Procedure and system for verifying a user's charging contract to authorize a charging process for charging an electric vehicle at a charging infrastructure

Abstract

Procedure for verifying a user's charging contract to authorise a charging process for charging an electric vehicle at a charging infrastructure (14), comprising the following steps: a) Generation of a feature associated with the user's charging contract by a charging power provider (10) (Step 100, Step 300); b) Encrypted transmission of the feature associated with the user's charging contract from the electricity provider (10) to a storage device on a mobile device (12) of the user (step 120, step 320); c) Transfer of data at least from the mobile device (12) to the charging infrastructure (14) using the feature assigned to the user's charging contract (step 140, step 340); d) Checking the data received from the charging infrastructure (14) under the attribute assigned to the user's charging contract (step 220, step 360); and e) Release of the charging process by the charging infrastructure (14) upon successful verification (step 240, step 380); where in step a) at least a digital contract certificate and a private contract key of the charging contract are generated for the user as the feature assigned to the user's charging contract (step 100), characterized by the fact that In step b) the feature from the charging provider (10) is transmitted in encrypted form to the memory of the mobile device (12), which is designed as a secure memory (step 120, step 320); wherein in step c) a challenge-response procedure is carried out between the charging infrastructure (14) and the mobile device (12) using the private contract key of the charging contract (step 140, step 160, step 180, step 200).

Description

[0001] The present invention relates to a method for verifying a user's charging contract for releasing a charging process for charging an electric vehicle at a charging infrastructure and a corresponding system.

[0002] Currently, RFID cards are primarily used to authenticate charging contracts at charging stations. Furthermore, with newer authentication methods, such as Plug and Charge, charging contracts are permanently stored in the user's vehicle. Another option for authenticating charging contracts at charging stations is remote activation. In this case, a user can, for example, initiate activation via an app through the charging station operator's backend.

[0003] RFID cards have the disadvantage of being easily forgotten, taking up extra space in a wallet, and being easily transferable, thus opening up possibilities for misuse. Plug and Charge's security concept involves a fixed contract linked to a specific vehicle. Simply transferring the card to another vehicle is therefore not possible. The aforementioned remote activation requires an internet connection, which is not always available.

[0004] German patent application DE 10 2009 037 968 ​​A1 discloses a method and a device for identifying an electric vehicle to a billing center. In this process, the billing center sends a contract key to the electric vehicle after the electric vehicle has initiated a charging process. The contract key is stored on the electric vehicle, and subsequent billing of the charging process is carried out using this contract key.

[0005] German patent application DE 10 2009 030 091 A1 discloses a method and a device for secure communication between a charging station and an electric vehicle. In this method, a public contract key and a private contract key are generated at the time of conclusion of a contract with an energy supplier, with the public contract key being stored in a billing center.

[0006] From WO 2012 / 149965 A1, a method and a device for supplying electrical energy to a vehicle are known. Information regarding the type of contract of a driver of the vehicle is stored in a central instance and is taken into account during the vehicle's charging process.

[0007] US 2012 / 0 331 301 A1 describes a method and an access control system for reserving and activating an electric vehicle charger via a server using at least one mobile device. The server transmits an encrypted digital token or certificate to the mobile device, which then sends it wirelessly to the charger.

[0008] WO 2013 / 017 446 A2 discloses a method for accessing an energy charging service, wherein a vehicle is connected to a controller linked to a removable token and to an energy charging station linked to a server. When the user is identified, the server sends a request to the token via the charging station and the controller, and the token sends the request, signed with the user's key, back to the server via the controller and the station.

[0009] US 2013 / 0 110 296 A1 describes a method for managing the charging of an electric vehicle. A network connection includes a mobile device positioned between an electric vehicle charging station and a cloud server to facilitate communication between the charging station and the cloud server. To authenticate a user, the cloud server or the mobile device generates a unique access key based on a valid charging station identification and sends the access key to the charging station via the network connection.

[0010] The object of the present invention is to further develop a method and a system mentioned above in such a way as to enable a user to charge an electric vehicle in the most convenient way possible and in a way that is as secure as possible against unauthorized access.

