Procedure for issuing a digital copy of a document

Abstract

The invention relates to a method for issuing a digital copy (174) of an issued digital document using a digital provisioning token (174). The provisioning token (174) entitles the user to receive the digital copy (174) of the issued digital document to be issued on an end device (151) and to cryptographically link it to the end device (151) during the issuance process. The method comprises, via a first server of the issuing service, receiving an issuance request for the copy (174) of the issued document from an end device (151) of a requesting party, receiving the provisioning token (174) from the end device (151), validating the provisioning token (174), issuing the copy (174) of the document, and sending the issued copy (174) of the document to the end device (151).

Description

[0001] The invention relates to a method for issuing a digital copy of a document, as well as a server and a system for implementing the method. Furthermore, the invention relates to a corresponding digital copy of a document.

[0002] Mobile devices, such as smartphones, are ubiquitous. They are used in many areas of life and situations to perform a wide variety of digital tasks or with the aid of digital tools.

[0003] However, it represents a technical challenge to provide digital documents, and in particular copies of documents, for appropriate end devices in a cryptographically secure manner.

[0004] The invention is based on the object of creating a method for cryptographically secure provision of a digital copy of a digital document.

[0005] The object underlying the invention is achieved by the features of the independent patent claims. Embodiments of the invention are specified in the dependent patent claims.

[0006] Embodiments include a method for issuing a digital copy of an issued digital document using a digital provisioning token.

[0007] The provisioning token proves authorization to receive the digital copy of the issued digital document to be issued using a terminal device and to cryptographically link it to the terminal device during the issuance process. The provisioning token comprises a first data set with a first hash value and an indicator. The first hash value is generated using a first combination of a first data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued, and a first salt value associated with the first data element. The indicator indicates that it is a provisioning token for a copy of the issued document. The first data set is signed with a first signature key of an issuer service that generates the provisioning token.

[0008] A first database entry with a first assignment of the first salt value to the first data element is stored in a first database.

[0009] A second database entry containing data elements of the issued document is stored in a second database.

[0010] The procedure includes, through a first server of the issuer service: o Receiving an issuance request for issuing the copy of the issued document to be issued from a terminal device of a requester, o Receiving the provisioning token from the terminal device, o Validating the provisioning token, wherein validating the provisioning token comprises: validating the signature of the provisioning token using a first signature verification key of the issuer service, reading the first database entry from the first database using the received first data element, checking the hash values ​​entered in the provisioning token using the read first database entry for a successful check, deleting at least the salt values ​​stored in the first database entry in the first database, o Issuing the copy of the document, wherein issuing the copy of the document comprises: reading the second database entry from the second database,Creating a second data record comprising one or more of the data elements of the second database entry associated with the document to be issued in plain text, wherein the second data record further comprises a plain text indicator indicating that it is a data record of a copy of the issued document, sending a key query to the terminal device, receiving a public cryptographic key associated with the terminal device, adding the received public cryptographic key of the terminal device to the second data record for cryptographically binding the second data record to the terminal device, signing the second data record with a second cryptographic signature key associated with the issuing service, providing the issued copy of the document in the form of the signed second data record,Storing an association of the received public cryptographic key of the terminal device with the issued copy of the document in the first database, o Sending the issued copy of the document to the terminal device. ,

[0011] Embodiments can have the advantage that a digital copy of a document can be issued that is cryptographically bound or coupled to a terminal device, in particular a mobile terminal device such as a smartphone. Authorization to use the corresponding copy of the document can be verified with a private cryptographic key of the terminal device that is associated with the public cryptographic key and is stored, for example, in a protected memory area of ​​the terminal device's memory, for example a security element. For this purpose, for example, a signature is created with the corresponding private cryptographic key, which can be validated with the public cryptographic key of the terminal device contained in the document. In particular, the copy of a document can be coupled to a different terminal device than the document.

[0012] The provisioning token is required to prove authorization to receive the digital copy of the document to be issued on the device and to cryptographically link it to the device during the issuance process. Anyone in possession of the corresponding provisioning token can initiate the issuance of the copy of the document.

[0013] By deleting at least the salt values ​​stored in the first database entry, it can be ensured that the provisioning token can only be used once to issue a copy of the document.

[0014] Data elements of the document or the copy of the document are not stored in the provisioning token in plain text, but only in hashed and thus protected form. This ensures that the corresponding data elements cannot be derived from the provisioning token. To further secure hashing, the data elements, e.g. the first data element, are each combined with a salt value and the resulting combination is used to generate the hash values ​​stored in the provisioning token, e.g. the first hash value. In cryptography, a salt value is a randomly selected string of characters, such as a random value, which is appended to a given plain text, e.g. a data element of the document, before its further processing, e.g. input to a hash function, in order to increase the entropy of the input.

[0015] The salt value is stored in the first database. After the provisioning token has been used to prove authorization to receive the copy to be issued, the salt value is deleted, for example. Since the salt value is required to validate the corresponding hash value in the provisioning token, the hash value can no longer be validated after the salt value has been deleted. Thus, after deletion, the provisioning token can no longer be used, for example, to successfully prove authorization to receive the digital copy of the document to be issued.

[0016] The provisioning token represents a cryptographically secured link between the identification of a requester when creating the provisioning token and the issuing of the copy of the document to be issued. Thus, the issuing can take place via a channel independent of the identification.

[0017] First, the provisioning token is validated. Validating the provisioning token includes validating the provisioning token's signature and validating the hash values ​​contained in the provisioning token. The indicator indicates that only one copy of the document can be issued with the corresponding provisioning token.

[0018] Upon successful validation of the provisioning token, a copy of the document signed by the issuing service is issued, which includes the data elements of the document in plain text as well as the public cryptographic key of the end device for cryptographic binding or coupling to the corresponding end device.

[0019] A corresponding provisioning token for a digital copy of a document allows the owner of the document to provide a digital copy to another user who does not have access to the document. Using the provisioning token, the other user can independently issue, download, or receive the copy of the document.

[0020] For example, the copy of the document is a copy of an electronic vehicle registration certificate (EVC). In this case, a vehicle owner can use this procedure to provide other drivers of a vehicle with a copy of the electronic vehicle registration certificate (EVC). This can be particularly advantageous in the case of other family members who use the same vehicle, employees who use the same company car, participants in a car-sharing service who share the same vehicle, or customers of a car rental company who rent the same vehicle.

[0021] The indicator of the issued copy indicates that it is a copy of the document. For example, such a copy differs from the original document only in the corresponding indicator and the cryptographic binding to a different device, i.e., a different cryptographic key included in the copy compared to the cryptographic key included in the original document.

[0022] The issued copy can be sent in various ways. For example, the copy can be sent automatically. For example, a QR code can be provided to download the copy. For example, information can be sent to the requester to verify authorization to download the copy. For example, the information includes a PIN and / or TAN. For example, the PIN and / or TAN are sent via an independent channel, such as a letter or SMS.

[0023] A document is understood here to mean, in particular, a certificate such as a birth certificate, a marriage certificate, proof of citizenship, an identification document, in particular a passport, identity card, visa, as well as a driving license, vehicle registration document or vehicle registration certificate.

[0024] A copy of a document is understood to be a version of the document that is identical in content and is explicitly marked as a copy by means of an indicator.

[0025] According to embodiments, the first database and the second database are parts of one and the same database. According to embodiments, the first database and the second database are independent databases.

[0026] The first database, for example, provides data used to verify the validity of provisioning tokens, documents, and / or document copies. The second database stores, for example, data elements of documents and / or document copies to be issued.

[0027] According to embodiments, the method further comprises receiving the first data element and using the received first data element to read the first database entry from the first database.

[0028] Embodiments may have the advantage that, using the first data element, the first database entry can be read out with the data necessary to validate the provisioning token, for example the salt values.

[0029] According to embodiments, the assignment of the received public cryptographic key of the terminal device to the issued copy of the document is stored in the first database entry of the first database.

[0030] Embodiments can have the advantage that the cryptographic binding or coupling to the corresponding terminal device can be stored or specified centrally at the issuing service.

[0031] According to embodiments, validating the provisioning token comprises, upon a successful check, deleting all data associated with the provisioning token from the first database entry in the first database.

[0032] Embodiments may have the advantage of ensuring that the provisioning token cannot be used again to issue a copy of the document.

[0033] According to embodiments, the second data set includes all of the data elements of the second database entry associated with the issued document in plain text. Embodiments may have the advantage that the issued copy of the document includes all of the data elements of the document as stored in the second database entry.

[0034] According to some embodiments, the first cryptographic signature key and the second cryptographic signature key of the issuer service are one and the same signature key. According to some embodiments, the first cryptographic signature key and the second cryptographic signature key of the issuer service are two different cryptographic signature keys.

[0035] According to embodiments, the provisioning token is received along with the issuance request. According to embodiments, upon receipt of the issuance request, a provisioning token query is sent to the requestor. In response to sending the provisioning token query, the provisioning token is received from the requestor.

[0036] According to embodiments, the first data element is used to provide a database access key for identifying the first database entry stored in the first database with the first assignment of the generated first salt value to the first data element.

[0037] Embodiments may have the advantage that, using the first data element that uniquely identifies the document of which a copy is to be issued, the first database entry in the first database can be accessed, which provides data used to check the validity of the provisioning token.

[0038] According to embodiments, the method further comprises receiving a second data element of the issued document, which is used to read the first database entry from the first database. The second data element is used to provide the database access key for identifying the first database entry stored in the first database.

[0039] For example, the second data element in combination with the first data element serves to provide a database access key, for example as a primary key, for accessing the first database entry in the first database.

[0040] According to embodiments, the second data element of the issued document is a data element that uniquely identifies the issued document.

[0041] According to embodiments, access to the second database is provided via a second server. Querying the second database entry comprises sending a query to the second server and receiving the second database entry in response to the query.

[0042] Embodiments may have the advantage that the first and second databases can be managed, for example, by two different services and, in particular, independently of one another. For example, the first server managing the first database can access the second database via the second server if necessary.

[0043] According to embodiments, the second database entry is queried using the first data element associated with the issued document, which uniquely identifies the issued document. According to embodiments, the query of the second database entry includes the first data element associated with the issued document, which uniquely identifies the issued document. The first data element serves, for example, to provide a database access key, for example, as a primary key, for accessing the second database entry.

[0044] According to embodiments, the second database entry is queried using the second data element associated with the issued document, which, for example, uniquely identifies the issued document. According to embodiments, the query of the second database entry includes the second data element associated with the issued document. For example, identification data of the identified requester can also be used to identify a second database entry in the second database associated with the requester.

[0045] According to embodiments, the first data set of the provisioning token further comprises a second hash value generated using a second combination of a one-time password and a second salt value associated with the one-time password. A second mapping of the second salt value to the one-time password is stored in the first database entry of the first database.

[0046] Validating the provisioning token further comprises receiving the one-time password and checking the second hash value using the received one-time password and the read first database entry.

[0047] Embodiments may have the advantage that, in addition to the possession of the provisioning token, the corresponding one-time password, such as a TAN, is necessary for the successful proof of authorization to receive the digital copy of the document to be issued with a terminal device and for the cryptographic coupling to the terminal device during the issuance.

[0048] According to embodiments, the second data record of the issued copy of the document further comprises an indication of a time of issuance of the copy.

[0049] Embodiments may have the advantage of assigning a time to the issuance of the copy of the document. The time specification may, for example, be an issue date. For example, the time specification includes, in addition to the issue date, an hour, minute, and / or second. Based on the time specification of the copy's issuance, it can be checked, for example, whether the corresponding copy is a current version with current data elements or whether an update is necessary.

[0050] According to embodiments, the method further comprises updating the issued copy of the document. Updating includes: o Receiving an update request for updating the issued copy of the document from the terminal device, wherein the update request comprises the issued copy, o Reading the second database entry from the second database using the first data element of the received copy of the document, wherein the second database entry comprises an indication of a time of a last update of the second database entry, o Comparing the indication of the time of issue of the received copy of the document with the indication of the time of the last update of the second database entry, o Determining that the last update of the second database entry occurred after the copy of the document was issued, o Issuing an updated copy of the document, wherein issuing the updated copy of the document comprises: creating a fourth data record,which comprises one or more of the data elements of the read second database entry associated with the copy of the document to be issued in plain text, wherein the fourth data record further comprises an indicator in plain text indicating that it is a data record of a copy of the issued document, adding the public cryptographic key of the terminal device from the received copy of the document to the fourth data record for cryptographically binding the fourth data record to the terminal device, signing the fourth data record with the second cryptographic signature key of the issuer service, providing the updated copy of the document in the form of the signed fourth data record, o sending the updated copy of the document to the terminal device. ,

[0051] Embodiments may have the advantage that, based on a comparison of the time of issue of the copy of the document with the time of the last update of the second database entry, it can be checked whether the copy is up-to-date, i.e., whether the last update of the second database entry in the second database is taken into account. If it is determined that the last update of the second database entry occurred after the copy was issued, an updated copy of the document is issued. This ensures that a current version of the copy of the document is always available.

[0052] According to embodiments, the received issued copy of the document is signed with a private cryptographic key associated with the terminal device. The method further comprises validating the received copy of the document. Validating comprises checking the signature of the received copy of the document with the private cryptographic key of the terminal device using the public cryptographic key of the terminal device included in the received copy of the document.

[0053] Embodiments may have the advantage that the copy is first validated as a prerequisite for an update. This ensures that an update is only performed for an authentic or valid copy.

[0054] According to embodiments, the copy of the document included in the update request is signed with the private cryptographic key of the end device. According to embodiments, the update request including the copy is signed with the private cryptographic key of the end device.

