Authentication systems and vehicles

Abstract

This approach aims to limit the increase in the number of digital certificates to be stored while minimizing a decrease in convenience. [Solution] The server performs a process that includes the steps of obtaining the maximum number of storable certificates (S102) and obtaining information on the stored digital certificates (S104) if it is determined that there is a notification of a change in priority (YES in S100), sending priority information (S108) and sending certificate data (S110) if it is determined that a digital certificate with a higher priority than an existing digital certificate will be set (YES in S106), and sending priority information (S112) if it is determined that a digital certificate with a higher priority than an existing digital certificate will not be set (NO in S106).

Description

Technical Field

[0001] This disclosure relates to an authentication system.

Background Art

[0002] Japanese Patent Publication No. 2022-527902 (Patent Document 1) discloses a charging station that verifies a vehicle digital signature received from a vehicle using a vehicle public key and enables power supply to the vehicle in response to successful verification.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Information about digital certificates including the above-mentioned vehicle digital signature is stored in the vehicle control device via a communication network. However, in the vehicle control device, the number of digital certificates that can be stored is limited by the storage capacity, standards, etc. For example, when entering into usage contracts with operators of multiple charging stations, it may not be possible to store all digital certificates, and the convenience of the charging stations corresponding to the digital certificates that could not be stored may decrease.

[0005] This disclosure has been made to solve the above-mentioned problems, and its object is to provide an authentication system and a vehicle that suppress a decrease in convenience while suppressing an increase in the number of digital certificates to be stored.

Means for Solving the Problems

[0006] An authentication system relating to a certain aspect of this disclosure comprises a server that transmits digital certificates used for authentication when using a power station that transmits power to a power storage device mounted on an electric vehicle, and a vehicle that includes a storage device that stores the digital certificates received from the server. When the server receives a digital certificate with a first priority, if the first priority is higher than the second priority of an existing digital certificate stored in the storage device, it transmits the digital certificate with the first priority to the vehicle; if the first priority is lower than the second priority, it does not transmit the digital certificate with the first priority to the vehicle.

[0007] In this way, if the first priority is higher than the second priority, the first priority digital certificate is sent to the vehicle, and by storing it in the vehicle's memory, the vehicle can use the power station corresponding to the first priority digital certificate. Also, if the first priority is lower than the second priority, the first priority digital certificate is not sent, so the increase in the number of digital certificates stored in the vehicle's memory can be suppressed while maintaining the high-priority digital certificate, thereby preventing a decrease in convenience.

[0008] In one embodiment, when a vehicle receives a first-priority digital certificate, it replaces the existing digital certificate with the first-priority digital certificate.

[0009] In this way, even if the number of digital certificates that can be stored is small, the decrease in convenience can be mitigated by maintaining high-priority digital certificates.

[0010] Furthermore, in one embodiment, if the vehicle receives a first-priority digital certificate and the storage device has reached its maximum number of digital certificates, it replaces the digital certificate with the lowest priority among the multiple digital certificates with the first-priority digital certificate.

[0011] This approach allows users to utilize power stations that support high-priority, first-priority digital certificates, thus mitigating any decrease in convenience.

[0012] In one further embodiment, the authentication system includes a terminal. The terminal sets a first priority according to the user's input and transmits information about the first priority to at least one of the server and the vehicle.

[0013] In this way, the server can decide whether or not to send the digital certificate to the vehicle based on the comparison result between the first priority and second priority received from the terminal.

[0014] In one further embodiment, the vehicle sets a first priority according to the user's input and transmits information about the first priority to the server.

[0015] In this way, the server can decide whether or not to send the digital certificate to the vehicle based on the comparison result of the first priority and second priority received from the vehicle.

[0016] In one further embodiment, if the first-priority digital certificate is already stored in the storage device, the server transmits information about the first priority to the vehicle.

[0017] In this way, if there is a change in the priority of the digital certificates stored in the vehicle's memory, the digital certificate can be used according to the changed priority, thus mitigating any decrease in convenience.

[0018] In one further embodiment, the vehicle includes a navigation system. The vehicle sets a higher priority for digital certificates that allow the use of power stations on or around a set driving route than for existing digital certificates, and transmits information about the set priority to a server.

