Onboard electronic control device, key management system, and key management method

Abstract

This onboard electronic control device is provided with a first key storage device having a first key storage unit, and a second key storage device having a second key storage unit, and is configured so that identical key values are stored in the first key storage unit of the first key storage device and in the second key storage unit of the second key storage device. This makes it possible to sustain security functions even if one of the key storage devices has experienced a malfunction, by using the other key storage device to read out the key value.

Description

On-vehicle electronic control device, key management system, and key management method

[0001] The present invention relates to an in-vehicle electronic control unit, a key management system, and a key management method.

[0002] In recent years, vehicles known as connected cars have been developed. Connected cars are a technology in which an on-board electronic control unit communicates with external devices such as a server to transmit information about the vehicle's status to the external devices and acquires information about the vehicle's surroundings from the external devices to appropriately control the vehicle. In the following description, the on-board electronic control unit will be referred to as an ECU (Electronic Control Unit).

[0003] In order to realize connected cars, it is important to have security measures in place when vehicles communicate with external devices. If security measures are insufficient, there is a risk of unauthorized access, and the safety of connected cars cannot be guaranteed.

[0004] Security measures for connected cars are implemented by safely storing security keys in a secure storage area called a Hardware Security Module (HSM). The security keys stored in the HSM are used for secure booting when the ECU is started, authentication during communication outside the vehicle, and authentication of important control data communicated between ECUs. Patent Document 1 describes a key management technology for an on-board computer using an HSM.

[0005] JP 2017-46038 A

[0006] The HSM is the core of the security functions installed in the ECU. Therefore, if a malfunction or a serious vulnerability occurs in the HSM, the connected car will not be able to perform its processing, which will have a significant impact on the vehicle's driving control. However, conventional ECUs have not been able to adequately deal with HSM malfunctions.

[0007] An object of the present invention is to provide an in-vehicle electronic control unit, a key management system, and a key management method that can ensure continuous security even if a malfunction occurs in an HSM.

[0008] In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above problems, and one example thereof is an on-vehicle electronic control device including a first key storage device having a first key storage unit and a second key storage device having a second key storage unit. Here, the same key value is stored in the first key storage unit of the first key storage device and the second key storage unit of the second key storage device.

[0009] According to the present invention, since multiple key storage devices are provided, even if a malfunction occurs in one key storage device, the security function can be continued by reading the key value using the other key storage device. Problems, configurations, and effects other than those described above will become clear from the description of the following embodiments.

[0010] FIG. 5A is a block diagram showing an example of a system configuration of a first embodiment of the present invention. FIG. 5B is a block diagram showing an example of a hardware configuration of an ECU of the first embodiment of the present invention. FIG. 5C is a diagram showing an example of key information M1 to M5 of the first embodiment of the present invention. FIG. 5D is a sequence diagram showing an example of a duplication response process for key information of the first embodiment of the present invention. FIG. 5E is a diagram showing an example of processing in a normal state (FIG. 5A) and when a malfunction of the first HSM occurs (FIG. 5B) of the first embodiment of the present invention. FIG. 5F is a block diagram showing an example of a system configuration of a second embodiment of the present invention. FIG. 5G is a sequence diagram showing an example of a duplication response process for key data of the second embodiment of the present invention.

[0011] First Embodiment An in-vehicle electronic control unit, a key management system, and a key management method according to a first embodiment of the present invention will be described below with reference to FIGS.

[0012] [Configuration of ECU and Key Management Device] Fig. 1 shows the configuration of an ECU 100 and a key management device 200 according to this embodiment. The ECU 100 is a device that is mounted on a vehicle (not shown) and controls the vehicle. The ECU 100 is configured as a computer as shown in Fig. 2 (described later), and a main control unit 101 controls the vehicle.

[0013] The ECU 100 includes two key storage devices 110 and 120 that store key information for security measures. In the following description, the key storage device 110 is referred to as the first HSM 110, and the key storage device 120 is referred to as the second HSM 120. As already explained in the Background Art section, HSM is an abbreviation for Hardware Security Module.

[0014] The first HSM 110 has a key data holding unit 111, a key updating unit 112, a key data verification unit 113, a verification result generation unit 114, a duplication key data generation unit 115, and a duplication key data holding unit 116. The duplication key data generation unit 115 functions as a duplication key information generation unit that generates key data (key information) to be stored in the second HSM 120. The second HSM 120 has a key data holding unit 121, a key updating unit 122, a key data verification unit 123, and a verification result generation unit 124.

