RU2831043C1 - Method and token for document authentication - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to a method of confirming a document, a method of verifying a document having a visual marking, and a marker for printing visual marking on a physical document. Method of authenticating a document comprises steps of: providing a registered marker with identification data of the marker, wherein the marker is configured to print visual markings, obtaining a document identifier based on at least the identification data of the marker and the time stamp, obtaining a document key, encoding a document identifier and a document key in the form of a visual marking, applying a visual marking to the document, obtaining a copy of the document with or without visual marking, copy is encrypted so that it can be decrypted using the document key, the encrypted copy is stored in conjunction with the document identifier.

EFFECT: high level of document counterfeit protection.

17 cl, 19 dwg

Description

The present invention relates to a method for verifying a document, a method for checking a document having a visual mark, and a marker for printing a visual mark on a physical document.

Counterfeiting and falsification of physical documents (i.e., primarily paper documents) is a widespread crime that poses a constant threat to society. It harms many types of businesses and organizations. It creates mistrust among citizens and toward government agencies. It harms the rule of law and has a negative impact on the healthy economic development of many countries.

Advances in digital photography and printing equipment, along with modern image processing software, have made it easier for criminals to forge documents not only occasionally, but sometimes even on a large scale.

Some of the most common types of physical features used for document authentication purposes include the use of handwritten signatures, features on seals and stamps, and more recently the use of holographic labels, special invisible and indelible inks, and even the use of synthetic DNA. The purpose of all these different types of features is to prove the authenticity of the document to which they have been applied.

Current authentication processes for the aforementioned physical authentication are cumbersome as they often involve forensic methods and methodologies and therefore the suspected counterfeit document must be subjected to laboratory testing. As a result, it takes a long time just to determine whether the document is genuine.

Much work has been done in recent years to develop digital document authentication methodologies. Powerful encryption algorithms, digital signatures, and combinations of public and private keys have enabled online document manipulation that is, in principle, less susceptible to counterfeiting than its physical counterpart.

Most of the methodologies that exist today are based on the use of two-dimensional (2D) matrix codes that are not related to the context to which they are applied and are based on first use only where the authenticity of the code itself is verified.

Document US 8 037 310 B2 discloses a method that combines digital and physical (or visual) authentication methodologies in an integrated, unified manner. Also, while providing features of digital authentication, a system according to such an invention forms a physical artifact that can be verified without assistance using human visual perception. The invention thus states that it should provide the ability to increase the level of trust in the authentication of documents, while maintaining the advantages of both traditional and digital authentication mechanisms. A limitation of such an invention is the requirement of at least one supporting document, as well as the lack of a token mechanism and a system for verifying the authority of the signatory performing the authentication method on the original document. A further limitation of such an invention is the inability to authenticate a completely electronic document or group of documents without the need to print these documents on a physical medium.

There is therefore a need for a reliable authentication (and verification) method and a corresponding verification method that is fast, simple, affordable and reliable.

Document US 2011/133887 A1 discloses a method for authenticating a printed document. The authentication is based on a comparison of the document with its electronic copy. The electronic copy is obtained using document management information embedded in barcode markers printed on the document itself. The document management information may contain a document identifier and may be encoded in a two-dimensional barcode. The document management information does not contain information regarding the identification data of the device used to create the barcode. There are no technical measures to support tracking of the barcode for its creator.

US 10 110 385 B1 discloses a method and system providing a scheme for signing physical documents. A user seeking to verify a signed document may use an identity verification token to scan a quick response (QR) code containing a document identifier obtained from the document. Using the document identifier, an electronic copy of the document may be obtained from the identity recorder and compared to the display.

Document WO 2016/113694 A1 discloses a scheme with a URL printed on a document, wherein the URL provides access to a copy of the original document for inspection.

Document US 2015/052615 A1 discloses a QR code added as a marking to a document containing an identifier for obtaining a copy of the document.

The object of the present invention is to create a verifiable link between a verified document and a specific trusted physical marker used for verification.

The invention proposes a method of the type indicated at the beginning, wherein said method comprises the steps of:

receive a registered marker with marker identification data, where the marker has the ability to print visual markings,

the presence of a document identifier based on at least the token identification data and the timestamp,

encode the document identifier into a visual mark,

apply visual marking to the document,

receive a copy of the document with or without visual marking,

save a copy in conjunction with the document identifier.

Alternatively, the method may include steps before saving the copy, such as:

print out visual markings using a marker, and

receive and check the printed visual marking.