[0019] By doing so, since the priority of the digital certificate that enables the use of a charging station on or around the driving route is set higher than the priority of the existing digital certificate, when the vehicle travels on the set driving route, charging and the like can be promptly performed when using the charging station.

[0020] A vehicle according to another aspect of the present disclosure includes a power storage device, a storage device that stores a digital certificate used for authentication when transmitting power between the power storage device and a charging station, a communication device configured to be communicable with a server that is the source of the digital certificate, and a control device that writes the digital certificate received from the server into the storage device when the digital certificate is received from the server. The control device compares the first priority of the digital certificate acquired by the server with the second priority of the existing digital certificate stored in the storage device, and if there is a change in the priority relationship, changes to the digital certificate to be preferentially used for authentication when using the charging station, and if there is no change in the priority relationship, does not change the digital certificate to be preferentially used.

Advantages of the Invention

[0021] According to the present disclosure, it is possible to provide an authentication system and a vehicle that suppress a decrease in convenience while suppressing an increase in the number of digital certificates to be stored.

Brief Description of the Drawings

[0022] [Figure 1] It is a diagram showing an example of the overall configuration of the authentication system according to the present embodiment. [Figure 2] It is a sequence diagram showing an example of the charging process among the vehicle, the charging station, and the server. [Figure 3] It is a flowchart showing an example of the process executed by the server. [Figure 4] It is a flowchart showing an example of the process executed by the vehicle. [Figure 5] It is a sequence diagram showing an example of the operation of the authentication system according to the present embodiment. [Figure 6]It is a sequence diagram showing another example of the operation of the authentication system according to this embodiment.

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0024] FIG. 1 is a diagram showing an example of the overall configuration of an authentication system 1 according to this embodiment. The authentication system 1 includes a vehicle 100, a power stand 300, a server 400, a terminal 500, and a certification authority 600.

[0025] The vehicle 100 will be described by taking as an example the case where it is a battery electric vehicle (BEV) without an engine, but any electric vehicle having an electric motor as a drive source may be used. For example, it may be a hybrid vehicle (HEV) having an engine, or alternatively, a plug-in hybrid vehicle (PHEV). The vehicle 100 includes a power storage device 200 that stores power for running. The vehicle 100 is configured to be able to run by supplying the power stored in the power storage device 200 to an electric motor (rotating electric machine).

[0026] The power stand 300 is configured to be able to transmit power to and from the power storage device 200 mounted on the vehicle 100. Specifically, the power stand 300 is configured to be able to charge the power storage device 200 by the PnC (Plug and Charge) charging method. The PnC charging method is a charging method in which, by simply connecting the connector 301 of the power stand 300 to the inlet 160 of the vehicle 100, processes such as charge authentication and charging for using the power stand 300 are automatically executed. The power stand 300 is assumed to be a charging stand capable of DC (Direct Current) charging, but may be, for example, a charging stand capable of AC (Alternating Current) charging or a power supply stand capable of various power supplies.

[0027] The server 400 includes a control device 401, a storage device 402, and a communication device 403. The control device 401 is composed of a processor such as a CPU (Central Processing Unit) and executes programs stored in the storage device 402, which includes RAM (Random Access Memory), etc. The communication device 403 is configured to communicate with the communication device 140 of the vehicle 100 and the communication device 503 of the terminal 500 via a communication network (not shown).

[0028] Server 400 stores information about vehicle 100, information about terminal 500, and information about users. Server 400 also stores, for example, a digital certificate for using the power station 300 in vehicle 100. The digital certificate is an electronic certificate that includes, for example, public key information. The digital certificate includes, for example, a charging contract certificate. The charging contract certificate certifies the contents of the contract concluded between the mobility operator (MO) providing the charging service and the user of vehicle 100.

[0029] The Certificate Authority 600, which includes servers belonging to the certification authority, issues digital certificates upon request, such as when an existing digital certificate expires or a new contract is concluded. The Certificate Authority 600 then transmits the issued digital certificate to the Server 400.

[0030] Vehicle 100 includes a monitoring module 130 and a control unit (ECU: Electronic Control Unit) 150.

