Off-line method for unambiguously marking and identifying physical objects - Patent Application 20070122999

Abstract

The invention relates to methods for unambiguously marking and identifying physical objects, methods for offline verification of physical objects, methods for hybrid offline and online verification of physical objects, methods of extending the marking with a further unique code, physical objects having optical security features for unambiguously marking and identifying them, serialization and / or track and trace systems based on such optical security features, and the use of such optical security features in serialization and / or track and trace systems and / or for object authentication, for offline and / or hybrid offline and online verification of physical objects and in methods of extending the marking with a further unique code.

Description

[Technical Field]

[0001] The present invention relates to methods for unambiguously marking and identifying physical objects, methods for offline verification of physical objects, methods for hybrid offline and online verification of physical objects, methods for extending marking to include other unique codes, physical objects having optical security features for unambiguously marking and identifying them, serialization and / or track and trace systems based on such optical security features, and the use of optical security features such as these in serialization and / or track and trace systems and / or for object authentication, for offline and / or hybrid offline and online verification of physical objects and in methods for extending marking to include other unique codes. [Background technology]

[0002] The current coronavirus pandemic has revealed how vulnerable globally networked supply chains and collaboration networks (in Industry 4.0) are to counterfeit goods. Large pharmaceutical companies are now warning that potentially counterfeit drugs or auxiliaries may reach end customers during the pandemic through unauthorized distribution channels or from unauthorized suppliers. Among other things, counterfeit certificates, counterfeit vaccines, and inferior protective oral and nasal masks with false vaccination certificates and test documents are on the market.

[0003] To prevent counterfeit products, process and supply chains in the global economy need to be made traceable and resilient through product authentication. Falsified certificates or products can be identified in this way and appropriate measures can be taken immediately. Product authentication requires data. These data need to be stored securely. To be considered secure, the following points must be met: Completeness of product data The authenticity of the product manufacturer Availability of data necessary for verification ·Protecting user privacy

[0004] All-encompassing product protection can only be guaranteed by an end-to-end system, from the producer, through, for example, customs, wholesalers and retailers, to the final customer. Everyone in this chain must be able to securely authenticate the product.

[0005] In the fight against counterfeiting, various technologies have been established worldwide that offer different approaches to the solution to the problem outlined in point 1. It should be said that the approach to solutions from serialization and tracking based on digital databases is dominating the market. These are used to record clear tracking of process steps in the production chain. Furthermore, (additional) product information can be transferred here. This requires an information storage medium that is placed on the product and has as its content a link to a database entry. The information storage media used are mainly radio frequency identifiers (RFID) or barcodes. The former are used to communicate via electromagnetic waves, while the latter are used to communicate via light waves. Barcodes are widely used because they can be easily generated and read by anyone. However, they have several weaknesses. -Easily copyable and portable Although the barcode contents can be read by the end customer, opportunities for product verification are very limited as database access is only available to a few individuals within the supply chain. Database connectivity is vulnerable to external influences, such as network outages and cyber attacks. In this case, a distinction is made between one-dimensional barcodes (dash-dotted lines), two-dimensional barcodes (QR Codes®), three-dimensional barcodes (e.g. colour barcodes) and four-dimensional barcodes (e.g. colour barcodes that appear on a display as they change over time), and five-dimensional barcodes (colour QR Codes® that offer time as well as fluorescence as another dimension). In the case of serialization and tracing, every product is provided with an identification. In this case, a distinction is made between three types of identification: Identification (ID): Used to identify an item or manufacturer (a class of entity), e.g., a barcode bearing the EAN (Europaeisches-Artikelnummer-System) on food packaging. Unambiguous Identification: Used to identify an individual entity. For example, a Data Matrix with an individual serial number for each medication packaging. The individual serial number is generated externally (human or machine) and is not directly connected to the product / object. Secure and unambiguous identity: used to identify and authenticate an individual entity. For example, a QR Code® with a second factor inseparably linked to the entity by a fingerprint of the object stored in a digitally signed form in the QR Code®. Secure identity means that it cannot be manipulated, forged, moved / copied or misused.

[0006] Individual authentication requires that all products are distinguishable from one another. To this end, there are two main approaches in the literature to achieve distinguishability: individualization is achieved either by clear marking, e.g., by digital watermarking or serialization, or by extracting manufacturing imperfections, e.g., as fingerprints or physically unclonable functions. Until the 2010s, it was not possible to establish product authentication solutions based on manufacturing imperfections (textile substrates, paint splatters, and barcode printing imperfections).

[0007] German patent application No. 10 2021 109 455.0 describes a method for clearly marking and identifying a product by means of a clear marking based on an inaccurate part of the product.

[0008] However, a partially unresolved data protection challenge for today's established solutions is when end customers are also involved, since databases are used (see Availability and Privacy). IT security requirements and implementations lead to complex architectures and high costs for both the establishment and operation of applicable solutions.

[0009] For this reason, the present invention has developed an offline product authentication that does not require database connectivity from the end customer. However, the end customer can still perform product authentication, as the data for verification is made available with the product. Therefore, this solution can be implemented without significant costs and data protection is respected. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] German Patent Application No. 10 2021 109 455.0 Summary of the Invention [Means for solving the problem]

[0011] The present invention relates to a method for unambiguously marking a physical object, the method comprising: defining a first region on at least one surface of a physical object; extracting features from the selected regions; - generating an unambiguous identity from at least some of the extracted features; - signing at least said unambiguous identification information and optionally other information in the form of a digital signature; generating a unique code containing at least said unambiguous identification information, optional other information and a digital signature; printing the unique code in at least one second area on at least one surface of the physical object; The present invention relates to a method comprising:

[0012] Additionally, the present invention provides a method for identifying a physical object marked using the distinct marking methods described herein, comprising: scanning said printed unique code containing at least said positive identification information, optional other information and a digital signature; reading said unambiguous identification information, optional other information and a digital signature from said unique code; verifying said digital signature; checking whether said digital signature relates to said unambiguous identification information and optionally other information in said unique code; Extracting features from at least one defined first region; comparing said extracted features with the distinct identification information read from said unique code; The present invention relates to a method comprising:

[0013] Furthermore, the present invention relates to a method for offline verification of a physical object by using the method for unambiguously marking a physical object and identifying a physical object as described herein, wherein data for unambiguous identification, preferably selected from features extracted from a defined first area of ​​said physical object, data relating to unambiguous identification information, and possibly other object data, such as production date, production location, batch number, validity data, such as expiry date, and references to further digital media, such as packaging leaflets or instructions for use or internet links to digital representations, are not called up from a database for unambiguously identifying the physical object.

[0014] Furthermore, the present invention relates to a method for hybrid offline and online verification of a physical object by using the method for unambiguous marking and identification of a physical object described herein, wherein data for unambiguous identification, preferably selected from at least some of the features extracted from a defined first area of ​​said physical object, and / or some of the other data for verifying a digital signature, such as a public key or a digital certificate, are stored in and retrieved from a database.

[0015] Additionally, the present invention relates to a method for extending marking to include other unique codes, wherein at least some of the steps for marking a physical object and at least some of the steps for identifying the marked physical object in the methods for unambiguously marking a physical object and identifying a physical object described herein are performed and pursued by any inspection authority in the life cycle of the physical object, such as manufacturers, customs, wholesalers and traders, and wherein the signed unambiguous identification information in the case of newly introduced additional unique codes is related to a representation of the most recently added unique code (e.g. a hash value of the data) rather than to extracted features.