The visual marking may be printed on the document if the document is a physical document, or the visual marking may be printed on any (physical) substrate if the document is an electronic document.

In one embodiment, the method may comprise encryption and/or scrambling of the copy before storing. The stored copy is not an exact copy, but an encrypted and/or scrambled version of the copy of the document. Scrambling in this case refers to a reversible (e.g., deterministic) operation performed on the data. For example, a random number generator with a given seed may be used for scrambling.

In this context, the present method may further comprise encrypting the copy using an encryption key associated with the identification data of the marker. The copy of the document stored in combination with the document identifier is then an encrypted copy. To access the content of the document, the encrypted copy must be encrypted with a decryption key, which may be the same key as the encryption key or a cryptographically related decryption key (e.g. a private key corresponding to a public key that is used as the encryption key).

For example, an additional embodiment of the method for confirming the authenticity of a document may comprise:

obtaining a registered marker with marker identification data, in which the marker has the ability to print visual markings,

obtaining a document identifier based on at least the token identification data and the timestamp,

obtaining a document key,

encoding the document identifier and document key in the visual marking,

applying visual markings to a document,

obtaining a copy of a document with or without visual marking,

encrypting the copy so that it can be decrypted using the document key,

saving an encrypted copy in conjunction with the document identifier.

Additionally, as an option, the token may be combined with an Internet-enabled host device that enables one or more of the following:

protection of the token login by means of biometric identification, password identification and/or PIN identification of the authorized user,

sending the document identifier to the document storage database,

obtaining visual markings from the mentioned database,

sending visual markings to the marker,

obtaining an image or sequence of images of a document,

sending encrypted and/or scrambled images to a document storage database,

Receiving a confirmation message from the document storage database.

The host device can typically be used as a gateway for the token to access the document storage database. The document storage database is not limited to a single database or location and can typically be provided by a document storage service.

In another embodiment, the document may be a physical document and obtaining a copy of the document may comprise obtaining an image of the physical document before or after applying the visual marking to the document. The image obtained from the physical document may be a digital image; in this case, the copy corresponds to the image data of said image. If the image is registered only after applying the visual marking to the document, the copy will contain a representation of the visual marking, potentially containing any information encoded in the visual marking; otherwise, no such representation and no information encoded therein will be present in the copy.

Applying a visual mark to a document may include printing the visual mark on a physical document using a marker. The marker may be a printing device, such as a hand-held printer, that is manually moved across the target medium.

In the case where the document is an electronic document, applying a visual mark to the document alternatively involves modifying the electronic document to include the visual mark. In other words, the electronic representation of the document is modified so that, for example, when the electronic document is viewed on a screen, the visual mark appears as part of the electronic document or as an attachment or annotation to the electronic document.

According to a further embodiment, storing a copy in association with a document identifier may comprise transmitting a copy together with a document identifier to a document storage service, where the document storage service stores the transmitted copy and the association with the document identifier. The document storage service may be a centrally managed service. It may be provided by a trusted third party, such as a provider of a physical token. The document storage service may also be a distributed service. The actual storage of the data of the document copies transmitted to the document storage service may be provided by a separate storage system, such as from another third party. In this case, the content of the document, on the one hand, and the association or reference between this content (in the form of the transmitted copy) and the document identifier may be stored in different systems and potentially in different locations. The document storage service may require authentication before accepting the transmitted copy of the document.

The document storage service may comprise a database of blocks, and storing the transmitted copy may comprise creating a block containing at least a cryptographic reference to the previous block, a timestamp of the document identifier, and a cryptographic hash of the transmitted copy. Typically, the database may be a list of records, where each position in the list is called a “block.” Successive blocks are cryptographically linked. For example, each block may contain a cryptographic hash of the previous block. Because the blocks are linked to each other in a chain, such a database is also called a “block chain.” Typically, the transmitted copy itself will not be part of a block, but it may be linked to a specific block via a cryptographic hash. The transmitted copy of a document may be stored in the same database or in different databases or systems. Different transmitted copies of documents may be stored in different locations. At the same time, copies from different storage locations may be linked (or be in a chain) from different blocks in the same block database.

At the same time and in accordance with the method of authenticating described above, the invention also proposes a method of checking a document having a visual marking, said method comprising the steps of:

receive visual marking from the document,

analyze visual markings to obtain a document identifier,

get a copy of the document using the document identifier,

provide a copy of the document for verification.

The document verification method applies in particular to documents verified in the manner described above. The visual marking obtained from the document and analyzed to obtain the document identifier is usually the same visual marking that was described in connection with the above authenticity verification method.

