sensor, Illuminating the security feature with the at least one light source of the mobile terminal at a second angle deviating from the first angle and checking whether this has caused at least a second optically active state of the security feature and detected by the image sensor, and Determining a product counterfeit if one of the optically active states could not be detected or could not be detected completely by the image sensor.

[0016] If the feature components are formed as holograms, particularly volume reflection holograms, they reconstruct the light radiation emitted by the mobile device's light source at different angles of incidence. Thus, all feature components of a complex security feature can be made "visible" with the mobile device and recorded using the image sensor. The recorded images are then used for authenticity verification, preferably by an evaluation device integrated into the mobile device, particularly in a microprocessor of the mobile device.

[0017] A "quasi-static" testing option according to the invention provides that the image sensor is the camera of the mobile device configured as a smartphone, that the light source is formed by a display of the smartphone, and that the display is selectively illuminated to induce at least two of the optically active states of the security feature. The display thus has a plurality of individual light sources that can be controlled individually or in groups to optically activate the individual feature components of the security feature so that they can be captured by the image sensor, in particular by the camera.

[0018] In this context, it is also possible to display a light bar on the display and adjust it in one direction along the display to illuminate different areas of the security feature, thus triggering at least two of the security feature's optically active states. This variant thus acts like a "scanner" that, with continuous movement, gradually optically activates all parts of the security feature, thus making them "visible" to the image sensor.

[0019] When adjusting the light bar, it can also change its color in a further design, so that a different coloration of the individual feature parts or their reconstruction is possible.

[0020] For all embodiments of the present invention, it should be noted that the illumination for activation and also the reconstruction or emission of the security feature or individual parts thereof can also occur in the non-visible range. Thus, for example, variants with infrared excitation (IR) with an IR response are feasible. Excitation in the ultraviolet (UV) range and emissions in the UV are also possible. Optical activation can also occur in the non-visible range, for example, in the infrared range, whereby the feature parts or the security feature are then detectable in the visible wavelength range (VIS) in the activated state.

[0021] It is useful for the display to illuminate different locations, making individual or all parts of the security feature visible simultaneously and captured by the camera. The display forms a multitude of individual light sources at different positions. Depending on the display control or the underlying programming, they behave like a single "mobile" light source. Thus, the behavior of the display depends on a graphical implementation.

[0022] It has also proven advantageous – but of secondary importance – to display illuminated fields, particularly colored fields with a predefined, different color scheme, at different locations on the display, making all components of the security feature visible and captured by the camera simultaneously. This reduces the number of images captured by the image sensor when verifying the authenticity of the valuable or security product, as only a single image is required to capture all activated components simultaneously.

[0023] It has also proven advantageous if the mobile device has a number of light sources corresponding to the number of feature parts of the security feature to be verified, and if the light sources are selectively switched on individually or repeatedly at certain times to trigger at least two of the optically active states of the security feature, which are then captured by the image sensor. In this way, multiple images or even a video stream can be captured by the image sensor, each of which optically activates a different feature part of the security feature, thus making it visible. All images are then digitally "superimposed" by an evaluation unit, whereby the resulting overall image can then be subjected to authenticity verification.

[0024] A "periodically recurring light source" is one that is not permanently switched on, but rather is switched on and off again at a predetermined frequency. Luminescent security features or luminescent feature components can also be used, for example, excited by a single flash of light from the light source. Continuous detection of the excited feature allows its decay behavior to be examined to determine whether the detected decay behavior corresponds to that of an unaltered valuable or security product.

[0025] It is also advantageous if the light sources are not selectively switched on individually, but all switched on simultaneously, or even all switched on simultaneously and repeatedly over time, in order to trigger at least two of the optically active states of the security feature, which are then detected by the image sensor. In this way, the feature components of the security feature are all optically activated simultaneously and can be detected by the image sensor in a single image.