[0016] The present invention provides a physical object having an optical security feature for unambiguously marking and identifying, preferably unambiguously and securely (securely) marking and identifying, on at least one region of a surface of the physical object, the physical object comprising: the optical security feature includes at least one first defined area and at least one second area having at least one printed unique code; said at least one printed unique code including unambiguous identification information and optionally other information related to said physical object, and a digital signature of said unambiguous identification information and optional other information; The unambiguous identification information also relates to a physical object generated from features extracted from the at least one first defined region.

[0017] Additionally, the present invention relates to a serialization and / or tracking tracing system based on at least one optical security feature on at least one surface of a physical object as described herein.

[0018] Furthermore, the present invention relates to the use of optical security features on at least one surface of a physical object as described herein in serialization and / or tracking systems and / or for object authentication.

[0019] Furthermore, the present invention relates to the use of optical security features on at least one surface of a physical object as described herein for offline verification and / or hybrid offline and online verification of the physical object.

[0020] Finally, the present invention relates to the use of optical security features on at least one surface of a physical object as described herein in a method of extending the marking to include other unique codes as described herein.

[0021] definition The term "distinct marking" in the context of the present invention means that an adequate number of individual marks are available to individualize each entity within a group of products to be marked, where each individual mark differs from the other individual marks in at least one characteristic. Thus, for a group of, say, one million products in total, at least one million individual marks that differ from each other in at least one characteristic must be available.

[0022] The term "secure and clear marking" in the context of the present invention includes clear and distinguishable marking as defined above (e.g. a unique serial number that is preferably inseparably incorporated into a product or document, e.g. through evaluation of a feature, e.g. a manufacturing imperfection), that is protected by cryptography (e.g. a digital seal) and therefore transfer to another product or document results in failure of the verification (check / read) of the marking.

[0023] The term "physical object" includes any type of item. This term refers here to the physical properties of the object, as opposed to immaterial goods such as services. A physical object in the context of the present invention is typically part of a set of physical objects that can be unambiguously marked and identified using the present invention. By way of example, physical objects include products and their intermediate stages, goods, documents, and machines. Some examples of products and their intermediate stages or goods are: branded products, consumer products, pharmaceuticals, health products, nutritional products, components, hardware components, electronic components, computer chips, books, manuals. In addition to the physical object itself, the term also includes packaging, product labels (tags), barcode cards and their barcode labels, as well as all other possibilities that would typically be used to mark physical objects during the manufacturing process and / or transportation, as long as they can be used to define areas on the surface and extract features from this surface.

[0024] The term "document" in the context of the present invention, as a subunit of the terms "physical object" and "printable physical object", includes (optionally printed) substrates, such as (optionally printed) natural cellulosic substrates, (optionally printed) artificial polymeric substrates and mixtures thereof, in particular banknotes, ID cards, passports, birth certificates, driver's licenses, admission tickets and other tickets, etc. Some other examples are: checks, bonds, bank cards, credit cards, check cards, currency, cash cards, identification items, identity items, admission items, items for issuing permits, personal ID cards, social security cards, driver's licenses, vaccination certificates, examination certificates, health cards, insurance cards, personalized items, passports, documents, paper documents, security documents, postal stamps, personalized documents, provisional documents, certificates, stock certificates, certificates of indebtedness, contracts, insurance policies, wills, parking passes, transport passes or admission tickets to events.

[0025] The term "printing composition" in the context of the present invention includes any desired composition that can be used, for example, as an ink formulation or a toner in the printing methods specified below. The printing composition may be a liquid printing composition, such as an ink formulation, or a solid or powder printing composition, such as a toner. The term "ink formulation" in the context of the present invention also includes any desired solvents and combinations thereof, as well as typical additives suitable for producing a liquid that can be used for printing. The term "toner" in the context of the present invention includes any desired solid or powder composition and combinations thereof, as well as typical additives suitable for producing a solid or powder that can be used in printing.

[0026] The term "ideal first area" refers to an ideal image of a defined first area without visual differences (errors). The defined first area here is typically a possibly partially or completely printed area on at least one surface of the physical object defined above.

[0027] The term "original digital image" in the context of the present invention includes a generated digital image that is printed onto a physical object using a printing composition. If the defined first area is completely printed, the original digital image can replace the ideal first area.

[0028] The term "feature" in the context of the present invention includes any type of visual difference between a defined first region of a physical object and an inspected region of the same physical object, an ideal first region, or possibly its original digital image. Features may be, for example, differences in the texture of the region, the color of the region, inclusions, depressions, and printed images. These differences may be manufacturing imperfections, as defined below, or differences intentionally introduced by the manufacturer or publisher onto the surface of the physical object, in the printing composition, or in the printed image. Intentional differences may be, for example, intentional manipulation of the surface of the product by adding foreign matter or inserting voids, adding substances, e.g., pigments, to the printing composition, specific defects or color errors in the printed image, etc.

[0029] The term "production imprecision" in the context of the present invention includes all possible variations in the manufacturing or manufacturing process of a physical object and variations in the printing process, resulting in individual feature images combined with the physical object. Additionally, in the context of the present invention, the term includes unintended inherent differences between an inspection area of ​​a physical object relative to an inspection area of ​​the same physical object and relative to its original digital image. These unintended inherent differences may be differences in the surface of the physical object itself, differences in the printed printing composition, or differences in the printed image of an identification pattern printed using the printing composition. Examples of surface differences of a physical object are surface irregularities, differences in fiber structure and / or fiber thickness, holes, protrusions, scratches, edge contours, graininess, roughness, and blurring. Examples of differences in the printed printing composition are differences in viscosity, surface tension, particle size, particle agglomeration, etc. Examples of differences in the printed image of an identification pattern printed using a printing composition are printing inaccuracies and printing defects, such as different line widths, line paths, line broadening, edge contours, satellite drops, multiple ink drops on an area, no ink drops, which result from individual errors and incorrect settings of the printer, such as missing printing impulses, clogged or incorrect settings of the printing nozzles, or inconsistent guidance of the substrate and / or print head. The term "manufacturing inaccuracies" does not encompass differences intentionally introduced by the manufacturer or publisher onto the surface of a physical object, in the printing composition, or in the printed image, such as the addition of foreign matter or the insertion of voids, or intentional manipulation of the surface of a product by added substances, such as pigments, or specific defects or color errors in the printed image. The term "feature extraction" in the context of the present invention includes measuring and evaluating the visual differences of a defined first region relative to an ideal first region or its original digital image, since in reality, almost all surfaces of physical objects have visual differences that may not be perceptible to the human eye and therefore often require optical measurement equipment, such as a spectrometer, a camera, or a smart device. If the difference can be measured during recording using an optical measurement instrument, such as a spectrometer, camera or smart device, the present invention refers to said difference as a feature.

[0030] The term "printing" in the context of the present invention includes the deposition of pigments on or in a solid substrate, typical examples being, but not limited to, offset printing, digital printing, inkjet printing, screen printing, transfer printing, stamp printing, roll-to-roll, non-contact printing, laser printing, spray printing, spray processes, thermographic printing, thermal transfer printing, and other methods.

[0031] The term "offline verification" describes a check of the authenticity of the manufacturer or issuer of a physical object and the integrity of the data relating to the product, using the data necessary for the verification, which are stored in a unique code, and a digital certificate which can be stored in the unique code, in the verification application, or loaded from a database.

[0032] The term "unique code" describes a one- or multi-dimensional code that is individually generated for each entity within a group of similar entities and that is distinct from all other unique codes for that entity within the group.

[0033] A "digital certificate" is a digital data set that carries certain metadata about a legal or natural person, such as name, city, country, as well as this person's public key and a signature of these data by a trusted authority. The trusted authority uses the signature of the digital certificate to verify the person's authenticity, which can then be verified. The integrity of the data can be tested by decrypting it using the public key of a signature cryptography. Digital certificates are usually issued by official certificate authorities.

