Processing device, method, and program

Abstract

To provide a processing device, method, and program capable of improving the authenticity of information regarding the validity of a public key certificate.SOLUTION: A processing device having a normal environment and a secure environment includes a validity confirmation processing unit operating in the normal environment that accepts a request for revocation confirmation of a public key certificate, a validity management unit operating in the normal environment that outputs information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request, and an inspection unit operating in the secure environment that inspects the normality of the validity management unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a processing device, a method, and a program. [Background technology]

[0002] OCSP (Online Certificate Status Protocol) is known as a communication protocol for obtaining the revocation status of a public key certificate (for example, Non-Patent Document 1). In a public key infrastructure (PKI), when a certificate issued by a certificate authority (CA) is to be revoked, a certificate revocation list (CRL) is created. An OCSP responder (i.e., a validity management function) can import and store the CRL and use it to check the validity of the certificate. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Stefan Santesson, Michael Myers, Rich Ankney, Ambarish Malpani, Slava Galperin, Carlisle Adams, "X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP", Internet Engineering Task Force (IETF), Request for Comments: 6960, June 2013 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the normality of the validity management function is not guaranteed, the authenticity of information regarding the validity of public key certificates may not be guaranteed.

[0005] An object of the present disclosure is to provide a processing device, method, and program that can improve the authenticity of information regarding the validity of a public key certificate. [Means for solving the problem]

[0006] The program disclosed herein causes a processing device having a normal environment and a secure environment to perform processing including accepting a request for revocation confirmation of a public key certificate in the normal environment, outputting information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request in the normal environment, and checking the normality of the normal environment in the secure environment.

[0007] The processing device according to the present disclosure is a processing device having a normal environment and a secure environment, and is equipped with a validity confirmation processing unit operating in the normal environment that accepts a revocation confirmation request for a public key certificate, a validity management unit operating in the normal environment that outputs information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request, and an inspection unit operating in the secure environment that inspects the normality of the validity management unit.

[0008] The method disclosed herein is a method executed by a processing device having a normal environment and a secure environment, and includes accepting a revocation confirmation request for a public key certificate in the normal environment, outputting information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request in the normal environment, and checking the normality of the normal environment in the secure environment. [Effects of the Invention]

[0009] The present disclosure makes it possible to provide a processing device, method, and program that can improve the authenticity of information relating to the validity of a public key certificate. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 illustrates an example of a system of the present disclosure. [Figure 2] FIG. 1 is a block diagram illustrating an example of a processing device of the present disclosure. [Figure 3] 10 is a flowchart illustrating an example of a processing operation of the processing device of the present disclosure. [Figure 4] FIG. 10 illustrates another example of a system according to the present disclosure. [Figure 5] FIG. 10 is a block diagram illustrating another example of a processing device according to the present disclosure. [Figure 6] 10 is a flowchart illustrating another example of the processing operation of the processing device of the present disclosure. [Figure 7] FIG. 10 illustrates another example of a system according to the present disclosure. [Figure 8] FIG. 10 is a block diagram illustrating another example of a processing device according to the present disclosure. [Figure 9] FIG. 10 is a diagram illustrating an example of a management table according to the present disclosure. [Figure 10] 10 is a flowchart illustrating another example of the processing operation of the processing device of the present disclosure. [Figure 11] 10 is a flowchart illustrating another example of the processing operation of the processing device of the present disclosure. [Figure 12] FIG. 2 illustrates an example of the configuration of a processing device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described with reference to the drawings. In this disclosure, the drawings may relate to one or more embodiments. Furthermore, each element in the drawings may apply to one or more embodiments. Furthermore, in the embodiments, identical or equivalent elements are given the same reference numerals, and redundant explanations will be omitted.

[0012] First Embodiment <System Overview> 1 is a diagram illustrating an example of a system according to the present disclosure. In FIG. 1, the system 1 includes a processing device 10 and a communication device 20.

[0013] The communication device 20 transmits a revocation check request for a public key certificate to be checked for revocation to the processing device 10. For example, the public key certificate is a public key certificate of a web server that the communication device 20 accesses using a browser, and the public key certificate includes, for example, the public key of the web server and the digital signature of the certification authority that issued the public key certificate.

[0014] The processing device 10 transmits to the communication device 20 information relating to the validity of the public key certificate corresponding to the revocation check request.

[0015] <Example of processing device configuration> Fig. 2 is a block diagram showing an example of a processing device of the present disclosure. In Fig. 2, processing device (processor) 10 has a virtual processor (normal environment) 10A and a virtual processor (secure environment) 10B. The normal environment 10A corresponds to an REE (Rich Execution Environment), and the secure environment 10B corresponds to a TEE (Trusted Execution Environment). For example, the TEE is provided as a Trust Zone in the processor architecture of ARM (Advanced RISC Machines), and as SGX (Software Guard Extensions) in the processor architecture of Intel.

