Information processing device, information processing method, and program

Abstract

To allow the status of quantum cryptography communication using an encryption key shared through quantum key distribution to be confirmed.SOLUTION: An information processing device is connected to at least a first communication device of the first communication device and a second communication device, and includes a processing unit. The first communication device acquires an encryption key shared between a first key management device and a second key management device by quantum key distribution from the first key management device. The second communication device acquires the encryption key from the second key management device. The processing unit acquires first attribute information indicating an attribute of the encryption key from the first communication device, or acquires the first attribute information from a message transmitted and received in communication. The processing unit acquires second attribute information indicating an attribute of the encryption key based on the information acquired from the first key management device. The processing unit outputs output information based on the first attribute information and the second attribute information.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to an information processing apparatus, an information processing method, and a program.

Background Art

[0002] Quantum key distribution technology (Quantum Key Distribution, hereinafter QKD) is a technology for securely sharing an encryption key between a QKD device that continuously transmits single photons and a QKD device that receives single photons, which are connected by an optical fiber link. The encryption key shared by QKD is guaranteed to be un窃听ed based on the principles of quantum mechanics. Information theory guarantees that data encrypted by using an encryption communication method called One Time Pad (OTP) with the shared encryption key cannot be decrypted by any eavesdropper with any knowledge.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention aims to provide an information processing device, an information processing method, and a program that enable the verification of the state of quantum cryptographic communication using cryptographic keys shared by quantum key distribution. [Means for solving the problem]

[0005] The information processing device of the embodiment is connected to at least the first communication device among the first and second communication devices, and includes a processing unit. The first communication device obtains an encryption key shared between the first key management device and the second key management device by quantum key distribution from the first key management device. The second communication device obtains an encryption key from the second key management device. The processing unit obtains first attribute information indicating the attributes of the encryption key from the first communication device, or obtains first attribute information from messages sent and received in communication. Based on the information obtained from the first key management device, the processing unit obtains second attribute information indicating the attributes of the encryption key. The processing unit outputs output information based on the first attribute information and the second attribute information. [Brief explanation of the drawing]

[0006] [Figure 1] Block diagram of the information processing system of the embodiment. [Figure 2] A block diagram showing other configuration examples of an information processing system. [Figure 3] Block diagram of the communication management device. [Figure 4] A diagram showing an example of the data structure of management information managed by a key management device. [Figure 5] A flowchart of the state confirmation process in the embodiment. [Figure 6] Flowchart of the state confirmation process in modified example 1. [Figure 7] Flowchart of the state confirmation process in modified example 2. [Figure 8] Flowchart of the status confirmation process in modified example 3. [Figure 9] Hardware configuration diagram of the device according to the embodiment. [Modes for carrying out the invention]

[0007] A preferred embodiment of the information processing device according to this invention will be described in detail below with reference to the attached drawings.

[0008] Figure 1 is a block diagram showing an example of the configuration of an information processing system according to the embodiment. As shown in Figure 1, the information processing system 10 according to the embodiment includes a communication management device 100 as an information processing device, communication devices 200a and 200b, key management devices 300a and 300b, and QKD devices 400a and 400b.

[0009] Since communication devices 200a and 200b have similar configurations, they may simply be referred to as communication device 200 when there is no need to distinguish between them. Similarly, key management devices 300a and 300b may simply be referred to as key management device 300. Also, QKD devices 400a and 400b may simply be referred to as QKD device 400.

[0010] In Figure 1, two communication devices 200, two key management devices 300, and two QKD devices 400 are shown, but the information processing system 10 may have three or more of each device.

[0011] Communication devices 200a and 200b are connected by network 501 and communicate through network 501. QKD devices 400a and 400b are connected by network 502. Communication management device 100 is connected to communication device 200a and key management device 300a by network 503.

[0012] Network 501 can be any type of network, but for example, it may be a local network such as a LAN (Local Area Network) or a wider network such as a WAN (Wide Area Network). Network 501 may also be a wireless communication network such as a fifth-generation mobile communication system (5G).

[0013] Network 502 is, for example, an optical fiber link and is used to generate and share encryption keys by QKD between QKD device 400a and QKD device 400b.

[0014] Network 503 can be any form of network, for example, a LAN or a WAN. Network 503 may be integrated with network 501.

