Label with protection against forgery

Abstract

A label (1) with protection against forgery comprises an unclonable security feature (10) and a hidden code (20). The hidden code (20) contains data describing the security feature (10). The data are coded in the hidden code in the form of characters (21). As a result, the characteristic properties of the security feature (10) are directly stored on the label (1), with the result that it is not necessary to access a database in order to authenticate the security feature (10). The characters (21) may be arranged on a substrate (30) with a covering layer (60) above which is opaque when illuminated with light in the visible spectrum and transparent when illuminated with light in at least one part of the invisible spectrum (for example transparent and readable with an infrared camera in the infrared spectral range), or which becomes transparent when heated above a temperature threshold value (for example made of thermochromic inks).

Description

[0001] Description

[0002] Anti-counterfeiting label

[0003] The following illustration concerns a label with protection against counterfeiting through a security feature arranged on the label.

[0004] Product manufacturers, for example, of popular or high-quality consumer goods or pharmaceutical products, frequently encounter counterfeit products on the market, which cause financial damage to the company. Counterfeiters brand lower-quality products with the company logos of well-known manufacturers and often offer them at a lower price. Product manufacturers are therefore interested in counterfeit-proof labeling of their products.

[0005] In addition to the economic damage suffered by the original manufacturer, consumers are also harmed by being deceived by counterfeit products and, particularly in the case of counterfeit products in the medical sector, even exposed to potential health damage. Consumers should therefore be able to identify counterfeit products on the market.

[0006] Products and labels used to identify products are often already provided with a security feature that makes it possible to reliably distinguish genuine goods from counterfeit products.

[0007] To ensure the highest possible level of security, such a security feature should not be easily copied by a counterfeiter. For this purpose, so-called non-clonable security features / PUFs (Physically Uncloneable Functions) are already being used on products or labels on the market. A non-clonable security feature has structures that arise randomly during the manufacture of a product or label and therefore cannot even be imitated or copied by the manufacturer themselves, which is why it is called a non-clonable security feature. Examples of such non-clonable security features include the random arrangement of fibers in paper or prints using any printing process, which are subject to natural variations from print to print, for example in the shape of the printed motifs.

[0008] Anti-counterfeiting protection that is based on characterizing such a PUF, i.e. generating features for a specific object in order to later confirm its authenticity by verifying these same features, has a particularly high level of security, since the specific features of the PUF cannot be deliberately reproduced due to their random creation.

[0009] A so-called (digital) fingerprint can be created from the PUF structures. Starting with an image of a surface area of ​​the label, interesting image regions characterized by any anomalies, such as white dots on a dark background or, conversely, dark dots on a white background, are identified. The points or anomalies are characterized in a feature vector. The features of the interesting image regions can be, for example, brightness values, gradients, or other values ​​or functions determined using image processing techniques.

[0010] To authenticate a non-clonable security feature, for example, an image of a defined area of ​​the object to be tested, such as a label, was previously stored in a central database, or characteristic features derived from the image were stored in the database. During authentication, the image of a sample to be tested, or features derived from it, are then compared with the information stored in the database to assess the authenticity of the security feature. Therefore, (online) access to a central database is necessary to authenticate a security feature on a test object or a label.

[0011] It is desirable to provide an anti-counterfeiting label where a non-clonable security feature / PUF present on the label can be easily authenticated, in particular without access to a central database or without a database at all.

[0012] A label with protection against counterfeiting, which allows the authenticity of a non-clonable security feature present on the label to be reliably verified in the simplest possible manner, is specified in patent claim 1.

[0013] The proposed embodiment of a label with anti-counterfeiting protection comprises, in addition to a non-clonable security feature, a hidden code containing data describing the security feature. The data is encoded in the form of characters of the hidden code. The authenticity of the security feature arranged on the label can be verified using the data of the hidden code also arranged on the label.

[0014] The advantage of the proposed combination of a non-clonable security feature / PUF with the storage of the data characterizing the security feature in the form of a code of characters on the object / label to be tested itself is that the data describing the security feature does not have to be retrieved from a (central) database. This would otherwise require immediate (online) access to the database or at least deferred access to the database. Furthermore, setting up and operating the database itself represents a significant effort that can be avoided with the proposed embodiment of a forgery-proof label, in which a non-clonable security feature and the hidden code describing this security feature are arranged together on the label.

