RU2803761C2 - Verifiable user access credentials - Google Patents

Abstract

FIELD: user access.

SUBSTANCE: invention is related to a machine-readable medium for verifiable user access credentials. The medium includes the first zone containing printed human-readable identification data related to the identity of the user, and the second zone with a magnetically induced applied mark having a flat layer of material and a machine-readable marking in form of a pattern representing encoded data, wherein the encoded data corresponds to at least partially human-readable identification data of the first zone. The magnetically induced mark material contains magnetically oriented reflective plate-like magnetic or magnetizable pigment particles. The machine-readable marking contains a signature of said identification data and is at least partially applied directly to the magnetically induced mark such that the machine-readable marking overlaps at least one area of a layer of material with magnetically oriented reflective platelet magnetic or magnetizable pigment particles.

EFFECT: ensuring automatic establishment of a high level of authentication and identification of reliability of any issued identification document and linking it with a duplicate digital ID.

15 cl, 15 dwg

Description

Field of technology to which the invention relates

This application relates to a user's verifiable access credential document and a method for a user to use such a verifiable credential document to access online sites and conduct online transactions using a smartphone or any tablet or computer connected to a communications network.

Prerequisites for creating the invention

It is well known to authorize a user's access to a given site through a communications network (eg, the Internet) to allow the user to carry out certain transactions (eg, financial transactions on the user's bank account). Typically, the user must "verify" their identity using a private key and/or password to submit a request to the authority managing the site: only if the password and/or key are correct is full access to the site authorized. However, the level of trust in such access is quite low, since the password or private key may be stolen, or the user may be registered with the site (or its supervisory authority) under a false identity. Thus, there is a need to increase the level of trust in personal access credentials.

On the other hand, it is well known to use secure government-issued identification documents (such as ID cards or passports) to confirm the owner's identity to a supervisory agent (for example, at the front desk) and then to access certain services. In this case, the agent will monitor some of the hard-to-forge security markings provided in the owner's identification document, perhaps check the similarity of the owner's face to the biometrics and/or photograph of the individual, and then, i.e., when the agent has obtained a sufficient level of confidence in the identity specified owner, it allows the owner to carry out certain authorized operations.

For example, WO 2014/160582 A1 discloses a method that includes the steps of: creating an association on a mobile device between a government-issued user identification document and a payment method; receiving on the mobile device the presentation of the user's government-issued identification document to support the payment request; verifying whether the government-issued identification document presented is a valid identification of the user; and in response to confirmation of presentation of government-issued identification, making payment using the specified payment method. A government-issued identification document may contain printed text, magnetic media, and a bar code.

An authentication method applicable to protected documents is also known, which is disclosed in US 2007/170248 A1. Said authentication method involves the reader capturing an image of the cardholder's face. Facial recognition software processes the image to create a hash function. The same reader is used to decode the digital watermark and/or barcode. The digital watermark (and/or barcode) includes an associated facial recognition hash function. If the hashes match, the identity and the identity document are authenticated.

WO 2006/078220 A1 discloses an object, such as a credit card, banknote, document, label, etc., that carries an identification layer that contains readable information. The identification layer may include randomly distributed conductive/magnetizable particles, a semiconductor particle, optically active particles, etc. The identification layer is sandwiched between the upper and lower layers to form an object. At least some of the particles are exposed along one edge of the object and can be read by a read head that moves along the edge.

The purpose of the present invention is to eliminate the need for prior identity verification through an agent and provide any user with direct access to online services provided by a private or public operator, while providing the operator with a high level of trust in the user's true identity (and therefore true transaction rights). ).

Brief description of the invention

In view of the above, the present invention allows the use of conventional equipment (e.g., smartphone, tablet, computer, etc.) to automatically establish a high level of authentication and identify the validity of any government-issued identification document (e.g., ID card, driver's license, passport, etc.). d.) and linking it with a duplicate digital ID. In addition, the present invention allows the material-based security feature provided by said government-issued identification document to be personalized to create a link between the identification document and its data content that can be read by such conventional equipment.

In one aspect, the present invention relates to a verifiable user access credential document comprising:

- a first zone containing printed human-readable identification data relating to the user's identity;

- a second zone with an applied magnetically induced mark having a flat layer of material containing magnetically oriented reflective plate-like magnetic or magnetizable pigment particles;

- a machine-readable marking in the form of a pattern representing encoded data and at least partially applied to the second zone, the encoded data corresponding to at least partially human-readable identification data of the first zone;

- machine-readable marking containing the signature of the specified identification data.

This document also describes verifiable access credential documents, whereby:

a) the magnetically induced mark is in the form of a mark containing magnetically oriented reflective platelet magnetic or magnetizable pigment particles, said pigment particles containing a magnetic metal selected from the group consisting of cobalt, iron, gadolinium and nickel; a magnetic alloy of iron, manganese, cobalt, nickel or a mixture of two or more of them; magnetic oxide of chromium, manganese, cobalt, iron, nickel or a mixture of two or more of them; or a mixture of two or more of them, and

b) the machine-readable marking is in the form of a pattern representing a code, which is preferably a pattern of a one-dimensional bar code, a stacked one-dimensional bar code, a two-dimensional or three-dimensional bar code carrying encoded data, preferably biographical information, and/or biometric information, and/or credentials.

This document also describes verifiable access credential documents, whereby:

at least a portion of the reflective plate-like magnetic or magnetizable pigment particles is formed by dielectric/reflector/magnetic material/reflector/dielectric multilayer structures and/or dielectric/reflector/dielectric multilayer structures/magnetic material/reflector/dielectric structures, preferably MgF ₂ /Al/ multilayer structures magnetic material/Al/MgF ₂ and multilayer structures MgF ₂ /Al/ MgF ₂ /magnetic material/Al/MgF ₂ , wherein the magnetic layer contains iron, and more preferably contains a magnetic alloy or mixture of iron and chromium.

Also described herein are verifiable access credential documents, wherein at least a portion of the reflective platelet magnetic or magnetizable pigment particles is formed at least in part by the reflective platelet color changing magnetic or magnetizable pigment particles, preferably magnetic thin film interference pigment particles.

Also described herein are verifiable access credential documents wherein the magnetic thin film interference pigment particles comprise a 5-layer Fabry-Perot absorber/dielectric/reflector/dielectric/absorber structure, wherein the reflector and/or absorber is a magnetic layer containing nickel , iron and/or cobalt, and/or magnetic alloy containing nickel, iron and/or cobalt, and/or magnetic oxide containing nickel (Ni), iron (Fe) and/or cobalt (Co), or 7-layer Fabry-Perot structure absorber/dielectric/reflector/magnetic material/reflector/dielectric/absorber, or 6-layer Fabry-Perot structure absorber/dielectric/reflector/magnetic material/dielectric/absorber,

the magnetic layer contains nickel, iron and/or cobalt; and/or a magnetic alloy containing nickel, iron and/or cobalt, and/or a magnetic oxide containing nickel, iron and/or cobalt.

Also described herein are verifiable access credential documents wherein the reflective plate-like magnetic or magnetizable first marking pigment particles are parallel to each other and have an inclination of the planes of the pigment particles preferably of at least 10° relative to the plane of the substrate of the identification document.

Also described herein are verifiable access credential documents, wherein the second marking is a two-dimensional bar code and is preferably a QR code.