[0016] 2, the processing device 10 has a validity confirmation processing unit 11, a validity management unit 12, and an inspection unit 13. The validity confirmation processing unit 11 and the validity management unit 12 operate in a normal environment 10A, while the inspection unit 13 operates in a secure environment 10B. Here, the validity confirmation processing unit 11 and the validity management unit 12 correspond to a verification authority function that verifies a public key certificate.

[0017] The validity checking processing unit 11 receives a request to check whether a public key certificate has been revoked. The request may include the public key certificate.

[0018] The validity management unit 12 outputs "information relating to the validity of the public key certificate" corresponding to the accepted revocation check request. Note that the validity check processing unit 11 may also transmit the information relating to the validity of the public key certificate to the device that sent the revocation check request (i.e., communication device 20 in this case).

[0019] The inspection unit 13 inspects the normality of the validity management unit 12 (i.e., the normal environment 10A). For example, the inspection unit 13 may store a genuine hash value of the execution code of the operation program of the validity management unit 12. The inspection unit 13 then acquires the execution code of the operation program of the validity management unit 12 from a memory (not shown). The inspection unit 13 then calculates a hash value of the execution code based on the acquired execution code. The algorithm used to calculate this hash value is not particularly limited, and may be, for example, SHA1 or SHA256. The inspection unit 13 then inspects the normality of the validity management unit 12 based on the calculated hash value and the genuine hash value. For example, if the calculated hash value matches the genuine hash value, the inspection unit 13 determines that the validity management unit 12 is normal (not tampered with), and if they do not match, the inspection unit 13 determines that the validity management unit 12 is abnormal (tampered with).

[0020] <Example of processing device operation> FIG. 3 is a flowchart showing an example of the processing operation of the processing device of the present disclosure.

[0021] The validity confirmation processing unit 11 receives a request to confirm the revocation of a public key certificate (step S11).

[0022] The validity management unit 12 outputs "information relating to the validity of the public key certificate" corresponding to the accepted revocation confirmation request (step S12).

[0023] The inspection unit 13 inspects the normality of the validity management unit 12 (step S13).

[0024] As described above, according to the first embodiment, the validity management unit 12 in the processing device 10 operates in the normal environment 10A, and outputs "information related to the validity of the public key certificate" corresponding to a revocation confirmation request received by the validity confirmation processing unit 11. The inspection unit 13 operates in the secure environment 10B, and inspects the normality of the validity management unit 12 (i.e., the normal environment 10A).

[0025] With this configuration of the processing device 10, the inspection unit 13 operating in the secure environment 10B inspects the normality of the validity management unit 12 (i.e., the normal environment 10A), so it is possible to inspect the normality of the validity management unit 12 (i.e., the normal environment 10A) while ensuring the authenticity of the inspection unit 13. This makes it possible to ensure the normality of the validity management unit 12 (i.e., the normal environment 10A). As a result, it is possible to ensure the authenticity of information regarding the validity of the public key certificate output by the validity confirmation processing unit 11.

[0026] The inspection unit 13 may directly or indirectly inspect the normality of the validity management unit 12. For example, the processing device 10 may have an inspection processing unit (not shown) that operates in the normal environment 10A and inspects the normality of the validity management unit 12. The inspection unit 13 may inspect the normality of the inspection processing unit (not shown). In this case, for example, the inspection unit 13 stores a genuine hash value of the execution code of the operation program of the inspection processing unit (not shown). The inspection unit 13 then acquires the execution code of the operation program of the inspection processing unit (not shown) from a memory (not shown). The inspection unit 13 then calculates a hash value of the execution code based on the acquired execution code. The inspection unit 13 then inspects the normality of the inspection processing unit (not shown) based on the calculated hash value and the genuine hash value. For example, if the calculated hash value matches the genuine hash value, the inspection unit 13 determines that the inspection processing unit (not shown) is normal (not tampered with) and also determines that the validity management unit 12 is normal. On the other hand, if the calculated hash value does not match the correct hash value, the inspection unit 13 determines that the inspection processing unit (not shown) is abnormal (has been tampered with), and also determines that the validity management unit 12 is abnormal. This allows the inspection unit 13 to indirectly inspect the normality of the validity management unit 12.

[0027] Second Embodiment <System Overview> 4 is a diagram showing another example of a system according to the present disclosure. In FIG. 4, a system 2 includes a processing device 30, a communication device 20, and a certificate authority 40.

[0028] When the certificate authority 40 revokes a public key certificate that it has issued, the certificate authority 40 creates a certificate revocation list (CRL).