[0034] A "digital signature" is an asymmetric cryptosystem that involves a sender using a private signing key (private key) to calculate a value for a digital message (i.e., any data); this value is also called a digital signature. This value allows anyone to test the undeniable authorship and integrity of the message using a public verification key (public key). To be able to attribute a signature generated with a signing key to a person, the associated verification key must be unambiguously linked to this person (see https: / / de.wikipedia.org / wiki / Digitale_Signatur).

[0035] Photoluminescence refers to the emission of photons following prior excitation by higher-energy photons, mostly in the ultraviolet but also in the visible or near-infrared regions. The excitation elevates electrons to a higher energy state. When the electrons return to a lower energy state, this energy is released again in the form of photons. In luminescent materials, a rough distinction is made between two types of excitation: in fluorescence, electrons fall from a higher singlet state back to a lower energy state, whereas in phosphorescence, excited electrons transition via spin-forbidden transitions to a raised triplet state, from which they again fall via spin-forbidden transitions back to a lower energy state. A blockchain is a continuously expandable list of data sets in individual blocks. New blocks are generated using a consensus method and cryptographically appended to an existing chain. In a similar code chain, the data sets are not stored in a database, but rather in the physical object itself. New blocks can similarly be appended to an existing chain by the methods described. DETAILED DESCRIPTION OF THE INVENTION

[0036] The essence of the present invention is the use of individual, unique features of the surface of a physical object as a physically unclonable function for securely marking and identifying the physical object. These features are extracted from a defined first area of ​​the surface, for example by an imaging method, and used as the basis for unambiguous identification information, for example in the form of a binary code. The unambiguous identification information is additionally signed and converted into a unique code that is printed, together with this signature, on a second area of ​​the surface of the physical object. This unique code therefore includes, first, the physically unclonable function for securely identifying the physical object and the author's signature for verifying its authenticity. Based on these two pieces of information, it is possible to dispense with the need for central storage of data for identifying and / or authenticating the physical object, for example, the storage of a key for decoding the serial number in a central database.

[0037] A first aspect of the present invention is a method for distinctively marking a physical object, comprising: defining a first region on at least one surface of a physical object; extracting features from the selected regions; generating unambiguous identification information from at least some of the extracted features; signing at least said distinct identification information, and optionally other information, in the form of a digital signature; generating a unique code containing at least said unambiguous identification information, optional other information and a digital signature; printing the unique code in at least one second area on at least one surface of the physical object; The present invention relates to a method comprising:

[0038] In a first step, a first area is defined on at least one surface of the physical object, and this at least one defined area is typically communicated to all inspection authorities in the life cycle of the physical object, e.g., manufacturer, customs, wholesaler, and trader, to enable identification of the physical object using the inventive methods described herein, offline verification of the physical object using the inventive methods described herein, and extension of the marking to include other unique codes using the inventive methods described herein.

[0039] Every surface of a physical object is unique and has individual, specific features, such as manufacturing imperfections (cracks, ridges, troughs, roughness, etc.), which are invisible to the human eye and are considered accidental, random, and uncontrollable in today's manufacturing processes, hence the term "physical hard-to-replicate function." Since every portion of the surface of a physical object is clearly different from any other portion on the surface or from other surface portions, the first region may be individually selected and defined. It is also possible to select whether features are extracted from the entire defined first region or from only a portion of the first region. All that is required is to ensure that the number of features still makes the physical object to be marked clearly distinguishable. This selection is then typically communicated to the reading unit / extraction unit and all inspection agencies in the physical object's life cycle.

[0040] In this process, one or more first regions may be defined. For cost reasons only, the number of first regions typically does not exceed 10. The number of surfaces of the physical object to be marked depends on the type and shape of the physical object to be marked. First regions may be defined on one or more surfaces of the physical object to be marked. The number of surfaces typically does not exceed 10.

[0041] This at least first region may be a region on any type of surface associated with the physical object, for example, as far as the characterization of the physical object allows, directly at least one region on the surface of the physical object, at least one region on the surface of the packaging of the physical object, at least one region of a label, tag, barcode card and / or barcode label used when the surface of the physical object is displayed or labeled, or a combination thereof (e.g., the surface of the physical object or a portion of the packaging of the physical object combined with at least a portion of the region of a label, tag, barcode card and / or barcode label).

[0042] Preferably, the same area on at least one surface of the physical object is defined for all instances of the number of physical objects to be marked.

[0043] The minimum size of the at least one first region depends on the number of physical object instances to be marked. The greater the number of instances, the larger the minimum size of the at least one first region. The at least one first region must be selected to be large enough for a sufficient number of extracted features to individualize every instance. The at least one first region is typically 10 cm 2 having a size less than

[0044] At least a portion of the at least one defined first region may be printed with at least one printing composition. In this case, the at least one printing composition may be printed directly onto at least a portion of the at least one defined first area on at least one surface of the physical object, as long as the characteristics of the physical object allow. The at least one printing composition may also be printed onto at least one label, and then at least one surface of the physical object that at least partially overlaps the defined first area may be tagged / labeled with the at least one printed label. If the shape and / or characteristics of the physical object do not allow for printing, at least one first region can also be defined on the surface of the packaging of the physical object, and at least a portion of the at least one printing composition can be printed directly onto the at least one defined first region on the surface of the packaging of the physical object. It is also possible for at least one label printed with the at least one printing composition to be adhered / attached to at least a portion of the at least one first defined region on the surface of the packaging of the physical object. The printing composition can also be printed onto a document. Printing on at least one portion of the defined surface expands the selection of features to be extracted to features based on differences in the printed image or printing composition on the printed area, thereby allowing the size of the at least one defined first area to be reduced in proportion to the printed area.

[0045] Printing can be performed using standard printing methods depending on the type of printing composition, and the printing composition is preferably printed onto at least one region of the surface of a physical object or document by offset printing, digital printing, inkjet printing, screen printing, transfer printing, stamp printing, roll-to-roll, non-contact printing, laser printing, spray printing, spray processes, thermographic printing, thermal transfer printing, and other methods.

[0046] Depending on the type of product, the printing composition can be printed directly onto at least one surface of the physical object, on packaging for the physical object, and on labels, signatures, barcode cards and / or barcode labels.

[0047] The printing composition is preferably a commercially available printing composition suitable for depositing pigments on or in a solid substrate. Depending on the type of printing, suitable printing compositions may be liquid printing compositions such as ink formulations, or solid or powder printing compositions such as toners. Typical examples are, but are not limited to, offset printing, digital printing, inkjet printing, screen printing, transfer printing, stamp printing, roll-to-roll, non-contact printing, laser printing, spray printing, spray processes, and other methods.

[0048] The printing composition may contain a color pigment, preferably a commercially available color pigment suitable for printing compositions, which allows the print on a defined area to be visible to the human eye.

[0049] The printing composition may contain photoluminescent materials that, under photon excitation, emit radiation in the range of up to 3000 nm, preferably up to 1800 nm, more preferably up to 1400 nm, and most preferably up to 1100 nm. Generally, this is suitable for photoluminescent materials that emit radiation under photon excitation with a lower limit of at least 200 nm, preferably at least 225 nm, more preferably at least 250 nm. In one preferred embodiment, the photoluminescent material emits radiation under photon excitation from a lower limit of at least 380 nm, preferably at least 390 nm, and most preferably at least 400 nm. In another preferred embodiment, the photoluminescent material emits radiation under photon excitation from a lower limit of at least 750 nm, preferably at least 780 nm, more preferably at least 800 nm, and most preferably at least 850 nm.

[0050] The photoluminescent material is preferably selected from photoluminescent dyes and semiconducting inorganic nanocrystals.