Also described herein are verifiable access credential documents wherein a dark, preferably black, ball of primer is provided between the backing of the verifiable access credential document and the first marking.

According to another aspect, the present invention relates to a method for verifying an access credential document and authorizing access to a user's website described herein using a portable device equipped with a light source capable of emitting visible light, an image forming apparatus, a processor with a memory and a communication unit configured to send and receive data via a communication network, the method comprising the steps of:

- placing a device for forming an image of a portable device at a given distance L above the second zone;

- illuminating the magnetically induced mark described herein with a light source and obtaining a plurality of digital images of the illuminated magnetically induced mark by an imaging device, the imaging device being positioned for each different digital image at a corresponding different viewing angle θ relative to said magnetic field. induced mark by moving the image forming device over the magnetically induced mark in a direction parallel to the flat layer;

- determining, for each acquired digital image, the calculation by the processor of the corresponding average intensity I of light reflected by the plates and collected by the image forming device at the corresponding viewing angle θ;

- storing the calculated values of the average intensity of the reflected light and the corresponding viewing angles to obtain the curve I(θ) of the intensity of the reflected light;

- comparing the stored reflected light intensity curve I(θ) with the stored reference reflected light intensity curve I _ref (θ) for said magnetically induced mark;

- determining whether the magnetically induced mark is genuine based on the result of the comparison;

- if the magnetically induced mark is considered genuine, the user illuminates the machine-readable marking and takes a photo of the image of the illuminated machine-readable marking;

- extracting the identification data signature from the resulting image of the machine-readable marking described in this document;

- sending a message containing the extracted signature via a communication unit to a server configured to authorize access to the site and connected to the communication network;

- checking on the server that the extracted signature matches the corresponding signature of the human-readable identification data, and, if a match, authorizing the user's access to the site through the communication network to carry out transactions on this site.

Finally, the present invention relates to a portable reader equipped with a processor having a memory, a light source, a camera, a display, a communications unit configured to send and receive messages via a communications network, and a computer program product that, when executed on the processor, provides a command to a reader configured to implement the steps of a method for verifying an access credential document described herein.

The verifiable access credential documents described herein include a magnetically induced mark described herein and a pattern representing encoded data, wherein said pattern at least partially overlaps the magnetically induced mark. Advantageously, the magnetically induced mark and the pattern representing the encoded data can be obtained at different times and places, and can also be obtained by different means. For example, a magnetically induced mark is typically produced by a printing process such as those described herein, and a pattern representing encoded data may be produced by printing, particularly inkjet printing, an etching or ablation method. The magnetically induced mark is printed during the serial production of the said document and prior to its personalization with details directed at the owner/user of the said document, and a pattern representing the encoded data is obtained during the personalization. The disclosed embodiments are directed to exploit the synergistic effect between a visible magnetically induced mark as an authentication feature and a second mark as a pattern representing encoded data to enable verification of an access credential document, verification of user identification information, and authorization of access to a site.

The present invention will now be described more fully with reference to the accompanying drawings, in which like numerals represent like elements in the different figures and in which the essential aspects and features of the present invention are illustrated.

Brief description of drawings

In fig. 1 illustrates a verifiable access credential document in accordance with the present invention.

In fig. 2A is a schematic illustration of a magnetic orientation pattern in which the magnetic axes of the pigment particles are parallel to each other and parallel to the plane, and the angle of inclination of the planes of the pigment particles is at least 10° relative to the plane of the substrate on which the pigment particles are applied (jagged effect).

In fig. 2B is a schematic illustration of a magnetic orientation pattern with a first portion and a second portion separated by a transition, with pigment particles aligned parallel to a first plane in the first portion and pigment particles in a second portion aligned parallel to the second plane (flip-flop effect).

In fig. 3 is a schematic illustration of a marking comprising a magnetically induced mark, a pattern representing encoded data, and optionally a layer of primer underneath the magnetically induced mark.

In fig. 4 is a schematic illustration of the detection of magnetically oriented partially reflective plate-like magnetic or magnetizable pigment particles of a magnetically induced tag using a smartphone due to the reflectivity of the particles (or not) depending on its position relative to the tag.

In fig. Figure 5 shows an example of a measurement setup using a smartphone and a sample that is scanned in a plane parallel to the smartphone and at a fixed distance from the smartphone.

In fig. Figure 6 illustrates the position of the magnetically induced mark in the image set and the illumination/observation angle θ for a known distance from the smartphone to the sample, with a graphical representation of the intensity profile.

In fig. 7 illustrates the intensity and relative intensity profiles of a magnetically induced mark extracted from an image sequence.

In fig. 8 is a schematic illustration of a magnetically induced mark with magnetically oriented partially reflective platelet magnetic or magnetizable pigment particles in two opposite directions.

In fig. 9 illustrates a specific printed pattern of one embodiment of the present invention that contains magnetically oriented partially reflective plate-like magnetic or magnetizable pigment particles in two different orientations in different regions of a magnetically induced mark (the two regions may also overlap each other).

In fig. 10 illustrates a specific printed pattern of one embodiment of the present invention that contains magnetically oriented partially reflective platelet magnetic or magnetizable pigment particles in two different orientations in different regions of a magnetically induced mark.

In fig. 11 is a schematic illustration of the positions of a smartphone over a magnetically induced mark with two different orientations of reflective plate-like magnetic or magnetizable pigment particles, as shown in FIG. 8–10, together with the resulting image frames in these two positions.

In fig. 12 is a schematic representation of the effect of 90° rotation of a magnetically induced mark or smartphone in the plane of the mark and the guide target on the screen.

In fig. 13 is a schematic representation of a magnetically induced tag with magnetically oriented partially reflective platelet magnetic or magnetizable pigment particles in the E direction (particles 1), and another class of particles (particles 2) oriented in the S direction, at an angle of 90° relative to particles 1.

In fig. 14 is a graphical representation of the intensity profile, its first derivative and second derivative with respect to position.

Detailed description

In the preferred embodiment of FIG. 1 shows a verifiable access credential document 100 comprising a first zone containing printed human readable identification data relating to the identity of the user 110, a second zone printed with a magnetically induced mark 120 having a flat layer of material containing magnetically oriented reflective plate magnetic or magnetizable pigment particles having a preferred orientation, machine-readable marking 130 in the form of a pattern (in this case a two-dimensional bar code) representing encoded data and at least partially applied to the second zone, wherein the encoded data corresponds to at least partially human-readable identification data the first zone, wherein the machine-readable marking 130 contains a signature of said identification data.

A digital signature of the user's identity, which may include the user's biometric data, is obtained through a one-way function of the corresponding digital identity. A one-way function can be a hash function. One such beneficial transformation is, for example, applying the hash function H( ) = hash( ) to digital data, which typically has the property of returning an output of known bit length regardless of the size of the input data: this technical effect is especially useful for creating a digital signature digital data, regardless of the size of the digital data. A hash function is a well-known example of a one-way function. If a cryptographic hash function is used, such as the SHA (Secure Hash Algorithm) function class, such as SHA-256, then there are the additional advantages that the function is virtually irreversible and collision resistant, meaning that there is a chance that two different groups input data will lead to the same output data is negligible. As will be clear from the description below, this is also not a requirement of the present invention, although it is advantageous for the same reasons as in other applications.

