Driving assistance device, decryption device, encryption system, encryption processing method, and decryption processing method

Abstract

To provide information of a specific classification without requiring complicated processing.SOLUTION: The driving assistance device 100 mounted on the vehicle 10 includes the sensor 120, the encryption unit 115 that encrypts the detection information acquired by the sensor using the public key different for each predetermined classification of the detection information, creates the table in which the encrypted information that is the encrypted detection information and the classification are associated with each other, and encrypts the table in the homomorphic encryption scheme, and the communication unit 112 that transmits the encrypted information and the encrypted table.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a driving assistance device, a decryption device, an encryption system, an encryption processing method, and a decryption processing method. [Background technology]

[0002] In autonomous driving of vehicles and driving assistance using an Advanced Driving Assistant System (ADAS), there is known a technology for transmitting information detected by various sensors to a data center outside the vehicle. When transmitting information, the driving assistance device performs encryption using multiple types of private keys, as described in Patent Document 1, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent Publication No. 11,295,028B2 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been an increasing demand for information detected by various sensors in vehicles. When the information desired by a data center is only a portion of the information detected by the various sensors, there has been a problem of wanting to provide only the desired information. Furthermore, when there are multiple data centers, there is a need to provide the desired information from each data center, which creates a problem of cumbersome processing. [Means for solving the problem]

[0005] The present disclosure has been made to solve the above-mentioned problems, and can be realized in the following forms.

[0006] According to one embodiment of the present disclosure, there is provided a driving assistance device (100) mounted on a vehicle (10). The driving assistance device includes a sensor (120), an encryption unit (115) that encrypts detection information acquired by the sensor using a different public key for each predetermined classification of the detection information, creates a table that associates the encrypted information, which is the encrypted detection information, with the classification, and encrypts the table using a homomorphic encryption method, and a communication unit (112) that transmits the encrypted information and the encrypted table.

[0007] According to this driving assistance device, in addition to the encrypted information encrypted with a different public key for each classification, a table indicating which classification each piece of information in the encrypted information belongs to is encrypted using homomorphic encryption. Therefore, it is possible to provide decodable information of a specific classification without requiring a process of decrypting all of the detection information to obtain information in all specific fields or a process of transmitting only the detection information of a specific classification. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating the configuration of a cryptographic system. [Figure 2] 10 is a flowchart illustrating an example of encryption processing. [Figure 3] FIG. 10 is an explanatory diagram illustrating an example of a table. [Figure 4] 10 is a flowchart illustrating an example of a decoding process. [Figure 5] 10 is a flowchart illustrating an example of encryption processing in the second embodiment. [Figure 6] 10 is a flowchart showing an example of a decoding process in the second embodiment. [Figure 7] FIG. 10 is a schematic diagram illustrating the configuration of a cryptographic system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. First embodiment: As shown in FIG. 1, the encryption system 500 in the first embodiment includes a vehicle 10 equipped with a driving assistance device 100 having an encryption device 110, and a server 20 having a decryption device 200.

[0010] The driving assistance device 100 is a device that assists in driving the vehicle 10 and realizes ADAS. The driving assistance device 100 includes an encryption device 110, a sensor 120, and a control device 130.

[0011] The sensor 120 acquires detection information. The detection information includes, for example, external environment information related to the outside world of the vehicle 10 and internal environment information related to the vehicle 10. The external environment information is, for example, information related to targets located around the vehicle 10. The internal environment information is, for example, information including information related to the traveling of the vehicle 10 and information related to the driver of the vehicle 10. In this embodiment, the sensor 120 includes an external environment sensor 121 that acquires external environment information and an internal environment sensor 122 that acquires internal environment information.

[0012] In this embodiment, the external sensor 121 includes a camera 123 and a distance measurement sensor 124. The camera 123 captures an image of the periphery of the vehicle 10 to acquire video. The distance measurement sensor 124 measures the distance to an object in the periphery of the vehicle 10. Examples of the distance measurement sensor 124 include Lidar (Light Detection and Ranging) and millimeter wave radar that use reflected waves.

