Mobile body, encryption key delivery system, encryption key delivery method and program

Abstract

A mobile body equipped with an input / output unit for receiving an encryption key from a transmission device and transmitting the encryption key to a receiving device, a storage control unit for controlling the storage of the encryption key in a storage unit, and a movement control unit for moving said mobile body to the receiving device after receiving the encryption key from the transmission device, wherein the storage control unit receives the encryption key from the transmission device and stores the same in the storage unit, and when an abnormality is detected, deletes the encryption key stored in the storage unit.

Description

Mobile object, encryption key distribution system, encryption key distribution method and program

[0001] The present invention relates to a technology for distributing encryption keys by mobile devices.

[0002] On the Internet and other networks, there is a risk of data being intercepted during transmission from a sending device to a receiving device. To prevent this, various encryption technologies are available to conceal the data being transmitted. Many encryption technologies use a key known as an encryption key to encrypt and transmit data, and the receiving device then decrypts the data using the same encryption key. Another method involves decrypting the data using a decryption key that corresponds to the encryption key stored in advance on the receiving device. Hereinafter, keys used to encrypt and / or decrypt data, including decryption keys, will be collectively referred to as encryption keys. Such encryption keys must be shared between the sending and receiving devices before data transmission.

[0003] Generally, an encryption key is generated by one party and then distributed to the other party, so it is important to improve the security of encryption key distribution.

[0004] There are various methods for distributing encryption keys, such as quantum cryptography (quantum cryptography key distribution method) that uses quantum mechanics (see, for example, Patent Document 1).

[0005] Quantum key distribution is a system that uses quantum communication to securely distribute encryption keys. However, the transmission path (transmission medium) is limited to optical fiber and laser light, and there are also distance limitations.

[0006] One technique for distributing encryption keys without the constraints of distance or transmission path is to use flying objects for delivery (see, for example, Patent Document 2). In the technique disclosed in Patent Document 2, only a portion of the information required to generate an encryption key is temporarily stored in the flying object. In other words, the encryption key is shared among multiple base stations without all of the information required to generate the encryption key being stored in the flying object at the same time.

[0007] JP 2017-055335 A JP 2022-002379 A

[0008] The following analysis is provided by the present invention.

[0009] The invention described in Cited Document 2 sequentially transmits multiple pieces of key information required to generate an encryption key, rather than the encryption key itself, from an airborne vehicle to multiple base stations (transmitter and receiver). Because the encryption key itself is not transmitted from the airborne vehicle, security during transmission and security on the airborne vehicle are not taken into consideration. Note that the invention described in this cited document is based on the premise that there is a transmission path using optical fiber or the like between the transmitter and receiver. Key information is transmitted from either the transmitter or receiver to the other using the transmission path, and key distillation processing is performed on the receiver.

[0010] The present invention has been made in consideration of the above circumstances, and aims to provide a technology for securely distributing encryption keys without the need for a transmission path between the sending and receiving sides and without the constraints of distance or transmission path.

[0011] According to a first aspect of the present invention, there is provided a mobile body comprising: an input / output unit that receives an encryption key from a transmitting device and transmits the encryption key to a receiving device; a storage control unit that controls storage of the encryption key in a storage unit; and a movement control unit that moves the mobile body to the receiving device after receiving the encryption key from the transmitting device, wherein the storage control unit stores the encryption key in the storage unit upon receiving it from the transmitting device, and erases the encryption key stored in the storage unit if an abnormality is detected.

[0012] According to a second aspect of the present invention, there is provided an encryption key distribution system comprising: the mobile body; the transmitting device; and the receiving device, wherein the transmitting device comprises a transmitting device communication unit that transmits the encryption key to the mobile body; and the receiving device comprises a receiving device communication unit that receives the encryption key from the mobile body.

[0013] According to a third aspect of the present invention, there is provided an encryption key distribution method comprising: a receiving step of receiving an encryption key from a transmitting device; a storage step of storing the received encryption key in a storage unit; a moving step of moving the device toward the receiving device after storing the encryption key; an erasing step of erasing the encryption key stored in the storage unit if an abnormality in the device is detected during movement; and a transmitting step of transmitting the encryption key stored in the storage unit to the receiving device upon arrival at a destination area.

[0014] According to a fourth aspect of the present invention, there is provided a program for causing a computer mounted on a mobile body to execute the following steps: a receiving step of receiving an encryption key from a transmitting device; a storage step of storing the received encryption key in a storage unit; a moving step of moving the mobile body toward the receiving device after storing the encryption key; an erasing step of erasing the encryption key stored in the storage unit if an abnormality in the mobile body is detected during movement; and a transmitting step of transmitting the encryption key stored in the storage unit to the receiving device upon arrival at a destination area.

[0015] These programs can be recorded on a computer-readable storage medium. The storage medium can be a non-transient medium such as a semiconductor memory, a hard disk, a magnetic recording medium, or an optical recording medium. The present invention can also be embodied as a computer program product.

[0016] No transmission path is required between the sender and receiver, and encryption keys can be securely distributed without restrictions on distance or transmission media.

[0017] 1A is a schematic diagram showing an example of an encryption key distribution system according to one embodiment of the present invention, and FIG. 1B is a functional block diagram of the flying object. (a) and (b) are respectively a functional block diagram and a hardware configuration diagram of an example of a transmitting device according to a first embodiment. (a) and (b) are respectively a functional block diagram and a hardware configuration diagram of an example of a receiving device according to the first embodiment. (a) and (b) are respectively a functional block diagram and a hardware configuration diagram of an example of an flying object according to the first embodiment. (a) is a flowchart of an example of encryption key distribution processing in the encryption key distribution system according to the first embodiment. (b) is a schematic diagram showing an example of the configuration of an encryption key distribution system according to a second embodiment. (a) and (b) are respectively a functional block diagram and a hardware configuration diagram of an example of a monitoring device according to the second embodiment. (a) is a functional block diagram of an example of an flying object according to a third embodiment, and (b) is an explanatory diagram for explaining an example of log information according to the third embodiment. (b) is a flowchart of an example of encryption key distribution processing in the flying object according to the third embodiment. FIG. 1 is a schematic diagram showing an example of the configuration of an encryption key distribution system of a fourth embodiment. FIG. 2 is an explanatory diagram for explaining an encryption key table of the fourth embodiment. FIG. 3 is a schematic diagram showing an example of the configuration of an encryption key distribution system of a modified example of the present invention. (a) is a schematic diagram showing an example of the configuration of an encryption key distribution system of a modified example of the present invention, and (b) is a flowchart of an example of encryption key distribution processing in an air vehicle of the same modified example. (b) is an explanatory diagram for explaining an example of an encryption key table of a modified example of the present invention. FIG. 4 is a schematic diagram showing an example of the configuration of an encryption key distribution system of a modified example of the present invention.

[0018] Hereinafter, examples of embodiments of the present invention will be described with reference to the drawings. Note that the attached reference numerals are attached to each element for convenience as an example to facilitate understanding, and are not intended to limit the present invention to the illustrated form. Furthermore, connecting lines between blocks in the drawings, etc. referred to in the following description include both bidirectional and unidirectional lines. Unidirectional arrows are used to schematically indicate the flow of the main signal (data) and do not exclude bidirectionality.

[0019] The program is executed via a computer device, which includes, for example, a processor, a storage device, an input device, a communication interface, and, if necessary, a display device. This computer device is configured to be able to communicate with internal or external devices (including computers) via the communication interface, either wired or wirelessly. Ports or interfaces are present at the input / output connection points of each block in the diagram, but are not shown. In the following description, "A and / or B" means either A or B, or both A and B.

[0020] A first embodiment, which is an example of an embodiment of the present invention, will be described. In this embodiment, an encryption key distribution system is realized using an airborne vehicle as a moving object, which is difficult to eavesdrop on. In this embodiment, an encryption key is carried on an airborne vehicle and transmitted from a device that is the source (sender) of the encryption key to a device that is the destination (receiver) of the encryption key. At this time, security is ensured using sensor signals from various sensors inside and outside the airborne vehicle. Hereinafter, in this embodiment, the device that sends the encryption key will be called the transmitter, and the device that receives the encryption key will be called the receiver.