[0029] The processing device 30 obtains and stores the certificate revocation list from the certificate authority 40 .

[0030] The processing device 30 generates information about the validity of the public key certificate corresponding to the revocation check request based on the certificate revocation list, and transmits the information about the validity of the public key certificate corresponding to the revocation check request to the communication device 20.

[0031] <Example of processing device configuration> Fig. 5 is a block diagram showing another example of a processing device according to the present disclosure. In Fig. 5, a processing device (processor) 30 includes a virtual processor (normal environment) 30A and a virtual processor (secure environment) 30B.

[0032] 5, the processing device 30 has a validity confirmation processing unit 31, a validity management unit 32, an inspection unit 33, and a storage unit 34. The validity confirmation processing unit 31 and the validity management unit 32 operate in a normal environment 30A, while the inspection unit 33 operates in a secure environment 30B. The storage unit 34 is disposed in the normal environment 30A.

[0033] The validity confirmation processing unit 31 accepts a request to check the revocation of a public key certificate, similar to the validity confirmation processing unit 11. The validity confirmation processing unit 31 may also transmit information about the validity of the public key certificate to the device that sent the revocation check request (i.e., communication device 20 in this case), similar to the validity confirmation processing unit 11.

[0034] The validity management unit 32 acquires a certificate revocation list used to determine validity from the certificate authority 40 and stores it in the storage unit 34 .

[0035] The validity management unit 32 determines the validity of the public key certificate corresponding to the revocation check request by referring to the certificate revocation list stored in the storage unit 34. For example, if information identifying the public key certificate corresponding to the revocation check request is listed in the certificate revocation list, the validity management unit 32 determines that the public key certificate corresponding to the revocation check request has been revoked. On the other hand, if information identifying the public key certificate corresponding to the revocation check request is not listed in the certificate revocation list, the validity management unit 32 determines that the public key certificate corresponding to the revocation check request has not been revoked.

[0036] The validity management unit 32 outputs the result of the determination on the validity of the public key certificate corresponding to the revocation check request as information on the validity of the public key certificate.

[0037] The inspection unit 33 inspects the normality of the validity management unit 32 (that is, the normal environment 30A) in the same manner as the inspection unit 13. The inspection unit 33 may also detect tampering with the storage unit .

[0038] <Example of processing device operation> FIG. 6 is a flowchart showing another example of the processing operation of the processing device of the present disclosure.

[0039] The validity management unit 32 acquires the certificate revocation list from the certificate authority 40 and stores it in the storage unit 34 (step S21).

[0040] The validity confirmation processing unit 11 receives a request to confirm the revocation of the public key certificate (step S22).

[0041] The validity management unit 32 refers to the certificate revocation list stored in the storage unit 34 and determines the validity of the public key certificate corresponding to the revocation confirmation request (step S23).

[0042] The validity management unit 32 outputs the result of the determination on the validity of the public key certificate corresponding to the revocation check request (step S24).

[0043] The validity confirmation processing unit 31 transmits the determination result regarding the validity of the public key certificate to the device that sent the revocation confirmation request (that is, the communication device 20 in this case) (step S25).

[0044] The inspection unit 33 inspects the normality of the validity management unit 32 (that is, the normal environment 30A) (step S26).

[0045] <Modification> Note that, when the result of inspecting the normality of the validity management unit 32 (i.e., normal environment 30A) shows that the validity management unit 32 (i.e., normal environment 30A) is normal, the validity confirmation processing unit 31 may transmit the determination result regarding the validity of the public key certificate. Furthermore, when the validity management unit 32 (i.e., normal environment 30A) is not normal, the validity confirmation processing unit 31 may not transmit the determination result regarding the validity of the public key certificate. Alternatively, when the validity management unit 32 (i.e., normal environment 30A) is not normal, the validity confirmation processing unit 31 may transmit information indicating that the reliability of the determination result is low, along with the determination result regarding the validity of the public key certificate.

[0046] <Third embodiment> <System Overview> Fig. 7 is a diagram illustrating another example of a system according to the present disclosure. In Fig. 7, a system 3 includes processing devices 50-1, 50-2, and 50-3, a communication device 20, and a certificate authority 60. Hereinafter, when there is no need to distinguish between the processing devices 50-1, 50-2, and 50-3, the processing devices 50-1, 50-2, and 50-3 may be collectively referred to as processing devices 50, or each of the processing devices 50-1, 50-2, and 50-3 may simply be referred to as a processing device 50. Note that, although Fig. 7 illustrates three processing devices 50, the number of processing devices 50 is not limited to three, and the number of processing devices 50 may be two, four, or more.

