Information processing device and key management device

Abstract

The present disclosure provides an information processing device and a key management device which can safely write key information even in a manufacturing environment other than one's own company. The information processing device 1, which performs key generation / management, comprises: a storage unit 100 which stores a public key received from a key management device 3; a key generation unit 13 which generates a use key; and a communication unit 11 which can communicate with the outside, wherein the key generation unit 13 generates the use key in an invalidation state where the communication unit 11 blocks a signal input from outside, and the communication unit 11 transmits the use key, which has been encrypted with the public key, to the key management device 3.

Description

[Technical Field]

[0001] The present invention relates to an information processing device that generates and manages keys and a key management device that manages keys. [Background technology]

[0002] Various security measures are being adopted to protect automobiles from cyberattacks. Among these measures, security measures that utilize cryptographic technology are crucial for preventing the compromise of key information used. Therefore, it is necessary to protect such key information from the manufacturing process throughout the product lifecycle. In particular, the use of electronics manufacturing services (EMS) as product manufacturing sites is increasing. Even in manufacturing environments such as EMS, where in-house governance may not be effective, there is a need to securely write confidential key information to products. Here, in this specification, the key described above will be referred to as a "usage key" to distinguish it from the key used for encryption and decryption (it may also be simply referred to as a "key").

[0003] As a technique for writing a new key to a device (ECU: Electronic Control Unit) mounted on a vehicle, Patent Document 1 discloses a technique in which a server verifies a secure boot result calculated based on key information previously mounted on the ECU, sends a key according to the verification result, and the ECU writes the key information. Patent Document 2 also discloses a technique in which a random number is generated after disabling a debug port, the random number is encrypted, and sent to a key issuing server, and an individual key encrypted with the random number is obtained from the key issuing server. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6683588 specification [Patent Document 2] Patent No. 5224512 specification Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional technology, the ECU does not have a working key installed at the start of manufacturing, which means that the manufacturing process includes a step of installing the working key in the ECU.

[0006] In this case, if the usage key information is simply sent to a third-party manufacturing environment along with the software to be written to the ECU, anyone involved in the manufacturing environment could easily access the usage key information. Furthermore, in the event that the usage key is compromised, it is desirable to be able to explain whether the usage key was written correctly during the manufacturing process in order to clarify the division of responsibility within the company. Furthermore, the technology in Patent Document 2 is characterized in that the individual key is generated on the key issuing server side, not on the ECU side, and therefore cannot utilize an EMS. Furthermore, resetting the generated random number makes it possible to generate the key multiple times, increasing the risk of key compromise.

[0007] The present invention has been made in consideration of the above problems, and aims to provide an information processing device and a key management device that can safely write usage key information even in a manufacturing environment where in-house governance is not effective, and that can explain that the usage key information was written under the correct circumstances. [Means for solving the problem]

[0008] An example of an information processing device according to the present invention that generates and manages keys includes a storage unit that stores a public key received from a key management device, a key generation unit that generates a usage key, and a communication unit that can communicate with the outside, wherein the key generation unit generates the usage key in a disabled state in which the communication unit blocks signal input from the outside, and the communication unit transmits the usage key encrypted with the public key to the key management device. [Effects of the Invention]

[0009] The information processing device according to the present invention generates keys only under predetermined conditions where there is no external interference, thereby preventing key leakage and suppressing fraudulent activities. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing the configuration of an information processing device according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a diagram showing an outline of a processing sequence relating to key generation and key registration. [Figure 3] FIG. 10 is a diagram showing an outline of a processing flow for determining whether a key can be generated. [Figure 4] FIG. 10 is a diagram showing an outline of the processing flow for generating evidence. [Figure 5] FIG. 2 is a diagram showing the data structure of key-related information. [Figure 6] FIG. 10 is a diagram showing the data structure of key generation condition rule information. [Figure 7] FIG. 10 is a diagram showing the data structure of evidence object information. [Figure 8] FIG. 2 is a diagram showing the data structure of evidence information. [Figure 9] FIG. 10 is a diagram showing the configuration of a key management device according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing an outline of the processing flow for updating a key from an individual key to a shared key. [Figure 11] FIG. 4 is a diagram showing the data structure of key master information. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the present invention will be described in detail using examples with reference to the drawings.