[0021] 1A shows an example of an encryption key distribution system 910 according to an embodiment of the present invention. As shown in the figure, the encryption key distribution system 910 includes a transmitting device 100, a receiving device 200, and an air vehicle 300.

[0022] In the example shown in the figure, the transmitting device 100 is installed at a base on land (ground). The receiving device 200 is installed at sea, for example, on a ship. The flying object 300 is, for example, a drone, which is an example of an autonomously navigable unmanned aerial vehicle (UAV). Note that the locations where the transmitting device 100 and the receiving device 200 are installed are not limited to this.

[0023] In the encryption key distribution system 910 of this embodiment, the transmitting device 100 sends the encryption key 500 to the flying object 300, which then flies to the receiving device 200, and the receiving device 200 receives the encryption key 500 from the flying object 300. If the flying object 300 detects an abnormality at this time, it erases the encryption key 500 it holds. Not only if there is an abnormality in the equipment, but also if there is a risk that the encryption key 500 will be intercepted or that the encryption key 500 will not be delivered due to an unexpected event such as contact with another flying object or a malfunction of the flying object 300 itself, the flying object 300 determines that an abnormality has occurred and erases the encryption key 500.

[0024] 1(b), the flying object 300 includes an input / output unit 311 that receives the encryption key 500 from the transmitting device 100 and transmits the encryption key 500 to the receiving device, a storage control unit 312 that stores the encryption key 500 in an encryption key storage unit 321 upon receiving the encryption key 500 from the transmitting device 100, and a movement control unit 315 that moves the flying object 300 from the transmitting device 100 to the receiving device 200. If an abnormality is detected during movement, the storage control unit 312 erases the encryption key 500 stored in the encryption key storage unit.

[0025] In this embodiment, it is not assumed that the flying object 300 will actually carry the file (information itself) to be transmitted or received. This is because real-time communication is not possible considering the flight speed of the flying object 300. Note that, since it is sufficient for the encryption key 500 to be shared before communication, the delivery of the encryption key 500 does not require real-time performance as compared to general communication.

[0026] <<First Embodiment>> A first embodiment of the present invention will be described below. In the first embodiment, in an encryption key distribution system 910, the flying object 300 is equipped with an anomaly detection means and detects an anomaly that occurs during movement. Each device will be described in detail below.

[0027] 2A is a functional block diagram of the configuration related to this embodiment of the transmitting device 100. As shown in this figure, the transmitting device 100 includes a communication unit 111, a control unit 112, an authentication unit 113, an encryption key storage unit 121, and an authentication information storage unit 122.

[0028] The encryption key storage unit 121 stores an encryption key 500. The encryption key 500 is generated within the transmitting device 100 or received from an external device.

[0029] The authentication information storage unit 122 stores authentication information. The authentication information is information for proving that the flying object 300 is authorized to distribute the encryption key 500. The authentication information is set in advance for each flying object 300, and the transmitting device 100, the receiving device 200, and the flying object 300 have the same information. The authentication information is stored in advance.

[0030] The communication unit 111 transmits and receives data to and from external devices. In this embodiment, the communication unit 111 transmits and receives the encryption key 500 and authentication information to and from the flying object 300.

[0031] As described above, the encryption key 500 is transmitted from the transmitting device 100 to the flying object 300 using, for example, laser light. Quantum communication can be imparted to communication using laser light. Therefore, the communication unit 111 transmits the encryption key 500 to the flying object 300 using, for example, quantum communication or quantum cryptography communication.

[0032] The communication unit 111 may transmit and receive the authentication information using laser light, similar to the encryption key 500. Alternatively, the authentication information may be transmitted and received using short-range wireless communication such as Bluetooth (registered trademark) or Wi-Fi (registered trademark).

[0033] The authentication unit 113 authenticates the flying object 300. When the authentication unit 113 receives authentication information via the communication unit 111, it compares the received authentication information with the authentication information stored in the authentication information storage unit 122 in accordance with instructions from the control unit 112. After the comparison, the authentication unit 113 notifies the control unit 112 of the comparison result. If the received authentication information matches the stored authentication information, the authentication unit 113 determines the comparison result as authentication success, and if they do not match, the authentication fails.

[0034] The control unit 112 controls the overall operation of the transmitting device 100 and also controls the transmission and reception of the encryption key 500 via the communication unit 111. Specifically, upon receiving a notification of successful authentication from the authentication unit 113, the control unit 112 reads out the encryption key 500 from the encryption key storage unit 121 and transmits it to the flying object 300 via the communication unit 111.

[0035] 2B is a hardware configuration diagram of the transmitting device 100 related to this embodiment. As shown in this figure, the transmitting device 100 includes a CPU 131, a storage device 132, and a communication device 133.

[0036] The CPU 131 loads a program stored in a non-volatile area of ​​the storage device 132 into a work area and executes the program, thereby realizing the above-mentioned functions and comprehensively controlling the entire transmitting device 100. Note that the CPU 131 may be replaced by one or more processors such as an MPU (Micro Processing Unit).

[0037] The storage device 132 is configured with memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage device 132 stores programs for executing each function and information such as communication parameters for communication. In this embodiment, each of the above storage units is constructed in the storage device 132.

[0038] The storage device 132 may include, in addition to memories such as ROM and RAM, storage media such as a solid state drive (SSD), a flexible disk, a hard disk, an optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a DVD, etc. The storage device 132 may also include multiple memories.

[0039] The communication device 133 realizes transmission and reception of data. In this embodiment, the communication device 133 includes, for example, an optical wireless communication device having a laser output device (light source) that outputs laser light and a laser receiving device, etc. Note that the light source may be an LD (Laser Diode), an LED (Light Emitting Diode), or the like that outputs visible laser light.

[0040] In addition, data transmission and reception may be realized using not only visible light but also infrared light, radio waves, sound waves, etc. Specifically, a transceiver using a communication method that complies with other wireless communication methods such as Bluetooth, Wi-Fi, and NFC (Near Field Communication) may be provided.

[0041] 3A is a functional block diagram of a configuration related to this embodiment of the receiving device 200. As shown in this figure, the receiving device 200 includes a communication unit 211, a control unit 212, an authentication unit 213, an encryption key storage unit 221, and an authentication information storage unit 222.

[0042] The control unit 212 controls the overall operation of the receiving device 200 and also controls the transmission and reception of the encryption key 500 via the communication unit 211. Specifically, when the control unit 212 receives a notification of successful authentication from the authentication unit 213, it generates an encryption key transmission request and transmits it to the flying object 300 via the communication unit 211. Furthermore, when the control unit 212 receives the encryption key 500 in response to the encryption key transmission request, it stores it in the encryption key storage unit 221. At this time, it may also transmit a signal indicating completion of storage to the flying object 300.

[0043] The other functions of the receiving device 200 are basically the same as the functions of the same name of the transmitting device 100, and therefore will not be described here. When it is necessary to distinguish between the functions of the transmitting device 100 and the receiving device 200, they will be referred to as a transmitting device communication unit 111, a receiving device communication unit 211, a transmitting device control unit 112, a receiving device control unit 212, a transmitting device authentication unit 113, and a receiving device authentication unit 213, respectively.

[0044] 3B is a hardware configuration diagram of the receiving device 200 related to this embodiment. As shown in this diagram, the receiving device 200 includes a CPU 231, a storage device 232, and a communication device 233. Each component is basically the same as the component of the transmitting device 100 with the same name, and therefore a description thereof will be omitted.

[0045] [Air Vehicle] Next, a description will be given of the air vehicle 300 that delivers the encryption key 500 from the transmitting device 100 to the receiving device 200. In this embodiment, as described above, a case where a drone is used as the air vehicle 300 will be described as an example.

[0046] 4A is a functional block diagram of the configuration related to this embodiment of the flying object 300. The flying object 300 of this embodiment includes an anomaly detection unit 313, an authentication request unit 314, and an authentication information storage unit 322 in addition to the input / output unit 311, the memory control unit 312, the movement control unit 315, and the encryption key storage unit 321 shown in FIG.