[0015] Communication management device 100 is a device that manages at least the communication by communication device 200a. QKD device 4,000 shares encryption keys with other QKD devices 400 by QKD. Key management device 300 is a device that manages the encryption keys shared by QKD device 400. For example, key management device 300a manages the encryption keys shared by QKD device 400a with QKD device 400b. Also, key management device 300b manages the encryption keys shared by QKD device 400b with QKD device 400a. Thereby, key management device 300a can share and manage the same encryption key as key management device 300b connected to QKD device 400b. The dotted line in FIG. 1 indicates that key management device 300a and key management device 300b are in such a correspondence relationship.

[0016] Note that key management device 300 and QKD device 400 may be integrated into one device. FIG. 2 is a block diagram showing an example of the configuration of information processing system 10-2 in such a case.

[0017] As shown in FIG. 2, information processing system 10-2 includes communication management device 100, communication devices 200a and 200b, and key management / QKD devices 300-2a and 300-2b. Key management / QKD devices 300-2a and 300-2b may simply be referred to as key management / QKD device 300-2 when there is no need to distinguish them. Key management / QKD device 300-2 corresponds to a device having the functions of both key management device ३०० and QKD device 400 in FIG. 1. A plurality of key management / QKD devices 300-2 are connected by network 502-2. Network 502-2 is, for example, an optical fiber link.

[0018] Returning to FIG. 1, each communication device 200 obtains an encryption key used for communication from the connected key management device 300. For example, communication device 200a (the first communication device) obtains, from key management device 300a (the first key management device), an encryption key shared between key management device 300a and key management device 300b (the second key management device) by QKD, which is the encryption key (decryption key) used for communication with communication device 200b. Also, communication device 200b obtains the encryption key used for communication with communication device 200a from key management device 300b.

[0019] In FIG. 1 (FIG. 2), one communication management device 100 is depicted, but information processing system 10 may include two or more communication management devices 100. For example, when communication device 200a and communication device 200b are provided at different sites (locations), one communication device 200 may be provided for each site. The communication management device 100 at each site may be connected to one or more communication devices 200 and one or more key management devices 300 installed at that site. One communication management device 100 may be connected to multiple communication devices 200 installed at multiple sites to manage the communication at each site.

[0020] Also, communication management device 100 may be incorporated into key management device 300a. In other words, communication management device 100 may have the functions of key management device 300a.

[0021] Hereinafter, the case where communication management device 100 is connected to communication device 200a and manages quantum key communication by communication device 200a will be described as an example.

[0022] Assume a scenario where data is transmitted via network 501 in either direction, from communication device 200a to communication device 200b, or vice versa. For example, communication device 200a encrypts plaintext using an encryption key obtained from key management device 300a and transmits the resulting ciphertext to communication device 200b via network 501. In such a scenario, mutual authentication, encryption of transmitted and received data, and verification of data validity are performed to ensure secure communication between communication devices 200a and 200b.

[0023] This embodiment primarily relates to data encryption among these functions. Conventional technologies such as HTTPS (Hypertext Transfer Protocol Secure) use symmetric-key cryptography for the data itself being sent and received (public-key cryptography is used to mutually share the symmetric key). Symmetric-key cryptography is based on computational security, and its security cannot be guaranteed when technologies with much faster computation speeds than those currently available, such as quantum computers, become commercially available. This is called computational security.

[0024] On the other hand, there is the OTP encryption method, which is based on information-theoretic security. In OTP, encryption and decryption are performed using one bit of encryption key for each bit of data. As long as the encryption key is generated correctly and is not leaked, the encryption key cannot be deciphered even by high-speed computers such as quantum computers.

[0025] In this situation, securely sharing the encryption key becomes a problem. That is, the encryption key must be shared in advance between the two parties communicating without being intercepted by others. Quick Key Disclosure (QKD) is used as a method to solve this problem.

[0026] In QKD, encryption keys are shared among multiple QKD devices 400 via an optical fiber link. If a third party intercepts the encryption key along the optical fiber link, the system can detect the interception and discard the key. This makes it possible to share the encryption keys that were not discarded, i.e., the keys that were not intercepted, among geographically separated QKD devices 400.

[0027] The technology that combines OTP and QKD to perform secure communication based on information-theoretic security is called quantum cryptography. To achieve secure communication using quantum cryptography, communication device 200a obtains from key management device 300a the encryption key that has been previously shared via QKD between key management device 300b, which is connected to communication device 200b, and key management device 300a, which is connected to itself. Communication device 200a encrypts the data using the encryption key obtained from key management device 300a and sends the encrypted data to communication device 200b. Communication device 200b decrypts the encrypted data using the encryption key obtained from key management device 300b. This makes quantum cryptography possible.