[0031] The monitoring module 130 includes various sensors to detect the state of the energy storage device 200 (e.g., voltage, current, and temperature) and outputs the detection results to the ECU 150. In addition to the above sensor functions, the monitoring module 130 may also be a BMS (Battery Management System) that further has a State of Charge (SOC) estimation function, a State of Health (SOH) estimation function, a cell voltage equalization function, a diagnostic function, and a communication function. The ECU 150 can acquire the state of the energy storage device 200 (e.g., temperature, current, voltage, SOC, and internal resistance) based on the output of the monitoring module 130. The energy storage device 200 is charged (externally charged) or discharged (externally powered) by exchanging power with the power stand 300.

[0032] The ECU 150 is configured to control the charging and discharging of the energy storage device 200. The ECU 150 includes a processor 151 consisting of a CPU, RAM 152, a storage device 153, and a signal receiving unit 154.

[0033] RAM152 functions as working memory to temporarily store data processed by processor 151.

[0034] The storage device 153 is configured to store stored information. The storage device 153 stores programs as well as information used by the programs (e.g., maps, formulas, and various parameters). The processor 151 executes the programs stored in the storage device 153, thereby performing various controls in the ECU 150. The storage device 153 also stores the aforementioned digital certificates. The ECU 150 controls charging authenticated by the digital certificates. When a new digital certificate is acquired, it is downloaded and written to the storage device 153.

[0035] The signal receiving unit 154 receives predetermined signals from devices other than the ECU 150 mounted on the vehicle 100. For example, the signal receiving unit 154 receives predetermined signals (information) from the HMI device 120 or the communication device 140, which will be described later.

[0036] The vehicle 100 further comprises a drive unit 110, an HMI (Human Machine Interface) device 120, a communication device 140, an inlet 160, a navigation system 170, and drive wheels W.

[0037] The drive unit 110 is configured to drive the vehicle 100 using the power stored in the energy storage device 200. The drive unit 110 includes, for example, a Power Control Unit (PCU) composed of an inverter, a converter, and a relay, a Motor Generator (MG) composed of a three-phase AC rotating electric machine, and a System Main Relay (SMR) that switches the disconnection state of the power path between the energy storage device 200 and the PCU (none of which are shown).

[0038] The PCU and SMR are controlled by the ECU 150. The MG is driven by the PCU and configured to rotate the drive wheels W. The PCU drives the MG using power supplied from the energy storage device 200. The MG is also configured to perform regenerative power generation and supply the generated power to the energy storage device 200. The SMR is closed (connected) when the vehicle 100 is running.

[0039] The energy storage device 200 is composed of a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery having a liquid or solid electrolyte. Alternatively, the energy storage device 200 may be composed of a capacitor or the like instead of a secondary battery.

[0040] The HMI device 120 includes an input device for receiving user input and a display device for displaying information to the user. The HMI device 120 may also include a touch panel display. The HMI device 120 displays information on the display device in response to control signals from the ECU 150.

[0041] The communication device 140 is configured to communicate with, for example, a terminal 500 (e.g., a smartphone) used by a user of the vehicle 100 and a server 400. The communication device 140 may also include a communication interface such as a Data Communication Module (DCM) that supports a predetermined communication format such as 5G (fifth-generation mobile communication system).

[0042] The inlet 160 is shaped to allow the connector 301 of the power stand 300 to be inserted. The connector 301 is located at the end of the cable 302 attached to the power stand 300. The vehicle 100 is electrically connected to the power stand 300 when the connector 301 is inserted into the inlet 160. This makes it possible to exchange power (charge and supply) between the power stand 300 and the vehicle 100.

[0043] The navigation system 170, for example, sets a driving route to the destination when the user sets a destination. The navigation system 170 guides the vehicle to the destination by displaying the vehicle's position on a map and the driving route on the display device of the HMI device 120 while driving. Furthermore, the navigation system 170 is configured to search for the locations of power stations 300 along or around the driving route and display the search results (location on the map, etc.) on the display device of the HMI device 120. The navigation system 170 is configured to communicate with the ECU 150.