Alternatively, as part of the method for verifying a document, analyzing the visual marking may comprise obtaining a document key, wherein the obtained copy is encrypted, and the method may comprise decrypting the encrypted copy using the document key to obtain an unencrypted copy, wherein the unencrypted copy is provided for document verification. The document key may be stored separately from the copy of the document. For example, the document key may be encoded in the visual marking and thus stored (possibly exclusively) on the original physical document itself.

According to one embodiment of a method for checking a document having a visual marking, said method may comprise the steps of:

receive visual marking from the document,

analyze the visual marking to obtain the document identifier and document key from the visual marking,

obtain an encrypted copy of the document using the document identifier,

decrypt the encrypted copy using the document key to obtain an unencrypted copy,

provide an unencrypted copy of the document for verification.

According to another embodiment of the above-described methods, the document may be a physical document and obtaining a visual mark from the document may comprise obtaining an image or a sequence of images of the physical document and determining the location of the visual mark within the images. The image or sequence of images may be obtained using a camera, such as a smartphone camera. Determining the location of the visual mark within the images may comprise pre-processing steps and/or pattern recognition, which are applied to the image data of said image.

Additionally, as an option, obtaining a copy of a document may comprise sending a request to a document storage service with a document identifier and receiving from the document storage service a copy of the document associated with the document identifier. Access to the document storage service may be limited to authenticated users; obtaining a copy of a document may thus follow an authentication process between the host device and the document storage service.

In another embodiment, providing a copy for verification of a document may comprise displaying the copy on a screen for visual comparison. Alternatively or additionally, providing a copy for verification of a document allows, for example, electronically processing of the received copy, i.e., determining a digital signature or other digital properties of the copy.

More specifically, providing a copy for verification of a document may optionally include performing a comparison between the copy and a new copy of the document with a visual mark and communicating the result of the comparison, where the new copy is obtained for verification purposes by comparison. Such automated comparison facilitates the identification of attempts at forgery and fraud.

At the same time and in accordance with the methods described above, the present invention also provides a marker for printing a visual marking, wherein the marker comprises a storage device containing identification data of the marker, and a printing unit, wherein the marker is configured to receive a visual marking encoding a document identifier associated with the identification data of the marker, and to print out the received visual marking. Alternatively, the marker can be configured to receive a visual marking encoding a document identifier associated with the identification data of the marker and a document key, and to print out the received visual marking. The storage device storing the identification data of the marker can be configured to ensure that the identification data cannot be erased, deleted or managed in any way. For example, the identification data can be determined by a numeric unique identifier of the device, for example, having more than 40 bits or more than 80 bits or 96 bits. The token identity is not necessarily limited to a single numerical value; there may be multiple equally valid representations, for example by reading and concatenating different parts (e.g. single bits, half-words or words) of the device identifier according to a given deterministic algorithm. This algorithm may produce a well-defined sequence of valid token identities, such that the next token identity can only be predicted by knowing two or more previous token identities generated from the device identifier. Therefore, in order to forge a valid token identity, it is necessary to know these previous token identities. If the token identities used are registered, for example by a document storage service, any irregularity in the expected sequence of token identities is immediately noticed and documents verified immediately before and after this point can be marked as potential forgeries.

The marker may be configured to check whether the marker identification data associated with the document identifier included in the received visual marking corresponds to the marker identification data for the marker itself, i.e., the marker identification data stored in its memory. Only if this check is successful, the printing unit is controlled to print the received visual marking.

The printing unit may be configured to remove the received visual marking after printing or even during printing, for example, in accordance with the printing process. The printing unit may be configured to control a limited period of validity of the visual marking, for example, a break associated with the visual marking. Such a break may be counted, for example, relative to a time stamp embedded in the visual marking, in order to avoid significant delays between the duration of the visual marking and the printing of the visual marking. Once the break time has expired, the marker irrevocably removes any information of the visual marking.

Alternatively, the token may be configured to authenticate the host device connected to the token before receiving the visual marking from said host device for printing. Following the authentication, a connection may be established between the token and the host device, for example represented by a procedure. The receipt of the visual marking for printing is accepted by the token only as long as the connection remains uninterrupted, until the visual marking has been successfully received by the token. Typically, the identification data of the token are transmitted during this connection from the token by the host device acting as a gateway to a remote generator of the visual marking. Such a generator of the visual marking may be configured to match the received identification data of the token with a list of authorized identification data of the token and generates the visual marking and, alternatively, also a document identifier for embedding in said visual marking, if a match is found. Alternatively, the document identifier may be generated, for example, by a marker and transmitted with the marker identification data to the visual marking generator.