[0047] The encryption key storage unit 321 stores the encryption key 500. The encryption key 500 is received from the transmitting device 100.

[0048] The authentication information storage unit 322 stores the authentication information of the flying object 300 .

[0049] The input / output unit 311 inputs and outputs data to and from external devices, such as the encryption key 500 and authentication information.

[0050] As described above, the input / output unit 311 receives the encryption key 500 from the transmitting device 100 via wireless communication and transmits the encryption key 500 wirelessly to the receiving device 200. The input / output unit 311 also transmits authentication information to the transmitting device 100 and the receiving device 200. The input / output unit 311 may have a function that enables data transmission and reception only under predetermined conditions such as time or location.

[0051] As described above, the encryption key 500 may be transmitted and received between the flying object 300 and the transmitting device 100 or the receiving device 200 by quantum communication using laser light or quantum cryptography communication, for example.

[0052] The authentication information may be transmitted and received using laser light, similar to the encryption key 500. Alternatively, the authentication information may be transmitted and received using short-range wireless communication such as Bluetooth or Wi-Fi.

[0053] The authentication request unit 314 requests authentication from the external device. In this embodiment, the authentication request unit 314 requests authentication from the transmitting device 100 and the receiving device 200. The authentication request unit 314 transmits the authentication information stored in the authentication information storage unit 322 to request authentication. Furthermore, the authentication request unit 314 requests authentication when it receives a notification from the movement control unit 315 (described later) that its own device (flying object 300) has entered an area where it can communicate with the external device for which authentication is requested (hereinafter referred to as a communication area).

[0054] The abnormality detection unit 313 monitors the state of the flying object 300, and if an abnormality is detected, sends an abnormality detection signal to the memory control unit 312.

[0055] The anomaly detection unit 313, for example, collects sensor detection values ​​transmitted from a sensor 334 (described later). If the collected sensor detection values ​​are abnormal (abnormal values), the unit outputs an anomaly detection signal. Whether or not a value is abnormal is determined by whether or not it exceeds a predetermined allowable range for each sensor. The allowable range is predetermined, for example, by a threshold value.

[0056] The abnormality detection unit 313 may also analyze the collected sensor detection values ​​and determine whether or not an abnormality exists. For example, the abnormality detection unit 313 may detect that the flying object 300 is no longer able to fly, has made an emergency landing, crashed, the battery has run out, or a program problem has occurred.

[0057] As described above, the storage control unit 312 controls the storage of the encryption key 500 in the encryption key storage unit 321. In this embodiment, for example, when the encryption key 500 is acquired via the input / output unit 311, it is stored in the encryption key storage unit 321. Furthermore, when an encryption key transmission request is received, the storage control unit 312 reads the encryption key 500 from the encryption key storage unit 321 and transmits the encryption key 500 to the requestor via the input / output unit 311. Furthermore, when an abnormality detection signal is received from the abnormality detection unit 313, the encryption key 500 stored in the encryption key storage unit 321 is erased.

[0058] As described above, the movement control unit 315 causes the flying object 300 to navigate to the destination. In this embodiment, the movement control unit 315 causes the flying object 300 to navigate from the transmitting device 100 to the receiving device 200. In this embodiment, upon receiving the encryption key 500 from the transmitting device 100, the movement control unit 315 controls a navigation device (described later) of the flying object 300 to move the flying object 300 to the receiving device 200.

[0059] The hardware configuration of the flying object 300 will be described. Fig. 4B is a hardware configuration diagram of the flying object related to this embodiment. As shown in this figure, the flying object 300 includes a CPU (Central Processing Unit) 331, a storage device 332, a communication device 333, a sensor 334, and a navigation device 335.

[0060] The CPU 331 loads a program stored in a nonvolatile area of ​​the storage device 332 into a work area and executes the program, thereby realizing the above-mentioned functions and comprehensively controlling the entire flying object 300. Note that the CPU 331 may be replaced by one or more processors such as an MPU (Micro Processing Unit).

[0061] The storage device 332 is configured with memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage device 332 stores programs for executing each function and information such as communication parameters for communication. In this embodiment, each of the above storage units is constructed in the storage device 332.

[0062] The storage device 332 may include, in addition to memories such as ROM and RAM, storage media such as a solid state drive (SSD), a flexible disk, a hard disk, an optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a DVD, etc. The storage device 332 may also include multiple memories.

[0063] The communication device 333 communicates with external devices. In this embodiment, for example, it communicates wirelessly with the transmitting device 100 and the receiving device 200. As described above, the encryption key 500 is transmitted and received using laser light. Therefore, the communication device 333 includes a laser input device and a laser receiving device. It may also include a short-range communication device that transmits and receives authentication information.

[0064] The sensors 334 are provided in each part of the flying object 300 and detect its state. The sensors 334 are configured and arranged to be able to detect (observe) all events that affect the flight of the flying object 300, such as vibration, contact, temperature change, voltage, position (latitude, longitude, and height), movement speed (flight speed), movement time, contact with and interference with other devices (other objects), etc. The sensors 334 may also be capable of detecting whether or not data is being sent or received with other devices. In this embodiment, the sensors 334 include, for example, a gyro sensor, an acceleration sensor, a barometric pressure sensor, an ultrasonic sensor, a geomagnetic sensor (electronic compass), a camera, a GPS device, a battery remaining capacity detection sensor, etc.

[0065] These detected values ​​are output to the abnormality detection unit 313 and the movement control unit 315 and are used to detect abnormalities and control navigation using the navigation device 335.

[0066] The navigation device 335 navigates the flying object 300 under the control of the movement control unit 315. In this embodiment, for example, it is equipped with a propeller and a motor that rotates the propeller. The movement control unit 315 controls the navigation device 335 and navigates the flying object 300 in accordance with a navigation program pre-stored in the storage device 332 and the output from the sensor 334. The movement control unit 315 adjusts the output of the motor and controls the rotation speed of the propeller based on information obtained from the sensor 334, for example.

[0067] [Encryption Key Distribution Method] A description will now be given of an example of the flow of encryption key distribution processing by the encryption key distribution system 910 having the above configuration. Fig. 5 is a flow diagram showing an example of encryption key distribution processing by the encryption key distribution system 910 of this embodiment.

[0068] When the flying object 300 reaches the communication area of ​​the transmitting device 100, it transmits authentication information to the transmitting device 100 (step S1301) and requests authentication.

[0069] When the transmitting device 100 receives authentication information as an authentication request from the flying object 300, it performs authentication (step S1101). Here, the authentication unit 113 compares the received authentication information with the authentication information stored in the authentication information storage unit 122. If the two match, the authentication unit 113 notifies the control unit 112 that the authentication was successful.

[0070] Upon receiving the notification of successful authentication, the control unit 112 reads out the encryption key 500 from the encryption key storage unit 121 and transmits it to the flying object 300 that made the authentication request via the communication unit 111 (step S1102).

[0071] If the authentication is unsuccessful, the transmitting device 100 does not transmit the encryption key 500 to the air vehicle 300 that requested the authentication. At this time, a message indicating the authentication failure may be transmitted to the air vehicle 300 that requested the authentication.

[0072] When the flying object 300 receives the encryption key 500, it stores it (step S1302) and starts moving (step S1303).

[0073] When the flying object 300 reaches the communication range of the receiving device 200 without detecting any abnormality (step S1304; No), the flying object 300 stops moving (step S1305). Then, the flying object 300 transmits authentication information to the receiving device 200 (step S1306) to request authentication.

[0074] When the receiving device 200 receives authentication information as an authentication request from the flying object 300, it performs authentication (step S1201). Here, the authentication unit 213 compares the received authentication information with the authentication information stored in the authentication information storage unit 222. If the two match, the authentication unit 213 notifies the control unit 212 that the authentication was successful.

[0075] Upon receiving the notification of successful authentication, the control unit 212 generates a request to send an encryption key and transmits it to the flying object 300 that made the authentication request via the communication unit 111 (step S1202).

[0076] If the authentication is unsuccessful, the receiving device 200 does not transmit a request to transmit an encryption key to the flying object 300 that has requested the authentication. At this time, a message indicating the authentication failure may be transmitted to the flying object 300 that has requested the authentication.