[0012] Example 1 [Information processing device 1] In this embodiment, an example of an information processing device 1 that implements a method for safely writing key information for security measures in the manufacturing process of an information processing device to be installed in an automobile will be described. However, the technical idea of the present invention is not limited to this embodiment.

[0013] 1 shows the configuration of an information processing device 1 in this embodiment. The information processing device 1 is, for example, a device mounted on a vehicle and controls the vehicle. However, the information processing device 1 may also be installed outside the vehicle or may be a device that controls an object other than a vehicle.

[0014] In the manufacturing process, the information processing device 1 is connected to the key management device 3 via a communication bus 2. The communication bus 2 may be connected by, for example, a LAN cable, and may perform communication via Ethernet (registered trademark), or may perform wireless communication in accordance with a predetermined standard.

[0015] The information processing device 1 includes a computing means (not shown) and a storage means (not shown). The computing means includes, for example, a CPU (Central Processing Unit). The storage means includes, for example, a non-volatile memory and a volatile memory. The computing means executes a program stored in the storage means, causing the information processing device 1 to realize the functions described in this specification.

[0016] For example, the information processing device 1 includes, as its functional units, a key management control unit 12, a key generation unit 13, a key generation feasibility determination unit 14, a key registration unit 15, an evidence recording unit 16, and an encryption processing unit 17. In this specification, the processes executed by the CPU or these functional units can also be said to be processes executed by the information processing device 1.

[0017] The information processing device 1 includes a storage unit 100. The storage unit 100 may be entirely non-volatile, or partly volatile. The information processing device 1 also includes a communication unit 11, which is a communication interface and performs calculations necessary for communication.

[0018] The functional block diagram shown in Fig. 1 is an example, and the units and names of the functions are not limited to this. For example, the functions realized by the key management control unit 12 in this embodiment may be realized by other functional units shown in Fig. 1 or by functional units not shown in Fig. 1.

[0019] The communication unit 11 transmits and receives messages to and from the key management device 3 via the communication bus 2. The key management control unit 12 controls whether to transition to key generation mode when it receives a key setting command from outside. The key generation unit 13 generates a common key and a public key pair. The key generation permission determination unit 14 determines whether the information processing device 1 is in a state where it is permitted to generate a key. The key registration unit 15 registers key information in the storage unit 100. The evidence recording unit 16 records evidence information related to key generation and key registration in the storage unit 100. The encryption processing unit 17 performs encryption processing in accordance with a predetermined algorithm. The processing performed by these functional units will be described in more detail below.

[0020] The memory unit 100 stores key-related information 101 including key values used in cryptographic processing, key generation condition rule information 102 defining the conditions under which keys can be generated, evidence object information 103 defining the content to be included in evidence, and evidence information 104 recording evidence information related to key generation and key registration.

[0021] The functional block diagram shown in Fig. 1 is also an example, and the units and names of the functions are not limited to these. For example, in this embodiment, the evidence information 104 may be held by another functional unit shown in the storage unit 100 in Fig. 1, or may be held by a functional unit not shown in the storage unit 100 in Fig. 1.

[0022] 2 is a sequence diagram showing the processing from when the information processing device 1 generates a usage key, to when it registers the usage key, and to when it notifies the result to the key management device 3. Each step described below is executed by, for example, a CPU (not shown) of the information processing device 1.

[0023] In step 201, the key management control unit 12 receives a key setting command sent to the information processing device 1 via the communication unit 11. For example, a device installed on the manufacturing process line may send the key setting command, or the key management device 3 may send the key setting command, or any other method may be used as long as the information processing device 1 receives a predetermined signal.