[0051] Semiconductor inorganic nanocrystals, under photon excitation, preferably emit radiation in the range of 400 nm to 3000 nm, more preferably 500 nm to 1800 nm, and most preferably 750 nm to 1100 nm.

[0052] Examples of suitable semiconductor inorganic fluorescent (core) nanocrystals include, among others, Ag2S, Ag2Se, Ag2Te, CdS, CdSe, CdTe, PbS, PbSe, PbTe, SnTe, ZnS, ZnSe, ZnTe, InP, InAs, Cu2S, In2S3, InSb, GaP, GaAs, GaN, InN, InGaN, ZnSSe, ZnSeTe, ZnSTe, CdSSe, CdSeTe, HgSSe, HgSeTe, HgSTe, ZnC dS, ZnCdSe, ZnCdTe, ZnHgS, ZnHgSe, ZnHgTe, CdHgS, CdHgSe, CdHgTe, ZnCdSSe, ZnHgSSe, ZnCdSeTe, ZnHgSeTe, CdHgSS e, CdHgSeTe, CuInS2, CuInSe2, CuInGaSe2, CuInZnS2, CuZnSnSe2, CuIn(S,Se)2, CuInZn(S,Se)2 and AgIn(S,Se)2. Other suitable examples include, but are not limited to, perovskite materials having the general formula ABX3 or A4BX6, where X may be selected from Cl, Br, I, O and / or mixtures thereof, A may be selected from Cs, CH3NH3, CH(NH2)2, Ca, Sr, Bi, La, Ba, Mg and / or mixtures thereof, and B may be selected from Pb, Sn, Sr, Ge, Mg, Ca, Bi, Ti, Mn, Fe and / or mixtures thereof. Furthermore, core / shell and / or core / multishell of semiconducting inorganic nanocrystalline structures of II-VI, III-V, IV-VI, I-VI, I-III-VI semiconductors or mixtures thereof, as well as core / shell and / or core / multishell of perovskite materials are other suitable examples.

[0053] The crystal lattice of the semiconducting inorganic nanocrystals may additionally contain, but is not limited to, one or more metal ions, such as Cu. + , Mg 2+ , Co2+ , Ni 2+ , Fe 2+ , Mn 2+ and / or may be doped with one or more rare earth metals, such as ytterbium, praseodymium or neodymium.

[0054] The semiconducting inorganic nanocrystals preferably have an average particle size (diameter) in at least one dimension, and preferably in all dimensions, of from 1 nm to 100 nm, more preferably from 2 nm to 50 nm, and most preferably from 3 nm to 15 nm.

[0055] The average particle size can be further increased / modified by various methods, typical examples being, but not limited to, silica shells, titanium oxide shells, halogen shells, and other methods to increase stability, masking, biocompatibility, water solubility, and / or coating.

[0056] A useful property of preferred semiconducting inorganic nanocrystals is that their excitation and emission spectra depend, inter alia, on their particle size.

[0057] The semiconducting inorganic nanocrystals are preferably photoluminescent materials that are brought to an electronically excited energy state by absorption of light and then return to a lower energy state by emitting light in the form of fluorescence.

[0058] The printing composition may also contain one or more other photoluminescent dyes instead of, or in addition to, the photoluminescent semiconducting inorganic nanocrystals. The photoluminescent dye, under photon excitation, preferably emits radiation in the range of 380 to 3000 nm, preferably 400 to 1800 nm, more preferably 450 to 1400 nm, and most preferably 750 nm to 1100 nm. The photoluminescent dye may be selected from fluorescent dyes, phosphorescent dyes and mixtures thereof. Fluorescent dyes are dyes that emit fluorescent radiation after photon excitation, whereas phosphorescent dyes are dyes that emit phosphorescent radiation after photon excitation. Suitable photoluminescent dyes may exhibit both a Stokes shift and an anti-Stokes shift under photon excitation. In addition, the luminescent material may exhibit both fluorescent and phosphorescent behavior. The luminescent material used may be either organic or inorganic crystals / molecules. The fluorescent dyes are usually selected from organic and inorganic fluorescent dyes or mixtures thereof. Organic dyes may be selected from the classes of proteins and peptides, small organic molecules, synthetic oligomers and polymers, and multi-component systems. Typical examples of polymers and peptides are green fluorescent protein (GFP), yellow fluorescent protein (YFP) or red fluorescent protein (RFP). Non-protein organic fluorescent dyes typically belong to the following classes: xanthene derivatives, cyanine derivatives, squaraine derivatives, squaraine-rotaxane derivatives, naphthalene derivatives, coumarin derivatives, oxadiazole derivatives, anthracene derivatives, pyrene derivatives, oxazine derivatives, acridine derivatives, arylmethine derivatives, tetrapyrrole derivatives, and dipyrromethane derivatives. Organic fluorescent dyes are typically commercially available in all emission spectral colors from blue (above 380 nm) to red (up to 1800 nm). In this regard, suitable organic dyes having an emission spectrum color of 800 nm or more are described, for example, in EP 0 933 407 A, U.S. Pat. No. 5,282,894, U.S. Pat. No. 5,665,151, WO 1998 / 018871, WO 2003 / 038003, U.S. Pat. No. 10,119,071 and U.S. Pat. No. 5,542,971. Suitable inorganic pigments are preferably semiconducting inorganic nanocrystals as described above. The phosphorescent dye is usually selected from doped oxides, nitrides, oxynitrides, sulfides, selenides, halides, silicates, and aluminates of calcium, strontium, barium, zinc, cadmium, manganese, silicon, and rare earth metals, and mixtures thereof. Most often, but not exclusively, sulfides of metals from Group II of the periodic table and zinc and aluminates of metals from Group II of the periodic table are used. The doping material can be, for example, a metal or a metal salt. Suitable examples of phosphorescent dyes are calcium, strontium, barium and zinc doped sulfides and aluminates, such as bismuth doped calcium / strontium sulfide, copper doped zinc sulfide, and europium doped strontium aluminate. Photoluminescent dyes with Stokes shift behavior are preferably photoluminescent materials that undergo optical absorption of higher energy photons to an electronically excited energy state and then return to a lower energy state by emitting light in the form of fluorescence or phosphorescence.

[0059] The photoluminescent material is preferably excited by visible light, such as blue or white light, and more energetic NIR radiation as the luminescent signal.

[0060] As mentioned above, photoluminescent materials emit radiation having wavelengths ranging from 200 nm to 3000 nm in the broadest spectral range under photon excitation. In particularly preferred embodiments, the photoluminescent material, under photon excitation, emits radiation having a wavelength in the range of 750 to 1800 nm, more preferably 800 to 1400 nm, and most preferably 850 to 1100 nm, which are in the non-visible near-infrared range (NIR range).

[0061] The proportion of photoluminescent material in the printing composition is preferably 0.01 to 70.0 wt. %, more preferably 0.05 to 40.0 wt. %, and most preferably 0.1 to 30.0 wt. %, measured based on the total weight of the printing composition. For digital and inkjet printing, the range of 0.01 to 30.0 wt. % is preferred.

[0062] The printing composition may contain multiple photoluminescent materials that have at least one or all, preferably all, of the following properties in common: emission wavelength, emission distribution, and emission maximum. In another embodiment, the printing composition may contain a mixture of multiple photoluminescent materials that have different values ​​for emission wavelength, emission distribution, and emission maximum.

[0063] Additionally, the printing composition may contain commercially available toner or ink color pigments. Commercially available printing compositions can be used, which can be mixed with the photoluminescent material.

[0064] The emitted radiation of the printing composition can produce a distinct fluorescence spectrum that depends on the type, volume, and particle size of the photoluminescent material, preferably semiconducting inorganic nanocrystals. In this regard, the individual fluorescence spectra can be detected using a spectrometer, and then compared to a previously stored reference spectrum.