[0011] This problem is solved by a method having the features of claim 1 and by a system having the features of claim 17.

[0012] The present invention is based on the understanding that mobile devices, such as smartphones, already offer the possibility of storing sensitive information in a secure memory protected from unauthorized access. Information stored in secure memory cannot be read by unauthorized apps or altered by unauthorized access. The possibility of storing sensitive information in the secure memory of a mobile device is already used, for example, to perform payment functions with a mobile device or – in the applicant's case – with the so-called Audi connect key, with which Audi digitizes the conventional vehicle key and transfers it, for example, to the secure memory of a smartphone. Thus, access to and starting of a motor vehicle can be enabled via the smartphone.

[0013] On smartphones, such as Samsung's Galaxy series, secure storage is also known as a secure folder. It allows you to protect private data, such as pictures, notes, and applications, from unauthorized access, even when the smartphone is unlocked. The "secure folder" function is a separate and secure storage location. It is not possible to transfer data from the secure folder to other devices using unauthorized sharing methods, such as Wi-Fi Direct or USB. Unofficial modifications to the software or operating system automatically lock the "secure folder" function, rendering it inaccessible. While a tech expert understands what secure storage or a secure folder means, further information is provided below: www.samsung.com / de / support / skp / faq / 1126479 or https: / / praxistipps.chip.de / galaxy-s8-sicherer-ordner-erstellen-und-nutzen_93099.

[0014] If a user saves their charging contract securely on their mobile device, they can take this contract with them into any vehicle and transmit it to a charging station as proof of purchase. This eliminates the need for extra wallet space and reliably prevents misuse. It's easy to take the contract into another vehicle. No internet connection is required for activation; instead, the necessary data transfers, as explained in more detail below, can be carried out via near-field communication.

[0015] In the method according to the invention, in step a) a feature associated with the user's charging contract is first generated by an electricity provider. In a subsequent step b), the feature associated with the user's charging contract is encrypted and transmitted by the electricity provider to a secure storage location on the user's mobile device. In a following step c), data is transmitted from the mobile device to the charging infrastructure using the feature associated with the user's charging contract. In a subsequent step d), the data received by the charging infrastructure is checked using the feature associated with the charging contract, and if the check is successful, the charging process is released by the charging infrastructure in a subsequent step e).

[0016] A first public key, hereinafter also referred to as the public contract key, concerns the communication between mobile device and charging infrastructure, while a second public key, hereinafter also referred to as the public device key, concerns the communication between mobile device and charging provider.

[0017] Preferably, the public device key is exchanged with the electricity provider via an app installed on the mobile device before the first charging process.

[0018] Two variants of the method according to the invention are described in more detail below. First, the first variant: In step a), at least one digital certificate, specifically a digital certificate and a private key for the charging contract, is generated for the user as the attribute assigned to the user's charging contract. These are referred to below as the contract certificate and the private contract key, respectively. If the charging provider only generates a digital contract certificate, a key pair already generated on the user's mobile device can be used instead. For this purpose, the mobile device generates a key pair consisting of a private key and a public key in a secure storage area in a preliminary step; in this case, the private contract key and the public contract key. The private contract key remains in the secure storage area, while the public contract key is sent to the charging provider.For this purpose, a Certificate Signing Request (CSR) is preferably used. The electricity provider can now create a digital contract certificate for the public contract key, i.e., the contract certificate mentioned above, and send it to the mobile device.

[0019] According to the invention, step c) provides for a challenge-response procedure to be carried out between the charging infrastructure and the mobile device using the private contract key of the charging contract.

[0020] In the subsequent step b), it is particularly advantageous that at least the digital contract certificate, specifically the digital contract certificate and the private contract key of the charging contract, are encrypted using the user's public device key and transmitted to the mobile device. The mobile device then decrypts the certificate using the user's own private device key. For this purpose, the public device key is exchanged between the mobile device and the charging provider in a preliminary step. This ensures that only the mobile device can decrypt the digital contract certificate, or the digital contract certificate and the private contract key of the charging contract. This reliably prevents misuse.The public and private device keys are generated before the public device key is transmitted, for example, during installation or the first launch of the corresponding app. Alternatively, a public and a private device key may already be present on the mobile device from the time of production, meaning they are generated during manufacturing.