[0024] In step 202, the key management control unit 12 determines whether or not it is possible to transition to key generation mode. If it is possible to transition to key generation mode, the process proceeds to step 203. If it is not possible to transition to key generation mode, the process ends. For example, the key management control unit 12 or the storage unit 100 may have a key generation mode transition possibility flag, and if the key generation mode transition possibility flag is "0", it may be determined that it is possible to transition to key generation mode, and if the key generation mode transition possibility flag is "1", it may be determined that it is not possible to transition to key generation mode. In this case, the initial value of the key generation mode transition possibility flag may be set to "0" in an initial state in which no key generation has ever been performed.

[0025] In step 203, the key generation possibility determination unit 14 determines whether or not key generation is possible based on the key generation condition rule information 102. The key generation condition rule information 102 will be described in detail later.

[0026] In step 204, if the key generation permission determination unit 14 determines that key generation is permitted in step 203, the process proceeds to step 205, and if not, the process ends.

[0027] In step 205, the key generation unit 13 generates the required number of keys. For example, one or more random numbers to be used as a common key may be generated. Alternatively, one or more public key pairs consisting of a public key and a private key according to the RSA encryption method, which is a well-known encryption method, may be generated.

[0028] In step 206 , the key registration unit 15 stores the key-related information 101 relating to the key generated in step 205 in the storage unit 100 .

[0029] 5 shows the data structure of key-related information 101 related to the key generated in step 205. Key-related information 101 includes a key slot ID 1011 for identifying the symmetric key stored in key-related information 101, key information 1012 indicating the value of the key, a public key pair ID 1013 for identifying the public key, key information 1014 indicating the value of the key, a secret communication public key ID 1015 indicating the public key used for secret communication with key management device 3, and key information 1016 indicating the value of the key. For example, the area where the key is stored is a memory area such as an HSM (Hardware Security Module) that ensures confidentiality and integrity for the symmetric key, or a memory area with a one-time programmable (OTP) function that ensures integrity or a memory area whose integrity is verified for the public key. Furthermore, the secret communication public key is stored in the key management device 3 with its paired private key, and may be pre-programmed in a program capable of performing the processing shown in FIG. 2 that is written during the manufacturing process.

[0030] In step 207, the evidence recording unit 16 stores the evidence information 104 created in accordance with the evidence object information 103 described below in the storage unit 100. Note that the processing of step 207 may be performed all at once at a timing after step 204 above, or the evidence information required in each step after step 204 above may be recorded.

[0031] In step 208, the key management control unit 12 prohibits the key generation unit 13 from generating keys in the subsequent processing. This prevents the key from being arbitrarily replaced with another key after shipping. Note that this step can be omitted. That is, there are cases where the key generation unit 13 generates keys multiple times. In such cases, it is possible to set a threshold value for the number of times a key is generated, and prohibit key generation when the number of times exceeds a predetermined number.

[0032] In step 209, the key management control unit 12 generates a response message for the key management device 3 using the encryption processing unit 17. For example, the response message includes the key-related information 101 registered in step 206 and the evidence information 104 recorded in step 207. The encryption processing unit 17 also encrypts the response message including the key-related information 101 and the evidence information 104 using key information 1016 linked to the secret communication public key ID 1015.

[0033] In step 210, the key management control unit 12 notifies the key management device 3 of the encrypted response message generated in step 209 above using the communication unit 11. When the key management device 3 receives the response message from the information processing device 1, it decrypts it using the private key that forms a pair with the key information 1016 linked to the secret communication public key ID 1015, and registers the acquired key-related information 101 and evidence information 104.

[0034] Through the above steps, the information processing device 1 can generate a key, register the key-related information 101 in the storage unit 100, and notify the key management device 3 of the generated key-related information and evidence information safely.

[0035] More preferably, by implementing some or all of the processes from step 202 to step 209 in a secure area such as an HSM that ensures tamper resistance, it becomes possible to prevent cyber attacks by insiders or third parties at manufacturing sites.

[0036] FIG. 3 is a flowchart showing the process for determining whether or not a key can be generated in step 203 above.