[0015] The information about the non-clonable security feature can be contained in coded form in the printed elements of the hidden code. For example, the information can be encoded in the form of the printed elements' shape, for example, in the form of dots, lines, or triangles, etc., or in the form of the orientation, fill, size, frequency, color, or height of the printed elements. Other encoding options include the relative placement of the printed elements to one another, for example, encoding based on the distance or angle between the printed elements.

[0016] According to one possible embodiment of the label, the hidden code can be designed such that the characters of the code are not recognizable to the human eye in the visible spectrum. According to another embodiment, the hidden code can be designed such that the characters of the code are generally recognizable to the human eye in the visible spectrum. However, the hidden code can be designed as a non-obvious background code, so that it appears invisible to an observer despite the characters' general recognizability in the visible spectrum.

[0017] The non-obvious background code can, for example, be designed such that its characters or structures are distributed homogeneously across a surface of the label. The structures, in particular dots or lines, can, for example, be almost equally spaced from one another or evenly distributed between other structures. It has proven advantageous if the non-obvious background code has an average print density of no more than 2%. In particular, the non-obvious background code can be designed as a (digital) watermark; in particular, the information can be conveyed using steganographic methods.

[0018] The advantage of storing the characteristics of the non-clonable security feature in the form of a non-obvious background code on the label is that the hidden code does not take up any space on the label. The entire available space on a label is thus available to the manufacturer for printing, for example, for arranging design elements.

[0019] Since no explicit space needs to be reserved for the hidden code on the label, redundancies can be incorporated into the hidden code, allowing the code to be read particularly robustly and thus remain recognizable regardless of partial defects or missing sections of the background pattern, poor lighting conditions, or poor image quality. The use of a non-clonable security feature / PUF on the label has the advantage that, due to its design, such a security feature cannot even be copied by the manufacturer itself. The use of a non-clonable security feature thus represents the maximum level of security for identifying the authenticity of a label or a product marked with the label.

[0020] The use of a non-clonable security feature on a label has the additional advantage that a test piece marked with the label can be uniquely identified and thus, for example, no additional explicit serial number needs to be associated with the test piece.

[0021] According to one possible embodiment, the non-clonable security feature can be designed as a so-called additive non-clonable security feature (PUF). In the additive embodiment, a randomly generated structure is deliberately added to the object or label to be tested, for example, through a dedicated manufacturing step.

[0022] According to another possible embodiment, the non-clonable security feature can be designed as a so-called non-additive security feature (PUF). In such a non-additive approach, the features used are characteristics that arise anyway during the production of the object or label to be tested, for example, a natural fluctuation in the contour of a font already present on the label or, for example, a printed 2D code.

[0023] The use of a non-additive, non-clonable security feature has the advantage that no additional elements need to be incorporated into the label material; instead, authenticity can be verified based on the existing design elements. This eliminates the need for additional material, especially specialized material, that would otherwise be required. Furthermore, the effort required to ensure the random formation of a characteristic structure is eliminated.

[0024] Various possible embodiments of a label with anti-counterfeiting protection are explained in more detail below using the figures. They show:

[0025] Figure 1 A is a plan view of a label with a non-clonable security feature in the form of fibres in the material of the label,

[0026] Figure 1B is a plan view of a label with a non-clonable security feature in the form of air bubbles in a print layer,

[0027] Figure IC is a plan view of a label with a non-clonable security feature in a configuration as differently coloured pigment grains,

[0028] Figure 2A is a plan view of a label with a non-clonable security feature and a hidden code for authenticating the security feature in different areas of the label,

[0029] Figure 2B is a plan view of a label with a non-clonable security feature and a hidden code for authenticating the non-clonable security feature in overlapping areas of the label,

[0030] Figure 3 is a plan view of a label with an enlarged area in which a hidden code is arranged to identify a non-clonable security feature of the label,

[0031] Figure 4 is a transverse view of an embodiment of a label with a cover layer for concealing a hidden code;

[0032] Figure 5 shows a plan view of an embodiment of a label with a non-clonable security feature and a hidden code in adjacent surface areas of the label. For authentication, i.e., to verify the authenticity of an object to be tested or a label applied to an object, a non-clonable security feature / PUF can be arranged on the label. Such a non-clonable security feature is characterized by structures that arise randomly during the production of an object to be tested or a label. Such security features represent a high security standard because they cannot be copied by a counterfeiter or even imitated by the manufacturer themselves. Exemplary embodiments of such non-clonable security features are shown in Figures 1A, 1B, and 1C.