[0013] In this embodiment, the internal sensors 122 include a vehicle position sensor 125, a vehicle speed sensor 126, and a yaw rate sensor 127. The vehicle position sensor 125 detects the current coordinate position of the vehicle 10. An example of the vehicle position sensor 125 is a Global Navigation Satellite System(s) (GNSS) such as a Global Positioning System (GPS). The vehicle speed sensor 126 measures the current traveling speed of the vehicle 10. The yaw rate sensor 127 is a detector that detects the yaw rate (rotational angular velocity) around the vertical axis of the center of gravity of the vehicle 10. For example, a gyro sensor can be used as the yaw rate sensor 127.

[0014] The encryption device 110 includes a storage unit 111, a CPU 112, and a communication unit 113. The CPU 112 executes a program pre-installed in the storage unit 111 to implement the functions of a classification unit 114 and an encryption unit 115. However, some or all of the functions of these units may be implemented by a hardware circuit. The encryption device 110 encrypts detection information including information about targets detected by the sensor 120 and transmits the information to the decryption device 200 via the communication unit 113. The encryption device 110 also creates and encrypts a table related to the encrypted detection information and transmits the table to the decryption device 200 via the communication unit 113.

[0015] The classification unit 114 classifies the detection information related to the vehicle 10 detected by the sensor 120 into predetermined classifications. Examples of classifications include classifications that classify the detection information into types of sensor devices of the sensor 120 that detected the detection information, and classifications that classify the detection information into types of objects recognized from video captured by the camera 123.

[0016] The encryption unit 115 encrypts the detection information related to the vehicle 10 detected by the sensor 120. The encryption unit 115 also creates a table relating to the classification of the encrypted detection information and encrypts the information using a homomorphic encryption method. Details of the encryption will be described later. The table is, for example, a table that associates the encrypted detection information with a classification. In other words, the table indicates which information belongs to which classification.

[0017] The communication unit 113 transmits the information encrypted by the encryption unit 115 to the decryption device 200 .

[0018] The control device 130 is a computer configured with a CPU, RAM, and ROM. The control device 130 realizes a driving assistance function by the CPU executing a program pre-installed in a storage area such as the RAM or ROM of the control device 130. More specifically, the control device 130 controls the steering and traveling speed of the vehicle 10 by controlling a driving force control device, a braking force control device, and a steering control device (not shown) mounted on the vehicle 10 based on information detected by the sensor 120 and information indicating the classification made by the classification unit 114. However, some or all of the functions of these units may be realized by hardware circuits.

[0019] The server 20 is installed in a data center. The decryption device 200 includes a storage unit 201, a CPU 202, and a communication unit 203. The CPU 202 executes a program pre-installed in the storage unit 201 to realize the functions of the decryption unit 204. However, some or all of the functions of these units may be realized by a hardware circuit. The decryption device 200 decrypts information encrypted by the encryption device 110.

[0020] The decryption unit 204 decrypts only the desired information from the detection information encrypted by the encryption device 110 and received via the communication unit 203. Details of the decryption will be described later.

[0021] 2 is a process in which the encryption device 110 encrypts the detection information. This process is repeatedly executed by the encryption device 110 while the vehicle 10 is traveling, for example, every 100 ms.

[0022] In step S100, the encryption unit 115 executes an "acquisition step" of acquiring detection information from the sensor 120.

[0023] In step S110, the classification unit 114 executes a "classification step" of classifying the detection information acquired in step S100 into predetermined categories. For example, the classification unit 114 classifies the detection information into categories for each type of object recognized from the video captured by the camera 123. The classification unit 114 also classifies information acquired by other sensor devices while the camera 123 was capturing an image of the object into information classified into the classification of that object. More specifically, the classification unit 114 classifies the detection information into "traffic light," "white line," "sign," and "pedestrian." The classification unit 114 also classifies the distance to the traffic light acquired by the ranging sensor 124 while the camera 123 was capturing an image of the "traffic light" and the internal world information acquired by the internal world sensor 122 into the "traffic light" category.

[0024] In step S120, the encryption unit 115 executes a "public key preparation step" of acquiring a public key and preparing a public key for each classification. The encryption unit 115 may generate a public key or may acquire an already generated public key from outside. In this embodiment, the encryption unit 115 selects a public key to be used for encryption of each classification from among a plurality of public keys generated in advance and stored in the storage unit 111. The encryption unit 115 also generates a table that associates the classification with the selected public key. Note that steps S100 to S120 can be performed in any order, or even in parallel, as long as step S110 is performed after step S100.