[0021] Preferably, step c) includes a sub-step c0), in which the digital contract certificate is transferred from the mobile device to the charging infrastructure. Step c) preferably further includes the following sub-steps: c1) Receiving a challenge from the charging infrastructure by the mobile device; c2) Signing the challenge with the private contract key of the charging contract by the mobile device; and c3) Transferring the signed challenge from the mobile device to the charging infrastructure.

[0022] In this context, the challenge can be transferred in a first step from the charging infrastructure to the electric vehicle and in a second step from the electric vehicle to the mobile device, and accordingly the signed challenge can be transferred in a first step from the mobile device to the electric vehicle and in a second step from the electric vehicle to the charging infrastructure.

[0023] In the subsequent step d), the charging infrastructure then verifies a signature generated using the private contract key and the validity of the digital contract certificate, in particular the validity period of the digital contract certificate.

[0024] In a second preferred variant, a token is generated in step a) as the attribute assigned to the user's charging contract, specifically according to the OAuth 2.0 standard. While in the first variant, any number of charging processes can be signed and thus authorized using a digital contract certificate – similar to a key opening a door – a token can only initiate one charging process – similar to an entry ticket. However, it is possible for the user to acquire multiple tokens in a single process, which they can then use successively.

[0025] In step b), it is then preferred that a communication channel between the electricity provider and the mobile device is encrypted, in particular by means of TLS encryption (Transport Layer Security). The process for encrypting a communication channel is well known to those skilled in the art, which is why further explanation is omitted here.

[0026] Subsequently, in step b), the token is transmitted from the electricity provider to the mobile device via the encrypted communication channel.

[0027] In the subsequent step c), the token is then transferred from the mobile device to the charging infrastructure. In step d), the charging infrastructure then queries the electricity provider, specifically an authorization server located there, to verify the token's validity.

[0028] For both variants, in step c) the data can be transferred in a first step from the mobile device to the electric vehicle and in a second step from the electric vehicle to the charging infrastructure.

[0029] The transmission between the mobile device and the electric vehicle on the one hand, and the transmission between the electric vehicle and the charging infrastructure on the other, is preferably carried out by near-field communication, preferably using at least one transmission method from the following group: WLAN (Wireless Local Area Network), Bluetooth, RFID (Radio-Frequency Identification), NFC (Near Field Communication). Alternatively, the transmission between the mobile device and the electric vehicle can be carried out by near-field communication or by wired communication, and the transmission between the electric vehicle and the charging infrastructure can also be carried out by near-field communication or wired communication, in particular via a charging cable.

[0030] Further advantageous embodiments are described in the dependent claims.

[0031] The preferred embodiments and their advantages presented in connection with the method according to the invention apply accordingly, where applicable, to a system according to the invention for verifying a user's charging contract for authorizing a charging process for charging an electric vehicle at a charging structure. This system comprises a charging infrastructure, an electricity provider, and a mobile device. The mobile device has a secure, i.e., unauthorized access-protected, first memory in which a private device key of the user is stored, a control device, and a communication device. The electricity provider has a device for generating a feature associated with the user's charging contract and a transmission device for transferring this feature to the first memory of the mobile device.The mobile device is designed to transmit data to the charging infrastructure using the attribute assigned to the user's charging contract. The charging infrastructure is designed to verify the received data using an attribute assigned to the user's charging contract and, if the verification is successful, to release the charging process.

[0032] In the following, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0033] These show: Fig. 1. A schematic diagram of a flowchart for a first variant of the method according to the invention; and Fig. 2 In schematic representation a flowchart for a second variant of the method according to the invention.

[0034] Fig. Figure 1 shows a schematic flowchart for a first embodiment of a method according to the invention. It illustrates actions that occur at or between the instances depicted in the embodiment: the electric vehicle power provider 10, the mobile device 12, and the charging infrastructure 14. The charging infrastructure 14 comprises a charging station, in particular with a device for wired or inductive charging, which in this case includes at least a control device and a communication device. The electric vehicle power provider 10 preferably comprises a computing device, a storage device, a control device, and also a communication device.