[0065] Additionally, this individual fluorescence spectrum can be used as another security feature for printing compositions that are individually mixed by the product manufacturer.

[0066] Printing compositions for inkjet printing preferably have a reciprocal Ohnesorge number of less than 14, more preferably 1-10, even more preferably 1-8, most preferably 2-4, for example.

[0067] The one or more printing compositions may contain exclusively color pigments, exclusively the photoluminescent materials described above, or a combination of color pigments and photoluminescent materials described above.

[0068] Preferably, at least one surface of the physical object is printed with at least one printing composition in the form of an identification pattern. In this case, the method of the invention preferably comprises the following further steps: providing one or more printing compositions; printing the printing composition onto at least one surface of a physical object in the form of an identification pattern; wherein at least a portion of the printed identification pattern overlaps with at least one defined first area.

[0069] The identification pattern may include one or more patterns, such as areas, stripes, lines, geometric shapes such as circles, triangles, rectangles, polygons, etc., alphanumeric characters, letters, images, or any combination thereof.

[0070] The identification pattern may be unique to each individual printable physical object being marked, meaning that the identification pattern of every instance of the physical object being marked differs in at least one characteristic from the identification patterns of other instances.

[0071] The identification pattern may include object data, such as manufacturing date, manufacturing location, batch number, validity data, such as expiry date, and references to further digital media, such as packaging leaflets or instructions for use or internet links to digital representations.

[0072] The discrimination pattern may be one-dimensional or multi-dimensional. Suitable dimensions for a multidimensional identification pattern are spatial dimensions, such as the x and / or y directions, or color dimensions, such as the inherent colors of dyes in the printing composition and / or the various emission spectra of semiconducting inorganic nanocrystals. The identification pattern may be a one-dimensional pattern, such as a barcode, a two-dimensional pattern, such as a QR code, or a three-dimensional pattern, such as a color barcode.

[0073] The identification pattern may also include or be a unique code. The identification pattern of each individual physical object to be marked is preferably unique in the present invention. This can preferably be achieved by first digitally signing at least one reference variable, and preferably multiple reference variables, relating to the physical object. Possible reference variables here are, for example, reference variables relating to the type and properties of physical objects such as serial numbers, lot numbers, CAS numbers in the case of chemical products, production locations, production times, delivery locations, manufacturers, suppliers, customers, etc. The secure key can be made available to the manufacturer or generated by the manufacturer itself. The digital signature is used to generate a code that is unique to the physical object, preferably to each individual packaging unit of the physical object, allowing the distinct marking of the present invention to be used as a secure and distinct marking.

[0074] At least a portion of the at least one defined first region preferably overlaps the at least one printed surface of the physical object. The at least one defined first region may be larger, smaller, or the same size as the at least one printed surface. The at least one defined first region may, but need not, be congruent with the at least one printed surface. The at least one defined first area may, but need not, have the same shape as the printing surface.

[0075] At least a portion of the at least one defined first region preferably overlaps with the at least one printing surface, for example, with an overlap in the range of 1% to 100%, for example 10% to 100%, preferably 25% to 100%, more preferably 50% to 100%, and most preferably 75% to 100%. This overlap allows for subsequent extraction of features from at least one defined first region and also results in the detection of features resulting from visual differences in the printed printing composition or visual differences in a printed image of an identification pattern printed using the printing composition. Features are extracted from at least one defined first region.

[0076] Qualifying features are all possible visual differences in at least one defined region from an ideal first region without visual differences. Typical features are, for example, differences in the texture of the region, the color of the region, inclusions, depressions, and printed images.

[0077] If the at least one defined area completely overlaps the at least one printing surface, it is also possible to use an original digital image of the at least one printing surface within the area of ​​the at least one defined first area as a reference instead of the ideal first area.

[0078] In one preferred embodiment, the feature is a manufacturing imprecision in at least one defined first region.

[0079] In the present invention, the manufacturing inaccuracies extracted from at least one defined first region include all types of manufacturing inaccuracies, i.e., as described above, unintended inherent differences in the surface of the physical object and / or the substrate itself, and / or unintended inherent differences in the printed printing composition, as well as unintended inherent differences in the printed image of the identification pattern printed using the printing composition. Unintended inherent variations in the surface and / or substrate of a physical object are the result of random and uncontrollable processes during the manufacturing of the physical object and / or substrate itself. These manufacturing inaccuracies can be expanded in the methods of the present invention to include unintended inherent variations in the printed printing composition and / or the printed image of the identification pattern printed using the printing composition in the overlap between at least one defined first region and at least one printing surface of the physical object. These unintended inherent variations are the result of random and uncontrollable processes during the printing of at least one printing composition onto at least one surface of the physical object by a particular printing composition and a particular printer. These manufacturing imprecisions are therefore well suited to individualizing one physical object from a large number of identical physical objects.

[0080] The features, preferably manufacturing inaccuracies, are preferably extracted from at least one defined first region using standard imaging methods, such as cameras, industrial cameras, NIR cameras, spectrometers, or smart devices such as smartphones or tablets, the accuracy of which is typically matched to obtain comparable extractions for all steps.

[0081] On the surface, the at least one defined first region typically does not exhibit any kind of feature, such as a manufacturing imperfection. However, when considering the micrometer scale, individual patterns are usually discernible. In inkjet printing, this can occur, for example, due to clogging of the print nozzle, partial clogging of the print nozzle, deflection of ink droplets, or delayed deposition of ink droplets from the print nozzle. This results in a random pattern at the micrometer level that is unique to every printing process. This unique pattern, along with the random and unique patterns of other features mentioned above, such as manufacturing imperfections, can be attributed to a single physical object as a unique overall pattern by IT applications.

[0082] To ensure true individualization, depending on the number of physical object entities to be individualized, a corresponding number of features, preferably manufacturing imperfections, must be identified and attributed to each individual entity. Statistically, a certain number of features, preferably manufacturing imperfections, per square centimeter of the at least one defined first area can only be expected in each case for each defined area, so the number of individualizable entities depends on the area of ​​the at least one defined first area.

[0083] The number of features, preferably manufacturing imperfections, per area of ​​the at least one defined first region can be increased by expanding the selection of features, preferably manufacturing imperfections, to include detectable features, preferably manufacturing imperfections, in the spectral range up to 3000 nm, in particular to include differences in at least one printed printing composition or differences in the printed image of at least one surface printed with at least one printing composition in the overlap with the at least one defined first region, and by expanding the detection spectrum enabled by the printing composition used from the emission in visible light (380 to 750 nm) of standard commercially available photoluminescent materials to emission in visible light and in the short- and long-wavelength spectral range of 200 to 3000 nm, in particular in the near-infrared range (up to 1800 nm, preferably up to 1400 nm, most preferably up to 1100 nm).

[0084] At least one defined first region can be irradiated with photons, and features, preferably manufacturing inaccuracies, can be extracted in the range of up to 3000 nm, preferably up to 1800 nm, more preferably up to 1400 nm, and most preferably up to 1100 nm. Such irradiation is particularly advantageous when at least one of the printing compositions used contains a photoluminescent material that, under photon excitation, emits radiation in the range of up to 3000 nm, preferably up to 1800 nm, more preferably up to 1400 nm, and most preferably up to 1100 nm. This allows the spectral range for extracting product inaccuracies to be extended into the infrared range, preferably the NIR range, thereby increasing the number of extracted features, preferably product inaccuracies, on the at least one defined first region. For illumination, white or blue light is usually used.