[0026] During evaluation and authentication, it has proven advantageous to combine all images of the security feature captured by the image sensor into a single image of the security feature or the entire valuable or security product, including the optically active states of the feature components, and to compare the feature components contained in the single image with a reference value for authentication verification. When overlaying the individual images, they can be trimmed to a "common denominator" so that only the area to be verified is exposed and subjected to authentication verification. This reduces the amount of data required for processing and verification in the evaluation unit, thus speeding up the verification process.

[0027] It is advantageous if the mobile device includes a position sensor. When the security feature is illuminated, the position of the mobile device relative to the valuable or security product is determined based on the data captured by the image sensor and the position sensor. This allows the combined image – possibly with edge trimming – to be compiled from this and the captured individual images. In this way, the position information can also be used to determine whether the position of the feature parts and the security feature on the valuable or security product is correct. In this case, even if the position is inconsistent, it can be concluded that the valuable or security product is counterfeit.

[0028] For improved authenticity verification, it has proven advantageous if the reference value for comparison is available as information on the valuable or security product, which is also captured when the security feature is recorded with the image sensor. In this way, the reference value is also captured in the data captured by the image sensor, which can then be compared in the evaluation unit with the at least one optically activated security feature. The reference value can, for example, be a text field, a barcode, a graphic, or the like. If a comparison with the reference value fails, it can be concluded that the valuable or security product is counterfeit.

[0029] It is also possible for the reference value for the comparison to be information stored in a database, either in the physical memory of the mobile device itself or in the physical memory of a higher-level server. The mobile device can exchange data with this higher-level server, for example, via a wireless communication connection, whereby the authenticity verification check can then be performed on the server's processors or on the processor of the mobile device.

[0030] It is advantageous if the light source is configured to emit different colors and if the light source changes its color depending on the angle of incidence of the light rays emitted by it onto the security feature. For this purpose, the light source is formed, for example, from a plurality of narrow-band LEDs emitting light at different wavelengths. In this way, with the "movement" of the light from the light source and the associated change in the angle of incidence, not only the location of a security feature—for example, a holographic one—on the valuable or security product changes, but also its color in a predetermined manner. The coloring and color sequence also allow for improved verification of authenticity.

[0031] In this context, it is preferred if the angle of incidence of the light rays on the security feature and thus on the entire valuable or security product is determined using the data recorded by the position sensor of the mobile device.

[0032] It is advantageous if a first feature part is formed by a first volume reflection hologram that reconstructs at a first reconstruction wavelength and a first reconstruction irradiation direction, and if at least a second feature part is formed by a second volume reflection hologram that reconstructs at a second reconstruction irradiation direction that differs from the first reconstruction irradiation direction. Both feature parts can reconstruct at the same reconstruction wavelength, so that the color of the light emitted by the light source has no influence on the type of reconstruction of the respective feature parts.

[0033] However, it is possible for the second volume reflection hologram to reconstruct exclusively at a second reconstruction wavelength that differs from the first reconstruction wavelength, thus creating improved protection for a valuable or security product that has increased security against counterfeiting.

[0034] Of course, more than two feature parts can be present. For example, a third feature part is present, which could be formed by a third volume reflection hologram. However, a different number of feature parts is also possible.

[0035] In order to improve the protection of the valuable or security product and at the same time improve machine readability, it has proven advantageous if the at least third volume reflection hologram is designed to reconstruct in a third reconstruction irradiation direction that differs from the first reconstruction irradiation direction and from the second reconstruction irradiation direction.

[0036] If more than two volume reflection holograms are used, the security feature formed from the multiple volume reflection holograms becomes more independent in its position on the substrate or card body. This independence is increasingly enhanced by increasing the number of possible reconstruction angles / reconstruction beam directions, thus increasing the number of volume reflection holograms.

[0037] It is possible that the volume reflection holograms have an identical shape, which improves their machine recognition, since a mobile device must then always check for the presence of the same pattern in order to verify the authenticity of the majority of volume reflection holograms.