[0028] From the perspective of a user of quantum cryptography, it is desirable to be able to recognize, for example, whether or not quantum cryptography is currently available. In conventional encrypted communication, which is not quantum cryptography, techniques are known to check whether or not encrypted communication is possible. For example, when communicating using a web browser, there is a technique that displays a key icon in the web browser when encrypted communication is in progress, and does not display the key icon in the web browser when encrypted communication is not in progress.

[0029] On the other hand, in quantum cryptography, no technology is known that would allow users to verify the state of the quantum cryptography communication. Quantum cryptography is expected to be used for sending and receiving more sensitive data (e.g., genome data). Therefore, it is desirable that users be able to verify whether or not data can be sent and received securely. For example, it is desirable that users be able to send data only after they have confirmed that they can share an encryption key using QKD between their own communication device (e.g., communication device 200a) and the destination communication device (e.g., communication device 200b), and that they can encrypt the data to be sent (uploaded, etc.) to the destination communication device using the shared encryption key.

[0030] Therefore, in this embodiment, a technology for confirming the state of quantum cryptographic communication is realized. Note that the confirmation of the state of quantum cryptographic communication is not limited to the purpose of confirming whether the communication is secure or not, as described above, but may be performed for any other purpose. For example, the amount of encryption key consumed may be confirmed as the state of quantum cryptographic communication for the purpose of collecting charges based on consumption (usage).

[0031] The information processing system 10 of this embodiment includes a communication management device 100 to realize such technology. Figure 3 is a block diagram showing an example of the configuration of the communication management device 100. As shown in Figure 3, the communication management device 100 includes an acquisition unit 101 (first acquisition unit), an acquisition unit 102 (second acquisition unit), a determination unit 103, an output control unit 104, and a storage unit 121.

[0032] The acquisition unit 101 acquires attribute information IA (first attribute information) from the communication device 200a, which indicates the attributes of the encryption key used for communication between the connected communication device 200a and the communication device 200b that is the destination of communication by the communication device 200a. The attributes can be any kind of information, but for example, they can be key identification information (hereinafter referred to as key ID) that identifies the encryption key.

[0033] For example, the acquisition unit 101 requests the communication device 200a to transmit the key ID of the encryption key to be used in the next quantum cryptographic communication. The communication device 200a stores and manages the information of the encryption key to be used in the next quantum cryptographic communication, for example, in a memory unit within its own device. The communication device 200a returns the key ID to the acquisition unit 101 in response to the request. The acquisition unit 101 acquires the key ID returned by the communication device 200a.

[0034] The acquisition unit 102 acquires attribute information IB, which indicates the attributes of the encryption key used for communication between communication device 200a and communication device 200b, based on the information acquired from the key management device 300a. In this embodiment, the acquisition unit 102 acquires the attribute information IB itself from the key management device 300a. For example, the acquisition unit 102 transmits device identification information to the key management device 300a that identifies the destination communication device 200b, and acquires attribute information IB, which is the key ID returned from the key management device 300a in accordance with the device identification information.

[0035] For example, the key management device 300a stores and manages information about the encryption key to be used for the next quantum cryptographic communication for each communication device 200 in its internal storage. Figure 4 shows an example of the data structure of the management information managed by the key management device 300a. As shown in Figure 4, the management information is information that associates an SAE ID (Secure Application Entity ID), which corresponds to device identification information, with a key ID. The SAE is an element that requests a key from the key management device 300, as defined in Non-Patent Literature 2, for example, and in this embodiment corresponds to the communication device 200. One key ID may be associated with one SAE ID, or multiple key IDs may be associated with one SAE ID.

[0036] The key management device 300a refers to the management information shown in Figure 4 to identify the key ID corresponding to the device identification information (SAE ID) transmitted from the acquisition unit 102, and returns the identified key ID to the acquisition unit 102.