[0037] In step 301, the key generation possibility determination unit 14 acquires predetermined state information regarding the information processing device 1. The state information may be included in a program as setting information, may be the result of executing a program, or may be information stored in a register or the like mounted on the information processing device.

[0038] In step 302, the key generation possibility determination unit 14 compares the state information acquired in step 301 with the rules stored in the key generation condition rule information 102. Note that in step 301, the state information of the information processing device 1 may be acquired in accordance with the rules stored in the key generation condition rule information 102.

[0039] 6 shows the data structure of the key generation condition rule information 102 referenced in step 302. The key generation condition rule information 102 is made up of a rule ID 1021 for identifying the key generation condition, a verification target 1022 indicating a verification target related to the state of the information processing device 1, and a specified state 1023 that specifies the state that the verification target 1022 should be in. The verification target 1022 is not limited to the one shown in the figure, and may also be a register value or a processing result by the information processing device.

[0040] For example, the key generation possibility determination unit 14 acquires the state of the verification target 1022 linked to the rule ID 1021 and compares it with the specified state 1023 to see if it matches. The unit reads setting information or register information related to JTAG (Joint Test Action Group), USB (Universal Serial Bus), UART (Universal Asynchronous Receiver / Transmitter), Wi-Fi, and Ethernet, and confirms that the state of the verification target is the same "disabled" state as the specified state 1023, and also confirms that the state of the CAN is the same "enabled" state as the specified state 1023. If all the states are the same as the specified state 1023, it determines that there is no rule violation, and otherwise it determines that there is a rule violation.

[0041] Here, the key generation condition rule information 102 shown in FIG. 6 is an example, and there are cases where not all verification targets necessarily satisfy the specified state. For example, consider a case where a debug port is included in the verification targets. A debug port is a signal terminal for communicating with the outside world, and the information included in the communication is more confidential than that of other signal terminals. In such a case, it is also possible to determine that a rule violation has occurred when only this debug port is in a disabled state in which communication with the outside world is blocked. This makes it possible to prioritize verification targets, thereby increasing the reliability of ensuring confidentiality and reducing the load of calculation processing.

[0042] In step 303, if the key generation possibility determination unit 14 determines that there is no rule violation as a result of the comparison in step 302, the process proceeds to step 304;

[0043] In step 304, the key generation permission determination unit 14 transitions to a key generation permission state as a result of the key generation permission determination process.

[0044] In step 305, the key generation permission determination unit 14 transitions to a key generation prohibited state as a result of the key generation permission determination process.

[0045] Through the above steps, the key generation possibility determination unit 14 can determine whether or not a key can be generated based on the state information of the information processing device 1.

[0046] FIG. 4 is a flowchart showing the process relating to the recording of evidence information in step 207 above.

[0047] In step 401 , the evidence recording unit 16 acquires the content of the evidence to be generated from the evidence object information 103 .

[0048] 7 shows the data structure of the evidence object information 103 that is referenced to confirm the evidence content generated in the above step 401. The evidence object information 103 consists of an evidence object ID 1031 that identifies the evidence content, and evidence content 1032 that indicates the content of the evidence.

[0049] In step 402, the evidence recording unit 16 generates evidence according to the evidence content 1032 acquired in step 401. For example, if the evidence object ID 1031 is "0x01", the evidence recording unit 16 generates, as evidence, the key information generated in step 205 above as the evidence content 1032. In addition, if the evidence object ID 1031 is "0x02", the evidence recording unit 16 generates, as evidence content 1032, the key information 1016 of the secret communication public key ID 1015 used to encrypt the response message in step 209 above; if the evidence object ID 1031 is "0x03", the evidence recording unit 16 generates, as evidence content 1032, the state information of the verification object 1022 used to determine whether the key can be generated in step 203 above; and if the evidence object ID 1031 is "0x04", the time information at which the evidence was generated in step 401 above as the evidence content 1032.