[0015] In addition to the main control unit 101, the ECU 100 also includes a key update control unit 102, an HSM identification information holding unit 103, and a key slot correspondence information holding unit 104 for managing key data. The key data held in the key data holding units 111 and 121 of the first HSM 110 and the second HSM 120 in the ECU 100 is managed by the key management device 200.

[0016] That is, the key update control unit 102 of the ECU 100 controls the process of storing key data (key values) in the key data storage units 111 and 121 while communicating with the key management device 200. The specific process of storing key data will be described later in the key data write process shown in FIG. 4 , but briefly, the key update control unit 102 performs the following process. That is, when authentication is established based on a first authentication value (data M1, M3, etc., described later) determined by the key data (data M2, described later) and an identifier identifying the first HSM 110, the key update control unit 102 causes the key data storage unit 111 to store the key data. Furthermore, when authentication is established based on a second authentication value (data M1′, M3′, etc., described later) determined by the key data and an identifier identifying the first HSM 110, the key update control unit 102 causes the key data storage unit 121 to store the key data.

[0017] The key management device 200 is installed outside the ECU 100 and communicates with the ECU 100 via a predetermined network to transfer data. The key management device 200 is installed in a manufacturing plant for the ECU 100 or a vehicle equipped with the ECU 100, a repair shop for the vehicle equipped with the ECU 100, or the like.

[0018] The key management device 200 includes a key data generation unit 201, and the key data generated by the key data generation unit 201 of the key management device 200 is transmitted to the ECU 100 and written to the key data storage unit 111 of the first HSM 110. The key data written to the key data storage unit 111 of the first HSM 110 is also written to the key data storage unit 121 of the second HSM 120. In order to perform this key data writing process, the key management device 200 includes a key update verification unit 202 and an HSM identification information storage unit 203.

[0019] The key data is written when a vehicle equipped with the ECU 100 is shipped, and is updated as needed when a service executed by the ECU 100 is added or deleted. A specific process for writing the key data will be described in the processing operation of FIG. 4.

[0020] 2 shows an example of the hardware configuration of the ECU 100. The ECU 100 is configured as a computer, and includes a CPU (Central Processing Unit) 100a, a memory 100b, an input / output unit 100c, and a communication interface (I / F) 100d, which are connected via a bus line 109 to enable mutual data transfer.

[0021] The CPU 100a executes a program stored in the memory 100b to realize the processing functions of the program. The processing functions of the program configure the various processing units and data storage units in the ECU 100 described in Fig. 1. Note that the use of the CPU 100a is merely an example, and a processor with a different configuration may also be used as the ECU 100.

[0022] The memory 100b stores programs and calculation result data, and provides the CPU 100a with a work area necessary for each process. The memory 100b here may be a semiconductor memory called RAM (Random Access Memory) or flash memory, or may be a large-capacity storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive).

[0023] 1 are also prepared using part of the storage area of ​​memory 100b. In this case, the first HSM 110 and the second HSM 120 may be configured in the same memory (storage device), or the first HSM 110 and the second HSM 120 may be configured in separate memories.

[0024] The input / output unit 100c outputs data for controlling various parts of the vehicle and inputs data detected by sensors installed in the vehicle. The communication interface 100d communicates with other ECUs in the vehicle and with external devices. The communication interface 100d also communicates between the ECU 100 and the key management device 200.

[0025] [Example of Key Data] Figure 3 shows an example of key data stored in the key data storage units 111, 121 of the first HSM 110 and the second HSM 120. The key data is composed of data M1, M2, M3, M4, and M5. Data M1 has a data size of 128 bits and is a parameter value combining an HSM ID, a key slot ID, etc. This data M1 is unencrypted plain text, and does not pose a security problem even if it is leaked. Data M1 functions as an identifier to identify the first HSM 110.

[0026] Data M2 has a data size of 256 bits and is data obtained by combining an update key value, a new counter value, and a flag setting and encrypting it with a key generated based on the authentication key. The update key value here is a random number. This data M2 is decrypted on the HSM side and used to update the key information. Data M3 has a data size of 128 bits and is a CMAC (Cipher-based Message Authentication Code) authentication value for data obtained by combining data M1 and data M2. This data M3 depends on the values ​​of data M1 and data M2 and is an authentication value used in the HSM to verify the authenticity of data M1 and data M2.