[0047] The processing device 50-1 is connected to the processing device 50-2 via a quantum key distribution link QL1. The processing device 50-1 is also connected to the processing device 50-2 via a communication link L1 that is different from the quantum key distribution link QL1 and is used for normal data communication. Communication via the communication link L1 may be communication using an encryption key generated based on information distributed via the quantum key distribution link QL1.

[0048] Furthermore, the processing device 50-1 is connected to the processing device 50-3 via a quantum key distribution link QL2. The processing device 50-1 is also connected to the processing device 50-3 via a communication link L2 that is different from the quantum key distribution link QL2 and is used for normal data communication. The communication via the communication link L2 may be communication using an encryption key generated based on information distributed via the quantum key distribution link QL2. In other words, the processing devices 50-1, 50-2, and 50-3 are each trusted nodes that transmit and receive encryption keys using the quantum key distribution links.

[0049] The processing devices 50-1, 50-2, and 50-3 each report the quantum bit error rate (QBER) of the quantum key distribution link in which it is the receiving node to the certificate authority 60 at a predetermined timing. The processing devices 50-1, 50-2, and 50-3 may, for example, report the quantum bit error rate to the certificate authority at regular intervals. For example, a quantum key distribution link in which the processing device 50-1 is the source node and the processing device 50-2 is the receiving node will be referred to as quantum key distribution link QL11. A quantum key distribution link in which the processing device 50-2 is the source node and the processing device 50-1 is the receiving node will be referred to as quantum key distribution link QL12. A quantum key distribution link in which the processing device 50-1 is the source node and the processing device 50-3 is the receiving node will be referred to as quantum key distribution link QL21. A quantum key distribution link in which the processing device 50-3 is the source node and the processing device 50-1 is the receiving node will be referred to as quantum key distribution link QL22. At this time, the processing device 50-1 measures the quantum bit error rates of the quantum key distribution links QL12 and QL22 and reports the respective measurement results to the certification authority 60. Furthermore, the processing device 50-2 measures the quantum bit error rate of the quantum key distribution link QL11 and reports the measurement results to the certification authority 60. Furthermore, the processing device 50-3 measures the quantum bit error rate of the quantum key distribution link QL21 and reports the measurement results to the certification authority 60. Here, each processing device 50 may transmit the measurement results of the quantum bit error rate together with identification information of the QKD link related to the measurement results to the certification authority 60. The identification information of the QKD link may be, for example, a combination of an identifier of the sending node and an identifier of the receiving node, or may be an identification number previously assigned to each quantum key distribution link.

[0050] The certificate authority 60 creates a management table of quantum bit error rates based on reports from the processing devices 50-1, 50-2, and 50-3. Then, the certificate authority 60 transmits the management table to the processing device 50. The certificate authority 60 may transmit the management table to the processing device 50 every time it updates it. This allows the processing device 50 to periodically update the management table.

[0051] <Example of processing device configuration> 8 is a block diagram showing another example of a processing device of the present disclosure. In FIG. 8, a processing device (processor) 50 includes a virtual processor (normal environment) 50A and a virtual processor (secure environment) 50B.

[0052] 8, the processing device 50 has a validity confirmation processing unit 51, a validity management unit 52, an inspection unit 53, a storage unit 54, a holding unit 55, a quantum bit error rate reporting unit 56, and a QKD function unit 57. The validity confirmation processing unit 51, the validity management unit 52, and the quantum bit error rate reporting unit 56 operate in a normal environment 50A, while the inspection unit 53 operates in a secure environment 50B. The storage unit 54 and the holding unit 55 are disposed in the normal environment 50A. The QKD function unit 57 may also be disposed in the normal environment 50A. Since the processing devices 50-1, 50-2, and 50-3 have the same configuration, the configuration of the processing device 50-1 will be described as an example.

[0053] The QKD functional unit 57 transmits the encryption key to adjacent nodes (here, the processing devices 50-2 and 50-3) via the quantum key distribution link. The QKD functional unit 57 also receives the encryption key from adjacent nodes (here, the processing devices 50-2 and 50-3) via the quantum key distribution link. At this time, the QKD functional unit 57 measures the quantum bit error rate. The quantum bit error rate indicates the probability that the bit value transmitted by the transmitter (Alice) and the bit value received by the receiver (Bob) differ with respect to the encryption key transmitted by QKD (quantum key distribution). The quantum bit error rate decreases due to distance attenuation as well as abnormalities in the propagation path (optical fiber) and eavesdropping. In other words, the quantum bit error rate can be used as a parameter related to the reliability of the quantum key distribution link and, ultimately, the reliability of adjacent nodes (for example, the reliability of the validity management unit of the adjacent node).