[0085] After irradiation, the printing composition on at least one defined first region, preferably the printing composition on at least one defined first region, more preferably the commercially available color pigment and / or photoluminescent material described above in the printing composition, emits radiation in the range of 200 to 3000 nm, preferably 225 to 1800 nm, more preferably 250 to 1400 nm, and particularly preferably 250 to 1100 nm. In one preferred embodiment, the emitted radiation has a lower limit of 380 nm, preferably 390 nm, and most preferably 400 nm. In another preferred embodiment, the emitted radiation has a lower limit of 750 nm, preferably 780 nm, more preferably 800 nm, and most preferably 850 nm. It is quite particularly preferred that radiation be emitted in the range of 380 to 3000 nm, for example, 380 to 1800 nm, preferably 390 to 1400 nm, and most preferably 400 to 1100 nm. Radiation above 750 nm, for example in the range of 750 nm to 1800 nm (NIR radiation), is not perceptible to the human eye. Instead, detection requires an electronic device capable of detecting emitted radiation throughout the range up to 3000 nm, for example 750 to 1800 nm, preferably 800 to 1400 nm, and most preferably 850 to 1100 nm. By way of example, suitable devices include spectrometers, industrial cameras, NIR cameras, or smart devices such as smartphones or tablets that have silicon-based image sensors within the camera system capable of detecting incident photons up to wavelengths of approximately 1100 nm. These smart devices can also be used to excite photoluminescent materials via a camera flash or device LED. The flash can be controlled by a suitable app for purposes of excitation and detection, such that the excitation and detection are followed by, for example, a corresponding photograph of the at least one defined first area appearing on the screen of the smart device. Due to the higher density of manufacturing imprecisions per area of ​​the at least one defined first region, the increase in the number of manufacturing imprecisions per area of ​​the at least one defined first region allows the area of ​​the at least one defined first region to be reduced to the extent that the at least one defined first region can be read using simple electronic and mobile smart devices, such as smartphones and tablets, or spectrometers, NIR cameras, or industrial cameras, using appropriate software, and the extracted features, preferably the manufacturing imprecisions, can be stored. Therefore, 10 cm 2 A defined first region having a maximum size of 100 may even be sufficient to distinguish individual entities from many physical objects in a region of tens of thousands. For example, 10cm 2 may be sufficient to identify individual entities from many physical objects in a region of over 100 million. 7cm2 A defined first region having a maximum size of 0.05 may be sufficient to identify individual entities from many physical objects in a region of up to 10 million. 5cm 2 A defined first region having a maximum size of 1 may be sufficient to identify individual entities from many physical objects in a region of up to 1 million. 3cm 2 A defined first region having a maximum size of 100,000 may be sufficient to identify individual entities from many physical objects in a region of up to 100,000. In another step, unambiguous identification information is generated from at least some of the extracted features, preferably from the imprecise part of the generation.

[0086] The proportion of extracted features, preferably manufacturing imprecision, used in generating a unique identification depends on the number of extracted features, preferably manufacturing imprecision, and the number of entities to which unambiguous identification needs to be assigned. The proportion of extracted features, preferably manufacturing imprecision, should be at least large enough to be able to generate unambiguous identification for every entity of many physical objects.

[0087] Although the method of the present invention is particularly suited for offline verification of physical objects, a hybrid approach may also involve data for verifying the physical object such as extracted features, preferably manufacturing inaccuracies, or other data stored in a database, such as a public key or digital certificate for verifying a digital signature, which allows for online verification in addition to offline verification of the physical object using data stored in a database. If only a certain percentage of the extracted features, preferably manufacturing imperfections, are used to generate a positive identification, all of the extracted features, preferably manufacturing imperfections, may still be stored in a database which can then be used for additional online verification of the physical object.

[0088] In addition to the extracted features, preferably manufacturing inaccuracies, the positive identification information may include other information. This other information may include object data, such as date of manufacture, place of manufacture, batch number, validity data, such as expiry date, and references to further digital media, such as packaging leaflets or instructions for use or internet links to digital representations.

[0089] The distinct identification information is typically a digital representation, preferably a string of characters.

[0090] This digital representation may be generated by an algorithm, preferably a hashing algorithm, from the extracted features, preferably imprecision parts of the generation, and optionally other information. The digital representation preferably produced by an algorithm, preferably a hashing algorithm, makes it impossible to produce an output data set that matches the hash algorithmically, i.e., not simply by trial and error. The digital representation typically has a size of at least 128 bits, for example 128 to 30000 bits, preferably 256 to 20000 bits, more preferably 512 to 10000 bits.

[0091] Additionally, authentication of physical objects requires a digital signature. The method of the present invention involves the manufacturer / distributor using a digital signature to sign at least positive identification information and optionally other information. This other information may, for example, include object data, such as manufacturing date, manufacturing location, batch number, validity data, such as expiry date, and references to further digital media, such as packaging leaflets or instructions for use or internet links to digital representations.

[0092] The digital signature involves data relating to the positive identity, preferably a digital representation of the positive identity, more preferably a cryptographic hash of the positive identity, and optionally other information that is digitally signed using the private key of the manufacturer or distributor of the physical object. The private key is preferably known exclusively to the manufacturer or distributor of the physical object, so the digital signature generally cannot be generated by an outsider.

[0093] The private key of the manufacturer or distributor of the physical object preferably has a public key associated with it by a digital certificate, which is typically issued by a public certificate authority. The public key and associated digital certificate can be used to unambiguously verify the authenticity of a digital signature without knowing the private key of the manufacturer or distributor of the physical object. The public key can also be incorporated into a unique code. The public key can also be stored in a database.

[0094] The steps of signing at least the positive identification information and optionally other information and generating the unique code preferably include the following steps: Extracting features, preferably manufacturing inaccuracies, from at least one defined first region; deriving unambiguous identification information from the extracted features, preferably manufacturing imperfections; computing a cryptographic hash of the distinct identifying information and optionally other information; encrypting the cryptographic hash using the private key of the manufacturer or distributor of the physical object; generating a unique code; Includes.

[0095] The private key preferably has a public key associated with it by means of a digital certificate, as described above.

[0096] In order to be able to guarantee that the extracted features, preferably product inaccuracies, are comparable, the present invention preferably applies the same specifications as above to the extraction of features, preferably product inaccuracies.

[0097] The public key is preferably generated by a natural or legal person. A certificate signing request, typically to a certificate authority, is preferably used to issue a digital certificate containing the public key, metadata about the person, and a digital signature that is a cryptographic hash of the two pieces of information. This digital certificate is typically provided to the person. For each digital signature, the person preferably also supplies a digital certificate, allowing any verification authority to use the digital certificate to verify the digital signature.

[0098] The selection of an encryption algorithm for encrypting the cryptographic hash is optional. However, it is advisable to follow the specifications of relevant organizations, such as the National Institute of Standards and Technology (NIST), the Bundesamts fuer Sicherheit und Informationstechnik (BSI), or other authorities / organizations. Encryption algorithms change over time, and key lengths are continuously adjusted by the organizations, which provide recommendations for specific periods. A shorter key length is usually sufficient for the shorter time periods during which tests are performed, and is suitable, for example, for physical objects with very short lifespans. On the other hand, a longer key length is advantageous for physical objects with long lifespans.

[0099] In the next step, a unique code is generated that contains at least the positive identification information, optionally other information, and a digital signature.

[0100] This can preferably be achieved by first digitally signing at least a portion of the data relating to the distinct identity.

[0101] The digital signature allows the unambiguous marking of the method of the present invention to be used as a secure and unambiguous marking.

[0102] Due to the size of the data set, and in particular as a result of unambiguous identification, it is preferred that the unique code is a multidimensional code so that the unique code can be printed on at least one surface of the physical object in as small an area as possible. Thus, the unique code is preferably printed on at least one second area on at least one surface of the physical object as a multidimensional barcode, e.g. as a two-dimensional or three-dimensional barcode, preferably as a grayscale, multicolor or watermark-modified barcode, e.g. as a two-dimensional or three-dimensional barcode, preferably as a grayscale or multicolor barcode, or as a watermark-modified two- or three-dimensional barcode.