[0038] In this context, it is useful for the volume reflection holograms to be formed as directly adjacent polygons. These can be, for example, triangles or quadrilaterals, especially rectangles or squares.

[0039] However, machine evaluation is also facilitated if the volume reflection holograms are formed as immediately adjacent circular sectors whose vertices lie at a common point.

[0040] The valuable or security product provided with the multi-part security feature can be a valuable or security document or a security element, i.e. an element that is, for example, connected to an object to be protected against imitation, forgery or falsification, such as a sticker, label or the like. Examples of valuable or security products that can be considered are a passport, identity card, driving license or other ID card or access control card, vehicle registration document, vehicle registration certificate, visa, check, other means of payment, in particular a banknote, check, bank, credit or cash payment card, customer card, health card, chip card, company ID card, proof of authorization, membership card or other ID document, whereby it should be ensured that this has a portrait photo or one is attached to it.

[0041] The valuable or security product is preferably in ID 1, ID 2, ID 3, or some other format, for example, in booklet form, similar to a passport-like item. The valuable or security product is generally a laminate of multiple document layers that are precisely bonded together under heat and increased pressure. These products should meet standardized requirements, for example, ISO 10373, ISO / IEC 7810, and ISO 14443.

[0042] The product layers preferably consist of a carrier material suitable for lamination. However, the valuable or security product can preferably be formed from a polymer selected from a group comprising polycarbonate (PC), in particular bisphenol A polycarbonate or a polycarbonate formed with a geminal disubstituted bis(hydroxyphenyl)cycloalkane, polyethylene terephthalate (PET), derivatives thereof, such as glycol-modified PET (PETG), polyethylene naphthalate (PEN), polyvinyl chloride (PVC), polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), polyimide (PI), polyvinyl alcohol (PVA), polystyrene (PS), polyvinylphenol (PVP), polypropylene (PP), polyethylene (PE), thermoplastic elastomers (TPE), in particular thermoplastic polyurethane (TPU), acrylonitrile-butadiene-styrene copolymer (ABS) and derivatives thereof, and / or paper and / or cardboard and / or glass and / or metal and / or ceramic.Furthermore, the product can also be made from several of these materials. It preferably consists of PC, PVC, and PET. The polymers can be either filled or unfilled. In the latter case, they are preferably transparent or translucent. If the polymers are filled, they are opaque. The above information refers both to films to be bonded together and to liquid formulations applied to a precursor, such as a protective or topcoat. The product is preferably made from three to twelve, preferably four to ten, films. The films can also carry printing layers. A laminate formed in this way can then be coated on one or both sides with the protective or topcoat or with a film. The film can, in particular, be a volume hologram, a film with a surface hologram (for example, a cinematic element), or a scratch-resistant film.Overlay layers formed in this way protect a security feature arranged underneath and / or provide the document with the necessary abrasion resistance.

[0043] The present invention is explained in more detail below with reference to figures, whereby the illustrated examples are merely exemplary and do not represent a limitation with regard to the scope of the described invention. They show in detail: Fig. 1 a schematic isometric representation of a valuable or security product in the form of an identity card, Fig. 2 a schematic sectional view of the identity card along the line II, Fig. 3 an arrangement not encompassed by the invention, in which the highly schematic valuable or security product is irradiated with an LED light source of a manually moved mobile terminal in order to optically activate the feature parts of the security feature, wherein the optically activated parts are detected by the image sensor of the mobile terminal (dynamic authenticity verification), Fig. 4 an arrangement in which the highly schematic valuable or security product is irradiated with a light source in the form of the display of the otherwise stationary mobile terminal in order to optically activate the feature parts of the security feature, wherein the optically activated parts are detected by the image sensor of the mobile terminal (quasi-static authenticity verification), Fig.5 shows an arrangement not encompassed by the invention in which the highly schematic valuable or security product is irradiated with a plurality of light sources of the mobile terminal in order to optically activate the feature parts of the security feature, wherein the optically activated parts are detected by the image sensor of the mobile terminal, and Fig. 6 shows an arrangement in which the highly schematic valuable or security product is irradiated with a plurality of light sources of the display of the mobile terminal in order to optically activate the feature parts of the security feature, wherein the optically activated parts are detected by the image sensor of the mobile terminal.