[0054] The quantum bit error rate reporting unit 56 transmits the quantum bit error rate measured by the QKD function unit 57 to the certification authority 60. As described above, the quantum bit error rate reporting unit 56 of the processing device 50-1 transmits to the certification authority 60 the quantum bit error rate of the quantum key distribution link QL12 and the quantum bit error rate of the quantum key distribution link QL22.

[0055] When the validity confirmation processing unit 51 receives the management table from the certificate authority 60, it causes the storage unit 55 to store the received management table.

[0056] The validity confirmation processing unit 51, like the validity confirmation processing unit 11, accepts a request to confirm the revocation of a public key certificate.

[0057] The validity confirmation processing unit 51 refers to the management table stored in the storage unit 55 and selects the validity management unit 52 of the source node of the quantum key distribution link that has the highest reliability in the management table (e.g., the lowest quantum bit error rate) as the confirmation destination for confirming the validity of the public key certificate.

[0058] Fig. 9 is a diagram showing an example of a management table of the present disclosure. As shown in Fig. 9, the management table stores identification information of a quantum key distribution link and the quantum bit error rate of the quantum key distribution link corresponding to the identification information, in association with each other. In the example of Fig. 9, the identification information of the quantum key distribution link includes an ID of a processing device on the transmitting side, an ID of a QKD function unit on the transmitting side, an ID of a processing device on the receiving side, and an ID of a QKD function unit on the receiving side. For convenience, Fig. 9 uses the symbols of processing devices 50-1, 50-2, and 50-3 as the IDs of the processing devices and the IDs of the QKD function units.

[0059] When referring to the management table shown in Figure 9, the validity confirmation processing unit 51 selects the validity management unit 52 of the processing device 50-3, which is the source node of the quantum key distribution link with the lowest quantum bit error rate value, "QBER=0.02", as the confirmation destination for confirming the validity of the public key certificate.

[0060] 8, the validity confirmation processing unit 51 transmits a request for revocation confirmation of the public key certificate to the validity management unit 52 of the processing device 50 selected as the destination of confirmation. Upon receiving the determination result regarding the validity of the public key certificate (i.e., information regarding the validity of the public key certificate) from the validity management unit 52 of the destination of confirmation, the validity confirmation processing unit 51 transmits the determination result regarding the validity of the public key certificate to the communication device 20 that sent the revocation confirmation request.

[0061] When the validity confirmation processing unit 51 receives a revocation confirmation request from another processing device 50 (i.e., processing devices 50-2, 50-3), it requests the validity confirmation from the validity management unit 52 of the processing device 50-1. That is, the validity confirmation processing unit 51 outputs the revocation confirmation request to the validity management unit 52 of the processing device 50-1. When the validity confirmation processing unit 51 receives the determination result on the validity of the open key certificate from the validity management unit 52 of the processing device 50-1, it transmits the determination result on the validity of the public key certificate to the other processing device 50 (i.e., processing devices 50-2, 50-3) that sent the revocation confirmation request.

[0062] The validity management unit 32 obtains the certificate revocation list used to determine validity from the certificate authority 60 and stores it in the storage unit 54 .

[0063] When the validity management unit 52 receives a revocation check request from the validity confirmation processing unit 51, it determines the validity of the public key certificate corresponding to the revocation check request by referring to the certificate revocation list stored in the storage unit 34. The validity management unit 52 outputs the determination result regarding the validity of the public key certificate corresponding to the revocation check request to the validity confirmation processing unit 51 as information regarding the validity of the public key certificate.

[0064] The inspection unit 53 inspects the normality of the validity management unit 52 (that is, the normal environment 50A) in the same manner as the inspection unit 13. The inspection unit 53 may also detect tampering with the storage unit .

[0065] <Example of processing device operation> Fig. 10 is a flowchart showing another example of the processing operation of the processing device of the present disclosure. The processing flow shown in Fig. 10 starts when the validity confirmation processing unit 51 receives a revocation check request for a public key certificate. Fig. 10 shows the processing flow when the validity confirmation processing unit 51 receives a revocation check request from the communication device 20.

[0066] The validity confirmation processing unit 51 refers to the management table stored in the storage unit 55 and selects the validity management unit 52 of the source node of the quantum key distribution link that has the highest reliability in the management table as the confirmation destination for confirming the validity of the public key certificate (step S31).

[0067] The validity confirmation processing unit 51 transmits a request to confirm the revocation of the public key certificate to the validity management unit 52 of the processing device 50 selected as the confirmation destination (step S32).

[0068] The validity confirmation processing unit 51 receives the result of the determination on the validity of the public key certificate from the validity management unit 52 (step S33).