[0027] Data M4 has a data size of 256 bits and is data that combines data M1 with an encrypted update counter value. This data M4 is used on the sender of data M1, M2, and M3 to confirm whether the memory slot has been correctly updated by the HSM. Data M5 is a CMAC authentication value of data M4. This data M5 is used on the sender of data M1, M2, and M3 to confirm the legitimacy of data M4.

[0028] 3, it is not possible to write the same key value to multiple HSMs 110, 120. That is, data M2 includes an updating key value, which is a random number value, and the updating key value changes each time key data is written by key management device 200. Therefore, it is not possible for key management device 200 to write the same key value to multiple HSMs 110, 120.

[0029] Furthermore, because data M1 also uses a unique value assigned to each HSM, different data M1 and data M3 are required for each HSM. For this reason, the key management device cannot write data M1 with the same value to both the first HSM 110 and the second HSM 120. In this embodiment, the process described below is executed to write data M1, which is key data that can be treated as the same key, to the first HSM 110 and the second HSM 120.

[0030] 4 is a sequence diagram showing an example of a process for writing key data (data M1 to M5) to the first HSM 110 and the second HSM 120 according to this embodiment. First, the key management device 200 communicates with the ECU 100 to acquire the HSM ID of the first HSM 110 (step S11). The HSM ID acquired by the key management device 200 is stored in the HSM identification information storage unit 203.

[0031] Next, the key data generation unit 201 of the key management device 200 generates a random number to be used as a key value (step S12).Then, the key data generation unit 201 generates data M1 to M5 using the random number generated in step S12 and the HSM ID (step S13).

[0032] The key management device 200 sends data M1, M2, and M3 of the generated data M1 to M5 to the first HSM 110 of the ECU 100 as key-related data for the first HSM 110 (step S14). The key update unit 112 of the first HSM 110 performs authentication processing by having the key data verification unit 113 verify the received data M1, M2, and M3 (step S15). The key update unit 112 also performs a first key value storage process in which the key data verification unit 113 verifies the data M2, which is the key value, and stores the data M2 in the key data storage unit 111 of the first HSM 110 (step S16). The duplication key data storage unit 116 also stores the data M2.

[0033] Then, the key update unit 112 of the first HSM 110 generates data M4 and data M5 (step S17) and transmits the generated data M4 and data M5 to the key management device 200 (step S18). In the key management device 200, the key update verification unit 202 verifies the data M4 and data M5 transmitted from the first HSM 110 and performs authentication processing (step S19).

[0034] Once the data M1 to M5 are stored in the first HSM 110, the key update unit 112 of the first HSM 110 communicates with the second HSM 120 to acquire the HSM ID of the second HSM 120 (step S20). The HSM ID acquired by the first HSM 110 is stored in the HSM identification information storage unit 103. Next, the duplication key data generation unit 115 of the first HSM 110 generates duplication key-related data from the HSM ID stored in the HSM identification information storage unit 103, the data M2 stored in the duplication key data storage unit 116, and the key slot information stored in the key slot correspondence information storage unit 104 (step S21).

[0035] Specifically, the duplication key data generator 115 generates data M1' from the HSM ID and key slot information of the second HSM 120. Furthermore, data M3' is generated from data M1' and data M2 for the first HSM.

[0036] The duplication key-related data (data M1', M2, and M3') generated in step S21 is transmitted to the second HSM 120 (step S22). The key update unit 122 of the second HSM 120 causes the key data verification unit 123 to verify the data M1', M2, and M3' (step S23). If the authentication process is successful, the key update unit 122 of the second HSM 120 executes a second key value storage process to store the data M1', M2, and M3' in the key data holding unit 121 (step S24).

[0037] Furthermore, the verification result generation unit 124 of the second HSM 120 generates data M4' and data M5' based on data M1', M2, and M3' (step S25), and transmits the generated data M4' and data M5' to the first HSM 110 (step S26). In the first HSM 110, the key data verification unit 113 verifies the transmitted data M4' and data M5' (step S27).

[0038] The data M1', M2, M3', M4', and M5' obtained by the processing up to this point are stored in the key data storage unit 121 of the second HSM 110. Of this data M1', M2, M3', M4', and M5', the data M2 is the same as the data M2 stored in the key data storage unit 111 of the first HSM 110, and the other data M1', M3', M4', and M5' are data corresponding to the second HSM 120.

[0039] The transmission of the data M4 and M5 from the first HSM 110 to the key management device 200 in step S18 may be performed after the authentication process by verifying the data M4' and M5' by the second HSM 120 in step S27 is completed.