[0050] The evidence may be the information itself, or the cryptographic processing unit 17 may generate a digest value as evidence using one of the key information generated in step 205. For example, cryptographic techniques such as AES (Advanced Encryption Standard)-CMAC (Cipher-based MAC) can be used as the digest.

[0051] In step 403 , the evidence recording unit 16 stores the evidence generated in step 402 in the evidence information 104 .

[0052] 8 shows the data structure of evidence information 104 that stores evidence in step 403 above. The evidence information 104 consists of an evidence ID 1041 that identifies the evidence, and evidence information 1042 that indicates its digest value. In step 210 above, the digest value and the evidence content used to calculate the digest value are transmitted to the key management device 3, whereby the key management device 3 uses the decrypted key information to calculate a digest value based on the received evidence content, verifies whether it matches the received digest value, and, if they match, confirms that the evidence content is correct. Note that evidence information 1042 does not have to be a digest value, and the evidence information generated in step 402 above may be stored as is.

[0053] Through the above steps, the information processing device 1 can record evidence information for verifying that key generation is performed in a correct state.

[0054] As described above, according to the first embodiment, in the manufacturing process of an information processing device to be installed in an automobile, key information for security measures can be securely written and the written key information can be securely notified to the key management device. Furthermore, the information processing device 1 generates keys only in a secure situation and can record status information at the time of key generation as evidence information. As a result, when a third party or an insider launches a cyberattack during the manufacturing process, accountability based on the evidence information can be fulfilled and a deterrent effect against cyberattacks can be expected.

[0055] The information processing device according to the present invention described above provides the following advantageous effects. (1) The information processing device of the present invention is an information processing device capable of generating and managing keys, and comprises a memory unit that stores a public key received from a key management device, a key generation unit that generates a usage key, and a communication unit that can communicate with the outside, wherein the key generation unit generates the usage key in a disabled state in which the communication unit blocks signal input from the outside, and the communication unit transmits the usage key encrypted with the public key to the key management device.

[0056] With the above configuration, it is expected that the leakage of the key can be prevented and fraudulent activities can be suppressed by generating the key only under predetermined circumstances where there is no external interference.

[0057] (2) The device further includes a key management control unit that manages the generation of usage keys, and the key management control unit prohibits the key generation unit from generating new keys when the key generation unit has generated usage keys a predetermined number of times or more. By appropriately setting the predetermined number of times, the key generation unit can be prevented from generating keys without limit, making it possible to prevent tampering with keys after shipment, for example.

[0058] (3) The communication unit has multiple signal terminals, and the key generation unit generates a usage key when a signal terminal that transmits and receives information with a predetermined level of confidentiality to and from the outside is in a disabled state. This makes it possible to prioritize the signal terminals to be verified, reliably guarantee confidentiality, and reduce the load on calculation processing.

[0059] (4) The information processing device further includes a storage unit that stores evidence information including information for identifying the generated usage key, and the evidence information includes status information of a signal terminal that transmits and receives information with a predetermined level of confidentiality to and from the outside when the usage key is generated by the key generation unit. This makes it possible to determine whether the key was generated correctly by comparing the evidence information stored in the information processing device with information sent from a third-party manufacturing base, which is expected to function as a deterrent to fraudulent activities.

[0060] (5) The evidence information includes information about the public key used to encrypt the usage key. This makes it possible to compare the public key held by the ECU with the public key held by the key management device and determine whether they match. This makes it possible to determine whether the public key on the ECU side has been tampered with due to unauthorized access by a third party. Furthermore, when the key generation unit is capable of generating a usage key multiple times, the evidence information includes information about the number of times the key generation unit has generated a usage key. This makes it possible to determine, as with the above, whether more keys than expected have been generated due to unauthorized access by a third party.

[0061] (6) The communication unit outputs evidence information in response to an external request. This makes it possible to suitably apply the present invention even when the manufacturing site and the manufacturing client are remote from each other.