[0069] The validity confirmation processing unit 51 transmits the result of the determination on the validity of the public key certificate to the communication device 20 that sent the revocation confirmation request (step S34).

[0070] Fig. 11 is a flowchart showing another example of the processing operation of the processing device of the present disclosure. The processing flow shown in Fig. 11 starts when the validity confirmation processing unit 51 receives a revocation confirmation request for a public key certificate. Fig. 11 shows the processing flow when the validity confirmation processing unit 51 of a processing device 50 receives a revocation confirmation request from another processing device 50. Here, the processing flow will be described as that of processing device 50-1.

[0071] The validity confirmation processing unit 51 outputs the received revocation confirmation request to the validity management unit 52 of the processing device 50-1 (step S41).

[0072] The validity management unit 52 refers to the certificate revocation list stored in the storage unit 34 and determines the validity of the public key certificate corresponding to the revocation confirmation request received from the validity confirmation processing unit 51 (step S42).

[0073] The validity management unit 52 outputs the determination result regarding the validity of the public key certificate to the validity confirmation processing unit 51 (step S43).

[0074] The validity confirmation processing unit 51 transmits the determination result regarding the validity of the public key certificate received from the validity management unit 52 to the other processing device 50 that is the sender of the revocation confirmation request (step S44).

[0075] As described above, according to the third embodiment, each of the processing devices 50-1, 50-2, and 50-3 in the system 3 has a public key certificate validity management function (i.e., validity management unit 52). That is, the public key certificate validity management function is distributed in the system 3.

[0076] This configuration of system 3 can improve the robustness of the public key certificate validity management function.

[0077] In addition, in the processing device 50, the validity confirmation processing unit 51 refers to the management table and selects the validity management unit 52 of the source node of the quantum key distribution link that has the highest reliability in the management table (e.g., the lowest quantum bit error rate) as the confirmation destination for confirming the validity of the public key certificate.

[0078] This configuration of the processing device 50 can improve the reliability of information regarding the validity of public key certificates.

[0079] <Other embodiments> FIG. 12 is a diagram illustrating an example of the configuration of a processing device. In FIG. 12, the processing device 100 includes a processor 101, a memory 102, and an interface 103. The processor 101 may be, for example, a microprocessor, a microprocessing unit (MPU), or a central processing unit (CPU). The processor 101 may include multiple processors. The memory 102 is configured by a combination of a volatile memory and a nonvolatile memory. The memory 102 may include storage located away from the processor 101. In this case, the processor 101 may access the memory 102 via an I (Input) / O (Output) interface (not shown).

[0080] The processing devices 10, 30, and 50 of the first to third embodiments may each have the configuration shown in FIG. 12 . The validity confirmation processing units 11, 31, and 51, the validity management units 12, 32, and 52, the inspection units 13, 33, and 53, the quantum bit error rate reporting unit 56, and the QKD function unit 57 of the processing devices 10, 30, and 50 of the first to third embodiments may be realized by the processor 101 reading and executing a program stored in the memory 102. That is, the processing devices 10, 30, and 50 of the first to third embodiments can be realized by software. The storage units 34 and 54 and the holding unit 55 may be realized by the memory 102. The program can be stored using various types of non-transitory computer-readable media and supplied to the processing devices 10, 30, and 50. Examples of non-transitory computer-readable media include magnetic recording media (e.g., floppy disks, magnetic tapes, hard disk drives) and magneto-optical recording media (e.g., magneto-optical disks). Further examples of non-transitory computer-readable media include CD-ROMs (Read Only Memory), CD-Rs, and CD-R / Ws. Further examples of non-transitory computer-readable media include semiconductor memories. Semiconductor memories include mask ROMs, programmable ROMs (PROMs), erasable PROMs (EPROMs), flash ROMs, and random access memories (RAMs). The program may be provided to the processing device 10, 30, 50 by various types of transitory computer-readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. The transitory computer-readable media may provide the program to the processing device 10, 30, 50 via wired communication paths such as electrical wires and optical fibers, or wireless communication paths.

[0081] Alternatively, the validity confirmation processing units 11, 31, and 51, the validity management units 12, 32, and 52, the inspection units 13, 33, and 53, the quantum bit error rate reporting unit 56, and the QKD function unit 57 of the processing devices 10, 30, and 50 of the first to third embodiments may each be realized by dedicated hardware. Furthermore, some or all of the components of each device may be realized by general-purpose or dedicated circuits, processors, etc., or a combination thereof. These may be configured by a single chip, or by multiple chips connected via a bus. Some or all of the components of each device may be realized by a combination of the above-mentioned circuits, etc., and a program. Furthermore, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field-Programmable Gate Array), a quantum processor (quantum computer control chip), etc., may be used as the processor.