[0035] First, in step 100, the charging provider 10 generates a feature assigned to the user's charging contract. The feature assigned to the user is at least a digital contract certificate, in particular a digital contract certificate and a private key of the charging contract.

[0036] In step 120, the attribute assigned to the user's charging contract is encrypted and transmitted by the electricity provider 10 to a secure storage location or storage area of ​​the user's mobile device 12, specifically one protected against unauthorized access. At least the digital contract certificate, and in particular the digital contract certificate and the private contract key of the charging contract, are encrypted with a second public device key of the user and transmitted to the mobile device 12. The data is then decrypted on the mobile device 12 using a private device key of the user's mobile device 12.

[0037] In a subsequent step 140, the contract certificate is sent from the mobile device 12 to the charging infrastructure. A challenge-response process then takes place between the charging infrastructure 14 and the mobile device 12 using the private contract key of the charging contract. In step 160, a challenge is received from the charging infrastructure 14 by the mobile device 12. In the following step 180, the challenge is signed by the mobile device 12 with the private contract key of the charging contract and, in a subsequent step 200, transmitted from the mobile device 12 to the charging infrastructure 14.

[0038] In step 220, the data received by the charging infrastructure 14 is verified using the user's public contract key from the contract certificate, specifically a signature generated using the user's mobile device 12's private contract key and the validity of the digital contract certificate, preferably its validity period. Subsequently, in step 240, if the verification is successful, the charging process is authorized by the charging infrastructure 14. Successful verification here means that the signature could be verified as originating from the user and that the digital contract certificate has not yet expired.

[0039] Fig. Figure 2 shows a second embodiment of the method according to the invention, wherein the following is shown with reference to Fig. The reference symbol inserted in 1 for identical and equivalent elements should be retained.

[0040] In step 300, the charging provider 10 generates a token, specifically according to the OAuth 2.0 standard, as the attribute assigned to the user's charging contract. In a subsequent step 320, the charging provider 10 encrypts and transmits the token to a secure storage location on the user's mobile device 12. For this purpose, a communication channel between the charging provider 10 and the mobile device 12 is first encrypted, specifically using TLS encryption. The token is then transmitted from the charging provider 10 to the mobile device 12 via this encrypted communication channel.

[0041] In step 340, the token is transferred from the mobile device 12 to the charging infrastructure 14. The charging infrastructure 14 verifies the data received using an authorization server of the electricity provider, specifically checking the validity of the token with the electricity provider 10.

[0042] If the token is found to be valid in step 360, the charging process is released by the charging infrastructure 14 in step 380.

[0043] As already mentioned, communication between the electricity provider 10 and the mobile device 12 on the one hand, and between the mobile device 12 and the charging infrastructure 14 on the other, can take place directly or indirectly via the electric vehicle. Communication between the electricity provider and the mobile device, or between the electric vehicle and the mobile device, preferably occurs via near-field communication (NFC), while communication between the mobile device 12 and the charging infrastructure 14 can occur via NFC or via wired communication, particularly via a charging cable.