[0077] When receiving the encryption key transmission request from the receiving device 200, the flying object 300 transmits the stored encryption key 500 to the requesting receiving device 200 (step S1307), and then erases the stored encryption key 500 (step S1308).

[0078] On the other hand, if an abnormality is detected during movement (step S1304; Yes), the flying object 300 erases the stored encryption key 500 (step S1308) and ends the process.

[0079] After receiving the encryption key 500 in step S1307, the receiving device 200 notifies the transmitting device 100 via radio waves or the like that the encryption key 500 has been received, and begins using the encryption key 500. The encryption algorithm used after receiving the encryption key 500 is not limited. Furthermore, the encryption key 500 to be transmitted and received may not be used directly for encryption and decryption, but may be converted using an algorithm stored in advance in the transmitting device 100 and the receiving device 200.

[0080] Next, an example of processing performed within the flying object 300 during encryption key distribution will be described. Fig. 6 is a flowchart of encryption key distribution processing performed by the flying object 300 of this embodiment.

[0081] The movement control unit 315 determines whether the transmitting device 100 has arrived within the communication range of the transmitting device 100 (step S1401). Any method of determination may be used, and various existing determination methods may be used. For example, a laser beam for distance measurement is transmitted to the communication unit 111, and if the obtained distance value is equal to or less than a predetermined value, it is determined that the transmitting device 100 has arrived. A captured image acquired by a camera may also be used for determination. Furthermore, if the position of the transmitting device 100 is known, for example, a GPS function may be used for determination.

[0082] When the communication area is reached, the authentication request unit 314 makes an authentication request. As described above, the authentication request unit 314 transmits the authentication information stored in the authentication information storage unit 322 to the transmitting device 100 (step S1402).

[0083] In response to the authentication request, when the encryption key 500 is received from the transmitting device 100 within a predetermined period of time (step S1403), the storage control unit 312 stores the encryption key 500 in the encryption key storage unit 321 (step S1404).

[0084] If the encryption key 500 is not received within a predetermined period, for example, if an authentication failure message is received, or if no reply is received, the flying object 300 ends the process.

[0085] Next, after storing the encryption key 500, the movement control unit 315 starts movement (step S1405). Here, the movement control unit 315 controls the navigation device 335 to move the flying object 300 to a communication area of ​​the receiving device 200 (step S1407).

[0086] If the abnormality detection unit 313 detects an abnormality during movement (step S1406), it outputs an abnormality detection signal to the storage control unit 312. Upon receiving the abnormality detection signal, the storage control unit 312 erases the encryption key 500 stored in the encryption key storage unit 321 (step S1412), and ends the process.

[0087] On the other hand, if the flying object 300 reaches the communication range without detecting any abnormality (step S1407), the movement control unit 315 terminates the movement of the flying object 300 (step S1408). Note that the method for determining whether the receiving device 200 has reached the communication range is the same as the determination method for the transmitting device 100.

[0088] Then, the authentication request unit 314 makes an authentication request to the receiving device 200. Here, the authentication request unit 314 transmits the authentication information stored in the authentication information storage unit 322 to the receiving device 200 (step S1409).

[0089] When an encryption key transmission request is received from the receiving device 200 within a predetermined period in response to the authentication request (step S1410), the storage control unit 312 reads the encryption key 500 from the encryption key storage unit 321 and transmits it to the receiving device 200 via the input / output unit 311 (step S1411). Thereafter, the storage control unit 312 erases the encryption key 500 from the encryption key storage unit 321 (step S1412) and ends the process.

[0090] If the encryption key transmission request is not received within a predetermined period, for example, if an authentication failure message is received, or if no reply is received, the process proceeds to step S1412.

[0091] As described above, in the encryption key distribution system 910 of this embodiment, the flying object 300 is used to distribute the encryption key 500 between the transmitting device 100 and the receiving device 200. The flying object 300 has an abnormality detection function, and if an abnormality is detected in the flying object 300, the encryption key 500 to be distributed is erased.

[0092] The flying object 300 is an unmanned, autonomously navigable object, such as a drone. As long as the flying object 300 is flying at a sufficient altitude, it is unlikely to be physically contacted. In this way, by using the flying object 300 to distribute the encryption key 500, the encryption key distribution system 910 of this embodiment can achieve highly secure key distribution with little risk of eavesdropping, without the constraints of distance or transmission path, even between two points without a transmission path.

[0093] For example, as shown in Figure 1(a), if the transmitting device 100 is installed at a land-based base and the receiving device 200 is installed on a ship sailing at sea, it is difficult to connect the two with a physical cable because the ship is moving. In such a situation where a transmission path cannot be secured, the encryption key distribution system 910 of this embodiment is particularly useful.

[0094] Furthermore, the encryption key distribution system 910 of this embodiment uses wireless communication to transmit and receive the encryption key 500 between the transmitting device 100, the receiving device 200, and the flying object 300. In other words, since the encryption key 500 can be transmitted and received without connecting a connector, there is no need to add new hardware to the flying object 300, thereby reducing costs.

[0095] Furthermore, the encryption key distribution system 910 of this embodiment uses laser light for this wireless communication. Laser light has low diffusion, and is focused onto an extremely small area when transmitting and receiving the encryption key 500 between the transmitting device 100, receiving device 200, and flying object 300. This allows the transmission and reception interface areas of the flying object 300, transmitting device 100, and receiving device 200 to be made smaller. Therefore, in the encryption key distribution system 910 of this embodiment, attacks on the transmission and reception interfaces are extremely difficult, enabling even more secure encryption key distribution to be achieved.

[0096] For example, consider a case where the flying object 300 is eavesdropped on during flight. It is extremely difficult to access the small laser light interface of the flying object 300 and obtain information. Therefore, it is conceivable that an attacker would capture the flying object 300 in order to obtain the encryption key 500.

[0097] However, in the encryption key distribution system 910 of this embodiment, if the flying object 300 comes into contact with an obstacle while flying, the anomaly detection unit 313 detects a change in vibration, radio waves, temperature, or the like and outputs an anomaly detection signal. The memory control unit 312 then immediately erases the encryption key 500 stored in the encryption key memory unit 321. Therefore, according to the encryption key distribution system 910 of this embodiment, even if an attacker captures the flying object 300, the encryption key 500 has been erased from the flying object 300, making it impossible for the attacker to obtain the encryption key 500. From this perspective, the encryption key distribution system 910 of this embodiment can also achieve highly secure encryption key distribution.

[0098] Furthermore, by using laser light, even though it is wireless communication, the transmission path can be visually confirmed, the area range can be easily set, and the positioning during transmission and reception can be accurately set. Therefore, encryption key distribution can be realized that is difficult to intercept or eavesdrop on and has a high probability of success. Furthermore, by using laser light, quantum cryptography can be used for transmission and reception of the encryption key 500 between the transmitting device 100, the receiving device 200, and the flying object 300. This makes it possible to realize encryption key distribution with the same level of security as when the encryption key 500 is directly distributed between the transmitting device 100 and the receiving device 200 using quantum cryptography.

[0099] In this embodiment, in communication between the flying object 300 and the transmitting device 100 and / or the receiving device 200, laser light may be output from the transmitting device 100 and / or the receiving device 200, or laser light may be output from the flying object 300 to these devices. Different transmission and reception mechanisms may be used between the transmitting device 100 and the flying object 300, and between the receiving device 200 and the flying object 300.

[0100] In this embodiment, the flying object 300 determines whether it has entered the communication area. However, this determination may be made by the transmitting device 100 and the receiving device 200.

[0101] In this case, the transmitting device 100 and the receiving device 200 are provided with sensors or the like for detecting the flying object 300, and these sensors detect that the flying object 300 has entered a communication area. Then, the transmitting device 100 or the receiving device 200 transmits a request to transmit authentication information to the flying object 300.

[0102] In this embodiment, the flying object 300 immediately deletes the encryption key 500 stored therein after transmitting the encryption key 500 to the receiving device 200, but this is not limiting. For example, the flying object 300 may be configured to delete the encryption key 500 after confirming that the receiving device 200 has received the encryption key.