The machine-readable marking 130 may be any of an alphanumeric marking, a one-dimensional bar code, or a two-dimensional bar code (e.g., DataMatrix, QR code, etc.). Preferably, the machine-readable marking provided on the verifiable access credential document described herein consists of a pattern representing a code, which preferably is a one-dimensional bar code, a stacked one-dimensional bar code, a two-dimensional bar code (such as a DataMatrix or QR code), wherein the specified pattern is read by a portable mobile device described in this document. Preferably, said portable mobile device is a smartphone.

The machine-readable markings provided on the verifiable access credential document described herein may be any type of marking or design, including machine-readable markings, bar codes, etc. Two-dimensional bar codes may include a DataMatrix or a DataMatrix symbol and Quick Response (QR) code (registered trademark) and so on. The barcode may be a GS1 (trademark) DataMatrix barcode in ECC200 version (GS1 is the international standards body for barcodes). This standard involves a barcode formed by two types of elements, namely an element of the first type and an element of the second type. The features may be in the form of dots or squares and may be marked or embodied on the identification document by any suitable means. The machine-readable markings described herein may be created by any suitable means, including printing processes (particularly inkjet printing), etching and ablation techniques (particularly laser etching or burning), embossing techniques, etc.

Decoding a machine-readable marking typically begins by obtaining a snapshot (digital) image of said machine-readable marking on document 100. Such image is then obtained as digital image data defining corresponding values for the pixels of the image. This digital image data is then subjected to image processing using a processing unit (e.g., CPU, computer, server, embedded system, ASIC, etc.). Such processing can be divided into various individual steps to finally decode the data that is encoded in the barcode.

The machine-readable marking described herein carries encoded data such as biographical data, biometric data, credentials, etc. Preferably, the machine-readable marking described herein carries encoded data representing biographical data and/or biometric data and/or credentials. As used in this document, the term “biographical information” is used to refer to information related to the personal life of the user or owner of the protected product. Typical examples of biographical data or biographical information include, without limitation, first name, last name(s), nationality, place or origin, place of birth, date of birth, gender, personal identification number and personal social number. As used in this document, the term “biometric data” is used to refer to a physical characteristic of the user or owner of a protected product. Biometric data may consist of an image or an alphanumeric description or encoding of a physical characteristic. Typical examples of biometric data include, but are not limited to, image and/or data corresponding to biometric data selected from the group consisting of faces, fingerprints, palm prints, iris patterns, retinal patterns, earlobe patterns, vein patterns, blood oxygen levels , bone density, gait, voices, smell and combinations thereof.

Magnetically induced mark 120 described herein refers to layers that contain at least a plurality of magnetically oriented reflective plate-like magnetic or magnetizable pigment particles, wherein said pigment particles are fixed or immobilized (fixed/immobilized) in position and orientation.

Unlike needle-shaped pigment particles, which can be considered as one-dimensional particles, platelet pigment particles are two-dimensional particles due to the large aspect ratio of their sizes. The platelet pigment particles can be considered a two-dimensional structure, where the X and Y dimensions are substantially larger than the Z dimension. The platelet pigment particles are also called oblate particles or flakes in the art. Such pigment particles can be described by a major X-axis corresponding to the largest dimension intersecting the pigment particle and a second Y-axis perpendicular to X, which also lies within said pigment particles.

The magnetically induced marks described herein comprise oriented reflective platelet magnetic or magnetizable pigment particles which, due to their shape, are characterized by anisotropic reflectivity. As used herein, the term "anisotropic reflectivity" means that the fraction of incident radiation at a first angle that is reflected by a particle in some viewing direction (second angle) depends on the orientation of the particles, i.e., that a change in particle orientation with respect to the first angle may result in different amounts of reflection in the viewing direction. Preferably, the reflective platelet magnetic or magnetizable pigment particles described herein have anisotropic reflectivity to incident electromagnetic radiation over some or all of the wavelength range from about 200 nm to about 2500 nm, more preferably from about 400 nm to about 700 nm , and in this case, a change in the orientation of a particle leads to a change in the reflection of this particle in a certain direction. Thus, even if the intrinsic reflectance per unit surface area (for example, per µm ² ) is the same over the entire surface of a plate-like particle, due to its shape, the reflectivity of the particle is non-isotropic, since the apparent area of the particle depends on the direction from which it is viewed. As is known to those skilled in the art, the reflective platelet magnetic or magnetizable pigment particles described herein differ from conventional pigments in that the conventional pigment particles have the same color and reflectivity, regardless of particle orientation, whereas magnetic or magnetizable The pigment particles described herein have either reflectivity, color, or both, depending on the orientation of the particles.

Suitable examples of reflective platelet magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles containing a magnetic metal selected from the group consisting of cobalt (Co), iron (Fe), gadolinium (Gd) and nickel (Ni) ; a magnetic alloy of iron, manganese, cobalt, nickel or a mixture of two or more of them; magnetic oxide of chromium, manganese, cobalt, iron, nickel or a mixture of two or more of them; or a mixture of two or more of them. The term "magnetic" in relation to metals, alloys and oxides refers to ferromagnetic or ferrimagnetic metals, alloys and oxides. Magnetic oxides of chromium, manganese, cobalt, iron, nickel, or mixtures of two or more of these may be pure or mixed oxides. Examples of magnetic oxides include, but are not limited to, iron oxides such as hematite (Fe ₂ O ₃ ), magnetite (Fe ₃ O ₄ ), chromium dioxide (CrO ₂ ), magnetic ferrites (MFe ₂ O ₄ ), magnetic spinels (MR ₂ O ₄ ), magnetic hexaferrites (MFe ₁₂ O ₁₉ ), magnetic orthoferrites (RFeO ₃ ), magnetic garnets M ₃ R ₂ (AO ₄ ) ₃ , where M is a divalent metal, R is a trivalent metal, and A is a tetravalent metal.

Examples of reflective platelet magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles comprising a magnetic layer M made of one or more magnetic metals such as cobalt (Co), iron (Fe), gadolinium (Gd), or nickel (Ni); as well as a magnetic alloy of iron, chromium, cobalt or nickel, wherein said pigment particles may be multilayer structures containing one or more additional layers. Preferably, the one or more additional layers are layers A, independently made from one or more materials selected from the group consisting of metal fluorides such as magnesium fluoride (MgF ₂ ), silicon oxide (SiO), silicon dioxide (SiO ₂ ) , titanium oxide (TiO ₂ ) and aluminum oxide (Al ₂ O ₃ ), more preferably silicon dioxide (SiO ₂ ); or layers B independently made from one or more materials selected from the group consisting of metals and metal alloys, preferably selected from the group consisting of reflective metals and reflective metal alloys, and more preferably selected from the group consisting of aluminum (Al) , chromium (Cr) and nickel (Ni), and even more preferably aluminum (Al); or a combination of one or more A layers, such as those described herein above, and one or more B layers, such as those described herein above. Typical examples of reflective platelet magnetic or magnetizable pigment particle multilayer structures described hereinabove include, but are not limited to, A/M multilayer structures, A/M/A multilayer structures, A/M/B multilayer structures, A/Multilayer structures B/M/A, multilayer structures A/B/M/B, multilayer structures A/B/M/B/A, multilayer structures B/M, multilayer structures B/M/B, multilayer structures B/A/M/ A, B/A/M/B multilayer structures, B/A/M/B/A/ multilayer structures, wherein the A layers, the magnetic layers M and the B layers are selected from those described above herein.