[0025] In step S130, the encryption unit 115 executes a "first encryption step" in which the detection information acquired in step S100 is encrypted using a different public key for each classification prepared in step S120. In the first encryption step, encryption is performed using, for example, RSA encryption.

[0026] In step S140, the encryption unit 115 executes a "second encryption step" in which a table is created that associates the encrypted information encrypted in step S130 with a classification, and the table is encrypted using a homomorphic encryption method. An example of a homomorphic encryption method is fully homomorphic encryption. The information encrypted in the second encryption step is also referred to as an "encryption table." The table that associates the encrypted information with a classification indicates which classification the encrypted information falls into. In other words, it indicates which classification the detection information before encryption was classified into. The encryption unit 115 creates a table that associates the address of each piece of information in the encrypted information with a classification, as shown in FIG. 3, for example.

[0027] In step S150 (FIG. 2), the encryption device 110 executes a "transmission step" of transmitting the encrypted information encrypted in step S130 and the encryption table encrypted in step S140 to the decryption device 200. In this embodiment, the encryption device 110 transmits the table created in step S120, which associates the classification with the public key, along with the encrypted information and the encryption table. Note that the encryption device 110 may execute the process of step S150 to transmit the encrypted information, etc. to the server 20 as soon as the process of step S140 is completed, or may execute the process of step S150 when it receives that the server 20 is in a state where it can receive encrypted information, etc.

[0028] 4 is a process in which the decryption device 200 decrypts information encrypted by the encryption device 110. This process is executed every time information is received from the encryption device 110, for example.

[0029] In step S200, the decryption unit 204 executes an "encryption information acquisition step" to acquire encryption information and an encryption table from the encryption device 110. In this embodiment, the encryption unit 115 receives from the encryption device 110 a table associating classifications with public keys, along with the encryption information and the encryption table.

[0030] In step S210, the decryption unit 204 executes a "private key preparation step" of preparing a private key for decrypting the information encrypted by the encryption device 110 in the first encryption process described above. The private key may be acquired from the encryption device 110 or may be stored in advance in the storage unit 201. In this embodiment, the decryption unit 204 uses a table that associates classifications with public keys and that is received from the encryption device 110 together with the encrypted information, to select a private key corresponding to a public key associated with the classification of the information desired by the decryption device 200 from among the private keys stored in advance in the storage unit 201. Note that step S200 and step S210 are not limited to this order and may be performed in any order, or may be performed in parallel.

[0031] In step S220, the decryption unit 204 executes an "extraction step" in which, using the encryption table received from the encryption device 110 in step S200, the decryption unit 204 searches for and extracts desired information, which is desired detection information, from the encrypted information received from the encryption device 110 in step S200. More specifically, the decryption unit 204 uses the access right table stored in the storage unit 201 to obtain encrypted information associated with the classification of the desired information from the encryption table. The decryption unit 204 uses the obtained information to extract the desired information from the encrypted information.

[0032] In step S230, the decryption unit 204 executes a "decryption step" in which the desired information extracted in step S220 is decrypted using the private key prepared in step S210. Note that steps S220 and S230 may be performed in parallel.

[0033] According to the driving assistance device 100 in the first embodiment described above, a table indicating which category each piece of information in the encrypted information belongs to is encrypted using homomorphic encryption in addition to the encrypted information encrypted with a different public key for each category. Therefore, information in a specific category can be provided in a decodable manner without requiring a process of decrypting all detection information to obtain information in all specific fields or a process of transmitting only detection information in a specific category.

[0034] Furthermore, in the second encryption process, the driving assistance device 100 encrypts the table that associates the encrypted information with the classification using a homomorphic encryption method, which allows encryption to be performed in a shorter time than when all the encrypted information is encrypted using a homomorphic encryption method.

[0035] Furthermore, if the decryption device 200 stores encrypted information received in the past, when the decryption device 200 desires additional information in a field different from the field desired by the decryption device 200, the information can be obtained by decrypting the information using a private key corresponding to the desired field. Therefore, the encryption device 110 can provide the decryption device 200 with information in the desired field contained in the past detection information without continuing to store the past detection information.