[0062] (7) The system further includes a key registration unit that acquires an update key from an external source, and the key management control unit updates the working key to the update key when the key registration unit acquires the update key. This allows for easy updating of the working key without generating a new working key, even when it is necessary to update the working key.

[0063] <Example 2> [Key management device 3] Next, we will explain the key management device 3, which is connected to the above-described information processing device 1 and manages the usage keys generated by the information processing device 1. When the key management device 3 wants to share product-specific key information generated by the information processing device 1 as key information with another information processing device, the key management device 3 sends a key update command to the information processing device 1. Then, in response to the command, the information processing device 1 updates the generated key to shared key information to be shared with the other information processing device.

[0064] 9 is a block diagram showing a schematic configuration of a key management device 3 according to an embodiment. The key management device 3 of this embodiment is connected to an information processing device 1 via a communication bus 2.

[0065] The key management device 3 includes a calculation means (not shown) and a storage means (not shown). The calculation means includes, for example, a CPU. The storage means includes, for example, a non-volatile memory and a volatile memory. The calculation means executes a program stored in the storage means, thereby causing the key management device 3 to realize the functions described in this specification.

[0066] The key management device 3 includes, as its functional units, an encryption processing unit 32, a key registration determination unit 33, an update key selection unit 34, a key update command unit 35, and a key update result verification unit 36. In this specification, the processes executed by the CPU or these functional units can also be said to be executed by the key management device 3.

[0067] The key management device 3 also includes a storage unit 37. The storage unit 37 may be entirely non-volatile, or partly volatile. The key management device 3 also includes a communication unit 31, which is a communication interface and performs calculations necessary for communication.

[0068] The functional block diagram shown in Fig. 9 is an example, and the units and names of the functions are not limited to this. For example, the functions realized by the key update result verification unit 36 in this embodiment may be realized by other functional units shown in Fig. 9 or by functional units not shown in Fig. 9.

[0069] The communication unit 31 transmits and receives messages to and from the information processing device 1 via the communication bus 2. The encryption processing unit 32 performs encryption processing in accordance with a predetermined algorithm. The key registration determination unit 33 determines whether to register the individual key information received from the information processing device 1 as is, or to update it to shared key information. The update key selection unit 34 selects an update key to be notified to the information processing device 1 when it is decided to update the individual key information to shared key information. The key update command unit 35 commands the information processing device 1 to update the individual key to be updated to the update key. The key update result verification unit 36 verifies that the key update result notified from the information processing device 1 has been correctly updated.

[0070] The storage unit 37 stores key master information 371 that stores key information relating to all keys used in all information processing devices.

[0071] 9 is an example of the functional block diagram of the storage unit 37, and the functional units and names are not limited to those shown therein. For example, the information held by the key master information 371 in this embodiment may be held by a functional unit not shown in the storage unit 37 in FIG.

[0072] Fig. 10 is a sequence diagram of a process for updating an individual key generated in the information processing device 1 to a shared key that is used in common with other information processing devices. In Fig. 10, the same processes as those described in Fig. 2 of the first embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0073] Step 210 is the same process as in Example 1. In step 501, the cryptographic processing unit 32 receives an encrypted response message from the information processing device 1 via the communication unit 31. Then, the cryptographic processing unit 32 decrypts the encrypted response message according to a predetermined algorithm using a private key paired with the public key information 1016 set to the secret communication public key ID 0x01.

[0074] In step 502, the key registration determination unit refers to the key master information 371 and determines whether each piece of key information received from the information processing device 1 can be registered as an individual key or whether it should be updated to a shared key.

[0075] 11 shows the data structure of key master information 371 that is referenced to determine whether or not to register a key in step 502. Key master information 371 includes product ID 3711 for identifying information processing device 1, key slot ID 3712 for identifying a key stored in information processing device 1, key type 3713 for identifying whether to change to a shared key, and key information 3714 that records key information registered in information processing device 1.

[0076] In step 503, if it is determined in step 502 that key updating is required rather than registration, the update key selection unit 34 selects an update key.