In one embodiment, at least a portion of the reflective platelet magnetic or magnetizable pigment particles described herein are dielectric/reflector/magnetic material/reflector/dielectric multilayer structures and dielectric/reflector/dielectric multilayer structures/magnetic material/reflector/dielectric structures wherein the reflective layers described herein are independently and preferably made of one or more materials selected from the group consisting of metals and metal alloys, preferably selected from the group consisting of reflective metals and reflective metal alloys, more preferably selected from group consisting of aluminum (Al), silver (Ag), copper (Cu), gold (Au), platinum (Pt), tin (Sn), titanium (Ti), palladium (Pd), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni) and alloys thereof, even more preferably selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni) and alloys thereof, and even more preferably aluminum (Al), wherein the dielectric layers are independently and preferably made of one or more materials selected from the group consisting of metal fluorides such as magnesium fluoride (MgF₂), aluminum fluoride (AlF₃), cerium fluoride (CeF₃), lanthanum fluoride (LaF₃), sodium aluminum fluorides (for example, Na₃AlF₆), neodymium fluoride (NdF₃), samarium fluoride (SmF₃), barium fluoride (BaF₂), calcium fluoride (CaF₂), lithium fluoride (LiF), as well as metal oxides such as silicon oxide (SiO), silicon dioxide (SiO₂), titanium oxide (TiO₂), aluminum oxide (Al₂O₃), more preferably selected from the group consisting of magnesium fluoride (MgF₂) and silicon dioxide (SiO₂), and even more preferably magnesium fluoride (MgF₂), and the magnetic layer preferably contains nickel (Ni), iron (Fe), chromium (Cr) and/or cobalt (Co); and/or a magnetic alloy containing nickel (Ni), iron (Fe), chromium (Cr) and/or cobalt (Co); and/or a magnetic oxide containing nickel (Ni), iron (Fe), chromium (Cr) and/or cobalt (Co). Alternatively, the dielectric/reflector/magnetic material/reflector/dielectric multilayer structures and dielectric/reflector/dielectric/magnetic material/reflector/dielectric multilayer structures described herein may be multilayer pigment particles that are considered safe for human health and environment, wherein said magnetic layer comprises a magnetic alloy having a substantially nickel-free composition comprising from about 40 wt. % to approximately 90 wt. % iron, from approximately 10 wt. % to approximately 50 wt. % chromium and from approximately 0 wt. % to approximately 30 wt. % aluminum. Particularly suitable reflective platelet magnetic or magnetizable pigment particles having a dielectric/reflector/magnetic material/reflector/dielectric multilayer structure include, but are not limited to, MgF₂/Al/magnetic material/Al/MgF₂And MgF₂/Al/ MgF₂/magnetic material/Al/MgF₂wherein the magnetic layer contains iron, preferably contains a magnetic alloy or mixture of iron and chromium.

Alternatively, the reflective platelet magnetic or magnetizable pigment particles described herein may be reflective platelet color-changing magnetic or magnetizable particles, particularly magnetic thin film interference pigment particles. Color changing elements (also referred to in the art as goniochromatic elements), such as, for example, pigment particles, inks, coatings or layers known in the security printing field, exhibit color depending on viewing angle or incident angle, and are used to protect security items. documents from forgery and/or illegal reproduction using commonly available office color scanning, printing and copying equipment.

Magnetic thin film interference pigment particles are known to those skilled in the art and are disclosed, for example, in US Pat. No. 4,838,648; WO 2002/073250 A2; EP 0686675 B1; WO 2003/000801 A2; US 6838166; WO 2007/131833 A1; EP 2402401 A1 and the documents referred to therein. Preferably, the magnetic thin film interference pigment particles are pigment particles having a five-layer Fabry-Perot structure and/or pigment particles having a six-layer Fabry-Perot structure and/or pigment particles having a seven-layer Fabry-Perot structure.

Preferred five-layer Fabry-Perot structures consist of absorber/dielectric/reflector/dielectric/absorber multilayer structures, wherein the reflector and/or absorber is also a magnetic layer, preferably the reflector and/or absorber is a magnetic layer containing nickel, iron and /or cobalt, and/or a magnetic alloy containing nickel, iron and/or cobalt, and/or a magnetic oxide containing nickel (Ni), iron (Fe) and/or cobalt (Co).

Preferred six-layer Fabry-Perot structures consist of absorber/dielectric/reflector/magnetic material/dielectric/absorber multilayer structures.

Preferred seven-layer Fabry-Perot structures consist of absorber/dielectric/reflector/magnetic material/reflector/dielectric/absorber multilayer structures, such as those described in US 4,838,648.

Preferably, the reflective layers of the multilayer Fabry-Perot structures described herein are independently made of one or more materials such as those described above herein. Preferably, the dielectric layers of multilayer Fabry-Perot structures are independently made of one or more materials such as those described herein above

Preferably, the absorber layers are independently made of one or more materials selected from the group consisting of aluminum (Al), silver (Ag), copper (Cu), palladium (Pd), platinum (Pt), titanium (Ti), vanadium ( V), iron (Fe), tin (Sn), tungsten (W), molybdenum (Mo), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni), oxides of these metals, sulfides of these metals , carbides of these metals, as well as alloys of these metals, more preferably selected from the group consisting of chromium (Cr), nickel (Ni), oxides of these metals and alloys of these metals, and even more preferably selected from the group consisting of chromium (Cr ), nickel (Ni) and alloys of these metals.

Preferably, the magnetic layer contains nickel (Ni), iron (Fe) and/or cobalt (Co); and/or a magnetic alloy containing nickel (Ni), iron (Fe) and/or cobalt (Co); and/or a magnetic oxide containing nickel (Ni), iron (Fe) and/or cobalt (Co). If the magnetic thin film interference pigment particles containing a seven-layer Fabry-Perot structure are preferred, it is particularly preferable that the magnetic thin film interference pigment particles contain a seven-layer Fabry-Perot absorber/dielectric/reflector/magnetic material/reflector/dielectric/absorber structure consisting of multilayer structure Cr/MgF ₂ /Al/Ni/Al/MgF ₂ /Cr.

The magnetic thin film interference pigment particles described herein may be multi-layer pigment particles that are considered safe for human health and the environment and are based on, for example, five-layer Fabry-Perot structures, six-layer Fabry-Perot structures and seven-layer Fabry-Perot structures. Feather, wherein said pigment particles comprise one or more magnetic layers comprising a magnetic alloy having a substantially nickel-free composition comprising from about 40 wt. % to approximately 90 wt. % iron, from approximately 10 wt. % to approximately 50 wt. % chromium and from approximately 0 wt. % to approximately 30 wt. % aluminum. Typical examples of multilayer pigment particles considered safe for human health and the environment can be found in EP 2402401 A1, which is incorporated herein by reference in its entirety.