[0044] Terminal 500 includes a control device 501, a storage device 502, a communication device 503, and a touch panel display 504. The control device 501 is composed of a processor such as a CPU and executes a program stored in the storage device 502, which includes RAM. The communication device 503 is configured to communicate with the communication device 140 of the vehicle 100 and the communication device 403 of the server 400. The touch panel display 504 includes an input device that accepts user input and a display device (neither of which is shown) that displays information to the user. Terminal 500 is the user's terminal for vehicle 100. In server 400, terminal 500, vehicle 100, and user are stored in association. Specifically, server 400 stores, for example, identification information that identifies the user, identification information that identifies the vehicle 100, and identification information that identifies terminal 500 in association with each other in the storage device 402. Furthermore, the server 400 associates this identification information with information about the digital certificates stored in the vehicle 100 and stores it in the storage device 402.

[0045] Figure 2 is a sequence diagram showing an example of the charging process between vehicle 100, power station 300, and server 400.

[0046] In step 10 (hereinafter referred to as step S), the charging process between the vehicle 100 and the power station 300 is initiated. For example, the charging process is initiated when the connector 301 is connected to the inlet 160.

[0047] In S20, a secure communication connection is established between the vehicle 100 and the power station 300.

[0048] In S30, various authentication processes are performed between the vehicle 100 and the power station 300 using a digital certificate stored in the vehicle 100. For example, processes such as identity verification, data verification, and authorization are performed.

[0049] In S40, settings are executed. For example, target settings and charge scheduling settings are performed.

[0050] In S50, charging takes place between the vehicle 100 and the power station 300. In S60, charging is completed.

[0051] In the charging process described above, the number of digital certificates that can be stored in the storage device 153 of the vehicle 100's ECU 150 is limited by storage capacity and standards. Therefore, for example, if a user contract is made with operators of multiple power stations 300, it may not be possible to store all digital certificates, which may reduce the convenience of the power stations 300 that correspond to the digital certificates that could not be stored.

[0052] Therefore, in this embodiment, when the server 400 receives the priority (first priority) of a new digital certificate, if the first priority is higher than the priority (second priority) of an existing digital certificate stored in the storage device 153, the server 400 transmits the new digital certificate to the vehicle 100; if the first priority is lower than the second priority, the server 400 does not transmit the new digital certificate to the vehicle 100.

[0053] In this way, if the first priority is higher than the second priority, a new digital certificate is sent to the vehicle 100, and by storing it in the vehicle 100's storage device 153, the vehicle can use the power station 300 corresponding to the new digital certificate. Also, if the first priority is lower than the second priority, no new digital certificate is sent, so the increase in the number of digital certificates stored in the vehicle 100's storage device 153 is suppressed, while the existing digital certificates with higher priority are maintained, thereby suppressing a decrease in convenience.

[0054] The following describes an example of processing performed by the server 400 (specifically, the control device 401), with reference to Figure 3. Figure 3 is a flowchart of an example of processing performed by the server 400. The series of processes shown in this flowchart are repeatedly executed at predetermined intervals.

[0055] In S100, the server 400 determines whether or not there is a notification of a change in priority. The server 400 determines that there is a notification of a change in priority if it receives a notification of a change in the priority of a digital certificate from, for example, at least one of the vehicle 100 and the terminal 500.

[0056] The user launches the app on terminal 500, for example. The app displays a list of charging services the user has contracted for, and a priority is set for each charging service. The user can set the priority of the charging services displayed in the list on the app. For example, if the user performs an input operation to change the priority, such as setting a newly contracted charging service to the highest priority, changing the priority of at least two of the existing charging services, or changing the charging service that is set to the highest priority among the existing charging services, terminal 500 notifies server 400 of the priority change. The priority change notification includes information about the charging service whose priority has been changed. Alternatively, if the user performs an input operation to change the priority as described above on the touch panel display of the HMI device 120 of vehicle 100, vehicle 100 notifies server 400 of the change in the priority of the digital certificate as described above. If it is determined that there is a notification of a priority change (YES in S100), the process moves to S102.