[0040] [Example of Use of First HSM and Second HSM] Figure 5 shows an example of use of the first HSM 110 and the second HSM 120 provided in the ECU 100. Figure 5A shows an example of use in a normal state. In a normal state, the main control unit 101 of the ECU 100 reads Key 1 to Key n stored in slots 1 to n (n is an arbitrary integer) of the first HSM 110 as key information for security measures. The main control unit 101 of the ECU 100 then uses the read data of Key 1 to Key n as a key for a first function, a key for a second function, ..., a key for an n-th function to execute security processing. In the state of Figure 5A, the key data stored in the second HSM 120 is not used.

[0041] 5B shows an example of a case where the first HSM 110 cannot be used due to some malfunction. When some malfunction occurs in the first HSM 110 or when a serious vulnerability occurs in the first HSM 110, the main control unit 101 of the ECU 100 switches to the key information held in the second HSM 120 as the key information for security measures.

[0042] That is, the main control unit 101 of the ECU 100 reads out, as key information for security measures, Key1' to Keyn' stored in slots 1 to n of the second HSM 120. Then, the main control unit 101 of the ECU 100 uses the read data of Key1' to Keyn' as a key for the first function, a key for the second function, ..., a key for the nth function to execute security processing.

[0043] Even if the state switches from using the key data of the first HSM 110 in FIG. 5A to using the key data of the second HSM 120 in FIG. 5B, as explained in FIG. 4, the data M2 is the same in both HSMs 110 and 120, so the same key value can continue to be used.

[0044] 5A using the key data of the first HSM 110 to the key data of the second HSM 120 using the key data of the second HSM 120, the process must be switched within one control cycle of the ECU 100 so that an immediate response can be made. This switching within a control cycle can be realized because the key data is already prepared in the key data storage unit 121 in the second HSM 120.

[0045] As described above, according to this embodiment, the ECU 100 has two key storage devices, the first HSM 110 and the second HSM 120. Therefore, for example, if some kind of malfunction occurs in the first HSM 110 or if a serious vulnerability occurs in the first HSM 110, security measures can be continued by switching to the second HSM 120. In this case, the key data held by the first HSM 110 and the key data held by the second HSM 120 are the same data M2 based on random numbers, so the same key data can be continuously used.

[0046] In this embodiment, the key management device 200 only needs to write key data to the first HSM 110 of the ECU 100. Therefore, the key management device 200 can be used in an existing key management device that writes key data to an ECU that has only one HSM.

[0047] Second Embodiment Next, an on-vehicle electronic control unit, a key management system, and a key management method according to a second embodiment of the present invention will be described with reference to Figures 6 and 7. In Figures 6 and 7, which describe this embodiment, parts corresponding to Figures 1 to 5 described in the first embodiment are given the same reference numerals, and duplicate explanations will be omitted. In the following description, reference numerals with a prime (') indicate partial differences from those with reference numerals without a prime described in the first embodiment.

[0048] 6 shows the configuration of an ECU 100′ and a key management device 200′ according to this embodiment. Like the ECU 100 according to the first embodiment, the ECU 100′ is mounted on a vehicle and controlled by a main control unit 101, and has a first HSM 110′ and a second HSM 120′ as key management devices for security purposes.

[0049] The first HSM 110′ includes a key data holding unit 111, a key updating unit 112, a key data verifying unit 113, and a verification result generating unit 114. The second HSM 120′ also includes a key data holding unit 121, a key updating unit 122, a key data verifying unit 123, and a verification result generating unit 124.

[0050] Like the key management device 200 described in the first embodiment, the key management device 200′ comprises a key data generation unit 201, a key update verification unit 202, and an HSM identification information holding unit 203. The key management device 200′ further comprises a key update control unit 211, an HSM identification information acquisition unit 212, a duplication key data generation unit 213, a duplication key data holding unit 214, and a key slot correspondence information holding unit 215. The HSM identification information acquisition unit 212 functions as a key information acquisition unit for the first HSM 110′ and the second HSM 120′.

[0051] The key data held in the key data holding units 111, 121 of the first HSM 110' and the second HSM 120' basically has the same data structure as the key data M1 to M5 described in Figure 3, and at least data M2 has the same key value in the first HSM 110' and the second HSM 120'.