Dielectric/reflector/magnetic material/reflector/dielectric multilayer structures described herein, absorber/dielectric/reflector/dielectric/absorber multilayer structures described herein, absorber/dielectric/reflector/magnetic material/dielectric/absorber multilayer structures, described herein, and the absorber/dielectric/reflector/magnetic material/reflector/dielectric/absorber multilayer structures described herein are typically produced by conventional techniques of depositing various desired layers onto a web. After the required number of layers have been deposited, for example by physical vapor deposition (PVD), chemical vapor deposition (CVD) or electrolytic deposition, the stack of layers is removed from the web either by dissolving the release layer in a suitable solvent or by stripping the material from the web. The material thus obtained is then broken down into lamellar magnetic or magnetizable pigment particles, which must be further processed by crushing, grinding (such as, for example, jet mill grinding processes) or any suitable method designed to obtain pigment particles of the required size. The resulting product consists of plate-like magnetic or magnetizable pigment particles with jagged edges, irregular shapes and varying aspect ratios. Further information on the preparation of suitable pigment particles can be found, for example, in EP 1710756 A1 and EP 1666546 A1, which are incorporated herein by reference.

The magnetically induced tag 120 described herein is produced by a method comprising the steps of a) applying to a document a verifiable access credential (if created by a suitable authority) to a coating composition comprising the reflective platelet magnetic or magnetizable pigment particles described herein ; b) exposing the coating composition to the magnetic field of a magnetic field generating device to orient at least a portion of the reflective platelet magnetic or magnetizable pigment particles, and c) solidifying the coating composition to fix the reflective platelet magnetic or magnetizable pigment particles in their positions, and orientations.

Preferably, the coating composition described herein contains reflective platelet magnetic or magnetizable pigment particles described herein dispersed in a binder material, wherein said reflective platelet magnetic or magnetizable pigment particles are present in an amount of from about 2 wt. % to about 40% by weight, more preferably from about 4% by weight to about 30% by weight, the weight percentage being calculated based on the total weight of the coating composition containing the binder material, reflective platelet magnetic or magnetizable pigment particles, and other optional components of the coating composition. The coating composition described herein may further contain one or more color components selected from the group consisting of organic pigment particles, inorganic pigment particles, as well as organic colorants and/or one or more additives. The latter include, without limitation, compounds and materials that are used to adjust the physical, rheological and chemical parameters of the coating composition, such as viscosity (for example, solvents, thickeners and surfactants), consistency (for example, anti-settling agents, fillers and plasticizers), foaming properties (e.g. antifoams), lubricating properties (waxes, oils), UV resistance (photostabilizers), adhesive properties, antistatic properties, storage stability (polymerization inhibitors), etc. Additives described herein , may be present in the coating composition in amounts and forms known in the art, including so-called nanomaterials in which at least one of the additive sizes is in the range of 1-1000 nm.

The application step a) described herein is carried out through a printing process, preferably selected from the group consisting of screen printing, rotary gravure printing and flexographic printing. These processes are well known to one skilled in the art and are described, for example, in Printing Technology, JM Adams and PA Dolin, Delmar Thomson Learning, ^5th edition, pages 293, 332 and 352.

While the coating composition containing the reflective platelet magnetic or magnetizable pigment particles described herein is still wet or soft enough to allow said pigment particles therein to move and rotate (i.e., while the coating composition is in the first state ), the coating composition is subjected to a magnetic field to achieve particle orientation. The step of magnetically aligning the reflective plate-like magnetic or magnetizable pigment particles involves the step of exposing the applied coating composition, while it is "wet" (i.e., still liquid and not very viscous), to a specified magnetic field generated by a magnetic field generating device, with by orienting reflective plate-like magnetic or magnetizable pigment particles along magnetic field lines to form an orientation pattern.

Subsequent to, partially or simultaneously with, application of the coating composition to the surface of the substrate, the reflective platelet magnetic or magnetizable pigment particles are oriented by using an external magnetic field to orient them according to the desired orientation pattern. The orientation pattern thus obtained may be any pattern except a random orientation pattern and except a pattern in which the magnetic axis of the reflective plate-like magnetic or magnetizable pigment particles is oriented so as to be parallel or perpendicular to the identification document on which said particles are applied.

[037] A wide variety of magnetically induced marks for decorative or security applications can be obtained through various methods disclosed, for example, in US 6,759,097, EP 2165774 A1 and EP 1878773 B1. Optical effects known as rolling band effects can also be obtained. Rolling band effects demonstrate one or more contrasting bands that appear to move ("roll") when the image is tilted relative to the viewing angle, these optical effects are based on a specific orientation of magnetic or magnetizable pigment particles, wherein said pigment particles are aligned in a curved manner, or along a convex curvature (also referred to in the art as a negatively curved orientation), or along a concave curvature (also referred to in the art as a positively curved orientation). Methods for obtaining rolling strip effects are disclosed, for example, in EP 2263806 A1, EP 1674282 B1, EP 2263807 A1, WO 2004/007095 A2 and WO 2012/104098 A1. It is also possible to obtain optical effects known as moving ring effects. Moving ring effects consist of optically illusory images of objects such as bells, cones, balls, circles, ellipses, and hemispheres that appear to move in any x-y direction, depending on the angle of said magnetically induced mark. Methods for obtaining moving ring effects are disclosed, for example, in EP 1710756 A1, US 8343615, EP 2306222 A1, EP 2325677 A2, WO 2011/092502 A2 and US 2013/084411.

It is possible to produce magnetically induced marks, known as jagged effects, as shown in FIG. 2A. The jagged effects include a portion of pigment particles whose magnetic axes are parallel to each other and parallel to a plane, wherein said plane is not parallel to the identification document substrate. In particular, optical effects in which the pigment particles are parallel to each other and have essentially the same angle of inclination of the planes of the pigment particles of at least 10° relative to the plane of the substrate on which the pigment particles are applied. Jagged effects involve pigment particles oriented so that along a particular viewing direction they give visibility to the underlying surface of the substrate, such that marks or other features present on or in the surface of the substrate become obvious to the observer while they obstruct visibility along another directions of observation. Methods for obtaining jagged distortion effects are disclosed, for example, in US 8025952 and EP 1819525 B1.

Magnetically induced notches, known as flip-flop effects (also referred to in the art as switching effects), are shown in FIG. 2B and can be obtained. Flip-flop effects include a first part and a second part separated by a transition, with pigment particles aligned parallel to a first plane in the first part and pigment particles in a second part aligned parallel to a second plane. Methods for obtaining flip-flop effects are disclosed, for example, in documents EP 1819525 B1 and EP 1819525 B1. Particularly suitable orientation patterns include the jagged effects and flip-flop effects described above herein.