[0044] In Figure 1A valuable or security product 100 provided with a security feature 500 is shown. The valuable or security document 100 can be a personal document, such as a passport, an identity card, an access pass, or the like, a check card, a banknote, or another document. All subsequent examples are described using such a card as a representative of other document types.

[0045] In the Figures 1 and 2The valuable or security product 100 is depicted in the form of an identity card, which, for example, has been assembled as a laminate of several internal polymer layers 140. For example, the polymer layers can be made of PC and / or PET. The individual layers can be unfilled or filled with fillers. In the latter case, they are opaque; otherwise, they are transparent. The layers can preferably be bonded together in such a way that they form a monolithic block that is practically impossible to split.

[0046] In Figure 2For illustrative purposes only, the layers separated prior to lamination are shown visible. In the finished laminate, the interfaces are no longer visible. The outer layers 150 of the card can be formed as a final plastic protective film or consist of a protective varnish that was applied to the card after lamination. The plastic protective film or the protective varnish are transparent, so that underlying information is visible from the outside. In particular, however, one or more print layers 140a, for example of a portrait image 110, remain visible, which is / are preferably arranged directly next to or behind the outer layer 150.

[0047] The valuable or security product 100 has a top side 101 and a bottom side 102. The top side 101 contains the facial or portrait image 110 of the cardholder, as well as data fields, namely, for example, a first data field 120 and a second data field 130 containing card and cardholder data in plain text. The data in the first and second data fields 120, 130 are created by printed layers located on an outer layer of the document, but directly beneath the outer protective layer 150. The data in a third data field 125 and a fourth data field 135 reproduce the personalization data in plain text in Braille.

[0048] It can be seen that the identity card is provided with a security feature 500, which is formed in the form of an Identigram (a registered trademark of the applicant) from several individual volume reflection holograms, thus from several individual feature parts 500a, 500b, 500c. The arrangement, size, and shape of the feature parts 500a, 500b, 500c are chosen purely as examples, so other arrangements, sizes, or dimensions are also possible.

[0049] In order to be able to read the identity card automatically, a Figures 3 to 6The mobile device 200 shown is used, which is provided with a light source 201 and at least one image sensor 204. This mobile device 200 is a smartphone, wherein the image sensor 204 is the smartphone's camera and the light source 201 is an LED of the smartphone assigned to the camera. The camera can be the front camera or the rear camera of the smartphone. This mobile device 200 is in any case used to verify the authenticity of the complex security feature 500 of the valuable or security product 100, formed from the multiple feature parts 500a, 500b, 500c, which is carried out in particular by the following steps: Illuminating the security feature 500 with the at least one light source 201 of the mobile terminal 200 at a first angle and checking whether this has caused a first optically active state of the security feature 500 and detected by the image sensor 204, illuminating the security feature 500 with the at least one light source 201 of the mobile terminal 200 at a second angle deviating from the first angle, or illuminating the security feature 500 with a second light source 202 and checking whether this has caused at least a second optically active state of the security feature 500 and detected by the image sensor 204, and determining a product counterfeit if one of the optically active states could not be detected or could not be detected completely by the image sensor 204.

[0050] In the Figure 3This illustrates the possibility, not encompassed by the invention, of moving the mobile terminal 200 relative to the valuable or security product 100 to detect the multiple feature parts 500a, 500b, 500c, so that different angles of incidence for irradiation by the light source 201 formed as an LED can be realized. During this movement, the image sensor 204 formed as a camera is simultaneously active or switched on and records the individual images or a video stream of the valuable or security product 100. The individual images are then digitally "superimposed" by a processor of the mobile terminal 200 and thus combined into a single image in which all feature parts 500a, 500b, 500c are displayed in an optically activated manner. In this way, the multi-part or complex security feature 500 can be fully verified for authenticity.