Claims

[1] Procedure for verifying a user’s charging contract to authorise a charging process for charging an electric vehicle at a charging infrastructure (14), comprising the following steps: a) Generation of a feature associated with the user's charging contract by a charging power provider (10) (Step 100, Step 300); b) Encrypted transmission of the feature associated with the user's charging contract from the electricity provider (10) to a storage device on a mobile device (12) of the user (step 120, step 320); c) Transfer of data at least from the mobile device (12) to the charging infrastructure (14) using the feature assigned to the user's charging contract (step 140, step 340); d) Checking the data received from the charging infrastructure (14) under the attribute assigned to the user's charging contract (step 220, step 360); and e) Release of the charging process by the charging infrastructure (14) upon successful verification (step 240, step 380); where in step a) at least a digital contract certificate and a private contract key of the charging contract are generated for the user as the feature assigned to the user's charging contract (step 100), characterized by , that In step b) the feature from the charging provider (10) is transmitted in encrypted form to the memory of the mobile device (12), which is designed as a secure memory (step 120, step 320); wherein in step c) a challenge-response procedure is carried out between the charging infrastructure (14) and the mobile device (12) using the private contract key of the charging contract (step 140, step 160, step 180, step 200). [2] Method according to claim 1, characterized by, that in step b) at least the digital contract certificate and the private contract key of the charging contract are encrypted with a public device key of the user and transmitted to the mobile device (12) and decrypted in the mobile device (12) using a private device key of the user's mobile device (12) (step 120). [3] Method according to one of claims 1 or 2, characterized by , that in step c) in substep c0) the digital contract certificate is transferred from the mobile device (12) to the charging infrastructure (14). [4] Method according to claim 1, characterized by , that step c) comprises the following sub-steps: c1) Receiving a challenge from the charging infrastructure (14) by the mobile device (12) (step 160); c2) Signing the challenge with the private contract key of the charging contract by the mobile device (12) (step 180); and c3) Transferring the signed challenge from the mobile device (12) to the charging infrastructure (14) (step 200). [5] Method according to claim 4, characterized by , that the challenge is transmitted in a first step from the charging infrastructure (14) to the electric vehicle and in a second step from the electric vehicle to the mobile device (12), and that the signed challenge is transmitted in a first step from the mobile device (12) to the electric vehicle and in a second step from the electric vehicle to the charging infrastructure (14). [6] Method according to any one of claims 1 to 5, characterized by , that in step d) the charging infrastructure (14) verifies a signature generated by means of the private contract key and the validity of the digital contract certificate (step 220). [7] Method according to claim 1, characterized by, that in step a) a token is generated as the characteristic assigned to the user's charging contract (step 300). [8] Method according to claim 7, characterized by , that in step b) a communication channel between the electricity provider and the mobile device is encrypted (step 320). [9] Method according to one of claims 7 or 8, characterized by , that in step b) the token is transmitted via the encrypted communication channel from the electricity provider (10) to the mobile device (12) (step 320). [10] Method according to any one of claims 7 to 9, characterized by , that in step c) the token is transferred from the mobile device (12) to the charging infrastructure (14) (step 340). [11] Method according to any one of claims 7 to 10, characterized by , that in step d) the validity of the token is checked with the electricity provider (10) (step 360). [12] Method according to any one of the preceding claims, characterized by, that in step c) the data are transferred in a first step from the mobile device (12) to the electric vehicle and in a second step from the electric vehicle to the charging infrastructure (14). [13] Method according to any one of the preceding claims, characterized by , that the transmission between mobile terminal (12) and electric vehicle on the one hand and the transmission between electric vehicle and charging infrastructure (14) on the other hand is carried out by near field communication. [14] Method according to any one of claims 1 to 12, characterized by , that the transmission between mobile terminal (12) and electric vehicle is carried out by near field communication or by wired communication and the transmission between electric vehicle and charging infrastructure (14) is carried out by near field communication or wired communication. [15] System for verifying a user’s charging contract to authorise a charging process for charging an electric vehicle at a charging infrastructure (14) comprising: - a charging infrastructure (14); - a 10-year electric vehicle power provider; as well as - a mobile device (12), wherein the mobile device (12) has: - an initial storage location in which the user's private key is stored, - a control device, as well as - a communication device; where the electricity provider (10) has a device for generating a feature associated with the user's charging contract and a transmission device for transferring this feature to the first memory of the mobile terminal (12); wherein the mobile terminal (12) is designed to transmit data to the charging infrastructure (14) using the feature assigned to the user's charging contract; wherein the charging infrastructure (14) is designed to verify the received data using a feature associated with the user's charging contract and, if the verification is successful, to release the charging process; where the associated feature is at least a digital contract certificate and a private contract key of the charging contract, characterized by , that the first storage of the mobile device (12) is designed as a secure storage, protected against unauthorized access, wherein the charging infrastructure (14) and the mobile device (12) are designed to carry out a challenge-response procedure between the charging infrastructure (14) and the mobile device (12) using the private contract key of the charging contract.

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