The present disclosure also alternatively provides a system comprising a token as described above, a host device enabling work on the Internet, and a document storage database, where the token is connected to the host device enabling work on the Internet, where the host device enabling work on the Internet is configured to provide one or more of the following: securing the login of the token by means of biometric identification, password identification and/or pin identification of an authorized user, sending an identifier of a document to the document storage database, receiving a visual marking from the document storage database, sending a visual marking to the token, receiving an image or a sequence of images of the document, sending encrypted and/or scrambled images to the document storage database, receiving a confirmation message from the document storage database.

In a further embodiment, the document storage database of the system may be provided with a document storage service and the document storage service is configured to receive and store an encrypted copy of a document in conjunction with a document identifier.

Turning now to the drawings, the numbers are intended to illustrate the present disclosure and not to limit it.

Fig. 1 - block diagram of the sequence of operations of the process of initializing the marker and using it in the method of confirming the authenticity of a document with visual marking;

Fig. 2-7 - steps performed during the method shown in Fig. 1, from the user's point of view;

Fig. 8 - block diagram of the sequence of operations of the process of checking a document having a visual marking;

Fig. 9-16 - steps performed during the method shown in Fig. 8, from the user's point of view;

Fig. 17 is a flow chart illustrating a method similar to the method shown in Fig. 1 for authenticating a physical document;

Fig. 18 is a flow chart of a method similar to that shown in Fig. 17, adapted for confirming a digital document; and

Fig. 19 is a flow chart of the operations of a method similar to the method shown in Fig. 8 for checking a document having a visual marking.

Fig. 1 shows a sequence of steps starting from the receipt of a token corresponding to the present disclosure and up to the completion of the document authentication. This sequence is an exemplary ideal sequence of steps, which for the purposes of illustration ignores any alternative paths based on situation-dependent conditions, user refusals or technical failures or errors. The initial steps, until the host device has a need, should be performed only once before the first use. These steps belong to the initialization procedure 1 (compare also with Fig. 17).

In the first step 2, the issuer, here called “Trustworthy Company Ltd”, purchases a physical token 3 (also called an “Authenticator”) from a trusted vendor. The physical token 3 contains a storage device containing the token’s identity in the form of a unique device identifier. The trusted vendor associates the physical token’s unique device identifier 4 with the issuer’s account and identity in a secure database managed by the trusted vendor. Subsequently, a software application (called the “Auth App”) is sent 5 to the issuer. The issuer distributes 6 these applications to authorized users within the company, who install the software application on their respective personal devices 7 (e.g., smartphones) and log in to the software application by entering their individual user credentials. Logging in to the system for access to the software application for authentication purposes may be performed by entering a pin code and an authentication dialog 8 8 displayed on the screen 9 of the personal device 7 (see Fig. 2). As shown in more detail in Fig. 7, after successful login, a connection 10 (for example, an encrypted wireless connection, such as using Bluetooth or Wi-Fi) is established between the physical token 3 and the personal device 7. The personal device will thus act as a host device for the token 3 as long as the connection 10 remains active. Through the connection 10, the host device 7 receives 11 identification data of the token. Using the received identification data of the token, the host device 7 sends a registration request 12 containing the received identification data of the token, as well as the identification data of the personal device 7 to the document storage service 13. The document storage service 13 compares the received token identification data with the list of allowed and available token identification data. It also checks 14 whether the user identified by the user credentials in the application has been associated with a registered issuer. If the comparison and verification are successful, the document storage service 13 transmits the private authorization key 15 to the host device 7 for future authentication by the document storage service 13. This step completes the initialization procedure 1.