[0103] The second area printed with the unique code is preferably locally adjacent to at least one defined first area. Preferably, the printed unique code is adjacent to or overlaps at least one defined first area. The printed unique code can be adjacent to or overlap one or more sides of the at least one defined first area, for example, the printed unique code can surround or overlap all sides of the at least one defined first area. In case of overlap, this is preferably in the range of 1 to 100%, for example 10% to 100%, preferably 25% to 100%, more preferably 50% to 100%, most preferably 75% to 100%.

[0104] In case of overlap, it is necessary to ensure that both the printed unique code on the at least one defined first area and the second area can be read independently of each other and without interference.

[0105] The unique code can be printed onto at least one second region on at least one surface of the physical object using any standard method. Suitable methods for printing onto at least one surface of the physical object using at least one printing composition are described above and can be used here as well.

[0106] Another aspect of the present invention is a method of identifying a physical object marked using the distinct marking methods described herein, comprising: scanning said printed unique code containing at least said positive identification information, optional other information and a digital signature; reading said unambiguous identification information, optional other information and a digital signature from said unique code; verifying said digital signature; checking whether said digital signature relates to said unambiguous identification information and optionally other information in said unique code; extracting features, preferably manufacturing inaccuracies, from said at least one defined first region; comparing said extracted features, preferably extracted manufacturing imperfections, with unambiguous identification information read from said unique code; The present invention relates to a method comprising:

[0107] First, the printed unique code containing at least the above-mentioned positive identification information, optional other information and digital signature is scanned to read the positive identification information, optional other information and digital signature.

[0108] This is preferably achieved by first checking the identity and validity of the digital certificate and thus the certificate owner. If the digital certificate is valid, the public key is read from the certificate and this is used to decrypt the digital signature. Decryption preferably results in a cryptographic hash of the contents of the signed information, signed by an authenticated person.

[0109] Furthermore, the contents of the unique code, specifically the unambiguous identification information and optionally other information, are preferably also used to calculate a cryptographic hash and compare it with the decrypted cryptographic hash from the previous step: if the two match, the signature is valid.

[0110] Therefore, the step of verifying the digital signature preferably comprises the steps of: - retrieving a public key associated with a private key of a manufacturer or distributor of a physical object using a digital certificate; verifying the digital signature using the public key; Includes.

[0111] If the digital signature is valid, the final step further comprises extracting features, preferably manufacturing imperfections, from at least one defined first region and comparing the features with the explicit identification information read from the unique code. If they match, object authentication is complete. In this case, more features, preferably manufacturing imperfections, than are recorded in the explicit identification information can be extracted. In this case, if features recorded in the explicit identification information are found among the features extracted to identify the physical object, the physical object is considered authenticated.

[0112] Thus, the method of the present invention can be used to safely and unambiguously mark physical objects.

[0113] The printed unique code is preferably scanned using a standard scanner suitable for this purpose, for example a barcode scanner suitable for this purpose that is capable of scanning and reading multidimensional barcodes such as grayscale barcodes, multicolor barcodes or watermark modified barcodes.

[0114] In the step of extracting features, preferably manufacturing imperfections, from at least one defined first region, the same steps and scales as described above are preferably applied to extract features, preferably manufacturing imperfections, from at least one defined first region while marking the physical object. Furthermore, it is preferable to use the same device or a device with equivalent equipment, resolution, and accuracy. Suitable devices are standard imaging devices, such as cameras, industrial cameras, NIR cameras, spectrometers, or smart devices such as smartphones or tablets. If the marking of the physical object results in manufacturing inaccuracies in the spectral range up to 3000 nm, preferably up to 1800 nm, more preferably up to 1400 nm, and most preferably 1100 nm being extracted, the process also includes irradiating at least one defined first region with photons and extracting features, preferably manufacturing inaccuracies, in the spectral range up to 3000 nm, preferably up to 1800 nm, more preferably up to 1400 nm, and most preferably 1100 nm, as described above.

[0115] Finally, the extracted features, preferably the inaccuracies of the product, are compared with the data relating to the positive identification information read from the unique code. Preferably, the data relating to the unambiguous identity is available as a digital representation, preferably as a string, which has preferably been generated by an algorithm, preferably a hashing algorithm, from the extracted features, preferably generated imprecision, and optionally other information.

[0116] For comparison with the data relating to the positive identity, the newly extracted features, preferably the inaccuracies of the product, are preferably converted into a digital representation using the same algorithm, preferably the same hashing algorithm, that generates the digital representation of the unique identity. The two digital representations are then preferably compared to each other.

[0117] This is preferably carried out using suitable software that is suitable both for reading the digital representation of the positive identification information and for creating digital representations from the extracted features, preferably inaccuracies of the product, and for comparing these digital representations with each other.

[0118] The process of identifying marked products described herein is preferably carried out using an electronic device suitable for this purpose, such as a camera, an industrial camera, a NIR camera, a spectrometer, or a smart device such as a smartphone or tablet.

[0119] Image processing, data reading, decoding and comparison can be performed using suitable software, e.g. an app.

[0120] The method of the present invention can be used to unambiguously associate entities, including many physical objects. As mentioned above, a possible additional digital signature, for example in the form of a unique code, allows the unambiguous marking to be made additionally secure. The unambiguity arises from any entity being able to assign a characteristic, preferably an individual pattern of manufacturing imperfections, which preferably results from an unclonable random process during the manufacturing of the physical object and the printing of the optional identification pattern. Therefore, this characteristic, preferably the product imperfections, is used as a physically unclonable function (PUF) as a second factor for secure identification.

[0121] The inventive method for marking and identifying a physical object is therefore suitable for generating a physically unclonable function (PUF) for the secure and unambiguous identification of a physical object and can therefore be used in serialization systems, in tracking and tracing applications or in conjunction with digital signatures for object authentication, e.g. document authentication.

[0122] The present invention also relates to a method for offline verification of a physical object by using the method for unambiguously marking a physical object and identifying a physical object as described herein, wherein preferably unambiguous identification data selected from features extracted from a defined first area of ​​said physical object, the unambiguous identification data and possibly other object data, such as production date, production location, batch number, validity data, such as expiry date, and references to further digital media, such as packaging leaflet or instructions for use or internet links to digital representations, are not called up from a database to unambiguously identify the physical object. The features described herein for the present method of distinctively marking and identifying a physical object can also be applied to the present method of offline verification of a physical object.

[0123] Although the method of the present invention for unambiguously marking and identifying a printable physical object is particularly suitable for offline verification of a printable physical object, the method of the present invention can also be used in a method for hybrid offline and online verification of a physical object, which in addition to the steps described herein comprises data for unambiguous identification, preferably selected from some of the features extracted from the defined first area of ​​said physical object, unambiguous identification information and possibly also other object data, such as production date, production location, batch number, validity data, such as expiry date, and references to further digital media, such as packaging leaflet or instructions for use or an internet link to a digital representation, and / or other data for verifying a digital signature, such as a public key or a digital certificate, which are stored in a database and called up from there in order to unambiguously identify the product. The features described herein for the present method of distinctively marking physical objects and identifying printable physical objects can also be applied to the present method of hybrid offline and online verification of physical objects.

[0124] Additionally, the present invention relates to a method for extending the marking to include other unique codes, wherein at least some of the steps for marking a physical object and at least some of the steps for identifying the marked physical object in the method described herein are performed and pursued by any inspection authority in the life cycle of the physical object, such as the manufacturer, customs, wholesalers and traders, and wherein the signed unambiguous identification information for newly introduced additional unique codes is not related to extracted features but to a representation of the most recently added unique code (e.g. a hash value of the data).