[0051] In the Figure 4This illustrates the possibility of using a display 206 of the mobile terminal 200 as the light source 201, wherein the display 206 can illuminate selectively in order to selectively optically activate the individual feature parts 500a, 500b, 500c and simultaneously capture this optically activated representation of the security feature 500 using the camera. Instead of selective illumination, the display 206 of the smartphone can also illuminate diffusely over a large area, so that all components of the security feature 500 can also be optically activated, allowing all optically active states to be captured and subsequently verified in a single image.An alternative or supplementary embodiment provides that a light bar is displayed on the display 206 and is adjusted in a direction along the display 206 in order to illuminate different areas of the security feature 500 so that the optically active states of the security feature 500 can be evoked in the manner of a "scanner" and captured by the image sensor 204, thus by the camera.

[0052] In the Figure 5The further possibility is illustrated, whereby the display 206 illuminates at different locations—sequentially or simultaneously—which also makes all feature parts 500a, 500b, 500c of the security feature 500 visible, preferably simultaneously, so that they can be captured by the camera. It is possible for a different color scheme to be distributed across the display 206, so that a predetermined color scheme can also be evoked for the reconstruction of the individual hologram parts.

[0053] The Figures 6 and 7refer to the possibility, not covered by the invention, that the mobile terminal 200 has at least or exactly one number of light sources 201, 202, 203 corresponding to the number of feature parts 500a, 500b, 500c of the security feature 500 to be checked, and that the light sources 201, 202, 203 can be selectively switched on individually or together in order to bring about the optically active states of the security feature 500, which are then detected by means of the image sensor 204.

[0054] Typically, the mobile terminal 200 formed as a smartphone of all the previously explained embodiments additionally comprises a position sensor, wherein the angle of incidence of the light rays on the security feature 500 can be determined using the data acquired by the position sensor, and wherein the possibility exists that, depending on the position data, the light source 201, 202, 203 is also configured to emit different colors.

[0055] For the final verification, it is possible to use a reference value, for example in the form of a text field, a barcode, a graphic, or the like, for comparison with the information of the security feature 500, wherein this reference value is preferably also present as information on the valuable or security product 100. Thus, this reference value is also detected by the image sensor 204 for the authenticity check. Alternatively or additionally, the reference value for the comparison can also be information stored in a database, which is stored in a physical memory of the mobile terminal 200 or in a physical memory of a higher-level server with which the mobile terminal 200 is in a communication connection.

[0056] Typically, each of the feature parts 500a, 500b, 500c is formed as a volume reflection hologram, each reconstructing at different angles of incidence or reconstruction irradiation directions.

[0057] In this case, there is a first volume reflection hologram (feature part 500a), a second volume reflection hologram (feature part 500b), and a third volume reflection hologram (feature part 500c). All volume reflection holograms have an identical shape and, in the example shown, are directly adjacent to one another. They are therefore designed, for example, as polygons, which are formed, in particular, from directly adjacent squares or rectangles.

[0058] If one of the feature parts 500a, 500b, 500c cannot be reconstructed in the specified or desired manner, it can be concluded that the valuable or security document 100 is forged. For this purpose, the mobile terminal 200 can then output a corresponding warning message visually on the display or acoustically via the loudspeakers. LIST OF REFERENCE SYMBOLS

[0059] 100Value or security product 101Upper substrate surface, upper card surface, top side 102Lower substrate surface, lower card surface, bottom side 110Facial image 120First data field 130Second data field 125Third data field 135Fourth data field 140Inner polymer layers 140aPrint layer 150Outer protective layer 200Mobile device / e.g. smartphone 201Light source / e.g. LED or display 202Second light source / e.g. LED 203Third light source / e.g. LED 204Image sensor / e.g. camera 206Display 500Security feature 500aFirst feature part / e.g. first volume reflection hologram 500bSecond feature part / e.g. second volume reflection hologram 500cThird feature part / e.g. third volume reflection hologram