Methods for producing a magnetically induced mark described herein include, partly simultaneously with step b) or after step b), step c) solidifying the coating composition to fix the partially reflective platelet magnetic or magnetizable pigment particles in their assumed positions and orientations in the necessary pattern for the formation of a magnetically induced mark, with the transformation of the coating composition into the second state. By this fixation a hard coating or hard layer is formed. The term "curing" refers to processes involving drying or fixing, reacting, curing, cross-linking or polymerizing binder components in the applied coating composition, including an optional cross-linking agent, an optional polymerization initiator and optional additional additives such that substantially a solid material that adheres to the surface of a substrate. As mentioned herein, the curing step c) can be carried out using different means or processes, depending on the materials contained in the coating composition, which also contains reflective platelet magnetic or magnetizable pigment particles. The curing step can generally be any step in which the viscosity of the coating composition is increased such that a substantially solid material is formed that is adhered to the load-bearing surface. The solidification step may involve a physical process based on evaporation of a volatile component, such as a solvent, and/or evaporation of water (i.e., physical drying). In this case, you can use hot air, infrared radiation, or a combination of hot air and infrared radiation. Alternatively, the curing process may involve a chemical reaction such as curing, polymerizing or cross-linking of the binder and optional starter compounds and/or optional cross-linking compounds contained in the coating composition. Such chemical reaction may be initiated by heat or IR radiation as described above for physical curing processes, but may preferably involve chemical reaction initiation by radiation, including but not limited to ultraviolet-visible curing (hereinafter referred to herein). as UV-visible curing) and electron beam curing (electron beam curing), oxypolymerization (oxidative reticulation, typically caused by the combined action of oxygen and one or more catalysts, preferably selected from the group consisting from cobalt-containing catalysts, vanadium-containing catalysts, zirconium-containing catalysts, bismuth-containing catalysts and manganese-containing catalysts); cross-linking reactions or any combination thereof. Radiation-induced curing is particularly preferred, and UV-visible curing is even more preferred, since these technologies advantageously result in very fast curing processes and therefore significantly reduce the turnaround time for any document containing magnetically induced marks described in this document. Additionally, radiation curing has the advantage of providing an almost immediate increase in viscosity of the coating composition upon exposure to curing radiation, thereby minimizing any further particle movement. As a consequence, any loss of information after the magnetic orientation step can generally be avoided. Particularly preferred is radiation curing by photopolymerization under the influence of actinic light having a wavelength component in the UV or blue portion of the electromagnetic spectrum (typically 200 nm to 650 nm, more preferably 200 nm to 420 nm). UV-visible curing equipment may include a high power light emitting diode (LED) lamp, or an arc lamp such as a medium pressure mercury arc (MPMA) lamp, or a metal vapor discharge lamp as the source actinic radiation.

The magnetically induced tags described herein are very difficult to counterfeit and thus provide an effective defense against fraud and contribute to a significant increase in confidence regarding the identity in a verifiable access credential document.

The verifiable access credential documents described herein may further comprise a layer of primer between the identification document substrate and the magnetically induced mark. If present, the primer layer is preferably dark, and more preferably black (see FIG. 3).

The machine-readable markings provided on the verifiable access credential document described herein may be any type of marking or design, including machine-readable markings, bar codes, etc. Two-dimensional bar codes may include a DataMatrix or a DataMatrix symbol and Quick Response (QR) code (registered trademark) and so on. The barcode may be a GS1 (trademark) DataMatrix barcode in ECC200 version (GS1 is the international standards body for barcodes). This standard involves a barcode formed by two types of elements, namely an element of the first type and an element of the second type. The features may be in the form of dots or squares and may be marked or embodied on the identification document by any suitable means. The machine-readable markings described herein may be created by any suitable means, including printing processes (particularly inkjet printing), etching and ablation techniques (particularly laser etching or burning), embossing techniques, etc.

According to one embodiment and as shown in FIG. 3, the verifiable access credential document described herein comprises a magnetically induced mark comprising magnetically oriented reflective plate-like magnetic or magnetizable pigment particles, a pattern representing encoded data (machine readable marking), said pattern at least in part covers the magnetically induced mark and optionally a layer of primer underneath the magnetically induced mark. For example and as shown in FIG. 2A or 3, the reflective plate-like magnetic or magnetizable pigment particles of the magnetically induced mark are oriented so as to be parallel to each other and have an inclination angle of the planes of the pigment particles of at least 10° relative to the document. The verifiable access credential document further comprises a dark, preferably black, layer of primer underneath the magnetically induced mark and contains a pattern representing the encoded data, said pattern being produced by laser marking using, for example, a Gravograph Fiber100 workstation (10W, 1064 nm). The black cells of the design are processed with a laser, while the white cells are not processed. Laser processing changes the optical properties of the layer, specifically the amount of light sent back into the camera. Non-laser treated areas have high intensity due to strong back reflection from the plate-like magnetic or magnetizable pigment particles, while laser treated areas appear darker because they only scatter a smaller portion of the flash light towards the camera.

According to another embodiment, a verifiable access credential document described herein comprises a magnetically induced mark comprising magnetically oriented reflective plate-like magnetic or magnetizable pigment particles, a pattern representing encoded data, wherein said pattern at least partially overlaps magnetically - an induced mark, wherein the reflective plate-like magnetic or magnetizable pigment particles of the magnetically induced mark are oriented so as to be parallel to each other and have an inclination angle of the planes of the pigment particles of at least 10° relative to the document, and wherein a pattern representing encoded data , are produced by printing with black ink, which may contain one or more luminescent compounds. The pattern, which represents the encoded data, can be applied through a printing process, particularly inkjet printing, at a resolution of 300 to 600 dpi per inch.

The combination of the machine-readable marking and the magnetically induced mark described herein and shown in FIG. 1 and fig. 3, advantageously confirms the digital security of the document and prevents an attack that combines the magnetically induced mark from the original passport and the altered machine-readable mark printed on a separate document.

Decoding a machine-readable marking typically begins by obtaining a snapshot (digital) image of said marking on document 100. This image is then obtained as digital image data defining corresponding values for the pixels of the image. This digital image data is then subjected to image processing using a processing unit (e.g., CPU, computer, server, embedded system, ASIC, etc.). Such processing can be divided into various individual steps to finally decode the data that is encoded in the barcode.

The machine-readable markings described herein carry encoded data, such as biographical data, biometric data, credentials, etc. Preferably, the machine-readable markings described herein carry encoded data, such as biographical data and/or biometric data . As used in this document, the term “biographical information” is used to refer to information related to the personal life of the user or owner of the protected product. Typical examples of biographical data or biographical information include, without limitation, first name, last name(s), nationality, place or origin, place of birth, date of birth, gender, personal identification number and personal social number. As used in this document, the term “biometric data” is used to refer to a physical characteristic of the user or owner of a protected product. Biometric data may consist of an image or an alphanumeric description or encoding of a physical characteristic. Typical examples of biometric data include, but are not limited to, image and/or data corresponding to biometric data selected from the group consisting of faces, fingerprints, palm prints, iris patterns, retinal patterns, earlobe patterns, vein patterns, blood oxygen levels , bone density, gait, voices, smell and combinations thereof.

Identification documents may typically contain a special space called a machine readable zone MRZ. In a passport, as one possible example of a security item, such an MRZ could be, for example, a space provided at the bottom of an identification information page where the same or corresponding identification information is encoded as is printed on the identification information page in optical character recognition format. The MRZ may contain biographical information of the user or ID holder and typically consists of two lines of 44 characters. Information that can be printed and encoded in the MRZ includes identification information, name, passport number, check digits, nationality, date of birth, gender, passport expiration date and personal identification number. The MRZ may additionally contain - often depending on the country - additional information.

To better understand the general concept of the disclosure and to point out certain preferred modifications of the general concept, authentication of a tag containing platelet magnetic or magnetizable pigment particles using a portable device will now be disclosed in more detail.