[0055] According to embodiments, if it is determined based on the comparison of the indication of the time of issue of the copy with the indication of the time of the last update of the second database entry that the last update of the second database entry occurred before the copy was issued, information is sent to the requester indicating that the issued copy of the document is a current copy with current data elements.

[0056] According to embodiments, the second data set further comprises an indication in plain text of a period of validity intended for the issued copy.

[0057] Embodiments may have the advantage of allowing a validity period to be specified for the copy of the document. This allows the owner of the document to effectively limit the validity period of the copy to be issued, even if the provisioning token for requesting the issuance of the copy is independently generated by another user.

[0058] According to embodiments, the provisioning token further comprises a third hash value which, using a third combination of the validity period indication with a third salt value, comprises a third assignment of the third salt value to the validity period indication stored in the first database entry in the first database.

[0059] Embodiments may have the advantage that the validity period can be encoded in cryptographically secured form as a hash value in the provisioning token.

[0060] According to embodiments, checking the hash values ​​entered in the provisioning token comprises checking the third hash value.

[0061] Embodiments may have the advantage of checking the period of validity.

[0062] According to embodiments, the method further comprises revoking the issued copy of the document. The revocation includes: o Receiving a revocation request to revoke the issued copy of the document from a terminal device cryptographically bound to the issued document, o Deleting at least the assignment of the public cryptographic key of the terminal device cryptographically bound to the copy of the document to be revoked from the first database, o Sending a revocation confirmation to the terminal device.

[0063] Embodiments may have the advantage of providing a way to revoke an issued copy of the document. Thus, the owner of the document can prevent the corresponding copy from being issued, even after the provisioning token has been handed over to another user to issue the copy of the document.

[0064] According to some embodiments, during the deletion process, all data relating to the copy of the document being revoked is deleted from the first database. In this case, the first database no longer contains any data for validating the copy of the document, and therefore it can no longer be used.

[0065] If the data for individual copies in the first database is individually identifiable, targeted deletion of data for specific copies of the same document can be carried out.

[0066] According to embodiments, during the deletion, data relating to all copies of the present digital document are deleted from the first database. If the data for individual copies of the document in the first database are not individually identifiable, for example, the data for all copies are deleted.

[0067] According to embodiments, the revocation request comprises the issued document. The received issued document is signed with a private cryptographic key associated with the terminal device cryptographically bound to the issued document. The method further comprises validating the received document. Validating comprises checking the signature of the received document with the private cryptographic key of the terminal device cryptographically bound to the issued document using the public cryptographic key of the terminal device cryptographically bound to the issued document, which is included in the received document.

[0068] Embodiments may have the advantage that revocation is only possible upon proof of appropriate authorization in the form of the issued document.

[0069] According to embodiments, the document encompassed by the revocation request is signed with the private cryptographic key of the end device cryptographically bound to the issued document. According to embodiments, the revocation request encompassing the document is signed with the private cryptographic key of the end device cryptographically bound to the issued document.

[0070] Depending on the embodiment, the issued copy of the document is a copy of a vehicle document, for example a copy of an electronic registration certificate Part I.

[0071] Embodiments may have the advantage of being able to issue a copy of an electronic registration certificate Part I. This can be particularly advantageous in the case of other family members who use the same vehicle, employees who use the same company car, participants in a car-sharing service who share the same vehicle, or customers of a car rental company who rent the same vehicle.

[0072] According to embodiments, the first data element is a unique vehicle ID, for example a vehicle registration number or a chassis number.

[0073] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0074] According to embodiments, the second data element is a data element assigned to the vehicle, for example a vehicle registration number or a chassis number.

[0075] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0076] Embodiments further include an issuer service server for issuing a digital copy of an issued digital document using a digital provisioning token. The server includes a processor, a memory with program instructions, and a communication interface for communication over a network.

[0077] The provisioning token proves authorization to receive the digital copy of the issued digital document to be issued using a terminal device and to cryptographically link it to the terminal device during the issuance process. The provisioning token comprises a first data set with a first hash value and an indicator. The first hash value is generated using a first combination of a first data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued, and a first salt value associated with the first data element. The indicator indicates that it is a provisioning token for a copy of the issued document. The first data set is signed with a first signature key of an issuer service that generates the provisioning token.

[0078] The server has access to a first database in which a first database entry with a first assignment of the first salt value to the first data element is stored.

[0079] The server also has access to a second database in which a second database entry with data elements of the issued document is stored.

[0080] Execution of the program instructions by the processor causes the processor to control the server to: o Receiving an issuance request for issuing the copy of the issued document to be issued from a terminal device of a requester, o Receiving the provisioning token from the terminal device, o Validating the provisioning token, wherein validating the provisioning token comprises: validating the signature of the provisioning token using a first signature verification key of the issuer service, reading the first database entry from the first database using the received first data element, checking the hash values ​​entered in the provisioning token using the read first database entry for a successful check, deleting at least the salt values ​​stored in the first database entry in the first database, o Issuing the copy of the document, wherein issuing the copy of the document comprises: reading the second database entry from the second database,Creating a second data record comprising one or more of the data elements of the second database entry associated with the document to be issued in plain text, wherein the second data record further comprises a plain text indicator indicating that it is a data record of a copy of the issued document, sending a key query to the terminal device, receiving a public cryptographic key associated with the terminal device, adding the received public cryptographic key of the terminal device to the second data record for cryptographically binding the second data record to the terminal device, signing the second data record with a second cryptographic signature key associated with the issuing service, providing the issued copy of the document in the form of the signed second data record,Storing an association of the received public cryptographic key of the terminal device with the issued copy of the document in the first database, o Sending the issued copy of the document to the terminal device. ,

[0081] According to embodiments, the server is configured to perform any of the previously described embodiments of the method for issuing the copy of the digital document.

[0082] Embodiments further include a system comprising a server of an issuer service according to any one of the preceding embodiments and a further server that provides access to the second database. The second server includes a further processor, a further memory with further program instructions, and a further communication interface for communication via the network.

[0083] Querying the second database entry comprises sending a query from the server to the further server and receiving by the server the second database entry sent by the further server in response to the query.

[0084] According to embodiments, the system is configured to perform any of the previously described embodiments of the method for issuing the digital copy of the document.

[0085] According to embodiments, the system further comprises the terminal device.

[0086] Embodiments further include a digital copy of an issued document. The copy includes a record of data elements and a plaintext indicator. The indicator indicates that it is a copy of the issued document. The record is signed with a signature key of an issuer service issuing the copy of the document. The record further includes a public cryptographic key of an end device for cryptographically binding the copy of the document to the end device.

[0087] According to embodiments, the digital copy of the document is a product of one of the previously described embodiments of the method for issuing the copy of the document.

[0088] According to embodiments, the signed data set further comprises an indication of a validity period of the copy of the document in plain text.

[0089] According to embodiments, the signed data record further comprises an indication of a time of issuance of the copy of the document in plain text.

[0090] Depending on the embodiment, the copy is a copy of a vehicle document, for example a copy of an electronic registration certificate Part I.

[0091] Embodiments include a method for generating a digital provisioning token by an issuing service. The provisioning token demonstrates authorization to receive a digital copy of an issued digital document with a terminal device and to cryptographically couple it to the terminal device during the issuance process.

[0092] The procedure includes, through a first server of the issuer service: o Receiving a creation request to create the provisioning token, o Identifying the requester using the issued digital document, o Creating the requested provisioning token in the form of a signed data record, wherein the creation comprises: receiving a first data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued, checking the first data element using a second database entry read from a second database, which includes data comprised by the issued document, generating a first salt value, which is associated with the first data element, wherein the association comprises storing a first association of the first salt value to the first data element in a first database,Calculating a first hash value using a first combination of the first data element and the first salt value, Creating a data record comprising the first hash value and an indicator, the indicator indicating that it is a provisioning token for a copy of the issued document, Signing the data record with a cryptographic signature key associated with the issuer service, Providing the requested provisioning token in the form of the signed data record, o Sending the provisioning token to the identified requester. ,

[0093] Embodiments may have the advantage of providing a provisioning token in a cryptographically secured manner. The provisioning token verifies authorization to receive a digital copy of an issued digital document with a terminal device and to cryptographically couple it to the terminal device during the issuance process. This authorization is confirmed by signing the data record with the cryptographic signature key assigned to the issuing service. The cryptographic signature key is, for example, a private cryptographic key of an asymmetric cryptographic key pair assigned to the issuing service.

[0094] First, the requester is identified using the issued digital document. For example, the issued digital document is sent with the creation request, whereby the creation request and / or the received document is signed with a private cryptographic key of the end device, for example, a mobile device, to which the document is cryptographically linked. For example, the data elements of the second database entry or the second database entry are assigned to a specific person or entity. By identifying the requester, it can be ensured, for example, that the requester is the corresponding authorized person or entity.

[0095] Furthermore, a check is made to determine whether the received data element is actually a data element stored in the second database entry and is therefore a correct data element. For example, in addition to the first data element, one or more additional data elements are received, which are then checked using the second database entry.

[0096] The first data element is used to identify the document to be issued. Thus, based on the first hash value stored in the provisioning token, which depends on the first data element, the database entry of the second database to be used to issue the corresponding copy of the document, namely the second database entry, can be identified. The first data element itself serves, for example, as a database access key, e.g., a primary key, or for deriving a database access key, e.g., a primary key. For example, the second database entry to be used for verification can be identified based on the first data element.

[0097] Data elements of the document or the copy of the document are not stored in the provisioning token in plain text, but only in hashed and thus protected form. This ensures that the corresponding data elements cannot be derived from the provisioning token. To further secure hashing, the data elements, e.g. the first data element, are each combined with a salt value and the resulting combination is used to generate the hash values ​​stored in the provisioning token, e.g. the first hash value. In cryptography, a salt value is a randomly selected string of characters, such as a random value, which is appended to a given plain text, e.g. a data element of the document, before its further processing, e.g. input to a hash function, in order to increase the entropy of the input.

[0098] The salt value is stored in the first database. This ensures that the provisioning token can only be used once. For example, after the provisioning token has been used to prove authorization to receive the digital copy of the document to be issued, the salt value is deleted. Since the salt value is required to validate the corresponding hash value in the provisioning token, the hash value can no longer be validated after the salt value is deleted. Thus, after deletion, the provisioning token can no longer be used, for example, to successfully prove authorization to receive the digital copy of the document to be issued.

[0099] The provisioning token thus represents a cryptographically secured link between the identification of a requester using a document intended only for the requester and the issuance of the copy of the document to be issued. The issuance of the copy of the document can be requested by another user who does not have access to the issued document. Thus, the issuance can take place via a channel independent of the identification process.

[0100] The provisioning token can be sent in various ways. For example, the provisioning token can be sent automatically. For example, a QR code can be provided to download the provisioning token. For example, information can be sent to the requester to verify authorization to download the provisioning token. For example, the information includes a PIN and / or TAN. For example, the PIN and / or TAN are sent via an independent channel, such as a letter or SMS.

[0101] According to embodiments, the first database and the second database are parts of one and the same database. According to embodiments, the first database and the second database are independent databases.

[0102] The first database, for example, provides data used to verify the validity of provisioning tokens, documents, and / or document copies. The second database stores, for example, data elements of documents and / or document copies to be issued.

[0103] A corresponding provisioning token for a digital copy of a document enables the owner of the document to provide a digital copy to another user who does not have access to the document. The other user receives the provisioning token and can, for example, independently issue, download, or receive a copy of the document.

[0104] For example, the copy of the document is a copy of an electronic vehicle registration certificate (EVC). In this case, a vehicle owner can provide other drivers of a vehicle with a copy of the electronic vehicle registration certificate (EVC). This can be particularly advantageous in the case of other family members who use the same vehicle, employees who use the same company car, participants in a car-sharing service who share the same vehicle, or customers of a car rental company who rent the same vehicle.

[0105] The indicator indicates that this is a provisioning token for a copy. For example, the provisioning token for a copy differs from a provisioning token for the original document only in the corresponding indicator.

[0106] According to embodiments, the first data element is used to provide a database access key for identifying a first database entry stored in the first database with the first assignment of the generated first salt value to the first data element.

[0107] Embodiments may have the advantage that, using the first data element that uniquely identifies the document for which a copy is to be issued, the first database entry in the first database can be accessed, which provides data used to check the validity of the provisioning token.

[0108] According to embodiments, the first data element is received from the requestor and the checking comprises checking whether the second database entry comprises the first data element.

[0109] Embodiments may have the advantage that it can thus be ensured that the first data element received from the requester is correct or that a database entry with data elements for the copy of the document to be issued is stored in the second database.

[0110] According to embodiments, the first data element is received as part of the second database entry of the second database, and checking comprises checking whether the first data element originates from the second database entry.

[0111] Embodiments may have the advantage that the first data element is read from the second database entry of the second database. This ensures that the received first data element is a correct data element or that a database entry with data elements for the copy of the document to be issued is stored in the second database.

[0112] According to embodiments, access to the second database is provided via a second server. Querying the second database entry comprises sending a query to the second server and receiving the second database entry in response to the query.

[0113] Embodiments may have the advantage that the first and second databases can be managed, for example, by two different services and, in particular, independently of one another. For example, the first server managing the first database can access the second database via the second server if necessary.

[0114] According to embodiments, the second database entry is queried using the first data element associated with the issued document for which a copy is to be issued, which uniquely identifies the issued document. According to embodiments, the query of the second database entry includes the first data element. The first data element serves, for example, to provide a database access key, for example, as a primary key, for accessing the second database entry.

[0115] According to embodiments, the second database entry is queried using identification data from the issued document. According to embodiments, the query of the second database entry includes the corresponding identification data. For example, identification data of the identified requester can also be used to identify a second database entry in the second database associated with the requester.