[0077] For example, the following describes the processing performed in steps 501 to 503 when the response message received from the information processing device 1 with product ID "A41" is decrypted and key-related information is obtained from the response message. For example, for keys with common key slot IDs 1011 of "0x01" and "0x02" of the information processing device 1, the key type 3713 is "individual," so key information 1012 is registered in key information 3714 as an individual key (see FIG. 5). For the key with common key slot ID 1011 of "0x03," the key type 3713 is "shared," so it is determined that a key update is necessary, and the key information pre-registered in key information 3714 for the information processing device 1 is selected as the update key. Note that if key information for an update request has not been generated in advance, an update key may be generated in step 502.

[0078] In step 504, the cryptographic processing unit 32 encrypts the update key information selected in step 503 using one of the keys generated by the information processing device 1 received in step 210, and also uses one of the keys generated by the information processing device 1 to attach a signature to the encrypted update key information, thereby generating key update command information. For example, AES-CBC may be used as the encryption algorithm, and AES-CMAC may be used for attaching the signature. Furthermore, a communication message including a data format (M1, M2, M3) in accordance with MUP of the SHE protocol may be generated as the key information to be encrypted and signed in step 504.

[0079] In step 505, the key update command unit 35 notifies the information processing device 1 via the communication unit 31 of the update command information generated in step 504 according to a predetermined algorithm.

[0080] In step 506, the key management control unit 12 of the information processing device 1 uses the encryption processing unit 17 to decrypt and verify the signature of the key update command information received from the key management device 3 in accordance with a predetermined algorithm.

[0081] In step 507, if the signature verification in step 506 is correct, the key management control unit 12 uses the key registration unit 15 to register the update key instructed by the key management device 3 in the key-related information 101. For example, the key management control unit 12 overwrites the key information 1012 with the key information 3714 having the common key slot ID 1011 of "0x03" received from the key management device 3.

[0082] In step 508, the key management control unit 12 notifies the key management device 3 of the result of the key update in step 507 above via the communication unit 11. For example, the notification may be a communication message including a data format (M4, M5) in accordance with MUP of the known SHE protocol.

[0083] In step 509, the key update result verification unit 36 of the key management device 3 verifies whether the key update was successful based on the update result notified in step 508, and if it is determined to be successful, completes the key update. For example, in accordance with MUP of the SHE protocol, M5' is generated using M4 received in step 508 and the key information used in step 504, and if M5 and M5' match, it is determined that the key update was successful.

[0084] Through the above steps, the individual key generated by the information processing device 1 can be safely updated to the same shared key as that of other information processing devices. Also, instead of a shared key used by multiple information processing devices, the key may be updated to individual key information designated in advance by the key management device 3. In this case, the key management device does not necessarily need to be connected to multiple information processing devices.

[0085] As described above, the key management device 3 determines whether to register the individual key as is or update it to a shared key based on the response message from the information processing device 1, and the information processing device 1 can update only the key for the target slot to a shared key based on the key update command from the key management device 3. This makes it possible to use a shared key for applications where a key that is to be shared among multiple information processing devices is desired, and to use individual keys for applications where a different key is desired for each information processing device, and it is expected that the impact of key leakage for applications where an individual key is used will be limited to one information processing device, rather than using a shared key for all applications.

[0086] The key management device according to the present invention described above provides the following advantageous effects. (8) A key management device capable of communicating with the information processing device of (1), comprising: a communication unit that acquires a usage key generated by the key generation unit from the information processing device; and a key update command unit that outputs a key update command to the information processing device to update the acquired usage key to an update usage key of a type different from the usage key.

[0087] As a result, even if the key generated by the information processing device is a different type of key from the key expected by the key management device, an update command makes it possible for the information processing device to re-generate the key by preferably adopting the present invention, and confidential key information can be safely written to products even in manufacturing environments such as EMS where there is a risk that the company's own governance may not be effective.

[0088] (9) A key registration determination unit is provided to determine whether or not the keys in use need to be updated. This makes it possible to update only the keys that need to be updated, thereby reducing the processing load.