[0033] Figure 1A shows an embodiment of a non-clonable security feature 10 on a label 1 in the form of fibers 11 randomly arranged in a material of the label, for example, a paper material. In this embodiment, the arrangement of the fibers represents a characteristic feature for verifying the authenticity of the label.

[0034] Figure 1B shows a non-clonable security feature 10 in the form of air bubbles 12 randomly distributed within a thick printed layer of the label. In this case, the distribution and shape of the air bubbles within the printed layer represent a characteristic feature for the authenticity of the label.

[0035] In the embodiment shown in Figure 1C, a non-clonable security feature 10 is formed by differently colored pigment grains 13 on the material of a label 1.

[0036] Figures 2A and 2B show embodiments of a label 1 with protection against counterfeiting, wherein the label has a non-clonable security feature 10. According to the invention, the label additionally comprises a hidden code 20 containing data describing or characterizing the security feature 10. The data is encoded in the form of characters 21 of the hidden code. Instead of storing the characteristic properties of the non-clonable security feature / PUF 10 applied to the label in an external (central) database, the characteristic properties of the non-clonable security feature 10 in the label according to the invention are stored in the form of the hidden code 20 on the label 1 itself. The authenticity of the non-clonable security feature 10 can thus be verified by reading the characters 21 and thus the data of the hidden code 20 encoded in these characters.

[0037] Figures 2A and 2B show the security feature 10 arranged on a surface 50 of the label and the hidden code 20 arranged on a surface 40 of the label. The border of the surface 40 shown in dashed lines in the figures is drawn only to better illustrate the surface 40, but is not present in practice. Instead, the hidden code is designed to be as inconspicuous as possible in the practical embodiment so that it is not visible to an observer at first glance. In the actual design of the label 1, the surface 40 or the surface 50 can optionally be marked by fine edge dots 22 at the four corners of the surface 40 and / or the surface 50.

[0038] The hidden code 20 can be arranged outside the area 50 provided for the non-clonable security feature 10. The hidden code 20 can, for example, be arranged on the area 40 of the label shown in Figure 2A, which lies outside the area 50 for the security feature 10.

[0039] According to another embodiment of the label 1 shown in Figure 2B, the hidden code 20 is arranged on a surface 40 and the non-clonable security feature 10 is arranged on a surface 50 of the label, wherein the surface 40 and the surface 50 overlap or are even identical. In this embodiment, the hidden code 20 is designed such that the security feature 10 remains on the surface 50 undisturbed by the hidden code 20. Thus, the hidden code 20 has no decisive influence on the characteristic properties of the non-clonable security feature 10 if the hidden code 20 is applied to the surface 50 overlapping with the surface 40 only after the characteristic properties of the non-clonable security feature 10 have been read for the first time.The use of a hidden code 20 to authenticate the non-clonable security feature 10 offers the advantage of transporting information about the non-clonable security feature 10 in the form of data or storing it on the label itself, without the code being immediately recognizable as such by the human eye. For example, when viewing surface 40 with the naked eye, no noticeable motifs that could represent the code are perceived.

[0040] According to one possible embodiment, the individual characters 21 of the hidden code 20, for example, dots or lines, can in principle be recognizable to the human eye in the visible spectral range. However, the code itself is designed as a non-obvious background code and is therefore not obviously recognizable to an observer. For example, a raster-printed surface can, on the one hand, be perceived as homogeneous and gray, and, on the other hand, still contain information in the alignment of the individual raster elements that is not noticeable upon mere observation. In particular, the hidden code 20 can be designed as a (digital) watermark.

[0041] The characters 21 of the hidden code, for example, dots, lines, or other structures of the code 20, can, for example, be distributed very thinly on the surface 40 of the label, i.e., arranged in small numbers and / or with large spacings from one another. In particular, the hidden code 20 can have characters 21 that are distributed almost homogeneously on the designated surface 40 of the label. According to an advantageous embodiment, the hidden code 20 can contain characters 21 that are arranged on the surface 40 of the label with an average print density of at most 2%.