[0082] Furthermore, when some or all of the components of the processing devices 10, 30, and 50 of the first to third embodiments are realized by a plurality of information processing devices, circuits, etc., the plurality of information processing devices, circuits, etc. may be centrally or distributedly arranged. For example, the information processing devices, circuits, etc. may be realized as a client-server system, a cloud computing system, etc., in which each device is connected via a communication network. Furthermore, the functions of the processing devices 10, 30, and 50 of the first to third embodiments may be provided in a SaaS (Software as a Service) format.

[0083] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0084] Each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0085] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes. (Appendix 1) a processing device having a normal environment and a secure environment; receiving a request for verifying the revocation of a public key certificate in the normal environment; outputting, in the normal environment, information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request; Inspecting the normality of the normal environment in the secure environment; A program that executes processing including (Appendix 2) The process comprises: In the normal environment, acquiring a certificate revocation list used to determine the validity and storing it in a first storage unit; detecting tampering with the first storage unit in the secure environment; 10. The program of claim 1, (Appendix 3) the processing includes, in the normal environment, determining the validity of the public key certificate corresponding to the revocation confirmation request by referring to the stored certificate revocation list; The program described in Appendix 2. (Appendix 4) The information regarding the effectiveness includes a determination result of the effectiveness. The program described in Appendix 3. (Appendix 5) the processing device is a trusted node that transmits and receives cryptographic keys using a quantum key distribution link; the trusted node is connected to each of at least one other trusted node via a quantum key distribution link; The process comprises: maintaining a correspondence relationship between at least one quantum key distribution link in which the trusted node is a source node and each of the at least one other trusted nodes is a destination node, and at least one quantum key distribution link in which each of the at least one other trusted nodes is a source node and the trusted node is a destination node, and a reliability of each quantum key distribution link; selecting a source node of the quantum key distribution link having the highest reliability in the correspondence relationship among the trusted node and the at least one other trusted node as a confirmation destination for confirming the validity of the public key certificate corresponding to the revocation confirmation request; Including, 5. The program according to any one of appendices 1 to 4. (Appendix 6) The reliability parameter is a quantum bit error rate. The program described in Appendix 5. (Appendix 7) the process includes transmitting information about the validity to a device that originated the revocation confirmation request; 7. The program according to any one of appendices 1 to 6. (Appendix 8) the revocation check request includes a public key certificate to be revoked; 8. The program according to any one of appendices 1 to 7. (Appendix 9) A processing device having a normal environment and a secure environment, a validity confirmation processing unit that operates in the normal environment and that accepts a request for validating a public key certificate; a validity management unit that operates in the normal environment and outputs information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request; a verification unit that operates in the secure environment and that checks the normality of the validity management unit; A processing device comprising: (Appendix 10) the validity management unit acquires a certificate revocation list used to determine the validity and stores it in a first storage unit; The inspection unit detects tampering with the first storage unit. 10. The processing device of claim 9. (Appendix 11) the validity management unit refers to the stored certificate revocation list to determine the validity of the public key certificate corresponding to the revocation confirmation request; 11. The processing device of claim 10. (Appendix 12) the validity management unit outputs the determination result of the validity as information regarding the validity. 12. The processing device of claim 11. (Appendix 13) the processing device is a trusted node that transmits and receives cryptographic keys using a quantum key distribution link; the trusted node is connected to each of at least one other trusted node via a quantum key distribution link; a storage unit that stores a correspondence between at least one quantum key distribution link in which the trusted node is a source node and each of the at least one other trusted node is a destination node, and at least one quantum key distribution link in which each of the at least one other trusted node is a source node and the trusted node is a destination node, and a reliability of each quantum key distribution link; the validity confirmation processing unit selects, from the validity management unit of the trusted node and the validity management unit of the at least one other trusted node, the validity management unit of a source node of the quantum key distribution link that has the highest reliability in the correspondence relationship, as a confirmation destination for confirming the validity of the public key certificate corresponding to the revocation confirmation request. 13. The processing device of any one of appendices 9 to 12. (Appendix 14) The reliability parameter is a quantum bit error rate. 14. The processing device of claim 13. (Appendix 15) the validity confirmation processing unit transmits information regarding the validity to the device that sent the revocation confirmation request; 15. The processing device of any one of appendices 9 to 14. (Appendix 16) the revocation check request includes a public key certificate to be revoked; 16. The processing device of any one of appendices 9 to 15. (Appendix 17) 1. A method performed by a processing device having a normal environment and a secure environment, comprising: receiving a request for verifying the revocation of a public key certificate in the normal environment; outputting, in the normal environment, information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request; Inspecting the normality of the normal environment in the secure environment; A method comprising: (Appendix 18) In the normal environment, acquiring a certificate revocation list used to determine the validity and storing it in a first storage unit; detecting tampering with the first storage unit in the secure environment; 18. The method of claim 17, comprising: (Appendix 19) and determining, in the normal environment, the validity of the public key certificate corresponding to the revocation confirmation request by referring to the stored certificate revocation list. The method described in Appendix 18. (Appendix 20) The information regarding the effectiveness includes a determination result of the effectiveness. The method described in Appendix 19. (Appendix 21) the processing device is a trusted node that transmits and receives cryptographic keys using a quantum key distribution link; the trusted node is connected to each of at least one other trusted node via a quantum key distribution link; The method comprises: maintaining a correspondence relationship between at least one quantum key distribution link in which the trusted node is a source node and each of the at least one other trusted nodes is a destination node, and at least one quantum key distribution link in which each of the at least one other trusted nodes is a source node and the trusted node is a destination node, and a reliability of each quantum key distribution link; selecting a source node of the quantum key distribution link having the highest reliability in the correspondence relationship among the trusted node and the at least one other trusted node as a confirmation destination for confirming the validity of the public key certificate corresponding to the revocation confirmation request; Including, 21. The method of any one of appendices 17 to 20. (Appendix 22) The reliability parameter is a quantum bit error rate. The method described in Appendix 21. (Appendix 23) transmitting information about the validity to a device that sent the revocation confirmation request; 23. The method of any one of appendices 17 to 22. (Appendix 24) the revocation check request includes a public key certificate to be revoked; 24. The method of any one of appendices 17 to 23. [Explanation of symbols]