[0103] In this case, upon receiving the encryption key 500, the receiving device 200 transmits a receipt notification to the flying object 300. The flying object 300 waits for the receipt notification to be received and then erases the encryption key 500. Note that the flying object 300 may be configured to transmit the encryption key 500 to the receiving device 200 multiple times until the receipt notification is received.

[0104] When the encryption key 500 is erased in the flying object 300, the flying object 300 may notify the transmitting device 100 and / or the receiving device 200 of this fact. Also, if the authentication is unsuccessful in step S1201, a message indicating the authentication failure may also be sent in plain text from the receiving device 200 to the transmitting device 100.

[0105] Second Embodiment Next, a second embodiment of the present invention will be described. The encryption key distribution system 910 of the first embodiment detects abnormalities during distribution using a sensor 334 mounted on the flying object 300. In this embodiment, the flying object 300 is further monitored by an external device, and abnormalities in the flying object 300 are detected.

[0106] An example of an encryption key distribution system 920 of this embodiment is shown in Figure 7. As shown in this figure, the encryption key distribution system 920 of this embodiment basically has the same configuration as the first embodiment. That is, it includes a transmitting device 100, a receiving device 200, and an air vehicle 300. The encryption key distribution system 920 of this embodiment further includes a monitoring device 400. The following description of this embodiment will focus on the monitoring device 400, which has a different configuration from the first embodiment.

[0107] The monitoring device 400 monitors the flying object 300 and its surroundings from the outside. The monitoring device 400 is composed of, for example, a camera and / or a radio wave receiving / transmitting device.

[0108] For example, if the monitoring device 400 is a camera, it is installed so that the flying object 300 is within its field of view. If the monitoring device 400 is a radio wave receiving and transmitting device, it is installed so that the flying object 300 is within the direction of radio wave transmission.

[0109] FIG. 8A shows the functional blocks of the monitoring device 400, and FIG. 8B shows the hardware configuration of the monitoring device 400.

[0110] As shown in these figures, the monitoring device 400 includes a communication unit 411, an information acquisition unit 412, and an abnormality detection unit 413. The monitoring device 400 also includes a CPU 431, a storage device 432, a communication device 433, and an information collection device 434.

[0111] The information collection device 434 collects information about the flying object 300 and its vicinity. If the information collection device 434 is a camera, it is an imaging unit, and if it is a radio wave receiving and transmitting device, it is a radio wave receiving and transmitting unit.

[0112] The information acquisition unit 412 controls the operation of the information collection device 434 and transfers the information collected by the information collection device 434 at predetermined time intervals to the abnormality detection unit 413. In this embodiment, image or reflected wave information is collected.

[0113] The abnormality detection unit 413 analyzes the image or reflected wave acquired by the information acquisition unit 412 and determines whether or not there is an abnormality in the flying object 300. If it determines that there is an abnormality, that is, if it detects an abnormality, it transmits an abnormality detection signal to the flying object 300 via the communication unit 411.

[0114] The communication unit 411, CPU 431, storage device 432, and communication device 433 are similar to the components of the same names in the transmitting device 100 in the first embodiment, for example, and therefore description thereof will be omitted.

[0115] The encryption key delivery process flow of this embodiment is also basically the same as that of the first embodiment, except that in step S1406, the storage control unit 312 erases the encryption key 500 stored in the encryption key storage unit 321 not only when an abnormality detection signal is received from the abnormality detection unit 313 but also when an abnormality detection signal is received via the input / output unit 311.

[0116] The monitoring device 400 may be installed on the ground or may be a floating object such as a satellite. For example, it may be a flying object that flies alongside the flying object 300. The monitoring device 400 may also be included in the transmitting device 100 or the receiving device 200.

[0117] As described above, this embodiment has the same configuration as the first embodiment, and therefore provides the same effects as the first embodiment. Furthermore, the encryption key distribution system 920 of this embodiment includes a monitoring device 400 that externally monitors the status of the flying object 300 and its surroundings. If the monitoring device 400 determines that there is an abnormality in the flying object 300, the flying object 300 also erases the encryption key 500 being distributed. Therefore, abnormalities in the flying object 300 can be detected with higher accuracy, and even more secure distribution of the encryption key 500 can be achieved.

[0118] In this embodiment, the flying object 300 does not necessarily have to include the abnormality detection unit 313 .

[0119] In this embodiment, when the monitoring device 400 detects an abnormality, it transmits an abnormality detection signal directly to the flying object 300. However, this is not limiting. For example, the monitoring device 400 may be configured to transmit the abnormality detection signal to the transmitting device 100 and / or the receiving device 200. In this case, the abnormality detection signal is transmitted from these devices to the flying object 300.

[0120] <<Third Embodiment>> Next, a third embodiment of this embodiment will be described. In each of the above embodiments, the flying object 300 is monitored in real time while moving, and abnormalities in the flying object 300 are detected. In this embodiment, sensor detection values ​​during movement are accumulated as log information. Then, for example, after the flying object 300 reaches the vicinity of the receiving device 200, this log information is further analyzed to detect whether or not there is an abnormality.

[0121] The configuration of the encryption key distribution system, the configuration of the transmitting device 100, the configuration of the receiving device 200, and the hardware configuration of the flying object 300 of this embodiment are basically the same as those of the first embodiment, so a description thereof will be omitted here.

[0122] 9A shows an example of a functional block of the flying object 300 of this embodiment. As shown in this figure, the flying object 300 of this embodiment includes a log information storage unit 323 in addition to the configuration of the flying object 300 of the first embodiment. The log information storage unit 323 is constructed in a storage device 332.

[0123] In addition to the processing of the first embodiment, the abnormality detection unit 313 of this embodiment stores the collected sensor detection values ​​as log information in the log information storage unit 323 in association with the detection time (or collection time).

[0124] In addition, the abnormality detection unit 313 collects and stores not only the sensor detection values ​​of the sensor 334 that detects the state of the flying object 300, but also the access history to the storage device 332 as log information.

[0125] Furthermore, the anomaly detection unit 313 of this embodiment performs a log information verification process after the receiving device 200 has reached the communication range and before making an authentication request. The log information verification process is a process of analyzing log information and verifying whether there are any anomalies. If an invalid log is detected in the log information verification process, the anomaly detection unit 313 determines that there is an anomaly and outputs an anomaly detection signal. As in the first embodiment, when the storage control unit 312 receives the anomaly detection signal, it erases the encryption key 500 from the encryption key storage unit 321.

[0126] For example, if log information 600 as shown in FIG. 9B is recorded as an access log to the encryption key storage unit 321, the abnormality detection unit 313 determines that an abnormality has occurred and outputs an abnormality detection signal.

[0127] When the flying object 300 receives the encryption key 500 from the transmitting device 100, it stores the encryption key in the encryption key storage unit 321, and there should be no access to the encryption key until it is handed over to the receiving device 200. However, the log information 600 records two reads (out). Therefore, the anomaly detection unit 313 determines that unauthorized access has occurred, i.e., that an anomaly exists.

[0128] An example of the process of delivering an encryption key by the flying object 300 of this embodiment is shown in Fig. 10. The process is the same as in the first embodiment up to the time of arrival at the receiving device 200 (step S1408).

[0129] In this embodiment, the anomaly detection unit 313 then performs a log information verification process (step S3101). If the log information verification process determines that an anomaly has occurred (step S3102; Yes), the anomaly detection unit 313 outputs an anomaly detection signal. In response to this, the storage control unit 312 erases the encryption key 500 from the encryption key storage unit 321 (step S1412).

[0130] On the other hand, if no abnormality is found in the log information verification process (step S3102; No), the process proceeds to step S1409 and continues the same process as in the first embodiment. Note that the log information verification process can be executed at any time between the end of the movement and the transmission of the encryption key.

[0131] As described above, this embodiment has the same configuration as the first embodiment and provides the same effects as the first embodiment. Furthermore, this embodiment also verifies the presence or absence of anomalies using the accumulated information. Therefore, it is possible to achieve more secure distribution of the encryption key 500.