[0037] The determination unit 103 determines whether the attribute indicated by attribute information IA acquired by the acquisition unit 101 matches the attribute indicated by attribute information IB acquired by the acquisition unit 102. For example, the determination unit 103 determines whether the key ID acquired as attribute information IA matches the key ID acquired as attribute information IB. If the two match, it corresponds to the encryption key managed by the communication device 200a and the encryption key managed by the key management device 300a being consistent. In other words, it corresponds to the quantum cryptography communication being in a normal state. As a determination result, the determination unit 103 may output information indicating whether the information indicated by the attribute information matches, or it may output information indicating the state of quantum cryptography communication (normal, abnormal, etc.).

[0038] Furthermore, if any abnormality occurs in quantum cryptography communication, it is possible that the attribute information may not match. For example, one such situation might occur where the encryption key is managed as valid in communication device 200a, but expired in key management device 300a.

[0039] The output control unit 104 controls the output of various types of information used by the communication management device 100. For example, the output control unit 104 outputs output information based on attribute information IA and attribute information IB. The output information can be in any format, but for example, it can be information indicating the determination result by the determination unit 103. This allows, for example, the receiving device to perform processing according to the determination result. The processing according to the determination result can be any processing, but for example, if the determination result indicates that the attribute indicated by attribute information IA matches the attribute indicated by attribute information IB, the processing involves outputting information (such as a key mark) indicating that quantum cryptography communication is being performed.

[0040] The output control unit 104 may output output information including attribute information IA and attribute information IB. By outputting such output information, for example, the receiving device can perform a check of the state of quantum cryptography communication using the output information. This configuration can be interpreted as a configuration in which the receiving device checks (determines) the state of quantum cryptography communication. In this configuration, the communication management device 100 does not need to have a determination unit 103.

[0041] At least a portion of each of the above components (acquisition unit 101, acquisition unit 102, determination unit 103, and output control unit 104) may be implemented by one or more processing units. Each of the above components may be implemented by, for example, one or more processors. For example, each of the above components may be implemented by having a processor such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit) execute a program, i.e., by software. Each of the above components may be implemented by a dedicated processor such as an IC (Integrated Circuit), i.e., by hardware. Each of the above components may be implemented by using both software and hardware. When multiple processors are used, each processor may implement one of the above components, or two or more of the above components.

[0042] The storage unit 121 stores various types of information used by the communication management device 100. For example, the storage unit 121 stores the acquired attribute information IA, attribute information IB, and the determination result from the determination unit 103. The storage unit 121 can be made up of any commonly used storage medium, such as flash memory, memory card, RAM (Random Access Memory), HDD (Hard Disk Drive), and optical disc.

[0043] The communication management device 100 may consist of one physical device or multiple physical devices. For example, the communication management device 100 may be built on a cloud environment.

[0044] When built on a cloud environment, the communication management device 100 may be configured to acquire attribute information IA and IB via a data collection function provided within the same network location as the communication device 200a, for example.

[0045] Next, the status confirmation process by the communication management device 100 of this embodiment will be described. The status confirmation process is a process that confirms the status of the quantum cryptography communication used by the communication device 200. The status confirmation process may be executed at any time, but for example, it may be executed as follows. • Executed when instructed to do so by a user or other party. This is executed when a function (such as an application) that performs quantum cryptography communication is started. For example, in the case of an application that sends data using a web browser, it is executed when the specific page used to send the data is displayed. • This process is performed at regular intervals (periodically). The regular intervals may be managed by the communication management device 100 or by an external device. In the latter case, the external device may instruct the communication management device 100 to perform the status check process at regular intervals.

[0046] Figure 5 is a flowchart showing an example of the state confirmation process in the embodiment. Below, we will explain using the case where communication device 200a performs quantum cryptography communication with communication device 200b as an example.

[0047] The acquisition unit 101 obtains the key ID of the encryption key to be used for communication with communication device 200b from communication device 200a (step S101). For example, the acquisition unit 101 passes the device identification information (SAE ID) of the destination communication device 200b to communication device 200a. Communication device 200a returns the key ID of the encryption key to be used for communication with communication device 200b to the communication management device 100. This allows the acquisition unit 101 to obtain the key ID. This key ID corresponds to attribute information IA.

[0048] The acquisition unit 102 obtains the key ID of the encryption key that communication device 200a uses to communicate with communication device 200b from the key management device 300a (step S102). For example, the acquisition unit 102 passes the device identification information (SAE ID) of communication device 200b to the key management device 300a. The key management device 300a returns the key ID of the encryption key that it passed to communication device 200a for communication with communication device 200b to the communication management device 100. As a result, the acquisition unit 102 can obtain the key ID. This key ID corresponds to attribute information IB.