[0036] Furthermore, in this embodiment, the encryption device 110 prepares a table that associates classifications with public keys, and transmits the table to the decryption device 200. Therefore, the decryption device 200 can more reliably prepare a private key that corresponds to the public key used for encryption.

[0037] B. Second embodiment: The encryption process in the second embodiment shown in Fig. 5 differs from the encryption process in the first embodiment in that in step S145, a table associating classifications with public keys is also encrypted using an encryption method having homomorphic encryption, but the other steps are the same as those in the first embodiment. Furthermore, the decryption process in the second embodiment shown in Fig. 6 differs from the decryption process in the first embodiment in that in step S215, a private key is prepared using an encryption table, but the other steps are the same as those in the first embodiment. The configuration of the encryption system 500 in the second embodiment is the same as that of the encryption system 500 in the first embodiment, and therefore a description of the configuration of the encryption system 500 will be omitted.

[0038] In step S145, the encryption unit 115 creates a table that associates the classifications in the table created in step S120 with the encrypted information encrypted in step S130, and encrypts the table using a homomorphic encryption method. That is, the encryption unit 115 creates a table that associates the classifications, public keys, and encrypted information, and encrypts the table.

[0039] In step S215, the decryption unit 204 uses the encryption table received from the encryption device 110 in step S200 to select a private key associated with the desired classification.

[0040] According to the driving assistance device 100 in the second embodiment described above, the encryption device 110 encrypts the table associating the classifications with the public keys by an encryption method including homomorphic encryption, and transmits the table to the decryption device 200. This makes it possible to omit the process of transmitting information associating the classifications with the public keys in advance to the decryption device 200, thereby improving the confidentiality of the combinations of the classifications and the public keys.

[0041] C. Third embodiment: The cryptographic system 500B of the third embodiment shown in FIG. 7 differs from the first embodiment in that it includes a server 30 having a cryptographic device 300 and that the cryptographic device 110 does not perform encryption processing, but has the same other configurations.

[0042] In the third embodiment, the driving assistance device 100 transmits detection information including information about the target detected by the sensor 120 to the encryption device 300.

[0043] The server 30 is installed in a data center. The encryption device 300 has the same configuration as the encryption device 110. The encryption device 300 includes a storage unit 301, a CPU 302, and a communication unit 303. The CPU 302 executes a program pre-installed in the storage unit 301 to implement the functions of the classification unit 304 and the encryption unit 305. However, some or all of the functions of these units may be implemented by a hardware circuit. The encryption device 300 performs the above-described encryption process on the detection information acquired from the driving assistance device 100 via the communication unit 303, and transmits the encrypted detection information to the decryption device 200 via the communication unit 303.

[0044] According to the encryption system 500B in the second embodiment described above, the encryption device 300 outside the vehicle 10 performs encryption processing, so the processing load on the driving assistance device 100 can be reduced.

[0045] D. Other Embodiments: (D1) In the above-described embodiment, the driving assistance device 100 includes multiple sensors, namely, the external sensor 121 and the internal sensor 122. However, the driving assistance device 100 may include only the external sensor 121 or only the internal sensor 122. Furthermore, the internal sensor 122 may include, for example, an in-vehicle camera that monitors the driver's state or a tactile sensor that detects whether the driver is gripping the steering wheel of the vehicle 10.

[0046] (D2) In the above-described embodiment, the encryption device 110 includes the classification unit 114. The encryption device 110 may not include the classification unit 114 as long as it includes the encryption unit 115. In this case, the classification unit 114 is realized by, for example, a microcomputer or the like configured with a CPU, RAM, and ROM different from the encryption device 110 included in the driving assistance device 100. In the above-described acquisition step, the encryption device 110 acquires, together with the detection information, information indicating which classification the detection information has been classified into.

[0047] (D3) In the above-described embodiment, the different public keys may be different keys using the same algorithm, or may be keys using different algorithms. For example, the key length of the public key for data classified as requiring high confidentiality, such as facial information of the driver of vehicle 10, may be 2048 bits, and the key length of the public key for data classified as other categories may be 1024 bits.

[0048] (D4) In the first and third embodiments described above, the encryption device 110 creates a table associating classifications with public keys and transmits the table to the decryption device 200. However, the present invention is not limited to this, and an external server 20 may create a table associating classifications with public keys and transmit the table to the decryption device 200.