[0132] For example, even if an attacker attempts to eavesdrop by disabling the anomaly detection function, such as by accessing the laser light interface without touching the flying object 300, the eavesdropping can be confirmed by checking the transmission and reception log of the encryption key 500.

[0133] In this embodiment, the flying object 300 accumulates log information and performs the log information verification process, but this is not limited to this. While the flying object 300 is moving, the log information of the flying object 300 may be transmitted to the transmitting device 100 or the receiving device 200, and these devices may accumulate the log information and perform the log information verification process. In this case, if an abnormality is detected, these devices may transmit an abnormality detection signal to the flying object 300.

[0134] Furthermore, this embodiment may include a monitoring device 400, as in the second embodiment. In this case, the monitoring device 400 may also accumulate collected information as log information and perform log information verification processing. Alternatively, the log information accumulated by the monitoring device 400 may be transmitted to the transmitting device 100 or the receiving device 200, and these devices may perform log information verification processing. In this case as well, if an abnormality is detected, these devices transmit an abnormality detection signal to the flying object 300.

[0135] Furthermore, the receiving device 200 may combine the monitoring results of the monitoring device 400 with log information to more precisely determine whether or not an abnormality exists. For example, tracking investigations are performed using satellite cameras, radio waves, etc., until the flying object 300 passes data to the receiving device 200. As a method of detecting an abnormality at this time, if an unexpected object approaches and contacts the flying object 300, the receiving device 200 may be notified. If an abnormality is confirmed after comparing the information with the log information (flight log and contact log) of the flying object 300, the receiving device 200 may determine that the flying object 300 is being used fraudulently. Furthermore, if an unexpected object contacts the flying object 300, it may assume that eavesdropping has occurred, transmit an abnormality detection signal to the flying object 300, and erase the encryption key 500 stored in the flying object 300.

[0136] Furthermore, the receiving device 200 may determine whether an unexpected event has occurred by inquiring of the transmitting device 100 and / or the monitoring device 400 about the flight log, sensor detection value log, transmission and reception log, etc. of the flying object 300. If an unexpected event has occurred, the receiving device 200 may erase the encryption key 500 in the flying object 300 as there is a risk of eavesdropping.

[0137] Furthermore, the appropriateness of the flight time may be determined in the receiving device 200. In this case, if the flying object 300 does not arrive within a predetermined time, the receiving device 200 may erase the encryption key 500 in the flying object 300.

[0138] In this case, for example, when transmitting the encryption key 500 to the flying object 300, the transmitting device 100 simultaneously transmits a message to the receiving device 200 indicating that the encryption key 500 has been transmitted. If the flying object 300 does not arrive within a predetermined time from receiving the message, the receiving device 200 generates an abnormality detection signal. At this time, the receiving device 200 may search for the flying object 300 and transmit the abnormality detection signal at the timing when the abnormality detection signal is generated. Furthermore, when authentication information is transmitted from the flying object 300, the receiving device 200 may return the abnormality detection signal without performing authentication.

[0139] In addition, the storage control unit 312 of the flying object 300 that receives the abnormality detection signal erases the encryption key 500 without transmitting it to the receiving device 200.

[0140] The flight time may also be determined by the flying object 300. That is, when a predetermined time has elapsed since the encryption key 500 was received, the storage control unit 312 erases the encryption key 500 from the encryption key storage unit 321.

[0141] The period until deletion can be specified at the time of individual delivery. For example, the storage control unit 312 may be configured to receive a specification of the period until deletion from the transmitting device 100 at the same time as receiving the encryption key 500. The storage control unit 312 deletes the encryption key 500 when this period has elapsed.

[0142] <<Fourth Embodiment>> Next, a fourth embodiment of the present invention will be described. In each of the above embodiments, one flying object 300 is caused to fly from the transmitting device 100 to the receiving device 200. On the other hand, in this embodiment, multiple flying objects 300 are caused to fly from the transmitting device 100 to the receiving device 200, and multiple encryption keys 500 are delivered.

[0143] An example of an encryption key distribution system 940 of this embodiment is shown in Fig. 11. As shown in this figure, the encryption key distribution system 940, like the first embodiment, includes a transmitting device 100 and a receiving device 200. Furthermore, in this embodiment, the encryption key distribution system 940 includes a plurality of flying objects 300.

[0144] The configurations of the transmitting device 100, the receiving device 200, and the flying object 300 are basically the same as those of the first embodiment. Hereinafter, the present embodiment will be described, focusing on the configurations that are different from those of the first embodiment.

[0145] Each flying object 300 has its own unique authentication information. The transmitting device 100 of this embodiment stores an encryption key 500 associated with the authentication information in the encryption key storage unit 121 as an encryption key table 140. In this embodiment, the authentication information storage unit 122 may not be provided.

[0146] The encryption key table 140 registers the encryption key 500 to be distributed in association with the authentication information of each flying object 300. An example of the encryption key table 140 of this embodiment is shown in FIG.

[0147] As shown in this figure, each record in the encryption key table 140 includes an authentication information storage section 141 and an encryption key storage section 142. The authentication information storage section 141 stores authentication information for each flying object 300 that is permitted to deliver an encryption key 500. The encryption key storage section 142 stores the encryption key 500 to be delivered by the flying object 300 identified by the corresponding authentication information.

[0148] Similarly, the receiving device 200 may also have an encryption key table consisting of records having the same items. The authentication information storage unit stores in advance the authentication information of all flying objects 300 that are permitted to deliver the encryption key 500.

[0149] In the authentication process of step S1101 in Figure 5, the authentication unit 113 compares the authentication information with all authentication information stored in the authentication information storage unit 141, and if there is any matching authentication information, it transmits the encryption key 500 registered in correspondence with that authentication information to the flying object 300.

[0150] If there is no matching authentication information stored in the authentication information storage unit 141, the authentication unit 113 determines that the authentication has failed.

[0151] 5, the receiving device 200 compares the received authentication information with all authentication information stored in the authentication information storage unit. If there is matching authentication information, the receiving device 200 transmits an encryption key transmission request to the flying object 300. The receiving device 200 then stores the encryption key 500 transmitted from the flying object 300 in the encryption key storage unit associated with the matching authentication information.

[0152] As a result, according to this embodiment, it is possible to increase the supply of encryption keys 500 within the same time period.

[0153] The same encryption key 500 may also be carried and delivered to multiple flying objects 300. In this case, the reliability of delivery of the encryption key 500 is increased.

[0154] Furthermore, in this embodiment, the encryption key 500 to be transmitted may include a dummy. A portion of the encryption key 500 to be transmitted may be a dummy, or the entire encryption key 500 delivered by a specific flying object 300 may be a dummy. The dummy key (bit) is not used as an encryption key. In this case, the encryption key 500 to be transmitted and received may also be converted using an algorithm stored in advance in the transmitting device 100 and the receiving device 200. Furthermore, whether or not the key is a dummy may be determined using an algorithm stored in advance in the transmitting device 100 and the receiving device 200. These techniques can reduce the risk of eavesdropping, capture, etc.

[0155] This embodiment may be combined with the second embodiment.

[0156] <Modification 1> In the above embodiments and modifications, when the encryption key 500 is transmitted and received between the transmitting device 100, the receiving device 200, and the flying object 300, the flying object 300 is in a gliding state, and the encryption key 500 is transmitted and received via wireless communication. However, this is not limited to this. For example, this communication may be wired communication, as shown in Fig. 13. Fig. 13 illustrates an encryption key distribution system 910 similar to that of the first embodiment.

[0157] In this case, the flying object 300 lands near the transmitting device 100 or the receiving device 200 when transmitting or receiving the encryption key 500. Then, as shown in the figure, the two are connected by a physical cable to transmit and receive the encryption key 500.

[0158] In this case, the communication device 133 of the transmitting device 100, the communication device 233 of the receiving device 200, and the communication device 333 of the flying object 300 are provided with connectors for wired communication. Furthermore, instead of the communication devices 133, 233, and 333, each device may be provided with an interface for inputting and outputting data via a medium, and the encryption key 500 may be transmitted and received via the medium.