[0049] The determination unit 103 compares the key ID obtained in step S101 with the key ID obtained in step S102 and determines whether the two match (step S103).

[0050] If both match (step S103: Yes), the output control unit 104 outputs output information indicating a match (step S104) and terminates the status confirmation process. If both do not match (step S103: No), the output control unit 104 outputs output information indicating a mismatch (step S105) and terminates the status confirmation process.

[0051] (Variation 1) In the above embodiment, attribute information IA is obtained from the communication device 200a. Attribute information IA may also be obtained from information obtained by monitoring communication. In modified example 1, the acquisition unit 101 obtains attribute information IA from messages transmitted and received between the communication device 200a and the communication device 200b. Communication monitoring is a process that, for example, collects (acquires) messages (packets, etc.) transmitted and received by communication and analyzes the collected messages. For example, it can be determined that a message is transmitted and received between the communication device 200a and the communication device 200b by referring to the source address and destination address specified in the header of the collected message.

[0052] For example, when communication device 200a sends data to communication device 200b, it encrypts the data itself and includes it in the payload of a packet (an example of a message to be sent), and includes the key ID of the encryption key used for encryption in plain text in the packet header.

[0053] The acquisition unit 101 can acquire the key ID contained in the header of a packet obtained by monitoring communication on network 501 as attribute information IA. Note that communication device 200a may communicate with multiple other communication devices 200. In such cases, the acquisition unit 101 only needs to monitor packets in the header, etc., that contain the identification information (device identification information, address, etc.) of the destination communication device 200 among the multiple communication devices 200.

[0054] Figure 6 is a flowchart showing an example of the state confirmation process in Modification Example 1.

[0055] The acquisition unit 101 monitors the communication between communication device 200a and communication device 200b and acquires the key ID within the packet obtained through monitoring (step S201).

[0056] The subsequent processes (steps S202 to S205) are the same as steps S102 to S105 in Figure 5, so their explanation will be omitted.

[0057] (Modification 2) The attributes of an encryption key are not limited to the key ID; they can be any other information. In Modification 2, the size of the data sent and received using the encryption key is used as the attribute of the encryption key.

[0058] In this modified example, the acquisition unit 101 monitors the communication of the network 501, calculates the size of the data encrypted using an encryption key and transmitted and received in the communication between communication device 200a and communication device 200b, and acquires the calculated size as attribute information IA.

[0059] In this modified example, the acquisition unit 102 acquires the remaining amount of encryption keys from the key management device 300a for multiple time periods, calculates the amount of encryption keys consumed based on the acquired remaining amount, and acquires the size corresponding to the amount of consumption as attribute information IB.

[0060] For example, the acquisition unit 102 provides the SAE ID of the communication device 200b to the key management device 300a as device identification information for the communication device 200b. The key management device 300a returns the remaining amount of encryption keys used for communication with the communication device 200b to the communication management device 100. By repeating this process of acquiring the remaining amount, the acquisition unit 102 can calculate the amount of encryption keys consumed by the key management device 300a.

[0061] Furthermore, the acquisition unit 102 can calculate the size of the transmitted and received data from the amount of encryption key consumed. For example, when an encryption method is used in which the size of the encryption key matches the size of the data to be encrypted, such as OTP, the acquisition unit 102 can determine the value of consumption as the size of the data. When an encryption method is used in which the size of the encryption key and the size of the data are expressed by a specific relationship (e.g., a relational expression), the acquisition unit 102 can determine the value of the data from the value of consumption according to that specific relationship.

[0062] In this modified example, the determination unit 103 determines whether the size of the data acquired by the acquisition unit 101 matches the size of the data acquired by the acquisition unit 102.

[0063] In a configuration where the size of encrypted transmitted and received data is required as attribute information, as in this modified example, the attribute information (data size) can be used, for example, to charge a fee based on the amount of encryption key consumed (data size).

[0064] The state confirmation process described in this modified version may be performed when sending dummy data before sending the desired data (e.g., genome data). This allows the system to be configured to send the desired data only when it is determined that quantum cryptography communication is possible.

[0065] In addition, the key management device 300 may generate new encryption keys. In such cases, the acquisition unit 102 acquires not only the remaining amount of encryption keys but also the amount of encryption keys generated (the amount of encryption keys newly shared between the key management device 300a and the key management device 300b) from the key management device 300a. The acquisition unit 102 can calculate the amount of encryption keys consumed by calculating the change in encryption keys from the remaining amount of encryption keys and subtracting the amount of generated keys from the change.