[0116] According to embodiments, creating the requested provisioning token further comprises: Generating a one-time password for the provisioning token associated with the identified requester, generating a second salt value associated with the one-time password, wherein the assigning comprises storing a second assignment of the second salt value to the one-time password using the first data element in the first database, calculating a second hash value using a second combination of the one-time password and the second salt value, using the second hash value to create the data set, wherein the data set includes the second hash value, sending the one-time password to the identified requester.

[0117] Embodiments can have the advantage that a one-time password can also be provided for the requester or the future user of the provisioning token and cryptographically bound to the provisioning token. Thus, in addition to possession of the provisioning token, the corresponding one-time password, such as a TAN, is required to successfully prove authorization to receive the digital document to be issued with a device and for cryptographically linking it to the device during the issuance of the copy.

[0118] According to embodiments, the one-time password is sent to the identified requester via a channel that is independent of the channel through which the issued provisioning token is sent to the identified requester. For example, the one-time password is sent to the requester by letter or SMS.

[0119] According to embodiments, creating the requested provisioning token further comprises: Receiving a second data element associated with the issued document for which a copy is to be issued, checking the second data element using the second database entry read from the second database, generating a third salt value which is associated with the second data element, wherein the association comprises storing a third association of the third salt value to the second data element using the first data element in the first database, calculating a third hash value using a third combination of the second data element with the third salt value, using the third hash value to create the data set, wherein the data set comprises the third hash value.

[0120] Embodiments may have the advantage that, in addition to the first data element, a further data element can be provided with the provisioning token for identifying the document for which a copy is to be issued. For example, the database access key is a combination of the first and second data elements.

[0121] According to embodiments, the second data element of the issued document is a data element that uniquely identifies the issued document for which a copy is to be issued.

[0122] According to embodiments, the second database entry is queried using the second data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued. According to embodiments, the query of the second database entry includes the second data element associated with the document to be issued. The second data element serves, for example, in combination with the first data element, to provide a database access key, for example, as a primary key, for accessing the second database entry.

[0123] According to embodiments, the second data element is used to provide the database access key for identifying the first database entry stored in the first database. For example, the second data element, in combination with the first data element, serves to provide a database access key, for example, as a primary key, for accessing the first database entry in the first database.

[0124] According to embodiments, the second data element is received from the requestor and the checking comprises checking whether the second database entry comprises the second data element.

[0125] Embodiments may have the advantage that it can thus be ensured that the second data element received from the requestor is correct or that a database entry with data elements for the copy of the document to be issued is stored in the second database.

[0126] According to embodiments, the second data element is received as part of the second database entry of the second database, and checking comprises checking whether the second data element originates from the second database entry.

[0127] Embodiments may have the advantage that the second data element is read from the second database entry of the second database. This ensures that the received second data element is a correct data element or that a database entry with data elements for the copy of the document to be issued is stored in the second database.

[0128] According to embodiments, creating the requested provisioning token further comprises: Receiving an indication of a validity period intended for the copy to be issued, using the validity period indication to create the record, the record including the validity period indication.

[0129] Embodiments may have the advantage that a validity period for the copy of the document to be issued can already be specified in the provisioning token. This allows the owner of the document to effectively limit the validity period of the copy of the document to be issued, even if the provisioning token for requesting the issuance of the copy is issued independently by another user.

[0130] According to embodiments, using the validity period indication to create the record further comprises: Generating a fourth salt value associated with the validity period indication, wherein the association comprises storing a fourth association of the fourth salt value with the validity period indication using the first data element in the first database, calculating a fourth hash value using a fourth combination of the validity period indication with the fourth salt value, using the fourth hash value to create the data record, wherein the data record comprises the validity period indication in the form of the fourth hash value.

[0131] Embodiments may have the advantage that the validity period can be encoded in cryptographically secured form as a hash value in the provisioning token.

[0132] According to embodiments, the indicator indicating that the provisioning token is a provisioning token for a copy of the issued document is included in the data set in the form of a fifth hash value. Creating the requested provisioning token further comprises: Generating a fifth salt value associated with the indicator, wherein the associating comprises storing a fifth association of the fifth salt value to the indicator using the first data element in the first database, calculating a fifth hash value using a fifth combination of the indicator with the fifth salt value, using the fifth hash value to create the data set.

[0133] Embodiments may have the advantage that the indicator can be encoded in cryptographically secured form as a hash value in the provisioning token.

[0134] According to embodiments, the data set is only signed if the requester has been successfully identified, so that the signature confirms successful identification.

[0135] Embodiments may have the advantage that the signed provisioning token can be used to prove the successful identification of the requester based on the issued document.

[0136] According to embodiments, the method further comprises revoking the provisioning token. Revoking comprises: o Receiving a revocation request to revoke the provisioning token from a terminal device cryptographically bound to the issued document, o Deleting at least the salt values ​​associated with the provisioning token to be revoked, o Sending a revocation confirmation to the terminal device.

[0137] Embodiments may have the advantage of providing a way to revoke an issued provisioning token. Thus, the owner of the document can prevent the corresponding copy from being issued, even after the provisioning token has been handed over to another user to issue the copy of the document.

[0138] Depending on the implementation, all data relating to the provisioning token to be revoked is deleted from the first database during the deletion process. In this case, the first database no longer contains any data for validating the provisioning token, which is why it can no longer be used.

[0139] If the data for individual provisioning tokens is individually identifiable in the first database, data for specific provisioning tokens can be deleted specifically.

[0140] According to embodiments, during the deletion process, data relating to all provisioning tokens that prove authorization to receive a digital copy of the present digital document are deleted from the first database. If the data for individual provisioning tokens in the first database cannot be individually identified, for example, the data for all provisioning tokens is deleted.

[0141] According to embodiments, the revocation request comprises the issued document. The received issued document is signed with a private cryptographic key associated with the terminal device cryptographically bound to the issued document. The method further comprises validating the received document. Validating comprises checking the signature of the received document with the private cryptographic key of the terminal device cryptographically bound to the issued document using the public cryptographic key of the terminal device cryptographically bound to the issued document, which is included in the received document.

[0142] Embodiments may have the advantage that revocation is only possible upon proof of appropriate authorization in the form of the issued document.

[0143] According to embodiments, the document encompassed by the revocation request is signed with the private cryptographic key of the end device cryptographically bound to the issued document. According to embodiments, the revocation request encompassing the document is signed with the private cryptographic key of the end device cryptographically bound to the issued document.

[0144] Depending on the embodiment, the copy to be issued is a copy of a vehicle document, for example an electronic registration certificate Part I. The issued document is the corresponding vehicle document.

[0145] Embodiments may have the advantage that a provisioning token can be used to prove an authorization to receive a copy of an electronic registration certificate Part I to be issued with a terminal device and for cryptographic coupling to the terminal device during the issuance process.

[0146] According to embodiments, the first data element is a unique vehicle ID, for example a vehicle registration number or a chassis number.

[0147] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0148] According to embodiments, the second data element is a data element assigned to the vehicle, for example a vehicle registration number or a chassis number.

[0149] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0150] Embodiments further include a server of an issuer service for generating a digital provisioning token. The server includes a processor, a memory with program instructions, and a communication interface for communication over a network. The provisioning token demonstrates authorization to receive a digital copy of an issued digital document to be issued with a terminal device and to cryptographically couple it to the terminal device during the issuance process.

[0151] Execution of the program instructions by the processor causes the processor to control the server to: o Receiving a creation request to create the provisioning token, o Identifying the requester using the issued digital document, o Creating the requested provisioning token in the form of a signed data record, wherein the creation comprises: receiving a first data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued, checking the first data element using a second database entry read from a second database, which includes data comprised by the issued document, generating a first salt value, which is associated with the first data element, wherein the association comprises storing a first association of the first salt value to the first data element in a first database,Calculating a first hash value using a first combination of the first data element and the first salt value, Creating a data record comprising the first hash value and an indicator, the indicator indicating that it is a provisioning token for a copy of the issued document, Signing the data record with a cryptographic signature key associated with the issuer service, Providing the requested provisioning token in the form of the signed data record, o Sending the provisioning token to the identified requester. ,

[0152] According to embodiments, the server is configured to execute any of the previously described embodiments of the method for generating the digital provisioning token.

[0153] Embodiments further include a system comprising a server of an issuer service according to one of the previously described embodiments and a further server providing access to a second database. The further server comprises a further processor, a further memory with further program instructions, and a further communication interface for communication via the network.

[0154] Querying the second database entry of the second database comprises sending a query from the server to the further server and receiving by the server the second database entry sent by the further server in response to the query.

[0155] According to embodiments, the system is configured to perform any of the previously described embodiments of the method for generating the digital provisioning token.

[0156] Embodiments further include a digital provisioning token for proving authorization to receive a digital copy of an issued digital document to be issued using a terminal device and for cryptographically coupling it to the terminal device during issuance. The provisioning token comprises a data set with a first hash value and an indicator. The first hash value is generated using a first combination of a first data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued, and a first salt value associated with the first data element. The indicator indicates that it is a provisioning token for a copy of the issued document. The data set is signed with a signature key of an issuer service that generates the provisioning token.

[0157] According to embodiments, the digital provisioning token is a product of one of the previously described embodiments of the method for generating the digital provisioning token.

[0158] According to embodiments, the signed data set further comprises a second hash value generated using a second combination of a one-time password associated with the identified requester and a second salt value associated with the one-time password.

[0159] According to embodiments, the signed data set further comprises a third hash value generated using a third combination of a second data element associated with the issued document for which the copy is to be issued and a third salt value.

[0160] According to embodiments, the signed data set further comprises an indication of a period of validity intended for the copy to be issued.

[0161] According to embodiments, the data set comprises the indication of the validity period intended for the copy to be issued in the form of a fourth hash value, which is generated using a fourth combination of the indication of the validity period and a fourth salt value.

[0162] According to embodiments, the data set comprises the indicator in the form of a fifth hash value generated using a fifth combination of the indicator and a fifth salt value.

[0163] Embodiments include a method for issuing a digital document using a digital provisioning token. The provisioning token verifies authorization to receive the digital document to be issued with a terminal device and to cryptographically couple it to the terminal device during issuance. The provisioning token comprises a first data set with a first hash value, which is generated using a first combination of a first data element associated with the document to be issued, which uniquely identifies the document to be issued, and a first salt value associated with the first data element. The first data set is signed with a first signature key of an issuer service generating the provisioning token.

[0164] A first database entry with a first assignment of the first salt value to the first data element is stored in a first database.

[0165] A second database entry containing data elements of the document to be issued is stored in a second database.

[0166] The procedure includes, through a first server of the issuer service: o Receiving an issuance request for issuing the document to be issued from a terminal device of a requester, o Receiving the provisioning token from the terminal device, o Validating the provisioning token, wherein the validation of the provisioning token comprises: validating the signature of the provisioning token using a first signature verification key of the issuer service, reading the first database entry from the first database using the received first data element, checking the hash values ​​entered in the provisioning token using the read first database entry for a successful check, deleting at least the salt values ​​stored in the first database entry in the first database, o Issuing the document, wherein the issuing of the document comprises: reading the second database entry from the second database, creating a second data record,which comprises one or more of the data elements of the second database entry associated with the document to be issued in plain text, sending a key query to the terminal device, receiving a public cryptographic key associated with the terminal device, adding the received public cryptographic key of the terminal device to the second data set for cryptographically binding the second data set to the terminal device, signing the second data set with a second cryptographic signature key associated with the issuer service, providing the issued document in the form of the signed second data set, storing an association of the received public cryptographic key of the terminal device to the issued document in the first database, o sending the issued document to the terminal device. ,

[0167] Embodiments can have the advantage that a digital document can be issued that is cryptographically bound or coupled to a terminal device, in particular a mobile terminal device, such as a smartphone. Authorization to use the corresponding document can be verified with a private cryptographic key of the terminal device associated with the public cryptographic key, which is stored, for example, in a protected memory area of ​​the terminal device's memory, for example, a security element. For this purpose, for example, a signature is created with the corresponding private cryptographic key, which can be validated with the public cryptographic key of the terminal device contained in the document.

[0168] The provisioning token is required to prove authorization to receive the digital document to be issued on the device and to cryptographically link it to the device during the issuance process. Anyone in possession of the corresponding provisioning token can initiate the issuance of the document.

[0169] By deleting at least the salt values ​​stored in the first database entry, it can be ensured that the provisioning token can only be used once to issue the document, i.e. that the corresponding document is issued only once.

[0170] For example, data elements of the document are not stored in the provisioning token in plain text, but only in hashed and thus protected form. This ensures that the corresponding data elements cannot be derived from the provisioning token. To further secure hashing, the data elements, e.g. the first data element, are each combined with a salt value and the resulting combination is used to generate the hash values ​​stored in the provisioning token, e.g. the first hash value. In cryptography, a salt value is a randomly selected string of characters, such as a random value, which is appended to a given plain text, e.g. a data element of the document, before its further processing, e.g. input to a hash function, in order to increase the entropy of the input.

[0171] The salt value is stored in the first database. After the provisioning token has been used to prove authorization to receive the digital document to be issued, the salt value is deleted, for example. Since the salt value is required to validate the corresponding hash value in the provisioning token, the hash value can no longer be validated after the salt value has been deleted. Thus, after deletion, the provisioning token can no longer be used, for example, to successfully prove authorization to receive the digital document to be issued.

[0172] The provisioning token represents a cryptographically secured link between the identification of a requester when creating the provisioning token and the issuance of the document to be issued. Thus, the issuance can take place via a channel independent of the identification.

[0173] First, the provisioning token is validated. Validating the provisioning token includes validating the provisioning token's signature and validating the hash values ​​contained in the provisioning token.