[0159] As described above, when the transmitting device 100, the receiving device 200, and the flying object 300 are equipped with multiple data communication and input / output interfaces, the exchange of the encryption key 500 between the transmitting device 100 and the flying object 300, and the exchange of the encryption key 500 between the receiving device 200 and the flying object 300 may each use a different communication method.

[0160] In this case, wired cables may also be used for transmitting and receiving information related to authentication between the flying object 300 and the transmitting device 100 and the receiving device 200. Note that in each embodiment and each modified example, wired cables may be used only for transmitting and receiving information related to authentication.

[0161] <Modification 2> In the above-described embodiments and modifications, an example has been described in which an encryption key 500 is delivered from one transmitting device 100 to one receiving device 200. However, the present invention is not limited to this. For example, as shown in Fig. 14(a), the same encryption key 500 may be delivered to multiple receiving devices 200 in sequence using the same flying object 300.

[0162] In this modification, the movement control unit 315 of the flying object 300 flies toward each receiving device 200 in a predetermined order. The flight route may be pre-programmed.

[0163] In this modified example, when receiving the encryption key 500, the storage control unit 312 receives the number of receiving devices 200 at the delivery destination from the transmitting device 100.

[0164] 14B shows the process flow when delivering an encryption key by the flying object 300 in this case. Note that here, the number of receiving devices 200 at the delivery destination is assumed to be N (N is an integer equal to or greater than 2), and n is a counter.

[0165] The flying object 300 sets the counter n to an initial value of 1 (step S4501), and then executes the processes of steps S1401 to S1411 in Fig. 6 to deliver the encryption key 500 to the receiving device 200 that is scheduled to be delivered nth (step S4502).

[0166] Thereafter, it is determined whether the encryption key 500 has been deleted (step S4503). For example, if an abnormality is detected during the delivery process in step S4502, the encryption key 500 has already been deleted. In this case, further delivery is not possible, and the process is terminated.

[0167] On the other hand, if the encryption key 500 has not been erased, the counter is incremented by one and the delivery process is repeated up to the last (Nth) receiving device 200 (steps S4504, S4505).

[0168] Then, when the delivery process is completed up to the last receiving device 200, the storage control unit 312 erases the encryption key 500 stored in the encryption key storage unit 321 (step S4506), and ends the process.

[0169] There may also be multiple transmitting devices 100. In this case, the flying object 300 travels around the multiple transmitting devices 100 in a predetermined order, and receives different encryption keys 500 from each transmitting device 100. Then, the flying object 300 delivers these encryption keys to one receiving device 200.

[0170] Furthermore, there may be a plurality of transmitting devices 100 and a plurality of receiving devices 200. A plurality of encryption keys 500 may be received from a single transmitting device 100, and a plurality of encryption keys 500 may be transmitted to a single receiving device 200.

[0171] In this case, the flying object 300 receives, along with the encryption key 500, for example, information (receiving device ID) that identifies the receiving device 200 to which the encryption key 500 is to be sent. The receiving device ID is then stored in the encryption key storage unit 321 as the second encryption key table 150. The receiving device 200 also holds the receiving device ID in advance.

[0172] An example of the second encryption key table 150 is shown in Fig. 15. The second encryption key table 150 includes an encryption key storage unit 151 and a receiving device ID storage unit 152. The encryption key storage unit 151 stores an encryption key 500. The receiving device ID storage unit 152 stores a receiving device ID. When one encryption key 500 is distributed to multiple receiving devices 200, as many records having the same encryption key 500 as the number of distribution destinations are registered.

[0173] Each time the flying object 300 arrives at the receiving device 200, it receives a request to transmit an encryption key from the receiving device 200 along with a receiving device ID, and transmits all encryption keys 500 stored in association with the received receiving device ID to the receiving device 200. Then, it erases the delivered records from the second encryption key table 150.

[0174] For example, in the example of FIG. 15 , when the flying object 300 arrives at a receiving device 200 whose receiving device ID is RCV001, it transmits encryption keys AAA and BBB to the receiving device 200. It then erases these records. When it arrives at a receiving device 200 whose receiving device ID is RCV002, it transmits encryption keys AAA and CCC and erases these records. When it arrives at a receiving device 200 whose receiving device ID is RCV003, it transmits encryption key CCC and erases the record. When it arrives at a receiving device 200 whose receiving device ID is RCV0004, it transmits encryption key AAA and erases the record.

[0175] <Variation 3> In the above embodiments, the flying object 300 has been described as an example of a flying object such as a drone that navigates according to a pre-stored program, but the flying object 300 is not limited to this. Any flying object capable of unmanned movement between two points (from the transmitting device 100 to the receiving device 200) may be used. For example, the flying object may be a remotely controlled flying object. Furthermore, the flying object may be, like a bullet or artillery shell, a flying object that is not self-propelled but moves only by initial thrust, but whose arrival position can be controlled. Furthermore, the flying object may be a manned flying device such as an airplane, helicopter, or glider. In this case, it is desirable that the storage unit that stores the encryption key 500 is configured to be inaccessible to the operator.

[0176] Furthermore, the device that delivers the encryption key 500 from the transmitting device 100 to the receiving device 200 is not limited to an airborne vehicle. Anything that can move between the two devices where a transmission path cannot be secured and that is difficult for other objects to access may be used, and may be, for example, a moving object such as a ground vehicle, an autonomous vehicle, or a ship.

[0177] <Modification 4> The encryption key distribution systems of the above embodiments and modifications may be configured to generate revenue.

[0178] In this case, as shown in Fig. 16, an encryption key distribution system 970 further includes a billing device 700 in addition to the configuration of each of the above embodiments. Note that the following example shows a case where the billing device 700 is added to the configuration of the first embodiment. The encryption key distribution system used as the base may be an encryption key distribution system of any of the other embodiments or modified examples.

[0179] The billing device 700 acquires predetermined billing parameters such as the number of routes, delivery distance, number of deliveries, data volume, and non-delivery information each time an encryption key delivery process is performed by the flying object 300 .

[0180] The number of routes is the number of combinations of the transmitting device 100 and the receiving device 200. The number of routes may be received from any of the transmitting device 100, the receiving device 200, and the flying object 300.

[0181] The delivery distance is the distance between the transmitting device 100 and the receiving device 200 for each delivery. The distance may be calculated, for example, from GPS data between the two, or may be the flight distance obtained from the flight log of the flying object 300. For example, when the transmitting device 100 and / or the receiving device 200 is moving, the distance may be the distance at the time of departure or the distance at the time of arrival.

[0182] The number of deliveries is the number of delivered encryption keys 500. The billing processing device 700 collects, for example, the number of encryption keys 500 transmitted by the transmitting device 100, the number of encryption keys 500 received by the receiving device 200, etc.

[0183] The data amount is the amount of data of the distributed encryption key 500. The billing device 700 collects, for example, the amount of data transmitted by the transmitting device 100, the amount of data received by the receiving device 200, and the like.

[0184] The non-delivery information is information indicating that the message has not been delivered. For example, if the flying object 300 erases the encryption key 500 before delivering it to the receiving device 200, the non-delivery information is also transmitted to the billing processing device 700. Alternatively, the non-delivery information may be transmitted via the transmitting device 100 or the receiving device 200.

[0185] The billing processing device 700 collects these billing parameters, tallying them up every predetermined period, calculating the amount according to predetermined calculation conditions, and charging the predetermined billing destination. The calculation conditions may be, for example, a calculation method such as multiplying the delivery distance and data volume of successful deliveries during a predetermined period by a predetermined coefficient. Alternatively, for example, a calculation method may be multiplying the delivery distance and data volume of deliveries that occurred regardless of whether they were successful during a predetermined period by a predetermined coefficient, and then subtracting a penalty for the number of undelivered deliveries from that multiplication. The calculation conditions are not limited to these and can be set arbitrarily.

[0186] The billing processing device 700 is realized by a general-purpose information processing device having a CPU, memory, and a communication interface.

[0187] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and further modifications, substitutions, and adjustments can be made without departing from the basic technical concept of the present invention. For example, the network configurations and the configurations of the elements shown in the drawings are examples to aid in understanding the present invention, and the present invention is not limited to the configurations shown in these drawings.