[0052] 7 is a sequence diagram showing an example of a process for writing key data (data M1 to M5) to the first HSM 110' and the second HSM 120' according to this embodiment. First, the key update control unit 211 of the key management device 200' communicates with the first HSM 110' of the ECU 100' to obtain the HSM ID of the first HSM 110' (step S101). The HSM ID obtained by the key management device 200' is stored in the HSM identification information holding unit 203.

[0053] Next, key data generation unit 201 of key management device 200' generates a random number to be used as a key value (step S102). Then, key data generation unit 201 generates data M1 to M5 using the random number generated in step S102, the HSM ID, and key slot correspondence information (step S103). The key slot correspondence information is obtained from key slot correspondence information storage unit 215. Generated data M2 is stored in duplication key data storage unit 214 in key management device 200'.

[0054] The key management device 200 sends data M1, M2, and M3 of the generated data M1 to M5 to the first HSM 110' of the ECU 100' as key-related data for the first HSM 110 (step S104). The key update unit 112 of the first HSM 110' has the key data verification unit 113 verify the received data M1, M2, and M3 (step S105). If this verification is successful, the key update unit 112 of the first HSM 110' writes the data M1, M2, and M3 to the key data storage unit 111 (step S106).

[0055] Then, the key update unit 112 of the first HSM 110′ generates data M4 and data M5 (step S107) and transmits the generated data M4 and data M5 to the key management device 200′ (step S108). In the key management device 200′, the key update verification unit 202 verifies the data M4 and data M5 transmitted from the first HSM 110′ (step S109).

[0056] Next, HSM identification information acquisition unit 212 of key management device 200' communicates with second HSM 120' of ECU 100' to acquire the HSM ID of first HSM 120' (step S110). The HSM ID acquired by key management device 200' is stored in HSM identification information holding unit 203. Thereafter, duplication key data generation unit 213 generates duplication key-related data from the HSM ID held by HSM identification information holding unit 203, data M2 held by duplication key data holding unit 214, and key slot information held by key slot correspondence information holding unit 215 (step S111).

[0057] Specifically, the duplication key data generator 213 generates data M1' from the HSM ID and key slot information of the second HSM 120. Furthermore, it generates data M3' from data M1' and data M2 for the first HSM.

[0058] The duplication key-related data (data M1', M2, and M3') generated in step S111 is transmitted to the second HSM 120 (step S112). The key update unit 122 of the second HSM 120 causes the key data verification unit 123 to verify the data M1', M2, and M3' (step S113). If the verification is successful, the key update unit 122 of the second HSM 120 causes the data M1', M2, and M3' to be written to the key data storage unit 121 (step S114).

[0059] Furthermore, the verification result generation unit 124 of the second HSM 120 generates data M4' and data M5' based on data M1', M2, and M3' (step S115), and transmits the generated data M4' and data M5' to the key management device 200' (step S116). In the key management device 200', the key update verification unit 202 verifies the transmitted data M4' and data M5' (step S117).

[0060] The data M1', M2, M3', M4', and M5' obtained by the processing up to this point are stored in the key data storage unit 121 of the second HSM 120'. Of this data M1', M2, M3', M4', and M5', the data M2 is the same as the data M2 stored in the key data storage unit 111 of the first HSM 110', and the other data M1', M3', M4', and M5' are data corresponding to the second HSM 120'.

[0061] As described above, according to this embodiment, the ECU 100′ has two key storage devices, the first HSM 110′ and the second HSM 120′. Therefore, as described in FIG. 5 of the first embodiment, when one HSM malfunctions, it is possible to switch to the other HSM. Furthermore, in this embodiment, key data is written to both the first HSM 110′ and the second HSM 120′ under the control of the key management device 200′. This eliminates the need for a processing configuration for the first HSM 110′ to write key data to the second HSM 120′, thereby simplifying the configuration of the ECU 100′. However, this embodiment requires a configuration for the key management device 200′ to write key data to the two HSMs 110′ and 120′.

[0062] <Modifications> Note that the embodiments described so far have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the described configurations. Furthermore, in the configuration diagrams shown in Figures 1 and 6, only control lines and information lines that are considered necessary for explanation are shown, and not all control lines and information lines are necessarily shown in the product. In reality, it can be considered that almost all configurations are connected to each other.