[0049] (D5) In the first and second embodiments described above, the driving assistance device 100 includes the encryption device 110. However, the driving assistance device 100 may not include the encryption device 110. In this case, the encryption device 110 is installed in the vehicle 10 separately from the driving assistance device 100.

[0050] (D6) In the second encryption step (see step S145 in FIG. 5) in the second embodiment described above, the encryption unit 115 creates a table in which encryption information is associated with a classification in a table in which classifications are associated with public keys, and encrypts the table using a homomorphic encryption method. Alternatively, the encryption unit 115 may create a table in which classifications are associated with public keys and a table in which encryption information is associated with classifications, and encrypt each of the tables.

[0051] (D7) In the third embodiment described above, the encryption device 110 provided in the vehicle 10 may perform the classification step and the first encryption step, and the encryption device 300 provided in the server 30 may perform the second encryption step. Alternatively, the encryption device 110 may perform the classification step, and the encryption device 300 may perform the first encryption step and the second encryption step. In this case, the encryption device 300 acquires, together with the detection information, information indicating the classification into which the detection information has been classified.

[0052] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0053] The cryptographic device 110 and methods described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and methods described herein may be implemented by a special-purpose computer configured with a processor configured with one or more dedicated hardware logic circuits. Alternatively, the restriction unit and methods described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium. [Explanation of symbols]

[0054] 10...vehicle, 20...server, 30...server, 100...driving assistance device, 110...encryption device, 111...storage unit, 112...CPU, 113...communication unit, 114...classification unit, 115...encryption unit, 120...sensor, 121...external sensor, 122...internal sensor, 123...camera, 124...distance measurement sensor, 125...vehicle position sensor, 126...vehicle speed sensor, 127...yaw rate sensor, 130...control device, 200...decryption device, 201...storage unit, 202...CPU, 203...communication unit, 204...decryption unit, 300...encryption device, 301...storage unit, 302...CPU, 303...communication unit, 304...classification unit, 305...encryption unit, 500, 500B...encryption system

Claims

1. A driving assistance device (100) mounted on a vehicle (10), a sensor (120); an encryption unit (115) that encrypts the detection information acquired by the sensor using a different public key for each predetermined classification of the detection information, creates a table that associates the encrypted information, which is the encrypted detection information, with the classification, and encrypts the information using a homomorphic encryption method; a communication unit (112) that transmits the encrypted information and the encrypted table.

2. The driving assistance device according to claim 1, The encryption unit creates the table that associates the classification with the public key associated with the classification, and encrypts the table using the homomorphic encryption method.

3. A decryption device (200) for decrypting the encrypted information according to claim 1 or claim 2, A decryption device comprising a decryption unit (204) that decrypts only the desired information from the encrypted information using the table and a private key corresponding to the classification of desired information, which is the desired detection information, selected using the table or information indicating a combination of the classification and the public key prepared in advance.

4. A cryptographic system (500, 500B), detection information including information detected by a sensor mounted on a vehicle; an encryption device (110, 30) that encrypts the detection information; a decryption device that decrypts the encrypted information encrypted by the encryption device, The cryptographic device encrypting the detection information using a public key that differs for each predetermined classification of the detection information; creating a table associating the encryption information with the classification, and encrypting the table using a homomorphic encryption method; transmitting the encrypted information and the encrypted table to the decryption device; The decryption device decrypts only the desired information from the encrypted information using the table and a private key corresponding to the classification of desired information, which is the desired detection information, selected using the table or information indicating a combination of the classification and the public key that has been prepared in advance.

5. 1. A cryptographic processing method, comprising: an acquisition step of acquiring detection information related to a vehicle from a sensor that detects the detection information; a first encryption step of encrypting the detection information using a different public key for each predetermined classification of the detection information; a second encryption step of creating a table that associates the encrypted information encrypted in the first encryption step with the classification, and encrypting the table using a homomorphic encryption method.

6. 6. A decryption processing method for decrypting the encrypted information according to claim 5, comprising: A decryption processing method including a decryption step of decrypting only the desired information from the encrypted information using the table and a private key corresponding to the classification of desired information, which is the desired detection information, selected using the table or information indicating a combination of the classification and the public key prepared in advance.

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