[0066] Figure 7 is a flowchart showing an example of the state confirmation process in modified example 2.

[0067] The acquisition unit 101 monitors the communication between communication device 200a and communication device 200b, calculates the size of the encrypted data transmitted and received in the communication between communication device 200a and communication device 200b, and acquires the calculated size as attribute information IA (step S301).

[0068] The acquisition unit 102 acquires the remaining amount of encryption key used by the communication device 200a for communication with the communication device 200b from the key management device 300a (step S302). For example, the acquisition unit 102 provides the key management device 300a with the device identification information (SAE ID) of the communication device 200b. The key management device 300a returns to the communication management device 100 the amount of encryption key to be given to the communication device 200a for communication with the communication device 200b. This allows the acquisition unit 102 to acquire the remaining amount of encryption key.

[0069] Furthermore, the acquisition unit 102 calculates the amount of encryption key consumed using the remaining amount acquired at multiple points in time, and calculates the size of the data corresponding to the amount consumed (step S303). The calculated size corresponds to the attribute information IB.

[0070] The determination unit 103 compares the size (attribute information IA) obtained in step S301 with the size (attribute information IB) obtained in step S303 and determines whether the two match (step S304).

[0071] If both match (Step S304: Yes), the output control unit 104 outputs output information indicating a match (Step S305) and terminates the status confirmation process. If both do not match (Step S304: No), the output control unit 104 outputs output information indicating a mismatch (Step S306) and terminates the status confirmation process.

[0072] In this modified example, the output control unit 104 may output output information indicating the amount of encryption key consumed. Such output information can be used, for example, in a function to collect a fee according to the amount of encryption key consumed.

[0073] (Variation 3) In Modification 2, the remaining amount of encryption keys is obtained from the key management device 300a, and the amount of encryption keys consumed is calculated from the obtained remaining amount. In Modification 3, the amount of encryption keys consumed is obtained from the key management device 300a.

[0074] In this modified example, the acquisition unit 101, similar to the modified example 2, monitors the communication of the network 501 to calculate the size of the encrypted data transmitted and received in the communication between communication device 200a and communication device 200b, and acquires the calculated size as attribute information IA.

[0075] In this modified example, the acquisition unit 102 acquires the amount of cryptographic key consumed from the key management device 300a and obtains the size corresponding to the acquired consumption amount as attribute information IB. The consumption amount is, for example, the amount of cryptographic key consumed during a predetermined period. The predetermined period is, for example, a certain amount of time in the past (for example, 10 seconds).

[0076] Figure 8 is a flowchart showing an example of the state confirmation process in Modification Example 3.

[0077] Step S401 is the same as step S301 in Figure 7 (Modification 2).

[0078] The acquisition unit 102 acquires from the key management device 300a the amount of encryption key consumed by the communication device 200a for communication with the communication device 200b (step S402). For example, the acquisition unit 102 provides the key management device 300a with the device identification information (SAE ID) of the communication device 200b. The key management device 300a returns to the communication management device 100 the amount of encryption key consumed that it provided to the communication device 200a for communication with the communication device 200b (for example, the amount consumed in the past 10 seconds). This allows the acquisition unit 102 to acquire the amount of encryption key consumed.

[0079] Furthermore, the acquisition unit 102 calculates the size of the data corresponding to the acquired consumption amount (step S403). The calculated size corresponds to the attribute information IB.

[0080] The subsequent processes (steps S404 to S406) are the same as steps S304 to S306 in Figure 7, so their explanation will be omitted.

[0081] Similar to Modification 2, the output control unit 104 in this modified version may also output output information indicating the amount of encryption key consumed. Such output information can be used, for example, in a function to collect a fee according to the amount of encryption key consumed.

[0082] Thus, the information processing systems of the embodiments and each modified example include an information processing device (communication management device) that checks the state of quantum cryptography communication using attribute information of the encryption key. This makes it possible to check the state of quantum cryptography communication using encryption keys shared by quantum key distribution.

[0083] Next, the hardware configuration of each device in the embodiment (communication management device, communication device, key management device) will be described using Figure 9. Figure 9 is an explanatory diagram showing an example of the hardware configuration of the device in the embodiment.