[0174] Upon successful validation of the provisioning token, the document signed by the issuing service is issued, which includes data elements in plain text as well as the public cryptographic key of the end device for cryptographic binding or coupling to the corresponding end device.

[0175] The document can be sent in various ways. For example, the document can be sent automatically. For example, a QR code can be provided to download the document. For example, information can be sent to the requester to verify authorization to download the document. For example, the information includes a PIN and / or TAN. For example, the PIN and / or TAN are sent via an independent channel, such as a letter or SMS.

[0176] According to embodiments, the first database and the second database are parts of one and the same database. According to embodiments, the first database and the second database are independent databases.

[0177] The first database, for example, provides data used to verify the validity of provisioning tokens, documents, and / or document copies. The second database stores, for example, data elements of documents and / or document copies to be issued.

[0178] According to embodiments, the method further comprises receiving the first data element and using the received first data element to read the first database entry from the first database.

[0179] Embodiments may have the advantage that, using the first data element, the first database entry can be read out with the data necessary to validate the provisioning token, for example the salt values.

[0180] According to embodiments, the assignment of the received public cryptographic key of the terminal to the issued document is stored in the first database entry of the first database.

[0181] Embodiments can have the advantage that the cryptographic binding or coupling to the corresponding terminal device can be stored or specified centrally at the issuing service.

[0182] According to embodiments, validating the provisioning token comprises, upon a successful check, deleting all data associated with the provisioning token from the first database entry in the first database.

[0183] Embodiments may have the advantage of ensuring that the provisioning token cannot be used again to issue the document.

[0184] According to embodiments, the second data set comprises all of the data elements of the second database entry associated with the document to be issued, in plain text. Embodiments may have the advantage that the issued document comprises all of the data elements of the document as stored in the second database entry.

[0185] According to some embodiments, the first cryptographic signature key and the second cryptographic signature key of the issuer service are one and the same signature key. According to some embodiments, the first cryptographic signature key and the second cryptographic signature key of the issuer service are two different cryptographic signature keys.

[0186] According to embodiments, the provisioning token is received along with the issuance request. According to embodiments, upon receipt of the issuance request, a provisioning token query is sent to the requestor. In response to sending the provisioning token query, the provisioning token is received from the requestor.

[0187] According to embodiments, the first data element is used to provide a database access key for identifying the first database entry stored in the first database with the first assignment of the generated first salt value to the first data element.

[0188] Embodiments may have the advantage that, using the first data element that uniquely identifies the document to be issued, the first database entry in the first database can be accessed, which provides data used to check the validity of the provisioning token.

[0189] According to embodiments, the method further comprises receiving a second data element of the document to be issued, which is used to read the first database entry from the first database. The second data element is used to provide the database access key for identifying the first database entry stored in the first database.

[0190] For example, the second data element in combination with the first data element serves to provide a database access key, for example as a primary key, for accessing the first database entry in the first database.

[0191] According to embodiments, the second data element of the document to be issued is a data element that uniquely identifies the document to be issued.

[0192] According to embodiments, access to the second database is provided via a second server. Querying the second database entry comprises sending a query to the second server and receiving the second database entry in response to the query.

[0193] Embodiments may have the advantage that the first and second databases can be managed, for example, by two different services and, in particular, independently of one another. For example, the first server managing the first database can access the second database via the second server if necessary.

[0194] According to embodiments, the second database entry is queried using the first data element associated with the document to be issued, which uniquely identifies the document to be issued. According to embodiments, the query of the second database entry includes the first data element associated with the document to be issued, which uniquely identifies the document to be issued. The first data element serves, for example, to provide a database access key, for example as a primary key, for accessing the second database entry.

[0195] According to embodiments, the second database entry is queried using the second data element associated with the document to be issued, which, for example, uniquely identifies the document to be issued. According to embodiments, the query of the second database entry includes the second data element associated with the document to be issued. For example, identification data of the identified requester can also be used to identify a second database entry in the second database associated with the requester.

[0196] According to embodiments, the first data set of the provisioning token further comprises a second hash value generated using a second combination of a one-time password and a second salt value associated with the one-time password. A second mapping of the second salt value to the one-time password is stored in the first database entry of the first database.

[0197] Validating the provisioning token further comprises receiving the one-time password and checking the second hash value using the received one-time password and the read first database entry.

[0198] Embodiments may have the advantage that, in addition to the possession of the provisioning token, the corresponding one-time password, such as a TAN, is necessary for the successful proof of authorization to receive the digital document to be issued with a terminal device and for the cryptographic coupling to the terminal device during the issuance process.

[0199] According to embodiments, the second data record of the issued document further comprises an indication of a time of issuance of the document.

[0200] Embodiments can have the advantage of assigning a time to the document's issuance. The time specification is, for example, an issue date. For example, the time specification includes, in addition to the issue date, an hour, minute, and / or second. Based on the time specification of the document's issuance, it can be checked, for example, whether the corresponding document is a current version with current data elements or whether an update is necessary.

[0201] According to embodiments, the method further comprises updating the issued document. The updating comprises: o Receiving an update request for updating the issued document from the terminal, wherein the update request comprises the issued document, o Reading the second database entry from the second database using the first data element of the received document, wherein the second database entry comprises an indication of a time of a last update of the second database entry, o Comparing the indication of the time of issue of the received document with the indication of the time of the last update of the second database entry, o Determining that the last update of the second database entry occurred after the document was issued, o Issuing an updated document, wherein issuing the updated document comprises: Creating a fourth data record which contains one or more of the data elements of the read second database entry,which are associated with the document to be issued, in plain text, adding the public cryptographic key of the terminal device from the received document to the fourth data set for cryptographically binding the fourth data set to the terminal device, signing the fourth data set with the second cryptographic signature key of the issuer service, providing the updated document in the form of the signed fourth data set, o sending the updated document to the terminal device. ,

[0202] Embodiments can have the advantage that, based on a comparison of the time of document issuance with the time of the last update of the second database entry, it can be checked whether the document is up-to-date, i.e., whether the last update of the second database entry is taken into account in the second database. If it is determined that the last update of the second database entry occurred after the document was issued, an updated document is issued. This ensures that a current version of the document is always available.

[0203] According to embodiments, the received issued document is signed with a private cryptographic key associated with the terminal device. The method further comprises validating the received document. Validating comprises checking the signature of the received document with the private cryptographic key of the terminal device using the public cryptographic key of the terminal device included in the received document.

[0204] Embodiments can have the advantage that the document is first validated as a prerequisite for an update. This ensures that an update is only performed for an authentic or valid document.

[0205] According to embodiments, the document included in the update request is signed with the private cryptographic key of the end device. According to embodiments, the update request including the document is signed with the private cryptographic key of the end device.

[0206] According to embodiments, if it is determined based on the comparison of the indication of the time of issuance of the document with the indication of the time of the last update of the second database entry that the last update of the second database entry occurred before the document was issued, information is sent to the requester indicating that the issued document is a current document with current data elements.

[0207] Depending on the embodiment, the issued document is a vehicle document, for example an electronic registration certificate Part I.

[0208] Embodiments may have the advantage that a registration certificate Part I can be issued in the form of a digital document.

[0209] According to embodiments, the first data element is a unique vehicle ID, for example a vehicle registration number or a chassis number.

[0210] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0211] According to embodiments, the second data element is a data element assigned to the vehicle, for example a vehicle registration number or a chassis number.

[0212] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0213] Embodiments further include a server of an issuer service for issuing a digital document using a provisioning token. The server includes a processor, a memory with program instructions, and a communication interface for communication over a network.

[0214] The provisioning token proves authorization to receive the digital document to be issued with a terminal device and to cryptographically link it to the terminal device during issuance. The provisioning token comprises a first data set with a first hash value, which is generated using a first combination of a first data element associated with the document to be issued, which uniquely identifies the document to be issued, and a first salt value associated with the first data element. The first data set is signed with a first signature key of an issuer service that generates the provisioning token.

[0215] The server has access to a first database in which a first database entry with a first assignment of the first salt value to the first data element is stored.

[0216] The server also has access to a second database in which a second database entry with data elements of the document to be issued is stored.

[0217] Execution of the program instructions by the processor causes the processor to control the server to: o Receiving an issuance request for issuing the document to be issued from a terminal device of a requester, o Receiving the provisioning token from the terminal device, o Validating the provisioning token, wherein validating the provisioning token comprises: validating the signature of the provisioning token using a first signature verification key of the issuer service, reading the first database entry from the first database using the received first data element, checking the hash values ​​entered in the provisioning token using the read first database entry for a successful check, deleting at least the salt values ​​stored in the first database entry in the first database, o Issuing the document, wherein issuing the document comprises: reading the second database entry from the second database, creating a second data record,which comprises one or more of the data elements of the second database entry associated with the document to be issued in plain text, sending a key query to the terminal device, receiving a public cryptographic key associated with the terminal device, adding the received public cryptographic key of the terminal device to the second data set for cryptographically binding the second data set to the terminal device, signing the second data set with a second cryptographic signature key associated with the issuer service, providing the issued document in the form of the signed second data set, storing an association of the received public cryptographic key of the terminal device to the issued document in the first database, o sending the issued document to the terminal device. ,

[0218] According to embodiments, the server is configured to execute any of the previously described embodiments of the method for issuing the digital document.

[0219] Embodiments further include a system comprising a server of an issuer service according to one of the previously described embodiments and a further server that provides access to the second database. The second server comprises a further processor, a further memory with further program instructions, and a further communication interface for communication via the network.

[0220] Querying the second database entry comprises sending a query from the server to the further server and receiving by the server the second database entry sent by the further server in response to the query.

[0221] According to embodiments, the system is configured to perform any of the previously described embodiments of the method for issuing the digital document.

[0222] According to embodiments, the system further comprises the terminal device.

[0223] Embodiments further include a digital document comprising a data set with data elements in plaintext. The data set is signed with a signature key of an issuing service issuing the document. The data set further includes a public cryptographic key of a terminal device for cryptographically binding the document to the terminal device.

[0224] According to embodiments, the digital document is a product of one of the previously described embodiments of the method for issuing the digital provisioning token.

[0225] According to embodiments, the signed data record further comprises an indication of a time of issuance of the document.

[0226] Depending on the embodiment, the document is a vehicle document, for example an electronic registration certificate Part I.

[0227] Embodiments include a method for generating a digital provisioning token by an issuing service. The provisioning token demonstrates authorization to receive a digital document to be issued with a terminal device and to cryptographically couple it to the terminal device during the issuance process.

[0228] The procedure includes, through a first server of the issuer service: o Receiving a creation request to create the provisioning token, o Identifying the requester using received identification data of the requester, o Creating the requested provisioning token in the form of a signed data record, wherein the creation comprises: receiving a first data element associated with the document to be issued, which uniquely identifies the document to be issued, checking the first data element using a second database entry read from a second database, which includes data to be included in the document to be issued, generating a first salt value, which is associated with the first data element, wherein the association comprises storing a first association of the first salt value to the first data element in a first database, calculating a first hash value using a first combination of the first data element and the first salt value,Creating a data set containing the first hash value, Signing the data set with a cryptographic signature key assigned to the issuing service, Providing the requested provisioning token in the form of the signed data set, o Sending the provisioning token to the identified requester. ,

[0229] Embodiments can have the advantage of providing a provisioning token in a cryptographically secured manner. The provisioning token verifies authorization to receive a digital document to be issued with a terminal device and to cryptographically couple it to the terminal device during the issuance process. This authorization is confirmed by signing the data record with the cryptographic signature key assigned to the issuing service. The cryptographic signature key is, for example, a private cryptographic key of an asymmetric cryptographic key pair assigned to the issuing service.

[0230] First, the requester is identified. For example, the data elements of the second database entry or the second database entry are assigned to a specific person or entity. By identifying the requester, it can be ensured that the requester is the corresponding authorized person or entity. For example, the second database entry contains reference data, or reference data is assigned to the second database entry, which can be used to verify whether the identified person or entity is actually the authorized person or entity to dispose of the data elements of the second database entry or the second database entry.

[0231] Furthermore, a check is made to determine whether the received data element is actually a data element stored in the second database entry and is therefore a correct data element. For example, in addition to the first data element, one or more additional data elements are received, which are then checked using the second database entry.

[0232] The first data element is used to identify the document to be issued. Thus, based on the first hash value stored in the provisioning token, which depends on the first data element, the document to be issued or the database entry of the second database to be used to issue the corresponding document, namely the second database entry, can be identified. The first data element itself serves, for example, as a database access key, e.g., a primary key, or for deriving a database access key, e.g., a primary key. For example, the second database entry to be used for verification can be identified based on the first data element.

[0233] For example, data elements of the document are not stored in the provisioning token in plain text, but only in hashed and thus protected form. This ensures that the corresponding data elements cannot be derived from the provisioning token. To further secure hashing, the data elements, e.g. the first data element, are each combined with a salt value and the resulting combination is used to generate the hash values ​​stored in the provisioning token, e.g. the first hash value. In cryptography, a salt value is a randomly selected string of characters, such as a random value, which is appended to a given plain text, e.g. a data element of the document, before its further processing, e.g. input to a hash function, in order to increase the entropy of the input.

[0234] The salt value is stored in the first database. This ensures that the provisioning token can only be used once. For example, after the provisioning token has been used to prove authorization to receive the digital document to be issued, the salt value is deleted. Since the salt value is required to validate the corresponding hash value in the provisioning token, the hash value can no longer be validated after the salt value is deleted. Thus, after deletion, the provisioning token can no longer be used, for example, to successfully prove authorization to receive the digital document to be issued.

[0235] The provisioning token thus represents a cryptographically secured link between the identification of a requester and the issuance of the document to be issued. Thus, the identification can take place via a channel independent of the issuance.