[0063] Furthermore, the key management device 200 shown in FIG. 1 and the key management device 200′ shown in FIG. 6 may be configured so that all processing is not performed by a single device but is distributed among multiple devices. That is, the system configurations shown in FIGS. 1 and 6 are preferred examples, and, for example, identification information and the like may be stored on a server separate from the key management device. The processing flows shown in FIGS. 4 and 7 are also preferred examples, and as long as the processing results are the same, the order of some of the processing may be changed or multiple processing may be executed simultaneously. The storage processing of key information into two HSMs described in FIGS. 4 and 7 is a preferred example, and other storage processing may cause the two HSMs to have the same key value. Note that the two HSMs within one ECU may be provided in separate memories within the same ECU, or in different storage areas within the same memory within the same ECU, and various other configurations are possible.

[0064] Furthermore, the ECU and key management device as the on-board electronic control device described in each of the above-mentioned embodiments are configured by implementing a program that executes the processing shown in Fig. 4 or Fig. 7. In this case, for example, in the case of the on-board electronic control device, the program is prepared in a memory in the computer shown in Fig. 2. In the case of the key management device, the program is prepared in a memory in a computer with a similar configuration. Alternatively, the program that executes the processing shown in Fig. 4 or Fig. 7 may be stored in an external memory, IC card, SD card, optical disk, or other recording medium, and transferred to and implemented in an existing on-board electronic control device or key management device, so that it functions as the ECU or key management device described in each of the above-mentioned embodiments.

[0065] DESCRIPTION OF SYMBOLS 100, 100'... ECU (on-vehicle electronic control unit), 100a... CPU, 100b... memory, 100c... input / output unit, 100d... communication interface, 101... main control unit, 102... key update control unit, 103... HSM identification information holding unit, 104... key slot correspondence information holding unit, 109... bus line, 110, 110'... first HSM (first key storage device), 111... key data holding unit, 112... key update unit, 113... key data verification unit, 114... verification result generation unit, 115... duplication key data generation unit, 116... duplication key data holding unit, 120, 120'... second HSM (second key storage device), 121... key data holding unit, 122... key update unit, 123... key data verification unit, 124... Verification result generation unit, 200, 200'... Key management device, 201... Key data generation unit, 202... Key update verification unit, 203... HSM identification information storage unit, 211... Key update control unit, 212... HSM identification information acquisition unit, 213... Duplication key data generation unit, 214... Duplication key data storage unit, 215... Key slot correspondence information storage unit

Claims

1. An in-vehicle electronic control device comprising: a first key storage device having a first key storage unit; and a second key storage device having a second key storage unit, wherein the same key value is stored in the first key storage unit of the first key storage device and the second key storage unit of the second key storage device.

2. The in-vehicle electronic control device according to claim 1, wherein the plurality of key storage devices are different hardware security modules.

3. The in-vehicle electronic control device according to claim 1, further comprising a key update control unit that, when authentication based on a first authentication value determined by the key value and an identifier identifying the first key storage device is established, stores the key value in the first key storage unit, and, when authentication based on a second authentication value determined by the key value and an identifier identifying the second key storage device is established, stores the key value in the second key storage unit.

4. The in-vehicle electronic control device according to claim 1, further comprising: a key updating unit that communicates with a key management device that generates first key information including the key value, a first identifier that identifies the first key storage device, and a first authentication value determined by the key value and the first identifier, and acquires the generated first key information; and a duplication key information generating unit that generates second key information including the key value included in the first key information acquired by the key updating unit, a second identifier that identifies the second key storage device, and a second authentication value determined by the key value and the second identifier.

5. An in-vehicle electronic control device as described in claim 1, which, when security is required, executes security measures using the key value stored in the first key storage unit of the first key storage device, and, when a malfunction occurs in the first key storage device, switches to the key value stored in the second key storage unit of the second key storage device and executes security measures.

6. A key management system including an on-board electronic control unit having a first key storage device and a second key storage device, and a key management device that communicates with the on-board electronic control unit, wherein the key management device acquires a plurality of identifiers that identify the first key storage device and the second key storage device provided in the on-board electronic control unit, and generates a plurality of key information including a key value, the identifier, and an authentication value determined by the key value and the identifier, and the on-board electronic control unit stores the same key value in each of the first key storage device and the second key storage device based on the plurality of key information received from the key management device.

7. A key management method for storing key information including a key value in an on-board electronic control unit equipped with a first key storage device having a first key storage unit and a second key storage device having a second key storage unit, the key management method comprising: a first key value storage process for storing the key value in the first key storage unit when authentication is established based on a first authentication value determined by the key value and an identifier identifying the first key storage device; and a second key value storage process for storing the key value in the second key storage unit when authentication is established based on a second authentication value determined by the key value and an identifier identifying the second key storage device.

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