In order to perform the authentication of the document, the user enters 16 into the application the command “create authentication stamp” (see Fig. 3). For example, this can be a graphical button capable of interacting with an order to issue a command. After this command, the application, at step 17, establishes (or re-establishes) a connection 10 between the host device 7 and the marker 3 and creates a document identifier, which is sent 36 (see Fig. 17) to the document storage service 13, optionally together with a document key, also generated by the application (or the document identifier is obtained from the document key). The document identifier can be in the form of a random reference to the location of the document storage in the document storage service 13. Alternatively, the application can download the marker identification data, the location coordinates (e.g. based on GPS), the current date and time, and a number from the host device 7, e.g. information about the storage device or system, and send this information or a part of this information to the document storage service 13 with the document identifier. In this context, the numbering means that for each marker, each stamp (or “stamp”) is counted (i.e., the total number per marker). This is the accumulated stamp, equal to the number corresponding to the number of times the marker has applied visual markings. In the next step 18, the document storage service 13 generates a visual marking, for example, in the form of a QR code. Due to the random nature and size of the document identifier, the visual marking is virtually unique (although, theoretically, the same visual marking can be generated multiple times by coincidence). In addition to the QR code, the visual marking can be extended using existing graphics to create a printed visual marking that is recognizable as is. The visual marking can contain additional information received from the host device. It can also contain a public key to access an encrypted copy of the document. Once it is ready, the visual marking is sent to the host device 7 and transmitted from there to the token 3 for printing. The visual marking can additionally be generated directly on the host device 7 such that the public key never leaves the host device 7 except for printing by the trusted token 3. In this case, the document storage service 13 can be informed of the document identifier, but cannot accept the full information contained in the visual marking.

Once the visual marking is received by the marker 3 for printing, the user applies (i.e. prints) 21 the visual marking 24 to the physical document 25 using the physical marker 3 (see Fig. 4). During printing and when the printing is finished, the marker 3 reports 22 the printing status to the host device 7 and the application. When the application receives a notification that the printing is finished, it automatically starts 23 a viewing 30 of the scanning of the marking (see Fig. 6). In the first step 31 of scanning, the user is required to scan the visual marking, i.e., to point the camera so that the visual marking is in the field of view of the camera of the host device 7. Based on this first viewing of the scanning, the application makes a check 28 of the visual marking 24 by detecting and extracting the visual marking 24 from the first scanned image and comparing it with the generated version of the visual marking. If this check 28 is successful, the application starts a scan view 26 of the document (see Fig. 5). In a second scanning step 27, the user is asked to scan the entire document. The process of scanning the visual marking and then the entire document can optionally be implemented using a video stream instead of individual photographs/scans. Using a video stream can provide additional reliability and security for the process. Based on the second scan view(s), the application scrambles and encrypts 32 the second scan view(s) showing the entire document and transmits 33 it as uploaded to the channel previously created in the document storage service 13. With the document data as transaction data, a block is created 106 and linked to the previous block by a cryptographic hash. When the block creation and linking are successful, the document storage service 13 and, upon receiving the authentication confirmation 35, the application confirm the confirmation by displaying a view 34 with a confirmation (see Fig. 7).

Fig. 17 shows additional approaches and changes to the method for confirming the authenticity of a document in accordance with the present disclosure. Namely, in the example shown in Fig. 17, the host device 7, after authenticating the user by requesting a login 105 to the system, establishes a connection with the token 3. The document identifier generated in step 18 in accordance with Fig. 1, in this case is transmitted 36 to the document storage service 13. The document storage service 13 performs a step 19 of generating a visual marking based on the received document identifier (in contrast to the embodiment shown in Fig. 1, where the visual marking is generated on the host device 7). In this example, a public key cryptographically associated with the private authorization key 15 is included in the visual marking. The generated visual marking is then transmitted 38, optionally in encrypted form, back to the host device 7, which acts as a gateway and forwards 39 the visual marking to the marker 3, optionally after decryption and conversion to an image format for printing. However, the host device 7 does not store the visual marking after it has been transmitted to the marker 3. The marker 3 stores the received visual marking (or, more precisely, the image information representing the visual marking to be printed) in random access memory (RAM). The printing step 21 for applying the visual marking to the document is performed by a user similar to that shown in Fig. 1, and after printing the marker 3 does not store any information related to the content of the visual marking. The marker 3 notifies 40 the host device 7 of the end of the printing operation. In the example shown in Fig. 17, the application then directly starts 29 a scan view of the marking (that is, the scan function of the host device 7). The user scans 31 a visual marking and the host device 7 directly performs the (final) check 32. In this case, no preliminary check 28 is required. If the (final) check 32 is successfully performed, the application starts 23 a scan view of the document 26 and uses the scan 27 of the remaining parts of the document. The scan views may be different views or they may be different periods of time in the same video recording. When the entire document has been scanned, the method proceeds to step 33, as described above. The document storage service 13 13, based on the received information about the document, creates 106 a block to add to the block chain maintained or accessed by the document storage service 13. As soon as a new block is added to the block chain, the document storage service 13 sends a confirmation 35 to the host device 7.