[0236] The provisioning token can be sent in various ways. For example, the provisioning token can be sent automatically. For example, a QR code can be provided to download the provisioning token. For example, information can be sent to the requester to verify authorization to download the provisioning token. For example, the information includes a PIN and / or TAN. For example, the PIN and / or TAN are sent via an independent channel, such as a letter or SMS.

[0237] According to embodiments, the first database and the second database are parts of one and the same database. According to embodiments, the first database and the second database are independent databases.

[0238] The first database, for example, provides data used to verify the validity of provisioning tokens, documents, and / or document copies. The second database stores, for example, data elements of documents and / or document copies to be issued.

[0239] According to embodiments, the first data element is used to provide a database access key for identifying a first database entry stored in the first database with the first assignment of the generated first salt value to the first data element.

[0240] Embodiments may have the advantage that, using the first data element that uniquely identifies the document to be issued, the first database entry in the first database can be accessed, which provides data used to check the validity of the provisioning token.

[0241] According to embodiments, the first data element is received from the requestor and the checking comprises checking whether the second database entry comprises the first data element.

[0242] Embodiments may have the advantage that it can be ensured that the first data element received from the requester is correct or that a database entry with data elements for the document to be issued is stored in the second database.

[0243] According to embodiments, the first data element is received as part of the second database entry of the second database, and checking comprises checking whether the first data element originates from the second database entry.

[0244] Embodiments may have the advantage that the first data element is read from the second database entry of the second database. This ensures that the received first data element is a correct data element or that a database entry with data elements for the document to be issued is stored in the second database.

[0245] According to embodiments, access to the second database is provided via a second server. Querying the second database entry comprises sending a query to the second server and receiving the second database entry in response to the query.

[0246] Embodiments may have the advantage that the first and second databases can be managed, for example, by two different services and, in particular, independently of one another. For example, the first server managing the first database can access the second database via the second server if necessary.

[0247] According to embodiments, the second database entry is queried using the first data element associated with the document to be issued, which uniquely identifies the document to be issued. According to embodiments, the query of the second database entry includes the first data element associated with the document to be issued, which uniquely identifies the document to be issued. The first data element serves, for example, to provide a database access key, for example as a primary key, for accessing the second database entry.

[0248] According to embodiments, the second database entry is queried using identification data of the identified requester. According to embodiments, the query of the second database entry includes the corresponding identification data of the requester. For example, identification data of the identified requester can also be used to identify a second database entry in the second database associated with the requester.

[0249] According to embodiments, creating the requested provisioning token further comprises: Generating a one-time password for the provisioning token associated with the identified requester, generating a second salt value associated with the one-time password, wherein the associating comprises storing a second association of the second salt value to the one-time password using the first data element in the first database, calculating a second hash value using a second combination of the one-time password and the second salt value, using the second hash value to create the data set, wherein the data set includes the second hash value, sending the one-time password to the identified requester.

[0250] Embodiments can have the advantage that a one-time password can also be provided to the requestor and cryptographically bound to the provisioning token. Thus, in addition to possession of the provisioning token, the corresponding one-time password, such as a TAN, is required to successfully prove authorization to receive the digital document to be issued with a device and for cryptographically linking it to the device during the issuance process.

[0251] According to embodiments, the one-time password is sent to the identified requester via a channel that is independent of the channel through which the issued provisioning token is sent to the identified requester. For example, the one-time password is sent to the requester by letter or SMS.

[0252] According to embodiments, creating the requested provisioning token further comprises: Receiving a second data element associated with the document to be issued, checking the second data element using the second database entry read from the second database, generating a third salt value which is associated with the second data element, wherein the association comprises storing a third association of the third salt value with the second data element using the first data element in the first database, calculating a third hash value using a third combination of the second data element with the third salt value, using the third hash value to create the data set, wherein the data set comprises the third hash value.

[0253] Embodiments may have the advantage that, in addition to the first data element, another data element can be provided with the provisioning token for identifying the document to be issued. For example, the database access key is a combination of the first and second data elements.

[0254] According to embodiments, the second data element of the document to be issued is a data element that uniquely identifies the document to be issued.

[0255] According to embodiments, the second database entry is queried using the second data element associated with the document to be issued, which, for example, uniquely identifies the document to be issued. According to embodiments, the query of the second database entry includes the second data element associated with the document to be issued. The second data element serves, for example, in combination with the first data element, to provide a database access key, for example, as a primary key, for accessing the second database entry.

[0256] According to embodiments, the second data element is used to provide the database access key for identifying the first database entry stored in the first database. For example, the second data element, in combination with the first data element, serves to provide a database access key, for example, as a primary key, for accessing the first database entry in the first database.

[0257] According to embodiments, the second data element is received from the requestor and the checking comprises checking whether the second database entry comprises the second data element.

[0258] Embodiments may have the advantage that it can thus be ensured that the second data element received from the requester is correct or that a database entry with data elements for the document to be issued is stored in the second database.

[0259] According to embodiments, the second data element is received as part of the second database entry of the second database, and checking comprises checking whether the second data element originates from the second database entry.

[0260] Embodiments may have the advantage that the second data element is read from the second database entry of the second database. This ensures that the received second data element is a correct data element or that a database entry with data elements for the document to be issued is stored in the second database.

[0261] According to embodiments, the identification data of the requester comprise one or more of the following data: a user name, a password, a signature created with a signature key of the requester in combination with a certificate with a signature verification key of the requester, one or more attributes of the requester read from an ID token of the requester, which are signed with a signature key of an ID provider service, attributes of the requester which are received from a computer system of an entity authorized to identify the user.

[0262] Embodiments can have the advantage that the requester can be identified in different ways. For example, an account can be assigned to the requester, to which the requester can log in using a username and password or other authentication factors. For example, verified identification data that identifies the requester is stored in the account.

[0263] For example, a corresponding certificate may contain verified identification data that identifies the requester. With a signature created using the requester's signature key, the requester can prove that the corresponding certificate with the associated signature verification key, and thus the corresponding identification data, are assigned to the requester.

[0264] For example, the requester is in possession of an ID token assigned to the requester, containing identification data in the form of attributes of the requester. One or more of these attributes of the requester are read, for example, by an ID provider service that has read authorization to read the corresponding attributes and signed with a signature key of an ID provider service. With the signature, the ID provider service guarantees that the corresponding attributes are attributes read from the ID token.

[0265] For example, attributes of the requester can also be received from a computer system of an entity authorized to identify the user. This could involve, for example, identification of the requester in a local branch or remotely, for example, via a video identification process.

[0266] According to embodiments, the data set is only signed if the requester has been successfully identified, so that the signature confirms successful identification.

[0267] Embodiments may have the advantage that the signed provisioning token can thus prove the successful identification of the requester.

[0268] Depending on the embodiment, the document to be issued is a vehicle document, for example an electronic registration certificate Part I.

[0269] Embodiments may have the advantage that a provisioning token can be used to prove authorization to receive an electronic registration certificate Part I to be issued with a terminal device and for cryptographic coupling to the terminal device during the issuance process.

[0270] In Germany and Austria, the registration certificate is an official document certifying the registration of vehicles for road traffic. The registration certificate includes, for example, data elements for individualizing the vehicle, usually using the vehicle identification number (VIN) assigned by the manufacturer, also known as the chassis number; for assigning a vehicle registration number to a specific person or entity; and for proving that the vehicle meets technical approval requirements, i.e., type approval. The person or entity listed in the registration certificate is the vehicle's keeper, who may or may not be the owner or possessor.

[0271] In detail, an electronic registration certificate Part I includes, for example, the following data elements: (B) Date of first registration of the vehicle; (2.1) Code for 2; (2.2) Code for D.2 with check digit; (J) Vehicle class; (4) Type of bodywork; (E) Vehicle identification number; (3) Check digit of the vehicle identification number, (D.1) Make, (D.2) Type / variant / version; (D.3) Commercial name(s); (2) Manufacturer’s abbreviated name; (5) Designation of the vehicle class and bodywork; (V.9) Pollutant class relevant for EC type-approval; (14) Designation of the national emission class; (P.3) Fuel type or energy source; (10) Code for P.3; (14.1) Code for V.9 or 14; (P.1) Engine capacity in cm3<; (22) Remarks and exceptions; (L) Number of axles; (9) Number of drive axles; (P.2 / P.4) Rated power in kW / rated speed at min -1< ; (T) Maximum speed in km / h; (18) Length in mm; (19) Width in mm without mirrors and attachments; (20) Height in mm; (G) Mass of the vehicle in use in kg unladen mass; (12) Volume of the tank in the case of tank vehicles in m 3< ; (13) Nose load in kg; (Q) Power to weight ratio in kW / kg (only for motorcycles); (V.7) CO 2 (in g / km) combined value; (F.1) Technically permissible maximum laden mass in kg; (F.2) Maximum laden mass in the Member State of registration in kg; (7.1) Max. axle load on axle 1 in kg; (7.2) Max. axle load on axle 2 in kg; (7.3) Max. axle load on axle 3 in kg; (8.1) Max. axle load on axle 1 in kg; (8.2) max. axle load axle 2 in kg; (8.3) max. axle load axle 3 in kg; (U.1) idle noise in dB(A); (U.2) engine speed in min -1< to U.1; (U.3) driving noise in dB(A); (0.1) technically permissible braked trailer load in kg; (0.2) technically permissible unbraked trailer load in kg; (S.1) seats including driver's seat; (S.2) standing places; (15.1) Tyres on axle 1; (15.2) Tyres on axle 2; (15.3) Tyres on axle 3; (R) Colour of the vehicle; (11) Code for R; (K) Number of the EC type-approval or ABE; (6) Date for K; (17) Type-approval feature; (16) Number of the registration certificate Part II; (21) Other information; (H) Period of validity; (I) Date of this registration; (7) Technically permissible maximum axle load / mass per axle group in kg; (7.1) axle 1 to (7.3) axle 3, (8) Maximum permissible axle load in the Member State of registration in kg, (8.1) axle 1 to (8.3) axle 3; and / or (15) Tyres.

[0272] According to embodiments, the first data element is a unique vehicle ID, for example a vehicle registration number or a chassis number.

[0273] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0274] According to embodiments, the second data element is a data element assigned to the vehicle, for example a vehicle registration number or a chassis number.

[0275] Embodiments may have the advantage of providing a unique vehicle ID, for example in the form of the vehicle registration number and / or a chassis number.

[0276] Embodiments further include a server of an issuer service for generating a digital provisioning token. The server includes a processor, a memory with program instructions, and a communication interface for communication over a network. The provisioning token verifies authorization to receive a digital document to be issued with a terminal device and to cryptographically couple it to the terminal device during the issuance process.

[0277] Execution of the program instructions by the processor causes the processor to control the server to: o Receiving a creation request to create the provisioning token, o Identifying the requester using received identification data of the requester, o Creating the requested provisioning token in the form of a signed data record, wherein the creation comprises: receiving a first data element associated with the document to be issued, which uniquely identifies the document to be issued, checking the first data element using a second database entry read from a second database, which includes data to be included in the document to be issued, generating a first salt value, which is associated with the first data element, wherein the association comprises storing a first association of the first salt value to the first data element in a first database, calculating a first hash value using a first combination of the first data element and the first salt value,Creating a data set containing the first hash value, Signing the data set with a cryptographic signature key assigned to the issuing service, Providing the requested provisioning token in the form of the signed data set, o Sending the provisioning token to the identified requester. ,

[0278] According to embodiments, the server is configured to execute any of the previously described embodiments of the method for generating the digital provisioning token.

[0279] Embodiments further include a system comprising a server of an issuer service according to one of the previously described embodiments and a further server providing access to a second database. The second server includes a further processor, a further memory with further program instructions, and a further communication interface for communication via the network.

[0280] Querying the second database entry of the second database comprises sending a query from the server to the further server and receiving by the server the second database entry sent by the further server in response to the query.

[0281] According to embodiments, the system is configured to perform any of the previously described embodiments of the method for generating the digital provisioning token.

[0282] Embodiments further include a digital provisioning token for proving authorization to receive a digital document to be issued with a terminal device and for cryptographically coupling it to the terminal device during issuance. The provisioning token comprises a data set with a first hash value, which is generated using a first combination of a first data element associated with the document to be issued, which uniquely identifies the document to be issued, and a first salt value associated with the first data element. The data set is signed with a signature key of an issuer service that generates the provisioning token.

[0283] According to embodiments, the digital provisioning token is a product of one of the previously described embodiments of the method for generating the digital provisioning token.

[0284] According to embodiments, the signed data set further comprises a second hash value generated using a second combination of a one-time password associated with the identified requester and a second salt value associated with the one-time password.

[0285] According to embodiments, the signed data set further comprises a third hash value generated using a third combination of a second data element associated with the document to be issued and a third salt value.