Claims

1. A method for verifying the authenticity of a security feature (500), which is formed from a plurality of feature parts (500a, 500b, 500c) and thereby has at least two different optically activatable states, of a value or security product (100), using a mobile device (200) in the form of a smartphone which has at least one light source (201) in the form of a display (206) and at least one image sensor (204) in the form of a camera of the smartphone, comprising the steps: - irradiating the security feature (500) with the at least one light source (201) of the mobile device (200) at a first angle and checking whether a first optically active state of the security feature (500) has thereby been caused and detected by the image sensor (204), - irradiating the security feature (500) with the at least one light source (201) of the mobile device (202) at a second angle differing from the first angle and checking whether at least a second optically active state of the security feature (500) has thereby been caused and detected by the image sensor (204), and - detection of a product counterfeit if one of the optically active states could not or not completely be detected by the image sensor (204) characterized in that for irradiating the security feature (500) with the at least one light source (201) of the mobile device (200) at the first angle and at the second angle, the display (206) is selectively illuminated at different locations of the display (206) to cause the at least two of the optically active states of the security feature (500).

2. The method according to claim 1, characterized in that a light bar is displayed on the display (206) and adjusted in a direction along the display (206) to illuminate different areas of the security feature (500) to cause at least two of the optically active states of the security feature (500).

3. The method according to claim 1, characterized in that illuminated fields light up at different points on the display (206), as a result of which all feature parts (500a, 500b, 500c) of the security feature (500) are made visible simultaneously and are detected by the camera.

4. The method according to claim 1, characterized in that the mobile device has at least a number of light sources (200, 201, 202) corresponding to the number of feature parts (500a, 500b, 500c) of the security feature (500) to be checked, and in that the light sources (200, 201, 202) are switched on at recurring intervals in order to produce at least two of the optically active states of the security feature (500), which are then detected by means of the image sensor (204).

5. The method according to any one of claims 1 to 4, characterized in that all images of the security feature (500) captured by the image sensor (204) are combined into a common image of the security feature (500) or of the entire value or security product (100) with the optically active states of the feature parts (500a, 500b, 500c), and in that the feature parts (500a, 500b, 500c) contained in the common image are compared with a reference value for authenticity verification.

6. The method according to claim 5, characterized in that the mobile device (200) comprises a position sensor, in that, when the security feature (500) is irradiated, the position of the mobile device (200) with respect to the value or security product (100) is determined on the basis of the data captured by the image sensor (204) and the data captured by the position sensor, in order to combine the common image edge-cropped therefrom and from the captured individual images.

7. The method according to claims 5 or 6, characterized in that the reference value for the matching is present as information on the value or security product (100), which is also captured with the image sensor (204).

8. The method according to claims 6 or 7, characterized in that the reference value for the comparison is information stored in a database which is stored in a physical memory of the mobile device (200) or in a physical memory of a higher-level server.

9. The method according to any one of claims 1 to 8, characterized in that the light source (201) is set up to emit different colors, and in that the light source (201) changes its colouring depending on an angle of incidence of the light beams emitted by it onto the security feature (500).

10. The method according to claim 9, characterized in that the mobile device (200) comprises a position sensor, and in that the angle of incidence of the light beams on the security feature (500) is determined using the data acquired by the position sensor.

11. The method according to any one of claims 1 to 10, characterized in that a first feature part (500a) is formed by a first volume reflection hologram which reconstructs at a first reconstruction wavelength and a first reconstruction single-beam direction, and in that at least a second feature part (500b) is formed by a second volume reflection hologram (500b) which reconstructs at a second reconstruction single-beam direction differing from the first reconstruction single-beam direction.

12. The method according to claim 11, characterized in that the second volume reflection hologram (500b) reconstructs exclusively at a second reconstruction wavelength differing from the first reconstruction wavelength.