Fig. 8 shows an exemplary version of a simple method for checking a document 41 having a visual marking 42. The purpose of the check is to determine the source of the visual marking 42 and, in addition, to check the integrity of the content of the document 41 bearing the visual marking 42. The method, as described here in detail, can be performed by a personal device 43 having a display 44, a camera and a data connection, such as a smartphone.

The user receives 45 the document 41 and wants to verify the authenticity of the document 41. To perform the verification, the verification application (for example, the mentioned “Ver App”) can be installed on the personal device 43. The user checks 46 whether the verification application is available on his personal device 43. If not 47, the user follows the instructions provided in the visual marking 42 and scans 48 a separate QR code (that is, separate from the secure QR code based on the document identifier) with a link to initiate the installation procedure for configuring the verification application on the personal device 43.

If the verification application was present from the beginning or was successfully installed, the user enters 49 a verification command in the verification application, for example by pressing a button labeled “Verify authenticity of document”. Initiated by this command, the application starts 50 a preview 51 of the scan of the marking. The user is prompted 52 and commanded to scan the secure QR code of the visual marking 42. As soon as the secure QR code is recognized and the document identifier is determined, the verification application starts downloading 53 a copy of the document from the document storage service 13. The downloaded copy may be encrypted. The verification application starts decrypting 54 the encrypted copy using the private key of the registered personal device 43 and using the document key embedded in the visual marking 42. In parallel, the application enters 55 a preview 56 of the scan of the document and the user is prompted 57 to scan the entire document to be verified. Once the entire scanned copy is available and the downloaded copy is decrypted, the verification application compares 58 two versions of the same document to determine if the two versions match. The comparison may take into account additional information about the item, such as location information, or add a timestamp to the information.

If these two versions match sufficiently well 59, the check has been successful and the check application displays 60 a confirmation 61 according to the check method. If the automatic comparison does not find a (sufficient) match, the check application offers 62 the user in a refusal message 63 the possibility of a “manual check of document” command using a correspondingly designated button. If the user decides to perform a manual check, it is carried out. The user is shown a scanned copy 70 (see Fig. 14), onto which he can respectively place the paper copy 71 for comparison 69. The official version is downloaded from the document storage service and, optionally, signed and/or encrypted. If the documents are completely identical 68, the verification process is completed 64. Otherwise, if necessary, in order to simplify the manual verification, the verification application may offer 65 to display additional detailed information related to the stamped products for detailed viewing 72 and/or viewing 73 of the location (to display the places of creation of the visual marking and the marker 3) (see Fig. 15). The verification application receives 66 all detailed information related to a specific marker. It is very significant that the presented disclosure can be made with the possibility for the user to make his own decision in the document 67 about the authenticity of the document. This is the last step of the verification method.

As can be seen in Fig. 16, the same steps of the method are, in principle, used for scanning electronic documents. In addition, visual markings of this type of document can be checked in the same way as described above. In particular, the personal device 43 is shown in a viewing 51 of the scanning of the marking, where the camera of the personal device 43 is directed at the screen 74 of the device 75 for viewing the document, for example, a tablet, a laptop or a personal computer. The visual marking 42 is displayed on said screen 74 together with the document 41, which in this case is an electronic document.

Accordingly, Fig. 18 shows a further variation of the method for confirming the authenticity of a document according to the present disclosure. Namely, in the example shown in Fig. 18, the document to be confirmed is an electronic document stored and processed on the document editing device 76. During the initialization procedure 1, the document authentication application is installed 77 on the document editing device 76. The connections and messages between the token 3, the host device 7 and the document storage service 13 are similar to those described in connection with Fig. 17. Only at the end of the procedure, a copy of the private authorization key 15 is additionally transmitted to the document editing device 76, optionally via the host device 7.