[0286] Embodiments of the invention will be explained in more detail below with reference to the drawings. They show: Figure 1 shows a flowchart of an exemplary method for creating a provisioning token for a digital document. Figure 2 shows a flowchart of an exemplary method for issuing a digital document. Figure 3 shows a flowchart of an exemplary method for updating a digital document. Figure 4 shows a flowchart of an exemplary method for creating a provisioning token for a copy of a digital document. Figure 5 shows a flowchart of an exemplary method for issuing a copy of a digital document. Figure 6 shows a flowchart of an exemplary method for updating a copy of a digital document. Figure 7 shows a flowchart of an exemplary method for revoking a copy of a digital document. Figure 8 shows a flowchart of an exemplary method for creating a provisioning token for a digital document.Figure 9 shows a flowchart of an exemplary method for creating a provisioning token for a digital document. Figure 10 shows a flowchart of an exemplary method for creating a provisioning token for a copy of a digital document. Figure 11 shows a flowchart of an exemplary method for creating a provisioning token for a digital document. Figure 12 shows a flowchart of an exemplary method for issuing a digital document. Figure 13 shows a flowchart of an exemplary method for issuing a copy of a digital document. Figure 14 shows a flowchart of an exemplary method for updating a digital document. Figure 15 shows a flowchart of an exemplary method for updating a copy of a digital document. Figure 16 shows a flowchart of an exemplary method for revoking a provisioning token or a copy of a digital document.Figure 17 shows an exemplary system for creating a provisioning token for a digital document, Figure 18 shows an exemplary system for issuing a digital document, Figure 19 shows an exemplary system for creating a provisioning token for a copy of a digital document, Figure 20 shows an exemplary system for issuing a copy of a digital document, Figure 21 shows an exemplary provisioning token for a digital document, Figure 22 shows an exemplary digital document, Figure 23 shows an exemplary provisioning token for a copy of a digital document, and Figure 24 shows an exemplary copy of a digital document.

[0287] Elements of the following embodiments that correspond to one another are identified by the same reference numerals.

[0288] Figure 1shows an exemplary method for generating a digital provisioning token by an issuing service. The provisioning token verifies authorization to receive a digital document to be issued with a terminal device and to cryptographically link it to the terminal device during the issuance process.

[0289] In block 200, the first server of the issuer service receives a creation request to create the provisioning token. In block 202, the requester is identified using received identification data from the requester. In block 204, the requested provisioning token is created in the form of a signed data record. Creating the signed data record comprises receiving a first data element associated with the document to be issued, which uniquely identifies the document to be issued. The first data element is verified using a second database entry read from a second database, which includes data to be comprehensively related to the document to be issued. Upon a successful verification, a first salt value is generated, which is associated with the first data element. The association comprises storing a first association of the first salt value with the first data element in a first database.A first hash value is calculated using a first combination of the first data element and the first salt value. The data set containing the first hash value is created. The data set is signed with a cryptographic signature key assigned to the issuing service. The requested provisioning token is provided in the form of the signed data set. In block 206, the provisioning token is sent to the identified requester.

[0290] Figure 2 shows an exemplary method for issuing a digital document using a digital provisioning token, such as is generated using the method according to Figure 1can be created. The provisioning token proves authorization to receive the digital document to be issued with a terminal device and to cryptographically link it to the terminal device during issuance. The provisioning token comprises a first data set with a first hash value, which is generated using a first combination of a first data element assigned to the document to be issued, which uniquely identifies the document to be issued, and a first salt value assigned to the first data element. For example, the data set can comprise further hash values ​​of data elements, which are generated using further salt values. In addition, the data set can comprise, for example, a hash value of a one-time password, which is also generated using a salt value, for example.The first data record is signed with a first signature key of an issuer service that generates the provisioning token.

[0291] A first database entry with a first assignment of the first salt value to the first data element is stored in a first database. Furthermore, the first database entry can store assignments of further salt values ​​to further data elements and / or an assignment of a salt value to a one-time password. A second database entry with data elements of the document to be issued is stored in a second database.

[0292] In block 220, a first server of the issuer service receives an issuance request for issuing the document to be issued from a terminal device of a requestor. In block 222, the provisioning token is received from the terminal device. In block 224, data elements whose hash values ​​are stored in the provisioning token are received. In block 226, a one-time password is also received. In block 228, the provisioning token is validated using the received data elements and the one-time password.

[0293] Validating the provisioning token includes validating the provisioning token's signature using a first signature verification key of the issuer service. Using the first data element, the first database entry is read from the first database. The hash values ​​entered in the provisioning token, for example, hash values ​​of data elements and / or the one-time password, are checked using the read first database entry. For this purpose, the salt values ​​stored in the first database entry are used. Upon successful verification, at least the salt values ​​stored in the first database entry are deleted from the first database. For example, all data associated with the corresponding provisioning token is deleted from the first database entry.

[0294] In block 230, the document is issued. Issuing the document includes, for example, reading the second database entry with the data elements of the document to be issued from the second database. A second data record is created, which includes one or more of the data elements of the second database entry associated with the document to be issued in plain text. A key query is sent to the requester's terminal device. A public cryptographic key associated with the terminal device is received. The received public cryptographic key of the terminal device is added to the second data record to cryptographically bind the second data record to the terminal device. The second data record is signed with a second cryptographic signature key associated with the issuing service. The issued document is stored in the form of the signed second data record.In addition, an assignment of the received public cryptographic key of the terminal device to the issued document is stored in the first database, for example, in the first database entry. Finally, in block 232, the document issued in block 230 is sent to the terminal device.

[0295] Figure 3shows an exemplary method for updating an issued document. The document includes an indication of a time of issuance of the document. In block 240, the updating includes receiving an update request for updating the issued document from a terminal device of a requestor, wherein the update request includes the issued document. In block 242, the second database entry is read from the second database using a data element of the received document. The corresponding data element is used, for example, to provide a database access key for accessing the second database entry. The second database entry includes an indication of a time of a last update of the second database entry.In block 244, the time of issuance of the received document is compared with the time of the last update of the second database entry. In block 246, a check is made to determine whether the document was issued before the last update of the second database entry. If not, the method continues with block 252, in which a timeliness confirmation, i.e., information, is sent to the requestor indicating that the issued document is a current document with current data elements.

[0296] If the document was issued after the last update of the second database entry, the method continues with block 248. In block 248, an updated document is issued. Issuing the updated document comprises creating a data record that includes one or more of the data elements of the read second database entry that are associated with the document to be issued in plain text. The public cryptographic key of the terminal device from the received document is added to the data record for cryptographically binding the data record to the terminal device. The resulting data record is signed with the second cryptographic signature key of the issuer service. The updated document is provided in the form of the signed data record and sent to the terminal device in block 250.

[0297] Figure 4shows an exemplary method for generating a digital provisioning token by an issuer service. The provisioning token verifies authorization to receive a digital copy of an issued digital document to be issued using a terminal device and to cryptographically couple it to the terminal device during issuance. In block 300, a first server of the issuer service receives a creation request to create the provisioning token. In block 302, the requester is identified using the issued digital document. For example, the requester sends the corresponding document with the request and signs the request and / or the sent document. The corresponding signature can be validated using the public cryptographic key contained in the document. The corresponding validation, for example, also identifies the requester.

[0298] In block 304, the requested provisioning token is created in the form of a signed data record. Creating comprises receiving a first data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued. A first data element is checked using a second database entry read from a second database, which includes data to be included in the document to be issued. For example, one or more further data elements are additionally checked. A first salt value is generated, which is assigned to the first data element. Assigning comprises storing a first assignment of the first salt value to the first data element in a first database. For example, salt values ​​are also generated for the further data elements, and the assignment is stored in the first database.A first hash value is calculated using a first combination of the first data element and the first salt value. For example, hash values ​​are also calculated for the additional data elements. A data record is created that includes the first hash value and an indicator. The indicator indicates that it is a provisioning token for a copy of the issued document. For example, the data record additionally includes the hash values ​​of the additional data elements. The data record is signed with a cryptographic signature key assigned to the issuing service. The requested provisioning token is provided in the form of the signed data record. Finally, in block 306, the provisioning token is sent to the identified requester.

[0299] Figure 5shows an exemplary method for issuing a digital copy of an issued digital document using a digital provisioning token, such as that generated using the method according to Figure 4can be created. The provisioning token proves authorization to receive the digital copy of the issued digital document to be issued using a terminal device and to cryptographically link it to the terminal device during the issuance process. The provisioning token comprises a first data set with a first hash value and an indicator. The first hash value is generated using a first combination of a first data element assigned to the issued document, which uniquely identifies the issued document for which a copy is to be issued, and a first salt value assigned to the first data element. The indicator shows that it is a provisioning token for a copy of the issued document. For example, the data set can comprise further hash values ​​of data elements which are generated using further salt values.In addition, the data set can include, for example, a hash value of a one-time password, which is also generated using a salt value, for example. The first data set is signed with a first signature key of an issuer service that generates the provisioning token.

[0300] A first database entry with a first assignment of the first salt value to the first data element is stored in a first database. Furthermore, the first database entry can store assignments of further salt values ​​to further data elements and / or an assignment of a salt value to a one-time password. A second database entry with data elements of the issued document is stored in a second database.

[0301] In block 320, a first server of the issuer service receives an issuance request for issuing the copy of the issued document to be issued from a terminal device of a requestor. In block 322, the provisioning token is received from the terminal device. In block 324, data elements whose hash values ​​are stored in the provisioning token are received. In block 326, a one-time password is also received. In block 328, the provisioning token is validated using the received data elements and the one-time password.

[0302] Validating the provisioning token includes validating the provisioning token's signature using a first signature verification key of the issuer service. Using the first data element, the first database entry is read from the first database. The hash values ​​entered in the provisioning token, for example, hash values ​​of data elements and / or the one-time password, are checked using the read first database entry. For this purpose, the salt values ​​stored in the first database entry are used. Upon successful verification, at least the salt values ​​stored in the first database entry are deleted from the first database. For example, all data associated with the corresponding provisioning token is deleted from the first database entry.

[0303] In block 330, the copy of the document is issued. Issuing the copy of the document comprises, for example, reading the second database entry from the second database. A second record is created, which comprises, in plain text, one or more of the data elements of the second database entry associated with the document to be issued. The second record further comprises a plain text indicator indicating that it is a record of a copy of the issued document. A key request is sent to the requester's terminal device. A public cryptographic key associated with the terminal device is received. The received public cryptographic key of the terminal device is added to the second record to cryptographically bind the second record to the terminal device. The second record is signed with a second cryptographic signature key associated with the issuer service.The issued copy of the document is provided in the form of the signed second data record. Furthermore, an association of the received public cryptographic key of the terminal device with the issued copy of the document is stored in the first database, for example, in the first database entry. Finally, in block 332, the copy of the document issued in block 330 is sent to the terminal device.

[0304] Figure 6shows an exemplary method for updating an issued document copy. The document copy includes an indication of a time of issuance of the document copy. In block 340, the updating includes receiving an update request for updating the issued document copy from a terminal device of a requestor, wherein the update request includes the issued document copy. In block 342, the second database entry is read from the second database using a data element of the received document copy. The corresponding data element is used, for example, to provide a database access key for accessing the second database entry. The second database entry includes an indication of a time of a last update of the second database entry.In block 344, the time of issuance of the received document copy is compared with the time of the last update of the second database entry. In block 346, a check is made to determine whether the document copy was issued before the last update of the second database entry. If not, the method continues with block 352, in which a timeliness confirmation, i.e., information, is sent to the requestor indicating that the issued document copy is a current document copy with current data elements.

[0305] If the document copy was issued after the last update of the second database entry, the method continues with block 348. In block 348, an updated document copy is issued. Issuing the updated document copy comprises creating a data record that includes, in plain text, one or more of the data elements of the read second database entry that are associated with the document copy to be issued. The data record further comprises a plain text indicator that indicates that it is a data record of a copy of the issued document. The public cryptographic key of the terminal device from the received document copy is added to the data record for cryptographically binding the data record to the terminal device. The resulting data record is signed with the second cryptographic signature key of the issuer service.The updated document copy is provided in the form of the signed data record and sent to the terminal device in block 350.

[0306] Figure 7 shows an exemplary procedure for revoking the Figure 5issued copy of the document. In block 360, the server of the issuer service receives a revocation request to revoke the issued copy of the document from a terminal device cryptographically bound to the issued document. For example, the revocation request comprises the issued document. The received issued document is signed with a private cryptographic key associated with the terminal device cryptographically bound to the issued document. The method further comprises validating the received document. Validating comprises checking the signature of the received document with the private cryptographic key of the terminal device cryptographically bound to the issued document using the public cryptographic key of the terminal device cryptographically bound to the issued document comprised in the received document.In block 362, at least one assignment of the public cryptographic key of the terminal device cryptographically bound to the copy of the document to be revoked is deleted from the first database. For example, all data associated with the copy of the document to be revoked can be deleted from the first database. In block 364, the server sends a revocation confirmation to the terminal device.

[0307] In a similar way, a provisioning token for receiving a digital copy of an issued digital document can also be revoked before the corresponding copy has been issued. In this case, for example, salt values ​​stored in the first database for the provisioning token to be revoked are deleted. For example, all data associated with the provisioning token to be revoked is deleted in the first database.

[0308] Figure 8shows an exemplary method for creating a digital provisioning token for a digital document to be issued. In block 400, the requestor who submits a request to create the provisioning token is identified. In block 402, the corresponding provisioning token is created. In block 404, the provisioning token is sent to the requestor.

[0309] Figure 9 shows the creation of the provisioning token according to block 402 of the Figure 8 In more detail. In block 410, salt values ​​are generated and stored in a first database 120. In block 412, hash values ​​for storage in the provisioning token are calculated using the salt values ​​generated in block 410. In block 414, the signed provisioning token is created using the hash values ​​from block 412 and sent to the requester in block 416.

[0310] Figure 10shows an exemplary method for creating a digital provisioning token for a digital copy of a digital document. In block 420, a requester submitting a request to create the corresponding provisioning token to the server of an issuer service is identified using the document in their possession. In block 422, a validity period is defined for the document copy to be obtained with the provisioning token. In block 424, the signed provisioning token is created and sent to the requester in block 426.

[0311] Figure 11shows another exemplary method for creating a digital provisioning token for a digital document to be issued. In block 430, the requestor making a request to create the provisioning token is identified. In block 432, a database entry 182 with data elements of the document to be issued is read from the second database 140. This database entry 182 is used to check that hash values ​​entered into the provisioning token are based on correct, existing data elements. In block 434, the provisioning token is created. During the creation of the provisioning token, hash values ​​are generated using the data elements and salt values. An assignment of the data elements to the salt values ​​is stored in a first database 120. In block 436, the created provisioning token is sent to the requestor, who receives it.