[0125] This is achieved by the inspection agency first performing the steps for identifying marked physical objects as described above. To update the code chain, the inspection agency then preferably marks the physical objects using at least the following method steps: - generating a digital signature of data relating to unambiguous identification information; generating a unique code containing said digital signature; and printing said unique code onto at least one third area on at least one surface of the product;

[0126] This includes the method steps of the method for distinctively marking a physical object. signing at least said unambiguous identification information, and optionally other information, in the form of a digital signature, generating a unique code containing at least the unambiguous identification information, optionally other information and a digital signature, printing the unique code in at least one second area on at least one surface of the physical object. Preferably, the same procedure is used.

[0127] Therefore, the inspection agency preferably uses this method to print another unique code, including at least a digital signature of the inspection agency, in at least one third area on at least one surface of the physical object.

[0128] In order to continuously update the code chain, these steps are preferably carried out by all inspection authorities in the life cycle of the physical object, for example the manufacturer, customs, wholesaler and trader.

[0129] This code chain allows the physical object to be tracked continuously.

[0130] Such code chains are therefore particularly suitable for tracking and tracing applications.

[0131] The inventive method described herein for distinctively marking and identifying physical objects can also be applied to the inventive method for extending the marking to include other unique codes.

[0132] The present invention provides a physical object having optical security features for unambiguously marking and identifying, preferably unambiguously and securely, the physical object on at least one region of a surface of the physical object, comprising: the optical security feature includes at least one first defined area and at least one second area having at least one printed unique code; said at least one printed unique code including unambiguous identification information and optionally other information related to said physical object, and a digital signature of said unambiguous identification information and optional other information; The unambiguous identification information also relates to a physical object generated from features extracted from the at least one first defined region.

[0133] In this regard, the optical security features are preferably placed on physical objects and used to mark and identify individual physical objects using all of the methods of the present invention described herein. In this regard, the methods of the present invention include the methods of distinctively marking physical objects as described herein, the methods of identifying physical objects as described herein, the methods of offline verification of physical objects as described herein, the methods of hybrid offline and online verification of physical objects as described herein, and the methods of extending marking to include other unique codes as described herein.

[0134] Thus, the optical security feature may also include a code printed on at least one surface of the physical object by an inspection agency in a manner that extends the marking to include other unique codes.

[0135] Additionally, the present invention relates to a serialization and / or tracking tracing system based on at least one optical security feature on at least one surface of a physical object as described herein.

[0136] Furthermore, the present invention relates to the use of optical security features on at least one surface of a physical object as described herein in serialization and / or tracking systems and / or for object authentication, e.g. document authentication.

[0137] Furthermore, the present invention relates to the use of optical security features on at least one surface of a physical object as described herein for offline verification and / or hybrid offline and online verification of the physical object.

[0138] Finally, the present invention relates to the use of optical security features on at least one surface of a physical object as described herein in a method of extending the marking to include other unique codes as described herein.

[0139] The features and optical security features described herein for the method of the present invention can also be applied to the serialization and / or tracking system of the present invention and the uses of the present invention.

Claims

1. 1. A method of marking a physical object, comprising: defining a first region on at least one surface of a physical object; extracting features from the selected regions; generating a unique identification from at least some of the extracted features; signing at least said unique identification information, and optionally other information, in the form of a digital signature; generating a unique code including at least said unique identification information, optionally said other information and said digital signature; printing the unique code in at least one second area on at least one surface of the physical object; A method comprising:

2. 2. The method of claim 1, wherein the features are manufacturing inaccuracies in at least one defined first region, the manufacturing inaccuracies including unintended inherent variations in the surface of the physical object and / or the substrate itself, and / or unintended inherent variations in a printed printing composition, and / or unintended inherent variations in a printed image of an identification pattern printed using the printing composition.

3. The method of claim 1 , wherein at least a portion of the defined first region is printed with at least one printing composition.

4. The method of claim 3 , wherein the printing composition contains a photoluminescent material that, under photon excitation, emits radiation in the range up to 3000 nm.

5. The method of claim 1 , wherein the other information signed may include, in addition to the extracted characteristics, at least one other object data, a manufacturing location, a batch number, validity data, and a reference to further digital media.

6. The method of claim 1 , wherein the unique identification information is a digital representation generated by an algorithm from the extracted features and optionally the optional other information.

7. The steps of signing at least the unique identification information and optionally other information and generating the unique code include the steps of: extracting features from at least one defined first region; deriving the unique identification information from the extracted features; computing a cryptographic hash of the unique identification information and optionally other information; encrypting the cryptographic hash using a private key of a manufacturer or distributor of the physical object; generating the unique code; 10. The method of claim 1, comprising:

8. 8. The method of claim 7, wherein the private key has a public key associated therewith by means of a digital certificate.

9. The method of claim 1 , wherein the second area printed with the unique code is locally adjacent to the defined first area.

10. The method of claim 1 , wherein the unique code is printed as a multi-dimensional bar code on the at least one second area on at least one surface of the physical object.

11. 10. A method of identifying a physical object marked using the unique marking method of claim 1, comprising: scanning the printed unique code containing at least the unique identification information, optionally the other information, and the digital signature; reading said unique identification information, optionally said other information and said digital signature from said unique code; verifying the digital signature; checking whether the digital signature relates to the unique identification information and optionally the other information in the unique code; extracting features from at least one defined first region; comparing the extracted features with the unique identification information read from the unique code; A method comprising:

12. The verification of the digital signature includes: using a digital certificate to retrieve a public key associated with a private key of a manufacturer or distributor of said physical object; verifying the digital signature using the public key; 12. The method of claim 11, comprising:

13. The method of claim 11, wherein an electronic smart device with appropriate software is used for each step.

14. 12. The method of claim 1 or claim 11, wherein at least one defined first region is illuminated with photons and the features are extracted from the at least one defined first region in a spectral range up to 3000 nm.

15. 12. A method for offline verification of a physical object by using the method of claim 1 or claim 11, wherein data for unique identification is not retrieved from a database to uniquely identify the physical object.

16. 12. A method for hybrid offline and online verification of a physical object by using the method of claim 1 or claim 11, wherein some of the data for the unique identification are stored in and retrieved from a database.

17. 12. A method for extending marking to include other unique codes, wherein at least some of the steps for marking the physical object and at least some of the steps for identifying the marked physical object in the method of claim 1 or claim 11 are performed and pursued by any inspection agency in the life cycle of the physical object, and wherein the signed unique identification information for newly introduced additional unique codes is related to a representation of the most recently added unique code rather than to extracted features.

18. A physical object having an optical security feature for uniquely marking and identifying the physical object on at least one region of a surface of the physical object, the optical security feature includes at least one first defined area and at least one second area having at least one printed unique code; the at least one printed unique code includes a unique identification, optionally other information about the physical object, and a digital signature of the unique identification and optionally the other information; The unique identification information is generated from features extracted from the at least one first defined region of the physical object.

19. 20. A serialization system based on at least one optical security feature on at least one surface of a physical object according to claim 18.

20. 20. A tracking and tracing system based on at least one optical security feature on at least one surface of a physical object according to claim 18.

21. 20. A method of using an optical security feature on at least one surface of a physical object according to claim 18 in a serialization and / or tracking system and / or for object authentication.

22. 20. A method of using an optical security feature on at least one surface of a physical object according to claim 18 for offline verification and / or hybrid offline and online verification of a physical object.

23. 20. A method of using an optical security feature on at least one surface of a physical object according to claim 18 in a method of extending a marking to include other unique codes according to claim 17.