[0089] (10) The system further includes a storage unit that stores key master information in which the key types of the usage keys that the key generation unit can generate are registered. The key registration determination unit identifies the key type of the usage key acquired by the communication unit based on the key master information and determines the update usage key to be output. By registering the key master information in advance, it is possible to easily identify the key type of the usage key. Furthermore, even if a key with an incorrect key value is generated due to a malfunction, it can be discarded as if it were not registered in the key master information.

[0090] (11) A device connected to multiple information processing devices, with key types including at least a shared key commonly used by the multiple information processing devices and an individual key that is different for each of the multiple information processing devices. This allows individual keys to be used for applications where different keys are required for each information processing device, and for applications where individual keys are used, the impact of a key leak can be expected to be limited to one information processing device, rather than using a shared key for all applications.

[0091] The present invention is not limited to the above-described embodiments, and various design modifications may be made without departing from the spirit of the present invention as defined in the claims. For example, the above-described embodiments have been described in detail to facilitate understanding of the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0092] 1 Information processing device, 2 Communication bus, 3 Key management device, 11, 31 Communication unit, 12 Key management control unit, 13 Key generation unit, 14 Key generation possibility determination unit, 15 Key registration unit, 16 Evidence recording unit, 17 Encryption processing unit, 33 Key registration determination unit, 35 Key update command unit, 37, 100 Storage unit

Claims

1. An information processing device that generates and manages keys, a storage unit that stores the public key received from the key management device; a key generation unit for generating a usage key; a communication unit capable of communicating with the outside; a storage unit that stores evidence information including information for identifying the generated usage key, the key generation unit generates the usage key in a disabled state in which the communication unit blocks external signal input; the storage unit stores, as the evidence information, state information of the information processing device when the usage key was generated in the revoked state; The communication unit transmits the usage key encrypted with the public key to the key management device. Information processing device.

2. 2. The information processing device of claim 1, a key management control unit that manages generation of the usage key; The key management control unit prohibits the key generation unit from generating a key when the key generation unit has generated the usage key a predetermined number of times or more. Information processing device.

3. 2. The information processing device of claim 1, the communication unit includes a plurality of signal terminals, the key generation unit generates the usage key when a signal terminal, among the plurality of signal terminals, that transmits and receives information having a predetermined level of confidentiality to and from an external device is in the disabled state. Information processing device.

4. 2. The information processing device of claim 1, The evidence information includes status information of a signal terminal that transmits and receives information having a predetermined level of confidentiality to and from the outside when the key generation unit generates the usage key. Information processing device.

5. 5. The information processing device of claim 4, The evidence information includes information on the public key for encrypting the key in use. Information processing device.

6. 5. The information processing device of claim 4, When the key generation unit is capable of generating the usage key a plurality of times, the evidence information includes information on the number of times the usage key has been generated by the key generation unit. Information processing device.

7. 5. The information processing device of claim 4, The communication unit outputs the evidence information in response to an external request. Information processing device.

8. 3. The information processing device of claim 2, further comprising a key registration unit that acquires an update key from an external device; the key management control unit updates the usage key to the update key in response to the key registration unit acquiring the update key. Information processing device.

9. A key management device capable of communicating with the information processing device according to claim 1, a communication unit that acquires the usage key generated by the key generation unit from the information processing device; a key update command unit configured to output a key update command to the information processing device to update the acquired usage key to an update usage key of a type different from the usage key; a key registration determination unit that determines whether the usage key needs to be updated; the storage unit stores key master information in which key types of the keys that can be generated by the key generation unit are registered; the key registration determination unit identifies the key type of the usage key acquired by the communication unit based on the key master information, and determines the update usage key to be output. Key management device.

10. 10. The key management device of claim 9, is connected to a plurality of the information processing devices, The key types include at least a shared key that is used in common among the plurality of information processing devices, and an individual key that is different for each of the plurality of information processing devices. Key management device.

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