[0312] Figure 12shows an exemplary method for issuing a digital document using a provisioning token. In block 440, the digital provisioning token is loaded onto a terminal device, for example, in an app. In block 442, the provisioning token is sent to a server of an issuing service, which validates a signature of the provisioning token. In block 444, the requester is requested to provide data elements for validating the hash values ​​contained in the provisioning token. For example, a one-time password of the requester is also requested. In block 446, the hash values ​​of the provisioning token are validated using the salt values ​​provided by the first database 120.Upon successful validation, the salt values ​​stored in the first database 120 for the provisioning token are deleted in block 448, so that the provisioning token cannot be used again to issue the document. In block 450, data elements for the document to be issued are read from a database entry in a second database 140. In block 452, a data record for the document is created using the data elements contained in the read database entry. In block 454, the requester requests a public cryptographic key of a terminal device of the requester in order to be able to cryptographically bind the document to the corresponding terminal device. In block 456, the requested public cryptographic key of the terminal device is sent to the server of the issuing service, which issues the document in block 458. In block 460, the issued, i.e., signed document with the data elements from the read database entry and the public cryptographic key of the end device is sent to the requester, who receives the document.

[0313] Figure 13shows an exemplary method for issuing a digital copy of a document using a provisioning token. In block 441, the digital provisioning token is loaded onto a terminal device, for example, in an app. In block 443, the provisioning token is sent to a server of an issuing service, which validates a signature of the provisioning token. In block 445, the requester is requested to provide data elements for validating the hash values ​​contained in the provisioning token. For example, a one-time password of the requester is also requested. In block 447, the hash values ​​of the provisioning token are validated using the salt values ​​provided by the first database 120.Upon successful validation, the salt values ​​stored in the first database 120 for the provisioning token are deleted in block 449 so that the provisioning token cannot be used again to issue a copy of the document. In block 451, data elements for the copy of the document to be issued are read from a database entry in a second database 140. In block 453, a data record for the copy of the document is created using the data elements contained in the read database entry. In block 455, the requester requests a public cryptographic key of a terminal device of the requester in order to cryptographically bind the copy of the document to the corresponding terminal device. In block 457, the requested public cryptographic key of the terminal device is sent to the server of the issuing service, which issues the copy of the document in block 459.In block 461, the issued, i.e., signed, document copy with the data elements from the read database entry and the public cryptographic key of the terminal is sent to the requester, who receives the copy.

[0314] Figure 14shows an exemplary method for updating an issued document. In block 470, a requester sends an update request to a server of an issuer service using a terminal device, for example, a mobile device and an app running on it. In block 472, the requester identifies himself with the issued document. For example, the corresponding document is sent along with the update request. In block 474, the document is received by the server. In block 476, a database entry with current data elements for the document is read from database 140. In block 478, an issue time of the document is compared with an update time of a last update of the read database entry. If the issuer time is more recent, this means that the document is up to date.In block 482, an up-to-dateness confirmation is sent to the requester's device, confirming that the document is up-to-date. In block 484, the up-to-dateness confirmation is displayed, for example, on the requester's device.

[0315] If the issuer time is older, this means that the document is not up to date. In block 486, an updated record is created with the current data elements from the read database entry. In block 488, an updated record is issued with the same device binding as the previous document, i.e., with the same public cryptographic key of the requester's device. In block 490, the updated document is sent to the requester, who receives the updated document on their device in block 492.

[0316] Figure 15shows an exemplary method for updating an issued copy of a document. In block 471, a requester sends an update request to a server of an issuer service using a terminal device, for example, a mobile device and an app running on it. In block 473, the requester identifies himself with the issued copy of the document. For example, the corresponding copy is sent along with the update request. In block 475, the document copy is received by the server. In block 477, a database entry with current data elements for the copy of the document is read from database 140. In block 479, an issue time of the document copy is compared with an update time of a last update of the read database entry. If the issuer time is more recent, this means that the copy is up to date.In block 483, an up-to-dateness confirmation is sent to the requester's device, confirming that the copy of the document is up-to-date. In block 485, the up-to-dateness confirmation is displayed, for example, on the requester's device.

[0317] If the issuer time is older, this means that the copy of the document is not up to date. In block 487, an updated record is created with the current data elements from the read database entry. In block 489, an updated record is issued with the same device binding as the previous document copy, i.e., with the same public cryptographic key of the requester's device. In block 491, the updated copy of the document is sent to the requester, who receives the updated copy of the document on their device in block 493.

[0318] Figure 16shows an exemplary method for revoking a digital provisioning token for issuing a digital copy of a digital document or the issued copy of the document. In block 500, a revocation request is made by a requester who is in possession of the document. In block 502, the requester identifies himself with the document; for example, the document is sent from a terminal device of the requester to a server of an issuer service together with the revocation request. In block 504, data associated with the provisioning token or the issued copy of the document is deleted in the first database 120. In the first case, for example, salt values; in the second case, for example, the public cryptographic key of the terminal device to which the copy is cryptographically bound. By deleting the corresponding data, the provisioning token orThe document copy can no longer be validated and thus can no longer be used. In block 506, a revocation confirmation is therefore sent to the requester, who receives the confirmation in block 508 on his or her terminal device and, for example, displays it on the same.

[0319] Figure 17shows an exemplary system 192 for generating a digital provisioning token 170 for a digital document by an issuer service. The system 192 includes a first server 100 of the issuer service. The server 100 includes a processor 102, a memory 104 with program instructions 112, and a communication interface 114 for communication via a network 190. Furthermore, the server 100 has access to a first database 120, for example. Execution of the program instructions 112 by the processor 102 causes the processor 102 to control the server 100 to execute a method for generating a digital provisioning token 170. For example, this is the method according to Figure 1 .

[0320] The system 192 further includes, for example, a second server 130, which provides the first server 100 of the issuing service with access to a second database 140. A database entry 182 containing data elements for a digital document is stored in the database 140. The second server 130 includes a processor 132, a memory 134 containing program instructions 136, and a communications interface 138 for communication via the network 190. Execution of the program instructions 136 by the processor 132 causes the processor 132 to control the server 130 to provide the database entry 182 to the first server 100.

[0321] Furthermore, the system 192 comprises, for example, a terminal 150, in particular a mobile terminal, such as a smartphone. The terminal 150 comprises a processor 152, a memory 154 with program instructions 162, and a communication interface 166 for communication via the network 190. Furthermore, the terminal 150 comprises, for example, a user interface 164, via which a user can control the terminal 150, for example, to request the creation of a provisioning token 170 for a digital document. Execution of the program instructions 162, which, for example, implement a corresponding app on the terminal 150, by the processor 152 causes the processor 152 to control the terminal 150 to request the provisioning token 170 from the server 100 of the issuing service via the network 190.

[0322] For example, the requester first identifies himself to the server 100 using the terminal 150 using the identification data 186. Furthermore, the terminal 150 can send one or more data elements 184 of the document to be issued to the server 100. Based on the received data elements, the server 100 can identify the database entry 182, which it reads from the second database 140 via the server 130. Using this database entry 182, the server 100 can check the correctness of the data elements 184 and calculate hash values ​​for provisioning tokens 170 from the data elements 182. For this purpose, salt values ​​are assigned to the data elements 182, and the corresponding assignments are stored in the first database 120 in a first database entry 180. The server 100 signs the created provisioning token 170 using the private cryptographic key 108, which is used as the signature key.The private cryptographic key 108 is stored, for example, in a protected storage area 106 of the memory 104. The resulting signature can be verified using a public cryptographic key 110 of the server 100 as a signature verification key. The provisioning token 170 thus created is made available to the terminal device 150 via the network 190.

[0323] For example, the terminal 150 also includes a symmetric cryptographic key pair assigned to the terminal 150. This asymmetric cryptographic key pair includes a private cryptographic key 158 and a public cryptographic key 160. The private cryptographic key 158 is stored, for example, in a protected memory area 156 of the memory 154.

[0324] Figure 18shows an exemplary system 192 for issuing a digital document using the provisioning token 170. The system 192 in Figure 18 corresponds to the system 192 in Figure 17 The terminal device 150 uses the provisioning token 170 to request that the server 100 issue the digital document 172. The server 100 validates the provisioning token 170. The validation includes, for example, a signature verification using the public cryptographic key 110 and the hash values ​​contained in the provisioning token 170. For this purpose, the salt values ​​from the first database entry 180 and data elements from the second database entry 182 are used, for example. Upon successful validation, the salt values ​​from the first database entry 180 are deleted, so that the provisioning token 170 cannot be used again.

[0325] Furthermore, document 172 is created, which includes data elements of the document from the second database entry 182 and is signed, for example, with the private cryptographic key 108. For a cryptographic binding of document 172 to the terminal 150, the public cryptographic key 160 of the terminal 150 is additionally added to the document 172. The resulting document is sent to the terminal 150, for example, via the network 190.

[0326] Figure 19 shows an exemplary system 192 for generating a digital provisioning token 174 for a copy of the digital document 172 by the issuer service. The system 192 in Figure 19 corresponds to the system 192 in Figure 18A user uses the terminal device to request a digital provisioning token 174 for a copy of an issued document, for example, document 172. The terminal device 150 identifies the requester to the server 100, for example, using the document 172. The server 100 creates a provisioning token 174 for a copy of the digital document 172. The creation of the provisioning token 174 corresponds, for example, to the creation of the provisioning token 170 in Figure 17. The provisioning token 174 differs from the provisioning token 170, for example, in that it includes an indicator indicating that it is a provisioning token for a copy of a document. Furthermore, the provisioning token 174 includes, for example, an indication of a validity period of the copy of the document to be issued. This validity period can be set, for example, by the user of the terminal 150. The created provisioning token 174 is sent from the server 100 to the terminal 150. The terminal 150 can forward the provisioning token 174, for example, to another terminal 151 of another user. This enables the other user to have a copy of the document 172 issued without any further action being required on the part of the user of the terminal 150, i.e., the owner of the document 172.

[0327] The terminal 151 is, for example, a mobile terminal, such as a smartphone. The terminal 151 comprises a processor 153, a memory 155 with program instructions 163, and a communication interface 167 for communication via the network 190. In addition, the terminal 151 comprises, for example, a user interface 165, via which a user can control the terminal 151, for example, to request the issuance of a copy of the document 172 using the provisioning token 174 received from the terminal 150. Execution of the program instructions 163, which, for example, implement a corresponding app on the terminal 151, by the processor 153 causes the processor 153 to control the terminal 151 to request the issuance of a copy of the document 172 via the network 190 from the server 100 of the issuing service. This is Figure 20 shown.

[0328] Figure 20shows an exemplary system 192 for issuing a copy of a digital document using the provisioning token 174. The system 192 in Figure 20 corresponds, for example, to the system in Figure 19 without the terminal 150, which plays no further role in issuing the copy of the document, for example.

[0329] The terminal device 151 uses the provisioning token 174 to request that the server 100 issue the digital copy 176 of the document. The server 100 validates the provisioning token 174. The validation includes, for example, a signature verification using the public cryptographic key 110 and the hash values ​​contained in the provisioning token 174. For this purpose, the salt values ​​from the first database entry 180 and data elements from the second database entry 182 are used, for example. Upon successful validation, the salt values ​​from the first database entry 180 are deleted, so that the provisioning token 174 cannot be used again.

[0330] Furthermore, a copy 176 of the document is created, which includes data elements of the document from the second database entry 182 and is signed, for example, with the private cryptographic key 108. For a cryptographic binding of the document copy 176 to the terminal 151, the public cryptographic key 161 of the terminal 151 is additionally added to the document 176. The resulting document copy 176 is sent to the terminal 151, for example, via the network 190.

[0331] The document copy 176 includes an indicator that identifies it as a copy, ie, that indicates that it is a copy of a document. Furthermore, the document copy 176 includes, for example, an indication of a validity period of the issued copy of the document.

[0332] For example, the terminal 151 also includes a symmetric cryptographic key pair assigned to the terminal 151. This asymmetric cryptographic key pair includes a private cryptographic key 159 and a public cryptographic key 161. The private cryptographic key 159 is stored, for example, in a protected memory area 157 of the memory 155.

[0333] Figure 21 shows an exemplary digital provisioning token 170 for proving authorization to receive a digital document to be issued with a terminal device and for cryptographically coupling it to the terminal device during the issuance process. A corresponding provisioning token 170 can be generated, for example, using the method according to Figure 1The provisioning token 170 comprises a data set 602 with hash values ​​604, 606, which are generated using combinations of data elements associated with the document to be issued, which uniquely identify the document to be issued, and salt values ​​associated with the data elements. The data set 602 is signed with a signature key of an issuer service generating the provisioning token 170, i.e., with the signature 600.

[0334] Figure 22 shows an exemplary digital document 172, which comprises a data record 612 with data elements 614, 615 in plain text. A corresponding document 172 can, for example, be created using the method according to Figure 2be issued. Data set 612 is signed with a signature key of an issuing service issuing the document, i.e., with signature 610. Data set 610 further includes a public cryptographic key 160 of a terminal device for cryptographically binding document 172 to the corresponding terminal device. In addition, data set 610 also includes, for example, an indication 618 of the time of issue of document 172.