[0057] In S102, the server 400 obtains the maximum number of items that can be stored. For example, the server 400 may associate the maximum number of items that can be stored with each managed vehicle 100 and store it in the storage device 402, and then read the maximum number of items that can be stored for the vehicle 100 corresponding to the terminal 500 that notified the change in priority, or for the vehicle 100 that notified the change, from the storage device 402. Alternatively, the server 400 may associate the type of standard adopted for digital certificates with each managed vehicle 100 and store it in the storage device 402, and then read the type of standard adopted for the vehicle 100 corresponding to the terminal 500 that notified the change in priority, or for the vehicle 100 that notified the change, from the storage device 402, and then determine the maximum number of items that can be stored from the standard that was read. Server 400 obtains the maximum number of storable digital certificates, for example, by assuming that in vehicle 100 adopting ISO (International Organization for Standardization) 15118-2 as the standard for digital certificates, the maximum number of storable digital certificates is "1", and in vehicle 100 adopting ISO 15118-20, the maximum number of storable digital certificates is a predetermined number of "2" or more. The predetermined number is a value determined by the memory capacity of ECU 150, etc. Furthermore, Server 400 may obtain the maximum number of storable digital certificates from the vehicle 100 corresponding to the notifying terminal 500 or from the notifying vehicle 100. The subsequent processing is moved to S104.

[0058] In S104, the server 400 retrieves the stored digital certificate information. The server 400 may also read from the storage device 402 information about the digital certificate stored in association with the vehicle 100 corresponding to the notifying terminal 500 among the managed vehicles 100. For example, when the server 400 sends the digital certificate to the vehicle 100 after the contract with the charging service is completed, it stores information about the digital certificate associated with the vehicle 100 in the storage device 402. The server 400 may also obtain information about the digital certificate from the vehicle corresponding to the notifying terminal 500 or from the notifying vehicle 100. The process then moves to S106.

[0059] In S106, the server 400 determines whether a digital certificate with a higher priority than the existing digital certificate stored in the vehicle 100's storage device 153 has been set.

[0060] For example, if a new digital certificate corresponding to a newly contracted charging service is set to a higher priority than an existing digital certificate, server 400 will determine that a digital certificate with a higher priority than the existing digital certificate has been set.

[0061] Alternatively, the server 400 determines that a digital certificate with a higher priority than the existing digital certificate has been set, for example, if the digital certificate that has been changed to the highest priority is different from an existing digital certificate stored in the vehicle 100's storage device 153.

[0062] Alternatively, the server 400 may determine, for example, that a digital certificate with a higher priority than the existing digital certificate has been set if the priority of an existing digital certificate stored in the storage device 153 of the vehicle 100 has been changed to a lower priority than before the change. If it is determined that a digital certificate with a higher priority than the existing digital certificate has been set (YES in S106), the process moves to S108.

[0063] In S108, server 400 transmits priority information to vehicle 100. The priority information includes information about the digital certificate corresponding to the changed priority. The process is then moved to S110.

[0064] In S110, server 400 sends the data of the highest priority digital certificate among the changed priorities to vehicle 100. If it is determined that no digital certificate with a higher priority than the existing digital certificate is set (NO in S106), the process moves to S112.

[0065] In S112, server 400 sends priority information to vehicle 100. The priority information is as described above, so a detailed explanation will not be repeated. If there is no notification of a change in priority (NO in S100), this process is terminated.

[0066] The following describes an example of processing performed by vehicle 100 (specifically, ECU 150), with reference to Figure 4. Figure 4 is a flowchart of an example of processing performed by vehicle 100. The series of processes shown in this flowchart are repeatedly executed at predetermined intervals.

[0067] In S200, vehicle 100 determines whether or not to receive priority information. As the priority information is as described above, a detailed explanation will not be repeated. If it is determined that priority information will be received (YES in S200), the process moves to S202.

[0068] In S202, vehicle 100 determines whether or not to receive the digital certificate data. The digital certificate data includes the data of the digital certificate with the highest priority among the modified priorities. If it is determined that the digital certificate data should be received (YES in S202), the process moves to S204.

[0069] In S204, vehicle 100 writes the data of the received digital certificate to the storage device 153. If, for example, the maximum number of data that can be stored in vehicle 100 is "1", vehicle 100 writes the received digital certificate after deleting an existing digital certificate. If, for example, the maximum number of data that can be stored in vehicle 100 is "2" or more, and there is one existing digital certificate, vehicle 100 may write the received digital certificate after deleting an existing digital certificate, or it may write the received digital certificate while maintaining the existing digital certificate. If, for example, the maximum number of data that can be stored in vehicle 100 is "2" or more, and there are multiple existing digital certificates, vehicle 100 may write the received digital certificate after deleting all existing digital certificates, or it may write the received digital certificate after deleting the digital certificate with the highest priority among the existing digital certificates, or it may write the received digital certificate after deleting the digital certificate with the lowest priority among the existing digital certificates. The criteria for deleting existing digital certificates may be predetermined in vehicle 100, or they may be specified by server 400 in accordance with standards adopted by vehicle 100. The process then moves to S208. If it is determined that certificate data will not be received (NO in S202), the process moves to S206.