The steps for performing the actual authentication, that is, immediately after the initialization procedure 1 is completed, begin with the login 78 of an authorized user with his credentials in the document editing device 76. Initiated by a command from the user, the document editing device 76 sends a request to the document storage service 13 for authentication and for performing the authentication of the electronic document. Without any particular order, but approximately simultaneously, the user also performs a login 105 in the system in the host device similar to what was described in connection with Fig. 17. With each login 78, 105, access to the private authorization key 15 is granted and with this access the host device 7 and, optionally, also the document editing device 76, establishes a connection 10, 79 with the token 3. The subsequent steps, from the transmission 36 of the document identifier to the scanning 31 of the printed visual marking and the execution of the check 32 coincide with what was described in connection with Fig. 17, except that the visual marking is not printed on the document to be verified, but on any arbitrary available substrate (for example, on any paper) and scanned from there. This printing process is used as a physical proof of authenticity that the marker 3 was in fact under the control of the user performing the verification. In parallel, the visual marking is transmitted 80 from the document storage service 13 to the document editing device 76, additionally protected by the authorization key 15 (for example, encrypted with a public key). This transmission can be performed via a universal data connection, for example via a cloud, or, alternatively, can be transmitted by proxy via the host device 7 and/or the marker 3. The document editing device 76 places the visual marking on the electronic document and then scrambles and encrypts 81 the resulting marked electronic document. When the verification 32 is successfully completed, the host device 7 transmits a message with a confirmation 82 to the document editing device 76. Alternatively, the scanning does not need to be performed by the host device 7, but it can be performed by a universal document scanner connected to the document editing device 76. In this case, the verification 32 can be performed locally by the document editing device 786. After receiving said confirmation of authenticity (or local verification), the document editing device 76 sends 83 a labeled version of the electronic document to the document storage service 13 for creating 106 a block in the blockchain database. Once the block is added to the blockchain, the document storage service 13 confirms 84 the completion of the confirmation of authenticity of the electronic document back to the document editing device 76. Based on this confirmation of authenticity, the document editing device 76 can print 85 a labeled version of the electronic document and/or start digital distribution (e.g. by e-mail).

Fig. 19 shows in more detail two variations of the method of checking a document 41 (physical or electronic) having a visual mark 42. During the initialization procedure 86, which is naturally a one-time process on the personal device 43, the user installs 48 (see Fig. 8) an inspection application on the personal device 43. When the user enters 49 a verification command, the application starts 50 a marking scan preview, which can be a video scanning function (i.e., a real-time preview with automatic recognition and document acquisition). The personal device 43 scans 52 the visual mark 42 on the document 41. The visual mark 42 can be a QR code having an encoded data content. The personal device 43 sends 87 the visual mark (or its data content) to the document storage service 13. The document storage service 13 determines a match between the visual marking and, for example, the document identifier contained in the received visual marking, and a stored copy of the identified document or a stored representation (for example, a hash) of this copy. Using this information, the document storage service 13 searches for 88 a block in its database of blocks containing a cryptographic hash of the same copy. If a matching block is found, the document storage service 13 sends 89 a confirmation 89 to the personal device 43 together with the corresponding copy (or with a link to said copy). In the meantime, the personal device 43 locally checks 90 the format of the visual marking 42 and continues scanning 91 all other parts of the document 41. After receiving a copy from the document storage service 13, the personal device 43 decrypts and reconstructs 92 (that is, descrambles) the received copy. In the first variation 93 of the method shown in Fig. 19, the verification is performed offline, for example, due to the lack of network coverage and online access. In this case, the above-mentioned steps are limited to a local verification 90 of the visual marking 42. Thereafter, the content of the data embedded in the visual marking 42 is displayed 94 on the personal device 43 for reference and manual verification. In the example shown, the displayed data contains information that requires verification of authenticity (e.g., regarding the issuer/authority, location, date and time). The user can check the plausibility of the displayed information.

In the second change 95, the verification method is performed with access to the document storage service 13, for example in the online access mode. In this case, the personal device 43, based on the received copy of the document, performs an automated comparison 96 of the first level image between the scanned document (at step 91) and the received copy. The results of this comparison are displayed 97 to the user for reference. In addition, the result of determining the match is transmitted 98 to the document storage service 13. The newly scanned copy is also transmitted 99 to the document storage service 13. The document storage service 13 performs an automated comparison 100 of the second level image between the document copy registered during the authentication and the new copy received from the personal device 43. It then sends 101 the result of this second level comparison to the personal device 43 to obtain user information. During these remote steps, the personal device 43 locally displays 102 the received copy of the document, previously received from the document storage service 13, to allow manual comparison 103 with the document requiring verification. Finally, after the personal device 43 receives the result of the second-level image comparison, it also displays 104 this result for review by the user. If both automated image comparisons result in a degree of similarity exceeding a certain threshold, the personal device 43 indicates confirmation 61 (see Fig. 12).