The method of authentication according to the present invention of magnetically induced marks 120 deposited on a substrate 2 using a handheld device 3 is based on a specific geometric arrangement of the imaging device 4, for example, a smartphone camera and a light source 5, i.e., an LED flash. On most smartphone models, the camera aperture and LED flash are located next to each other, less than 15mm apart. Therefore, for a particular magnetic orientation of the plate-like magnetic or magnetizable pigment particles 6 in the mark 1 relative to the viewing direction, in combination with a suitable imaging distance, the geometric condition for the light emitted by the flash is satisfied, i.e., the radiation 7 must be reflected back to the camera, i.e. .reflection 8, while for other orientations the reflection is directed outside the camera. This is illustrated in FIG. 4 and 5. The smartphone 3 is moved parallel to the substrate 2 at a given distance L, for example L = 80 mm, while obtaining a set of images or video sequence that will be used for authentication. Alternatively, the magnetically induced mark 120 also moves relative to the smartphone 3 in a parallel plane.

To authorize a user to access the site, the user must position the smartphone camera at a given distance L from the magnetically induced mark 120 of the second zone. Some prompts on the smartphone display can help the user to hold the smartphone at a distance L.

The user illuminates the magnetically induced mark 120 with a light source (typically an LED) of a smartphone and obtains multiple digital images of the illuminated magnetically induced mark using a camera, the camera being held for each different digital image at a corresponding different viewing angle θ relative to said magnetically induced mark. by moving the imaging device over the magnetically induced mark in a direction parallel to the flat layer, as shown in FIG. 4 and 5.

For each acquired digital image, an application running on a smartphone allows the processor to calculate the corresponding average intensity I of light reflected by the plates and collected by the imaging device at the corresponding viewing angle θ. Due to the structure of the magnetized plates, there is a strong change in the collected light from the magnetically induced mark, which is largely characteristic of the magnetically induced mark 120.

The application running on the smartphone then stores the calculated average reflected light intensity and corresponding viewing angles to produce a reflected light intensity curve I(θ) showing strong characteristic anisotropy (see Fig. 6).

The stored reflected light intensity curve I(θ) is then compared to a stored reference reflected light intensity curve I _ref (θ) for said magnetically induced mark.

In fig. Figure 6 illustrates the position x ₁ ^' …x _n ^' of the magnetically induced mark in a set of images at the corresponding viewing angle θ for a known distance L from the smartphone to the sample, using a camera lens with a graphical representation of the intensity profile of the magnetically induced mark, where I ₁ …I _n represent the average intensity values at the corresponding viewing angle θ.

In fig. 7 illustrates the intensity and relative intensity profiles of a magnetically induced mark extracted from an image sequence. The first graph shows the uncorrected intensity profile of the magnetically induced mark zone, which still represents the effect. The change in background zone (BKG) intensity in the second graph shows the phone's chaotic auto-tuning. The third graph shows the corrected intensity profile of the magnetically induced mark, which shows the position-dependent reflectivity of the mark.

In particular, the authentication is carried out by calculating for each digital image the corresponding average intensity I of light reflected by the partially reflective plate-like magnetic or magnetizable pigment particles and collected by the image forming device at the corresponding viewing angle θ;

storing the calculated average reflected light intensity and corresponding viewing angles to obtain a reflected light intensity curve I(θ);

comparing the stored reflected light intensity curve I(θ) with the stored reference reflected light intensity curve I _ref (θ) for the specified mark, and

determining whether the magnetically induced mark is genuine based on the comparison result.

In one proposed embodiment of the present invention, the magnetically induced mark is configured to display one or more discrete zones, each of which has a particular orientation of lamellar magnetic or magnetizable pigment particles. For example, platelet magnetic or magnetizable pigment particles oriented at 15° in the W direction for the first zone and particles oriented at 15° in the E direction.

Examples of such magnetically induced marking 120 are shown in FIG. 9, which illustrates a mark comprising plate-like magnetic or magnetizable pigment particles 6 (petals) and pigment particles 6' (discs), and FIG. 10, which illustrates a mark containing particles 6 (outer petals) and particles 6' (inner petals)). In this way, the reflection can be obtained from the particles of the first zone by placing a mark on the right edge of the field of view of the smartphone, while the reflection of the other zone is obtained by placing the mark on the left edge of the field of view of the smartphone. This is further demonstrated in FIG. 11, which shows the positions of the smartphone and the corresponding images obtained at these positions.

The exact location of the mark on the smartphone screen preview and the distance from the smartphone to the mark precisely determines the angle at which reflection can be obtained from the plate-like magnetic or magnetizable pigment particles. By providing target 9 targeting on the smartphone screen preview, the user can easily position the smartphone sideways at a precise location, so that the precise angle can be obtained with additional viewing distance control.

The vertical position (viewing distance) can be determined by the size of the target, which must match the size of the mark at the correct distance, or by a second target, which must simultaneously be aimed at a second mark or bar code printed outside the magnetically oriented pattern, or by a written message on the screen , instructing the user to move closer or further.

This makes the authentication method very sensitive to the exact angle of inclination of the plate-like magnetic or magnetizable pigment particles and therefore allows good discrimination between potential imitations that do not reproduce the exact orientation.

Authentication is carried out by analyzing the reflection intensity in the first and second zones of the tag in two images taken at two precise positions of the smartphone, which confirms the orientation angles. In addition, a sequence of images can be obtained while moving the smartphone between two positions in a direction parallel to the planar layer of the tag. The intensity is then extracted from two different zones with plate-like magnetic or magnetizable pigment particles oriented in either direction and recorded as a function of position. Two intensity profiles are obtained which can be analyzed in a similar manner as shown in FIG. 14.

In view of this, in FIG. 14 is a graphical representation of the intensity profile, its first derivative and second derivative with respect to position. The value of the first derivative shows the rate of change of intensity, and the position of zero gives the position of the maximum intensity. The second derivative shows that the intensity profile has two inflection points (inversion).

In a similar embodiment, the video sequence can be obtained during controlled lateral movement of the smartphone in a plane parallel to the tag. This movement can be controlled using augmented reality, where a moving target is displayed on the smartphone display and the user is asked to move the phone while maintaining a mark within the target. Thus, the rate of change in the intensity of magnetically oriented radiant plate-like magnetic or magnetizable pigment particles as a function of viewing angle (as calculated from the position of the mark on the smartphone screen and the distance of the smartphone to the mark) can be extracted from the video sequence. This rate of change in intensity is a strong authentication parameter because it is very sensitive to the precise angle at which the platelet magnetic or magnetizable pigment particles are oriented. The rate of change of intensity can be obtained from the first derivative of the profile, as illustrated in FIG. 14. The second derivative can also be used as a strong authentication parameter, allowing the location of inflection points in a profile to be determined. Modern magnetic orientation can ensure the angular position of plate-like magnetic or magnetizable pigment particles is accurate to within +/- 2 degrees. Even if a counterfeiter is able to produce a mark with oriented plate-like magnetic or magnetizable pigment particles, it is unlikely that an accurate angle of orientation can be obtained and the counterfeit mark can then be identified as counterfeit by this method with high accuracy.

The video sequence can also be used to obtain the relative intensity as a function of the illumination angle of the tag, which corresponds to the position of the tag on the screen during controlled lateral movement of the phone, as well as to obtain the dispersion of pixel intensities within the tag. Both relative intensity and dispersion profiles depend on the orientation of the lamellar magnetic or magnetizable pigment particles in the magnetically induced mark.