[0084] The apparatus of this embodiment includes a control device such as a CPU 51, a storage device such as a ROM (Read Only Memory) 52 and RAM 53, a communication interface 54 that connects to a network for communication, and a bus 61 that connects each part.

[0085] The program to be executed by the apparatus of this embodiment is provided pre-installed in ROM 52 or the like.

[0086] The program executed by the apparatus of the embodiment may be configured to be provided as a computer program product by recording it in an installable or executable file format onto a computer-readable recording medium such as a CD-ROM (Compact Disk Read Only Memory), a flexible disk (FD), a CD-R (Compact Disk Recordable), or a DVD (Digital Versatile Disk).

[0087] Furthermore, the program executed by the device of the embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Alternatively, the program executed by the device of the embodiment may be provided or distributed via a network such as the Internet.

[0088] A program executed in the apparatus of this embodiment can cause the computer to function as a component of the apparatus described above. This computer can read a program from a computer-readable storage medium onto its main memory and execute it using the CPU 51.

[0089] An example of the configuration of the embodiment is described below. (Configuration Example 1) An information processing device, among the first and second communication devices, which is connected to at least the first communication device, The first communication device obtains from the first key management device an encryption key shared between the first key management device and the second key management device by quantum key distribution, which is used for communication with the second communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device, Obtain first attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device from the first communication device, or obtain the first attribute information from a message transmitted and received in communication between the first communication device and the second communication device. Based on the information obtained from the first key management device, second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device is obtained. Output information based on the first attribute information and the second attribute information. Processing section An information processing device equipped with the following features. (Configuration example 2) The aforementioned attribute is key identification information that identifies the cryptographic key. The information processing device described in Configuration Example 1. (Configuration Example 3) The processing unit transmits device identification information to the first communication device to identify the second communication device, and obtains from the first communication device the first attribute information, which is the key identification information that the first communication device has returned in response to the device identification information. The information processing device described in Configuration Example 2. (Configuration example 4) The processing unit obtains the first attribute information, which is the key identification information, from the messages transmitted and received in the communication between the first communication device and the second communication device. The information processing device described in Configuration Example 2. (Configuration example 5) The aforementioned attribute is the size of the data transmitted and received using the aforementioned encryption key. The information processing device described in Configuration Example 1. (Configuration example 6) The processing unit obtains the remaining amount of the encryption key from the first key management device over multiple time periods, determines the amount of the encryption key consumed based on the obtained remaining amount, and obtains the size corresponding to the amount of consumption. The information processing device described in Configuration Example 5. (Configuration example 7) The processing unit obtains the amount of cryptographic key consumed from the first key management device and obtains the size corresponding to the amount of consumption. The information processing device described in Configuration Example 5. (Configuration example 8) The processing unit determines whether the attribute indicated by the first attribute information matches the attribute indicated by the second attribute information, and outputs the output information which is the result of the determination. An information processing device as described in any one of Configuration Examples 1 to 7. (Configuration example 9) The first key management device is provided, An information processing device as described in any one of Configuration Examples 1 to 8. (Configuration example 10) An information processing method performed by an information processing device connected to at least the first communication device, among the first and second communication devices, The first communication device obtains from the first key management device an encryption key shared between the first key management device and the second key management device by quantum key distribution, which is used for communication with the second communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device, The information processing device obtains first attribute information from the first communication device indicating the attributes of the encryption key used for communication between the first communication device and the second communication device, or obtains the first attribute information from a message transmitted and received in communication between the first communication device and the second communication device. The information processing device acquires second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device, based on the information acquired from the first key management device. The information processing device outputs output information based on the first attribute information and the second attribute information. Information processing methods. (Configuration Example 11) A program to be executed by a computer provided in at least one of the first and second communication devices, which is connected to the first communication device, The first communication device obtains from the first key management device an encryption key shared between the first key management device and the second key management device by quantum key distribution, which is used for communication with the second communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device. Obtain first attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device from the first communication device, or have the first attribute information obtained from messages transmitted and received in communication between the first communication device and the second communication device. Based on the information obtained from the first key management device, second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device is obtained. Output information based on the first attribute information and the second attribute information, program. (Configuration Example 12) An information processing system comprising an information processing device and a first key management device, The information processing device is connected to at least the first communication device, among the first and second communication devices. The first key management device is The encryption key is shared with the second key management device via quantum key distribution. The encryption key used for communication between the first communication device and the second communication device is output to the first communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device, The aforementioned information processing device is Obtain first attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device from the first communication device, or obtain the first attribute information from a message transmitted and received in communication between the first communication device and the second communication device. Second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device is obtained from the first key management device, Output information based on the first attribute information and the second attribute information. Equipped with a processing unit, Information processing system.