[0086] 1 System 2. System 3. System 10 Processing equipment 10A normal environment 10B Secure Environment 11 Validation processing section 12 Effectiveness Management Department 13 Inspection Department 20. Communication Equipment 30 Processing equipment 30A normal environment 30B Secure Environment 31 Validation processing unit 32 Effectiveness Management Department 33 Inspection Department 34 Storage area 40 Certificate Authority 50 Processing equipment 50A normal environment 50B Secure Environment 51 Validation confirmation processing section 52 Effectiveness Management Department 53 Inspection Department 54 Storage area 55 Holding part 56 Quantum Bit Error Rate Reporting Section 57 QKD function section 60 Certificate Authority

Claims

1. a processing device having a normal environment and a secure environment; receiving a request for verifying the revocation of a public key certificate in the normal environment; outputting, in the normal environment, information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request; Inspecting the normality of the normal environment in the secure environment; A program that executes processing including

2. The process comprises: In the normal environment, acquiring a certificate revocation list used to determine the validity and storing the list in a first storage unit; Detecting tampering with the first storage unit in the secure environment; The program of claim 1 , comprising:

3. the processing includes, in the normal environment, determining the validity of the public key certificate corresponding to the revocation confirmation request by referring to the stored certificate revocation list; The program according to claim 2.

4. The information regarding the effectiveness includes a determination result of the effectiveness. The program according to claim 3.

5. the processing device is a trusted node that transmits and receives cryptographic keys using a quantum key distribution link; the trusted node is connected to each of at least one other trusted node via a quantum key distribution link; The process comprises: maintaining a correspondence relationship between at least one quantum key distribution link in which the trusted node is a source node and each of the at least one other trusted nodes is a destination node, and at least one quantum key distribution link in which each of the at least one other trusted nodes is a source node and the trusted node is a destination node, and a reliability of each quantum key distribution link; selecting a source node of the quantum key distribution link having the highest reliability in the correspondence relationship among the trusted node and the at least one other trusted node as a confirmation destination for confirming the validity of the public key certificate corresponding to the revocation confirmation request; Including, The program according to any one of claims 1 to 4.

6. The reliability parameter is a quantum bit error rate. The program according to claim 5.

7. the process includes transmitting information about the validity to a device that originated the revocation confirmation request; The program according to any one of claims 1 to 4.

8. the revocation check request includes a public key certificate to be revoked; The program according to any one of claims 1 to 4.

9. A processing device having a normal environment and a secure environment, a validity confirmation processing unit that operates in the normal environment and that accepts a request for revocation confirmation of a public key certificate; a validity management unit that operates in the normal environment and outputs information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request; a verification unit that operates in the secure environment and that verifies the normality of the validity management unit; A processing device comprising:

10. 1. A method performed by a processing device having a normal environment and a secure environment, comprising: receiving a request for verifying the revocation of a public key certificate in the normal environment; outputting, in the normal environment, information regarding the validity of the public key certificate corresponding to the accepted revocation confirmation request; Inspecting the normality of the normal environment in the secure environment; A method comprising:

Images