[0188] Finally, preferred embodiments of the present invention will be summarized. Note that some or all of the above-described embodiments and modified examples may be described as follows, but are not limited to the following. [First Embodiment] (See the mobile body according to the first aspect above.) [Second Embodiment] Preferably, the mobile body further includes an abnormality detection unit that detects the abnormality and notifies the storage control unit. [Third Embodiment] Preferably, the input / output unit receives from an external device that the abnormality has been detected and notifies the storage control unit. [Fourth Embodiment] Preferably, the mobile body further includes an authentication request unit that requests authentication of the mobile body prior to transmission and reception of the encryption key, in the transmitting device and the receiving device. [Fifth Embodiment] Preferably, the input / output unit in the mobile body communicates the encryption key with the transmitting device and the receiving device using laser light. [Sixth Embodiment] Preferably, the input / output unit in the mobile body communicates the encryption key with the transmitting device and the receiving device using quantum cryptography communication. [Seventh Mode] In the above mobile body, the abnormality preferably includes at least one of an abnormal value in at least one of vibration, temperature, voltage, position, movement speed, and movement time of the mobile body, interference with the mobile body by another object, transmission and reception of data between the mobile body and another device, and an abnormality obtained as a result of analyzing log information of the mobile body. [Eighth Mode] In the above mobile body, the mobile body is preferably a flying object. [Ninth Mode] (See the encryption key distribution system according to the second aspect.) [Tenth Mode] In the above encryption key distribution system, preferably, the transmitting device further includes a transmitting device authentication unit that authenticates the mobile body, the receiving device further includes a receiving device authentication unit that authenticates the mobile body, and if the transmitting device authentication unit succeeds in authentication, the transmitting device communication unit transmits the encryption key to the mobile body, and if the receiving device authentication unit succeeds in authentication, the receiving device communication unit receives the encryption key from the mobile body. [First Mode] In the encryption key distribution system, it is preferable that the mobile body further comprises a second mobile body, and the second mobile body receives from the transmitting device an encryption key that is the same as the encryption key distributed by the mobile body.[Twelfth Mode] Preferably, the encryption key distribution system further comprises the mobile body as a second mobile body, and the second mobile body receives from the transmitting device an encryption key different from the encryption key distributed by the mobile body. [Thirteenth Mode] Preferably, the encryption key distribution system further comprises a billing processing device that collects parameters related to billing incurred in the encryption key distribution system and performs billing. [Fourteenth Mode] (See the encryption key distribution method according to the third aspect.) [Fifteenth Mode] (See the program according to the fourth aspect.) Note that, like the first mode, the fourteenth and fifteenth modes can be expanded into the second to eighth modes.

[0189] The disclosures of the above-mentioned patent documents and other documents are incorporated herein by reference. Modifications and adjustments of the embodiments and examples are possible within the scope of the entire disclosure of the present invention (including the scope of the claims), and further based on the basic technical concept thereof. Furthermore, various combinations and selections of the various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible within the scope of the disclosure of the present invention. In other words, the present invention naturally includes various modifications and alterations that would be possible by a person skilled in the art in accordance with the entire disclosure, including the scope of the claims, and the technical concept thereof. In particular, with regard to the numerical ranges described herein, any numerical value or subrange included within the range should be construed as being specifically described, even if not otherwise specified.

[0190] 100: transmitting device, 111: (transmitting device) communication unit, 112: (transmitting device) control unit, 113: (transmitting device) authentication unit, 121: encryption key storage unit, 122: authentication information storage unit, 131: CPU, 132: storage device, 133: communication device, 140: encryption key table, 141: authentication information storage unit, 142: encryption key storage unit, 150: second encryption key table, 151: encryption key storage unit, 152: receiving device ID storage unit, 200: receiving device, 211: (receiving device) communication unit, 212: (receiving device) control unit, 213: (receiving device) authentication unit, 221: encryption key storage unit, 222: authentication information storage unit, 231: CPU, 232: storage device, 233: communication device, 300: flying object, 311: input / output unit, 312: memory control unit, 313: abnormality detection unit, 314: authentication request unit, 315: movement control unit, 321: encryption key storage unit, 322: authentication information storage unit, 323: log information storage unit, 331: CPU, 332: storage unit, 333: communication device, 334: sensor, 335: navigation device, 400: monitoring device, 411: communication unit, 412: information acquisition unit, 413: abnormality detection unit, 431: CPU, 432: storage unit, 433: communication device, 434: information collection device, 500: encryption key, 600: log information, 700: billing processing device 910: encryption key distribution system, 920: encryption key distribution system, 940: encryption key distribution system, 960: encryption key distribution system, 970: encryption key distribution system

Claims

1. an input / output unit that receives an encryption key from a transmitting device and transmits the encryption key to a receiving device; a storage control unit that controls storage of the encryption key in a storage unit; a movement control unit that moves the device to the receiving device after receiving the encryption key from the transmitting device, The storage control unit stores the encryption key in the storage unit when it receives the encryption key from the transmission device, and erases the encryption key stored in the storage unit if an abnormality is detected.

2. The moving body according to claim 1, The mobile object further comprises an abnormality detection unit that detects the abnormality and notifies the memory control unit.

3. The moving body according to claim 1, The input / output unit receives information that the abnormality has been detected from an external device and notifies the storage control unit.

4. The moving body according to claim 1, The mobile body further comprises an authentication request unit that requests authentication of the mobile body in the transmitting device and the receiving device prior to transmission and reception of the encryption key.

5. The moving body according to claim 1, The input / output unit communicates the encryption key with the transmitting device and the receiving device using laser light.

6. The moving body according to claim 1, The input / output unit communicates the encryption key with the transmitting device and the receiving device through quantum cryptography communication.

7. The moving body according to claim 1, A moving body, wherein the abnormality includes at least one of abnormal values ​​of the moving body's vibration, temperature, voltage, position, moving speed, and moving time, interference with the moving body by other objects, transmission and reception of data between the moving body and other devices, and an abnormality obtained as a result of analyzing log information of the moving body.

8. The moving body according to claim 1, The moving body is a flying object.

9. A moving body according to any one of claims 1 to 8; The transmitting device; The receiving device, the transmitting device includes a transmitting device communication unit that transmits the encryption key to the mobile unit; The receiving device includes a receiving device communication unit that receives the encryption key from the mobile object.

10. 10. The encryption key distribution system according to claim 9, The transmitting device further includes a transmitting device authentication unit that authenticates the mobile object, The receiving device further includes a receiving device authentication unit that authenticates the mobile object, the transmitting device communication unit transmits the encryption key to the mobile unit when the transmitting device authentication unit has succeeded in authentication; The receiving device communication unit receives the encryption key from the mobile unit if the receiving device authentication unit succeeds in authentication.

11. 10. The encryption key distribution system according to claim 9, The moving body according to claim 1 is further provided as a second moving body, An encryption key distribution system in which the second mobile body receives from the transmitting device an encryption key that is the same as the encryption key distributed by the second mobile body.

12. 10. The encryption key distribution system according to claim 9, The moving body according to claim 1 is further provided as a second moving body, An encryption key distribution system, wherein the second mobile body receives from the transmitting device an encryption key different from the encryption key distributed by the second mobile body.

13. 10. The encryption key distribution system according to claim 9, The encryption key distribution system further comprises a billing processing device that collects parameters related to billing generated in the encryption key distribution system and performs billing.

14. a receiving step of receiving an encryption key from a transmitting device; a storage step of storing the received encryption key in a storage unit; a moving step of moving the device toward the receiving device after storing the encryption key; an erasing step of erasing the encryption key stored in the storage unit when an abnormality in the device itself is detected during movement; a transmitting step of transmitting the encryption key stored in the storage unit to the receiving device upon arrival at a destination area.

15. A computer installed in a moving vehicle a receiving step of receiving an encryption key from the transmitting device; a storage step of storing the received encryption key in a storage unit; a moving step of moving the device toward the receiving device after storing the encryption key; an erasing step of erasing the encryption key stored in the storage unit when an abnormality in the device itself is detected during movement; a transmission step of transmitting the encryption key stored in the storage unit to the receiving device upon arrival at the destination area.