[0042] Figure 3 shows, in an area or surface 40 of the label 1, which is delimited by four edge points 22, characters 21 of the hidden code 20 in the form of a dot structure with a low dot density, for example, a dot structure in which the dots taken together cover only 2% of the total printing surface 40 and are thus practically invisible to the human eye. The data of the hidden code encoded with the characters 21, which describe the non-cloneable security feature 10, depend, for example, on the shape of the characters 21 or the orientation of the characters 21 or the size of the characters 21 or the filling of the characters 21 or the height of the characters 21 or the color of the characters 21. According to another embodiment, the data contained in the hidden code can depend on the frequency of occurrence of the characters 21 on the surface 40 of the label or on the shape of the placement of the characters 21 relative to one another.

[0043] According to one possible embodiment, the hidden code 20 can be designed such that the characters 21 of the hidden code 20 are not recognizable to the human eye in the visible spectrum. The hidden code 20 can thus only be made visible to the eye using technical aids. For example, the hidden code 20 can be designed such that the characters 21 are only recognizable by irradiation with light in the non-visible spectral range using a reading device. The data / information contained in the code regarding the non-clonable security feature 10 can thus, to a certain extent, not be present in the visible but in another spectral range, for example, the UV or NIR range, and can be recognized by viewing with an appropriate camera.

[0044] According to another possible embodiment of the label, the hidden code 20 can be designed such that the characters 21 of the code can be excited by illumination to emit light in the visible spectrum, so that the characters 21 only become visible under special illumination, and the data contained in the code can then be read in the visible spectrum. The hidden code 20 can, for example, contain characters 21 made of luminescent colors or upconverters.

[0045] According to another possible embodiment, the characters 21 can be hidden by appropriate measures. Such a design of a label 1 is shown in Figure 4. In the label 1 shown in cross-section in Figure 4, the characters 21 of the hidden code 20 are arranged on a substrate 30. A cover layer 60 is arranged over the hidden code 20. According to one possible embodiment, the cover layer 60 can be designed such that the cover layer 60 is opaque when illuminated with light in the visible spectrum and transparent when illuminated with light in at least part of the non-visible spectrum. The cover layer 60 can, for example, be a colored layer through which the underlying code 20 is initially not recognizable in the visible spectral range.However, the cover layer 60 is designed in such a way that it is transparent in the infrared spectral range, so that the hidden code 20 lying beneath it can be read with an infrared camera.

[0046] According to another embodiment, the cover layer 60 can be configured such that it becomes transparent when heated above a temperature threshold. The cover layer 60 can, for example, be configured as a layer of thermochromic inks that become transparent when the temperature rises above a certain threshold. As a result, the hidden code 20 arranged beneath the cover layer 60 is initially invisible to the human eye and only becomes visible after the temperature threshold is exceeded.

[0047] According to another possible embodiment, the hidden code 20 can have redundancies to ensure a certain degree of fault tolerance. This makes the hidden code robust against manufacturing errors, damage, or reading errors.

[0048] Figure 5 shows a further embodiment of a label 1, in which the hidden code 20 is arranged multiple times on a plurality of surfaces 40a, 40b, and 40c of the label, each of which represents a basic cell of the hidden code, and thus already has redundancies. The surfaces 40a, 40b, and 40c can be arranged at a distance from one another. For example, there can be (narrow) gaps between the surfaces. However, the surfaces 40a, 40b, and 40c can also be adjacent to one another without gaps, as shown in the embodiment of Figure 5. The surfaces or basic cells 40a, 40b, and 40c can, for example, be arranged next to one another in a tile-like manner. This has the advantage that a reading device, for example a camera, does not have to be aimed at a specific position on the object to be checked in order to read the hidden code.Since the tiled surfaces or base cells in the example shown are seamlessly connected to one another, no edges or boundaries are visible. In addition to the tiled surfaces shown, conceivable geometries for such base cells include rectangles, quadrilaterals, equilateral hexagons or hexagons in general, triangles, or Einstein tiles.

[0049] A hidden code can, in principle, be printed onto a substrate layer using any digital printing process, such as inkjet printing, thermal transfer printing, or laser printing. However, other variable marking methods, such as laser marking or similar processes, can also be used instead of a printing process.