In the method described herein, the application then determines whether the magnetically induced mark is genuine based on the result of the comparison (within a certain error tolerance). Preferably, a message indicating the result of the comparison is displayed. If the magnetically induced mark is deemed to be genuine, the user takes a snapshot of an image of the machine-readable mark 130 and the application extracts the identification signature from the resulting machine-readable mark image. The extracted signature is then sent in a message via the smartphone's communication unit to a server (an authority capable of providing authorization for access to the site) connected to the communication network.

The server then verifies that the extracted signature matches the corresponding signature of the human-readable credentials and, if a match, authorizes the user to access the specified site through the communications network to perform transactions on that site. Preferably, the server sends a message to the smartphone indicating whether the signatures match. Instead of allowing access to the site, the server can send back to the user an offer for verifiable credentials or a token, this token can then be used in many ways, including to gain access to the site or service (this does not require future access to the server) .

Claims (33)

1. A machine-readable medium (100) of verifiable user access credentials, containing: a first zone containing printed human-readable identification data related to the user's identity (110); a second zone with a magnetically induced mark (120) having a flat layer of material; And a machine-readable marking (130) in the form of a pattern representing encoded data, the encoded data corresponding to at least partially human-readable identification data of the first zone; characterized in that the material of the magnetically induced mark (120) contains magnetically oriented reflective plate-like magnetic or magnetizable pigment particles, and the machine-readable marking (130) contains a signature of said identification data and is at least partially applied directly to the magnetically induced mark (120) such that the machine-readable marking (130) overlaps at least one region of a layer of material with magnetically oriented reflective platelet magnetic or magnetizable pigment particles. 2. Machine-readable medium (100) of verifiable access credentials according to claim 1, characterized in that: a) the magnetically induced mark (120) is in the form of a mark containing magnetically oriented reflective platelet magnetic or magnetizable pigment particles, said pigment particles containing a magnetic metal selected from the group consisting of cobalt, iron, gadolinium and nickel; a magnetic alloy of iron, chromium, manganese, cobalt, nickel or a mixture of two or more of them; magnetic oxide of chromium, manganese, cobalt, iron, nickel or a mixture of two or more of them; or a mixture of two or more of them, and b) the machine-readable marking (130) is in the form of a design that is a design of a one-dimensional barcode, a stacked one-dimensional barcode, a two-dimensional or three-dimensional barcode carrying encoded data. 3. A machine-readable medium (100) of verifiable access credentials according to claim 2, characterized in that the encoded data is biographical information and/or biometric information and/or credentials. 4. A machine-readable medium (100) of verifiable credentials for access according to any of the previous paragraphs, characterized in that: at least a portion of the reflective plate-like magnetic or magnetizable pigment particles is formed by dielectric/reflector/magnetic material/reflector/dielectric multilayer structures and/or dielectric/reflector/dielectric multilayer structures/magnetic material/reflector/dielectric structures. 5. A machine-readable medium (100) of verifiable access credentials according to claim 4, characterized in that at least part of the reflective plate-like magnetic or magnetizable pigment particles is formed by multilayer structures MgF ₂ /Al/magnetic material/Al/MgF ₂ and/or multilayer structures MgF ₂ /Al/MgF ₂ /magnetic material/Al/MgF ₂ , with the magnetic layer containing iron. 6. A machine-readable medium (100) of verifiable access credentials according to claim 4 or 5, characterized in that the magnetic layer contains a magnetic alloy or mixture of iron and chromium. 7. A machine-readable medium (100) of verifiable access credentials according to claim 1, characterized in that at least a portion of the reflective platelet magnetic or magnetizable pigment particles is formed by the reflective platelet color-changing magnetic or magnetizable pigment particles. 8. A machine-readable medium (100) of verifiable access credentials according to claim 7, characterized in that at least a portion of the reflective plate-like magnetic or magnetizable pigment particles is formed by magnetic thin-film interference pigment particles. 9. A machine-readable medium (100) of verifiable access credentials according to claim 7 or 8, characterized in that the magnetic thin-film interference pigment particles contain a 5-layer Fabry-Perot structure absorber/dielectric/reflector/dielectric/absorber, where the reflector and/ or the absorber is a magnetic layer containing nickel, iron and/or cobalt, and/or a magnetic alloy containing nickel, iron and/or cobalt, and/or a magnetic oxide containing nickel (Ni), iron (Fe) and/or cobalt (Co), or 7-layer Fabry-Perot structure absorber/dielectric/reflector/magnetic material/reflector/dielectric/absorber, or 6-layer Fabry-Perot structure absorber/dielectric/reflector/magnetic material/dielectric/absorber, wherein the magnetic layer contains nickel, iron and/or cobalt; and/or a magnetic alloy containing nickel, iron and/or cobalt, and/or a magnetic oxide containing nickel, iron and/or cobalt. 10. A machine-readable medium (100) of verifiable credentials for access according to any of the previous paragraphs, characterized in that the reflective plate-like magnetic or magnetizable pigment particles of the magnetically induced mark (120) are parallel to each other and have an inclination angle of the planes of the pigment particles of at least 10 ° relative to the plane of the carrier substrate. 11. A machine-readable medium (100) of verifiable credentials for access according to any of the previous paragraphs, characterized in that the machine-readable marking (130) is a QR code. 12. A machine-readable medium (100) of verifiable credentials for access according to any of the previous claims, characterized in that a dark layer of primer is provided between the substrate of the medium and the magnetically induced mark (120). 13. A machine-readable medium (100) of verifiable access credentials according to claim 12, characterized in that the primer layer is black. 14. A method for verifying a machine-readable medium (100) of access credentials according to any one of claims. 1–13 and authorization of access to the user's site using a portable device equipped with a light source capable of supplying visible light, an image forming device, a processor with memory and a communication unit configured to send and receive data via a communication network, characterized in that that the method includes the steps: placing a device for forming an image of a portable device at a predetermined distance L above the second zone; illuminating the magnetically induced mark (120) with a light source and obtaining a plurality of digital images of the illuminated magnetically induced mark (120) by an imaging device, the imaging device being positioned for each different digital image at a corresponding different viewing angle θ relative to said magnetically induced marks (120) by moving the image forming device over the magnetically induced mark (120) in a direction parallel to the flat layer; for each acquired digital image, calculating by the processor a corresponding average intensity I of light reflected by the plates and collected by the imaging device at a corresponding viewing angle θ; storing the calculated average reflected light intensity and corresponding viewing angles to obtain a reflected light intensity curve I(θ); comparing the stored reflected light intensity curve I(θ) with the stored reference reflected light intensity curve Iref(θ) for said magnetically induced mark (120); determining whether the magnetically induced mark (120) is genuine based on the comparison result; in the event that the magnetically induced mark (120) is considered genuine, the user illuminates the machine-readable mark and takes a photo of an image of the illuminated machine-readable mark (130); extracting the signature of the identification data from the obtained image of the machine-readable marking (130); sending a message containing the extracted signature via a communication unit to a server configured to authorize access to the site and connected to the communication network; checking on the server that the extracted signature matches the corresponding signature of the human-readable identification data, and, if a match, authorizing the user's access to the site through the communication network to carry out transactions on this site. 15. A portable reader equipped with a processor with a memory, a light source, a camera, a display, a communications unit configured to send and receive messages via a communications network, and containing a computer program product that, when executed on the processor, gives a command to the reader configured with the possibility of implementing the steps of a method for verifying a machine-readable medium (100) of access credentials according to claim 14.