[0070] In S206, vehicle 100 determines whether or not there has been a change in priority. If the relationship between the digital certificate and priority included in the received priority information matches the relationship between the digital certificate and priority stored in vehicle 100's storage device 153, vehicle 100 determines that there has been no change in priority. If they do not match, vehicle 100 determines that there has been a change in priority. If it is determined that there has been a change in priority (YES in S206), the process moves to S208.

[0071] In S208, vehicle 100 changes the priority of the digital certificate. Specifically, vehicle 100 changes the priority of the digital certificate by matching the relationship between the digital certificate and priority stored in vehicle 100's storage device 153 with the relationship between the digital certificate and priority included in the received priority information. The process is then terminated. Note that if it is determined that priority information has not been received (NO in S200) or if it is determined that there is no change in priority (NO in S206), the process is then terminated.

[0072] An example of the operation of authentication system 1 based on the above configuration and flowchart will be explained with reference to Figures 5 and 6.

[0073] Figure 5 is a sequence diagram showing an example of the operation of the authentication system 1 according to this embodiment. As shown in (A-1) of Figure 5, when the priority of the charging service is changed on the application of terminal 500, terminal 500 notifies server 400 of the change in priority setting.

[0074] If server 400 determines that there is a notification of a change in priority (YES in S100), the maximum number of storage slots is obtained (S102), as shown in (B-1) of Figure 5, and information about the stored digital certificates is obtained (S104), as shown in (B-2) of Figure 5.

[0075] If the server 400 determines that a digital certificate with a higher priority than an existing digital certificate stored in the storage device 153 of the vehicle 100 has been set (YES in S106), then priority information is transmitted (S108) as shown in (B-3) of Figure 5, and the digital certificate data is transmitted to the vehicle 100 (S110) as shown in (B-4) of Figure 5.

[0076] In vehicle 100, when priority information is received (YES in S200) and digital certificate data is received (YES in S202), the digital certificate is written to the storage device 153 of vehicle 100 (S204), as shown in (C-1) of Figure 5. Then, the priority information is updated (S208), as shown in (C-2) of Figure 5.

[0077] Figure 6 is a sequence diagram showing another example of the operation of the authentication system 1 according to this embodiment. As shown in (A-1) of Figure 6, when the priority of the charging service is changed on the application of terminal 500, terminal 500 notifies server 400 of the change in priority setting.

[0078] If server 400 determines that there is a notification of a change in priority (YES in S100), the maximum number of storage slots is obtained (S102), as shown in (B-1) of Figure 6, and information about the stored digital certificates is obtained (S104), as shown in (B-2) of Figure 6.

[0079] If the server 400 determines that no digital certificate with a higher priority than the existing digital certificate stored in the storage device 153 of the vehicle 100 is set (NO in S106), priority information is sent (S112) as shown in (B-3) of Figure 5.

[0080] In vehicle 100, priority information is received (YES in S200), but digital certificate data is not received (NO in S202). If there is a change in priority (YES in S206), the priority information is updated (S208) as shown in (C-2) of Figure 5.

[0081] As described above, according to the authentication system 1 of this embodiment, when the first priority is higher than the second priority, that is, when a digital certificate with a higher priority than an existing digital certificate is set, the digital certificate with the first priority is transmitted to the vehicle, and is stored in the storage device 153 of the vehicle 100, allowing the vehicle to use the power station corresponding to the digital certificate with the first priority. Furthermore, when the first priority is lower than the second priority, the digital certificate with the first priority is not transmitted, so the increase in the number of digital certificates stored in the storage device 153 of the vehicle 100 can be suppressed. Therefore, it is possible to provide an authentication system and vehicle that suppress the increase in the number of digital certificates to be stored and suppress the decrease in convenience.