[0335] Figure 23 shows an exemplary digital provisioning token 174 for proving an authorization to receive a digital copy of an issued digital document with a terminal device and for cryptographically coupling it to the terminal device during the issuance process. A corresponding provisioning token 174 can be generated, for example, using the method according to Figure 4The provisioning token 174 comprises a data set 622 with hash values ​​624, 626, 628 and an indicator 630. The hash values ​​624, 626 are generated using a combination of a data element associated with the issued document, which uniquely identifies the issued document for which a copy is to be issued, and salt values ​​associated with the data elements. The hash value 628 is, for example, a hash value indicating a validity period of the document copy to be issued, which is generated using a salt value. The indicator 630 indicates that this is a provisioning token 174 for a copy of the issued document. The data set 620 is signed with a signature key of an issuer service that generates the provisioning token 174, i.e., with the signature 620.

[0336] Figure 24shows an exemplary digital copy 176 of an issued document. A corresponding document copy 176 can be created, for example, using the method according to Figure 5 be issued. The copy 176 comprises a data record 642 with data elements 644, 645 and an indicator 652 in plain text. The indicator 652 indicates that it is a document copy. The data record 642 is signed with a signature key of an issuing service issuing the copy 176 of the document, i.e., with the signature 640. The data record 642 further comprises a public cryptographic key 161 of a terminal device for cryptographically binding the copy 174 of the document to the terminal device. Finally, the data record 642 also comprises, for example, an indication 648 of a time of issue of the document copy 176 and an indication 650 of a validity period of the document copy 176. List of reference symbols

[0337] 100 first server 102 processor 104 memory 106 protected memory area 108 private key 110 public key 112 program instructions 114 communication interface 120 first database 130 second server 132 processor 134 memory 136 program instructions 138 communication interface 140 second database 150 mobile device 151 mobile device 152 processor 153 processor 154 memory 155 memory 156 protected memory area 157 protected memory area 158 private key 159 private key 160 public key 161 public key 162 program instructions 163 program instructions 164 user interface 165 user interface 166 communication interface 167 communication interface 170 provisioning token 172 document 174Provisioning token 176Document copy 180First database entry 182Second database entry 183Assignment salt value 184Data elements 186Identification data 190Network 192System 600Signature 602Data record 604Hash value 606Hash value610Signature 612Data record 614Data element 616Data element 618Indication of issue time 620Signature 622Data record 624Hash value 626Hash value 628Hash value 630Indicator 640Signature 642Data record 644Data element 646Data element 648Indication of issue time 650Indication of validity period 652Indicator

Claims

1. A method for issuing a digital copy (174) of an issued digital document using a digital provisioning token (174), wherein the provisioning token (174) proves authorization to receive the digital copy (174) of the issued digital document to be issued with a terminal device (151) and to cryptographically couple it to the terminal device (151) during the issuance process, wherein the provisioning token (174) comprises a first data set (622) with a first hash value (624) and an indicator, wherein the first hash value (624) is generated using a first combination of a first data element (644) associated with the issued document (172), which uniquely identifies the issued document (172) for which a copy (174) is to be issued, and a first salt value associated with the first data element (644), wherein the indicator (630) indicatesthat it is a provisioning token (174) for a copy (174) of the issued document, wherein the first data set (622) is signed with a first signature key (108) of an issuer service generating the provisioning token (174), wherein a first database entry (180) with a first assignment of the first salt value to the first data element (644) is stored in a first database (120), wherein a second database entry (182) with data elements (644) of the issued document (172) is stored in a second database (140), wherein the method comprises, by a first server (100) of the issuer service: o receiving an issuance request for issuing the copy (174) of the issued document to be issued from a terminal (151) of a requester, o receiving the provisioning token (174) from the terminal (151), o validating the provisioning token (174),wherein validating the provisioning token (174) comprises: • validating the signature of the provisioning token (174) using a first signature verification key (110) of the issuer service, • reading the first database entry (180) from the first database (120) using the received first data element (644), • checking the hash values ​​(624, 626, 628) entered in the provisioning token (174) using the read first database entry (180), • upon a successful check, deleting at least the salt values ​​stored in the first database entry (180) in the first database (120), ∘ issuing the copy (174) of the document, wherein issuing the copy (174) of the document comprises: • reading the second database entry (182) from the second database (140), • creating a second data record (642) which contains one or more of the Data elements of the second database entry (182),which are associated with the document (172) to be issued, in plain text, wherein the second data set (642) further comprises an indicator (652) in plain text indicating that it is a data set of a copy (174) of the issued document, • sending a key query to the terminal device (151), • receiving a public cryptographic key (161) associated with the terminal device (151), • adding the received public cryptographic key (161) of the terminal device (151) to the second data set (642) for cryptographically binding the second data set (642) to the terminal device (151), • signing the second data set (642) with a second cryptographic signature key (108) associated with the issuer service, • providing the issued copy (174) of the document in the form of the signed second data set (642),• Storing an assignment of the received public cryptographic key (161) of the terminal (151) to the issued copy (174) of the document in the first database (120), o Sending the issued copy (174) of the document to the terminal (151)., 2. The method according to claim 1, wherein the method further comprises receiving the first data element (644) and using the received first data element (644) to read the first database entry (180) from the first database (120), and / or wherein the assignment of the received public cryptographic key (161) of the terminal (151) to the issued copy (174) of the document is stored in the first database entry (180) of the first database (120), and / or wherein validating the provisioning token (174), upon a successful check, comprises deleting all data associated with the provisioning token (174) from the first database entry (180) in the first database (120), and / or wherein the second data record (642) comprises all of the data elements of the second database entry (182) associated with the issued document (172) in plain text,and / or wherein the first data element (644) is used to provide a database access key for identifying the first database entry (180) stored in the first database (120) with the first assignment of the generated first salt value to the first data element (644), and / or wherein the method further comprises receiving a second data element (646) of the issued document (172), which is used to read the first database entry (180) from the first database (120), wherein the second data element (646) is used to provide the database access key for identifying the first database entry (180) stored in the first database (120), and / or wherein access to the second database (140) is provided via a second server (130),wherein querying the second database entry (182) comprises sending a query to the second server (130) and receiving the second database entry (182) in response to the query, and / or wherein the first data set (622) of the provisioning token (174) further comprises a second hash value generated using a second combination of a one-time password and a second salt value associated with the one-time password, wherein a second association of the second salt value with the one-time password is stored in the first database entry (180) of the first database (120), wherein validating the provisioning token (174) further comprises receiving the one-time password and checking the second hash value using the received one-time password and the read-out first database entry (180).

3. The method according to any one of the preceding claims, wherein the second data record (642) of the issued copy (174) of the document further comprises an indication (648) of a time of issuance of the copy (174).

4. The method according to claim 3, wherein the method further comprises updating the issued copy (174) of the document, wherein the updating comprises: o receiving an update request for updating the issued copy (174) of the document from the terminal (151), wherein the update request comprises the issued copy (174), o reading the second database entry (182) from the second database (140) using the first data element (644) of the received copy (174) of the document, wherein the second database entry (182) comprises an indication of a time of a last update of the second database entry (182), o comparing the indication (648) of the time of issuance of the received copy (174) of the document with the indication of the time of the last update of the second database entry (182), o determining,that the last update of the second database entry (182) occurred after the copy (174) of the document was issued, o issuing an updated copy of the document, wherein issuing the updated copy of the document comprises: • creating a fourth data record which comprises one or more of the data elements of the read second database entry (182) associated with the copy (174) of the document to be issued, in plain text, wherein the fourth data record further comprises an indicator (652) in plain text indicating that it is a data record of a copy of the issued document, • adding the public cryptographic key (161) of the terminal (151) from the received copy (174) of the document to the fourth data record for cryptographically binding the fourth data record to the terminal (151),• Signing the fourth data record with the second cryptographic signature key (108) of the issuer service, • Providing the updated copy of the document in the form of the signed fourth data record, o Sending the updated copy of the document to the terminal (151)., 5. The method of claim 4, wherein the received issued copy (174) of the document is signed with a private cryptographic key (159) associated with the terminal (151), the method further comprising validating the received copy (174) of the document, wherein the validating comprises checking the signature of the received copy (174) of the document with the private cryptographic key (159) of the terminal (151) using the public cryptographic key (161) of the terminal (151) included in the received copy (174) of the document.

6. The method according to one of the preceding claims, wherein the second data record (642) further comprises an indication (650) of a validity period provided for the issued copy (174) in plain text. wherein the provisioning token (174) further comprises, for example, a third hash value (626) which, using a third combination of the indication (650) of the validity period with a third salt value, a third assignment of the third salt value to the indication (650) of the validity period is stored in the first database entry (180) in the first database (120), wherein checking the hash values ​​entered in the provisioning token comprises, for example, checking the third hash value (626).

7. The method according to any one of the preceding claims, wherein the method further comprises revoking the issued copy (174) of the document, wherein the revoking comprises: o receiving a revocation request to revoke the issued copy (174) of the document from a terminal device (150) cryptographically bound to the issued document (172), o deleting at least the assignment of the public cryptographic key (161) of the terminal device (151) cryptographically bound to the copy (174) of the document to be revoked from the first database (120), o sending a revocation confirmation to the terminal device (150).

8. The method of claim 7, wherein the revocation request comprises the issued document (172), wherein the received issued document (172) is signed with a private cryptographic key (158) associated with the terminal device (150) cryptographically bound to the issued document (172), the method further comprising validating the received document (172), wherein the validating comprises checking the signature of the received document (172) with the private cryptographic key (158) of the terminal device (150) cryptographically bound to the issued document (172) using the public cryptographic key (160) of the terminal device (150) cryptographically bound to the issued document (172) comprised by the received document (172).

9. Method according to one of the preceding claims, wherein the issued copy (174) of the document (172) is a copy of a vehicle document, for example a copy of an electronic registration certificate Part I.

10. The method according to claim 9, wherein the first data element (644) is a unique vehicle ID, for example a vehicle registration number or a chassis number, and / or wherein the second data element (646) is a data element associated with the vehicle, for example a vehicle registration number or a chassis number.

11. Server (100) of an issuer service for issuing a digital copy (174) of an issued digital document using a digital provisioning token (174), wherein the server (100) comprises a processor (102), a memory (104) with program instructions (112) and a communication interface (114) for communication via a network (190), wherein the provisioning token (174) proves an authorization to receive the digital copy (174) of the issued digital document to be issued with a terminal (151) and for cryptographic coupling to the terminal (151) in the course of issuing, wherein the provisioning token (174) comprises a first data record (622) with a first hash value (624) and an indicator, wherein the first hash value (624) is generated using a first combination of a first data element (644) assigned to the issued document (172), which first data element (172),for which a copy (174) is to be issued, and a first salt value associated with the first data element (644), wherein the indicator (630) indicates that it is a provisioning token (174) for a copy (174) of the issued document, wherein the first data record (622) is signed with a first signature key (108) of an issuer service generating the provisioning token (174), wherein the server (100) has access to a first database (120) in which a first database entry (180) with a first assignment of the first salt value to the first data element (644) is stored, wherein the server (100) further has access to a second database (140) in which a second database entry (140) with data elements of the issued document (172) is stored, wherein an execution of the program instructions (112) by the processor (102) Processor (102) causesto control the server (100) to: o receive an issuance request for issuing the copy (174) of the issued document to be issued from a terminal (151) of a requester, o receive the provisioning token (174) from the terminal (151), o validate the provisioning token (174), wherein the validation of the provisioning token (174) comprises: • validating the signature of the provisioning token (174) using a first signature verification key (110) of the issuer service, • reading the first database entry (180) from the first database (120) using the received first data element (644), • checking the hash values ​​(624, 626, 628) entered in the provisioning token (174) using the read first database entry (180), • upon a successful check, deleting at least the hash values ​​(624, 626, 628) entered in the first database entry (180) stored salt values ​​in the first database (120),o Issuing the copy (174) of the document, wherein issuing the copy (174) of the document comprises: • Reading the second database entry (182) from the second database (140), • Creating a second data record (642) comprising one or more of the data elements of the second database entry (182) associated with the document (172) to be issued in plain text, wherein the second data record (642) further comprises an indicator (652) in plain text indicating that it is a data record of a copy (174) of the issued document, • Sending a key query to the terminal (151), • Receiving a public cryptographic key (161) associated with the terminal (151), • Adding the received public cryptographic key (161) of the terminal (151) to the second data record (642) for cryptographically binding the second data record (642) to the terminal (151),• Signing the second data set (642) with a second cryptographic signature key (108) assigned to the issuer service, • Providing the issued copy (174) of the document in the form of the signed second data set (642), • Storing an assignment of the received public cryptographic key (161) of the terminal (151) to the issued copy (174) of the document in the first database (120), o Sending the issued copy (174) of the document to the terminal (151)., 12. A system (192) comprising a server (100) of an issuer service according to claim 11 and a further server (130) which provides access to the second database (140), wherein the further server (130) comprises a further processor (132), a further memory (134) with further program instructions (136) and a further communication interface (138) for communication via the network (190), wherein querying the second database entry (182) comprises sending a query from the server (100) to the further server (130) and receiving the second database entry (182) sent by the further server (130) in response to the query by the server (100).

13. The system (192) of claim 12, wherein the system (192) further comprises the terminal (150, 151).

14. A digital copy (174) of an issued document, the copy (174) comprising a data set (642) with data elements and an indicator (652) in plain text, the indicator (652) indicating that it is a copy (174) of the issued document, the data set (642) being signed with a signature key (108) of an issuer service issuing the copy (174) of the document, the data set (642) further comprising a public cryptographic key (161) of a terminal (151) for cryptographically binding the copy (174) of the document to the terminal (151).

15. Digital copy (174) according to claim 14, wherein the signed data record (642) further comprises an indication (650) of a period of validity of the copy (174) of the document in plain text, and / or wherein the signed data record (642) further comprises an indication (648) of a time of issue of the copy (174) of the document in plain text, and / or wherein the copy (174) is a copy of a vehicle document, for example a copy of an electronic registration certificate Part I.

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