[0050] Depending on the case, direct images in the visible spectral range of the relevant area can be used as a basis for extracting the features contained therein, or the visual results of other measurements, for example from other spectral ranges or other methods for visualizing results, for example from height measurements, can be used to extract the features.

[0051] In order to reconstruct the information from the hidden code, the well-known methods of classical image processing can be used, for example the cross-correlation of the (unaligned) image with the template or alternatively first the determination of a relevant area based on the origin, the scaling and the orientation and then the reading of the actual information within the now known frame.

[0052] It should be noted that instead of a hidden code, a 2D code, for example, a QR code or a data matrix code, or another suitable code in which the information describing the non-clonable security feature 10 is stored, can also be used on the label 1. The non-clonable security feature 10 can be designed as an additive security feature or a non-additive security feature. Additive security features are shown, for example, in Figures 1A, 1B, and 1C. With this type of non-clonable security feature, the security feature is specifically incorporated into the label material by a manufacturer with defined properties.When using a non-additive security feature, the characteristics to be characterized are structures that are already present in the label, for example the paper structure or pressure fluctuations in the contour of an already printed font or a 2D code.

[0053] List of reference symbols

[0054] 1 label

[0055] 10 non-clonable security feature 11 fiber

[0056] 12 air bubble

[0057] 13 pigment grains

[0058] 20 hidden code

[0059] 21 characters 22 margin points

[0060] 30 substrate layer

[0061] 40 Area for hidden code

[0062] 50 Area for security feature

[0063] 60 top layer

Claims

Patent claims 1. Anti-counterfeiting label comprising: - a non-clonable security feature (10), - a hidden code (20) containing data describing the security feature (10), the data being encoded in the form of characters (21).

2. Label according to claim 1, wherein the hidden code (20) is designed such that the characters (21) are not recognizable to the human eye in the visible spectrum.

3. Label according to claim 1 or 2, wherein the hidden code (20) is designed such that the characters (21) are recognizable by illuminating the label with light in the non-visible spectrum by means of a reading device.

4. Label according to one of claims 1 to 3, wherein the hidden code (20) is designed such that the characters (21) can be excited by illumination to emit light in the visible spectrum.

5. Label according to one of claims 1 to 4, comprising: - a substrate layer (30) on which the characters (21) of the hidden code (20) are arranged, - a cover layer (60) arranged above the hidden code (20), - wherein the cover layer (60) is designed such that the cover layer (60) is opaque when illuminated with light in the visible spectrum and transparent when illuminated with light in at least part of the non-visible spectrum.

6. Label according to one of claims 1 to 4, comprising: - a substrate layer (30) on which the hidden code (20) is arranged, - a cover layer (60) arranged above the hidden code (20), - wherein the cover layer (60) is designed such that the cover layer (60) becomes transparent when heated above a temperature threshold.

7. Label according to one of claims 1 to 6, wherein the hidden code (20) is formed as a digital watermark.

8. A label according to any one of claims 1 to 7, wherein the data contained in the hidden code (20) depend on the shape of the characters (21) or the orientation of the characters (21) or the size of the characters (21) or the filling of the characters (21) or the height of the characters (21) or the color of the characters (21).

9. Label according to one of claims 1 to 8, wherein the data contained in the hidden code (20) depend on the frequency of occurrence of the characters (21) or on the form of placement of the characters (21) relative to one another.

10. A label according to any one of claims 1 to 9, wherein the hidden code (20) has redundancies.

11. A label according to any one of claims 1 to 10, wherein the hidden code (20) is arranged multiple times on a plurality of surfaces (40a, 40b, 40c) of the label.

12. A label according to any one of claims 1 to 11, wherein the hidden code (20) is arranged on a first surface (40) of the label which lies outside a second surface (50) of the label on which the security feature (10) is arranged.

13. Label according to one of claims 1 to 11, - wherein the hidden code (20) is arranged on a first surface (40) of the label, - wherein the security feature (10) is arranged on a second surface (50) of the label, - wherein the first and second surfaces (40, 50) overlap.

14. Label according to one of claims 1 to 13, wherein the security feature (10) is designed as an additive security feature.

15. Label according to one of claims 1 to 13, wherein the security feature (10) is designed as a non-additive security feature.

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