[0082] The following describes variations. In the above-described embodiment, one example was explained where a change in the priority setting is notified to the server 400 upon receiving user input from at least one of the terminal 500 and the vehicle 100. However, for example, when a driving route is set in the navigation system of the vehicle 100, the priority may be changed so that the priority of charging services available at power stations 300 on or around the driving route is increased, and the change in the priority setting is notified to the server 400.

[0083] In this way, the priority of the digital certificate that allows the use of power stations 300 on or near the driving route is set higher than the priority of the existing digital certificate, so that when the vehicle 100 is driving along the set driving route, it can quickly charge or otherwise use the power stations 300.

[0084] Furthermore, in the above-described embodiment, an example was explained in which the server 400 is notified of a change in priority settings after receiving user input from at least one of the terminal 500 and the vehicle 100. However, the terminal 500 may, for example, set a higher priority for the charging service the more recent the timing of the charging service contract (the more recent), and notify the server 400 of the change in priority settings.

[0085] In this way, since the new contract may be used more frequently than the existing contract for the charging service, storing it in the vehicle's storage device 153 allows for quick access to the power station 300 that supports the new contract's charging service.

[0086] Furthermore, in the above-described embodiment, the case in which the terminal 500 receives user input and notifies the server 400 of the change in priority settings was explained as an example. However, the terminal 500 may, for example, notify the vehicle 100 of the change in priority settings in addition to the server 400.

[0087] In this way, the priority of existing digital certificates stored in the vehicle 100's storage device 153 can be changed without waiting for priority information from the server 400.

[0088] Furthermore, the above-mentioned modifications may be implemented by combining all or part of them as appropriate. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0089] 1 Authentication system, 100 vehicles, 110 drive units, 120 HMI devices, 130 monitoring modules, 140, 403, 503 communication devices, 150 ECUs, 151 processors, 152 RAM, 153, 402, 502 memory devices, 154 signal receivers, 160 inlets, 170 navigation systems, 200 energy storage devices, 300 power stands, 301 connectors, 302 cables, 400 servers, 401, 501 control devices, 500 terminals, 504 touch panel displays, 600 authentication authorities.

Claims

1. A server that transmits digital certificates used for authentication when using power stations that transmit power to and from the energy storage devices installed in electric vehicles, A vehicle comprising a storage device that stores the digital certificate received from the server, Authentication system wherein, upon receiving a first priority digital certificate, the server transmits the first priority digital certificate to the vehicle if the first priority is higher than the second priority of an existing digital certificate stored in the storage device, and does not transmit the first priority digital certificate to the vehicle if the first priority is lower than the second priority.

2. The authentication system according to claim 1, wherein the vehicle, upon receiving the first-priority digital certificate, replaces an existing digital certificate with the first-priority digital certificate.

3. The authentication system according to claim 1, wherein the vehicle receives the first priority digital certificate, and if the storage device has the maximum number of digital certificates stored, it replaces the digital certificate with the lowest priority among the plurality of digital certificates with the first priority digital certificate.

4. The authentication system includes a terminal, The authentication system according to claim 1, wherein the terminal sets the first priority according to the user's input and transmits information about the first priority to at least one of the server and the vehicle.

5. The authentication system according to claim 1, wherein the vehicle sets the first priority according to the user's input and transmits information about the first priority to the server.

6. The authentication system according to claim 1, wherein the server transmits information about the first priority to the vehicle if the first priority digital certificate is already stored in the storage device.

7. The aforementioned vehicle includes a navigation system, The authentication system according to claim 1, wherein the vehicle sets the priority of the digital certificate that allows the use of the power station on or around the driving route set by the navigation system to be higher than that of the existing digital certificate, and transmits information about the set priority to the server.

8. Energy storage device, A storage device that stores a digital certificate used for authentication when using a power station that transmits power to the aforementioned energy storage device, A communication device configured to communicate with the server that sent the digital certificate, The system includes a control device that writes the digital certificate to the storage device when it receives the digital certificate from the server, The control device compares the first priority of the digital certificate acquired by the server with the second priority of the existing digital certificate stored in the storage device, and if there is a change in the priority relationship, changes the digital certificate to be used preferentially for authentication when using the power station, and if there is no change in the priority relationship, does not change the digital certificate to be used preferentially.

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