Claims (48)

1. A method for confirming the authenticity of a document (25), comprising the steps of: provide a registered marker (3) with marker identification data, wherein the marker (3) is configured to print visual markings, obtain (18) a document identifier based on at least the identification data of the marker and the timestamp, receive the document key, encode (19) the document identifier and the document key in the form of a visual marking (24), apply visual marking (24) to the document (25), receive (27) a copy of the document (25) with or without visual marking (24), encrypt the copy so that it can be decrypted using the document key, save an encrypted copy in conjunction with the document identifier. 2. The method according to item 1, in which before the step of saving the encrypted copy print (21) a visual marking (24) using a marker (3), and extract (31) and check the printed visual marking (24). 3. The method according to claim 1 or 2, wherein the marker (3) is connected to an Internet-connected host device (7) which is configured to perform one or more of the following: protection of the entrance (105) to the marker (3) by means of biometric identification, password identification and/or pin identification of the authorized user, sending (36) document identifier to the document storage database, extracting (38) visual markings from said database, package (39) visual marking (24) marker (3), obtaining (31, 27) an image or sequence of images of a document (25), sending (33) encrypted and/or scrambled images to a document storage database, receiving (35) a confirmation message from the document storage database. 4. The method according to any one of paragraphs 1-3, in which the document (25) is a physical document, and at the stage of obtaining a copy of the document, an image of the physical document is obtained (27) before or after applying a visual marking (24) to the document (25). 5. The method according to claim 4, wherein at the stage of applying the visual marking (24) to the document (25), the visual marking (24) is printed (21) on the physical document using a marker. 6. The method according to any one of paragraphs 1-3, in which the document (25) is an electronic document, and at the stage of applying a visual marking to the document, the electronic document is modified (80) to include a visual marking therein. 7. The method according to any of paragraphs 1-6, in which, at the stage of storing the encrypted copy in conjunction with the document identifier, the encrypted copy is transmitted (33) together with the document identifier to the document storage service (13), wherein the document storage service (13) (13) stores the transmitted copy and the connection with the document identifier. 8. The method according to claim 7, wherein the document storage service (13) contains a database of blocks, and at the stage of storing the transmitted copy, a block is created containing at least a cryptographic reference to the previous block, a timestamp of the document identifier and a cryptographic hash of the transmitted copy. 9. A method for checking a document (41) having a visual marking (42), wherein the method comprises the steps of: extract visual markings (42) from the document (41), analyze the visual marking (42) to obtain a document identifier and a document key from the visual marking (42), extract (89) an encrypted copy of the document using the document identifier, decrypt the encrypted copy using the document key to obtain an unencrypted copy, provide an unencrypted copy of the document for verification. 10. The method according to claim 9, wherein the document is a physical document, and in the step of extracting a visual marking from the document, an image or sequence of images of the physical document is obtained (52) and the location of the visual marking (42) within the images is determined. 11. The method according to item 9 or 10, wherein at the stage of retrieving an encrypted copy of a document, a request with a document identifier is sent (87) to the document storage service (13) and an encrypted copy of the document associated with the document identifier is received (89) from the document storage service (13). 12. The method according to any of paragraphs 9-11, wherein at the stage of providing an unencrypted copy for verification of the document, the unencrypted copy is displayed (102) on the screen for visual comparison. 13. The method according to any one of paragraphs 9-12, in which, at the stage of providing an unencrypted copy for verification of the document, a comparison is performed (96) between the unencrypted copy and a new copy of the document with a visual marking and the result of the comparison is reported (97), wherein the new copy is obtained for the purpose of verification by comparison. 14. A marker (3) for printing a visual marking, comprising a storage device storing identification data of the marker, and a printing unit, wherein the marker (3) is configured to receive a visual marking (24) encoding a document identifier associated with the identification data of the marker and a document key, and to print the received visual marking (24). 15. The marker (3) according to claim 14, characterized in that it is designed with the ability to authenticate the host device (7) connected to the marker (3) before receiving from said host device (7) a visual marking (24) for printing. 16. A system for confirming the authenticity of a document, comprising a marker (3) according to item 14 or 15, a host device (7) connected to the Internet and a database for storing documents, wherein the marker (3) is connected to the host device (7) connected to the Internet, the host device (7) connected to the Internet is configured to provide one or more of the following: protection of the entrance (105) to the marker (3) by means of biometric identification, password identification and/or pin identification of the authorized user, sending (36) document identifier to the document storage database, extracting (38) visual markings from said database, package (39) visual marking (24) marker (3), obtaining (31, 27) an image or sequence of images of a document (25), sending (33) encrypted and/or scrambled images to a document storage database, receiving (35) a confirmation message from the document storage database. 17. The system according to item 16, in which the database for storing documents is provided by a document storage service (13), and the document storage service (13) is configured to receive and store an encrypted copy of a document in conjunction with a document identifier.

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