[0090] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0091] 10, 10-2 Information Processing Systems 100 Communication management device 101 Acquisition Department 102 Acquisition Department 103 Judgment section 104 Output Control Unit 121 Storage section 200a, 200b Communication equipment 300a, 300b Key management device 300-2a, 300-2b Key management / QKD device 400a, 400b QKD equipment

Claims

1. An information processing device, among the first and second communication devices, which is connected to at least the first communication device, The first communication device obtains from the first key management device an encryption key shared between the first key management device and the second key management device by quantum key distribution, which is used for communication with the second communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device, Obtain first attribute information from the first communication device indicating the attributes of the encryption key used for communication between the first communication device and the second communication device, or obtain the first attribute information from a message transmitted and received in communication between the first communication device and the second communication device. Based on the information obtained from the first key management device, second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device is obtained. Output information based on the first attribute information and the second attribute information, Processing section An information processing device equipped with the following features.

2. The aforementioned attribute is key identification information that identifies the cryptographic key. The information processing apparatus according to claim 1.

3. The processing unit transmits device identification information to the first communication device to identify the second communication device, and obtains from the first communication device the first attribute information, which is the key identification information that the first communication device has returned in response to the device identification information. The information processing apparatus according to claim 2.

4. The processing unit obtains the first attribute information, which is the key identification information, from the messages transmitted and received in the communication between the first communication device and the second communication device. The information processing apparatus according to claim 2.

5. The aforementioned attribute is the size of the data transmitted and received using the aforementioned encryption key. The information processing apparatus according to claim 1.

6. The processing unit obtains the remaining amount of the encryption key from the first key management device over multiple time periods, determines the amount of the encryption key consumed based on the obtained remaining amount, and obtains the size corresponding to the amount of consumption. The information processing apparatus according to claim 5.

7. The processing unit obtains the amount of encryption key consumed from the first key management device and obtains the size corresponding to the amount of consumption. The information processing apparatus according to claim 5.

8. The processing unit determines whether the attribute indicated by the first attribute information matches the attribute indicated by the second attribute information, and outputs the output information which is the result of the determination. The information processing apparatus according to claim 1.

9. The first key management device is provided, The information processing apparatus according to claim 1.

10. An information processing method performed by an information processing device connected to at least the first communication device, among the first and second communication devices, The first communication device obtains from the first key management device an encryption key shared between the first key management device and the second key management device by quantum key distribution, which is used for communication with the second communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device, The information processing device obtains first attribute information from the first communication device indicating the attributes of the encryption key used for communication between the first communication device and the second communication device, or obtains the first attribute information from a message transmitted and received in communication between the first communication device and the second communication device. The information processing device acquires second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device, based on the information acquired from the first key management device. The information processing device outputs output information based on the first attribute information and the second attribute information. Information processing methods.

11. A program to be executed by a computer provided in at least one of the first and second communication devices, which is connected to the first communication device, The first communication device obtains from the first key management device an encryption key shared between the first key management device and the second key management device by quantum key distribution, which is used for communication with the second communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device. Obtain first attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device from the first communication device, or have the first attribute information obtained from messages transmitted and received in communication between the first communication device and the second communication device. Based on the information obtained from the first key management device, second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device is obtained. Output information based on the first attribute information and the second attribute information, program.

12. An information processing system comprising an information processing device and a first key management device, The information processing device is connected to at least the first communication device, among the first and second communication devices. The first key management device is The encryption key is shared with the second key management device via quantum key distribution. The encryption key used for communication between the first communication device and the second communication device is output to the first communication device. The second communication device obtains the encryption key used for communication with the first communication device from the second key management device, The aforementioned information processing device is Obtain first attribute information from the first communication device indicating the attributes of the encryption key used for communication between the first communication device and the second communication device, or obtain the first attribute information from a message transmitted and received in communication between the first communication device and the second communication device. Second attribute information indicating the attributes of the encryption key used for communication between the first communication device and the second communication device is obtained from the first key management device, Output information based on the first attribute information and the second attribute information, Equipped with a processing unit, Information processing system.

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