JP2015139011A - Radio communication device, and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent message transmission from an attacker impersonating as a vehicle.SOLUTION: A radio communication device includes: behavior information acquisition means for acquiring behavior information; behavior information storage means for storing a behavior information history acquired from the behavior information acquisition means; determination means for determining whether or not the behavior information history stored in the behavior information storage means is coincident with the behavior of the vehicle; and transmission means for performing message transmission only when the determination means determines that the behavior information history is coincident with the vehicle behavior.

Description

  The present invention relates to a wireless communication device, and more particularly to a wireless communication device capable of preventing message transmission pretending to be a vehicle.

  With the development of information communication technology in recent years, a system in which an information processing device and a wireless communication device are mounted on a vehicle and wireless communication is performed between the vehicles or between the vehicle and a roadside device has been actively studied. Such vehicle-to-vehicle communication, road-to-vehicle communication, and the like are applied to, for example, a traffic safety system and a platooning system, so it is necessary to ensure communication security.

  As an attack on the system, it is conceivable that an attacker impersonates a vehicle and sends false information. For example, in a traffic safety system in which a traveling vehicle exchanges position information and traveling direction with each other, and when there is a risk of contact, the steering, the brake, and the accelerator are automatically operated to perform an avoidance operation, the attacker If it is assumed that the communication is performed, an operation that does not match the original situation is induced for the driving of the communication partner vehicle. If such an attack is made, the function of the traffic safety system will deteriorate, so it is necessary to prevent spoofing by a third party.

  Non-Patent Document 1 performs authentication using a PKI (Public Key Cryptographic Infrastructure) and a digital signature to determine whether a communication partner can be trusted. In particular, it is disclosed that vehicles that communicate with each other authenticate each other using a set of a public key with a signature of a certificate authority and a secret key.

M. Raya, J. P. Hubaux, "The security of vehicular ad hoc networks", 3rd ACM Workshop on Security of Ad Hoc and Sensor Networks 2005, pp. 11-21, 2005

  In the method of Patent Literature 1, authentication is performed on the premise that the subject that performs communication is a vehicle, and it is confirmed whether or not it is a reliable partner. However, when the in-vehicle wireless communication device is removed from the vehicle and used for communication, or when a new wireless communication device having an equivalent function is created and used for communication, the other vehicle is used for communication based on unauthorized use. It cannot be detected.

  An object of the present invention is to provide a wireless communication technique capable of preventing an attacker from impersonating a vehicle and transmitting a message.

  A wireless communication apparatus according to an aspect of the present invention includes behavior information acquisition means for acquiring behavior information, behavior information storage means for storing a history of behavior information acquired from the behavior information acquisition means, and the behavior information storage means The determination means for determining whether or not the history of behavior information stored in the vehicle matches the behavior of the vehicle, and the determination means determines that the history of behavior information matches the behavior of the vehicle. Only in some cases, a transmission means for performing message transmission.

According to such a configuration, message transmission is performed only when the history of behavior information matches the behavior of the vehicle. Therefore, message transmission is performed when the wireless communication device according to the present invention is detached from the vehicle and used. I will not. Therefore, it is possible to prevent an attacker from impersonating a vehicle and sending a message.

  As the behavior information in the present invention, any information can be adopted as long as the information represents the behavior of the wireless communication device according to the present invention or a device in which the wireless communication device is mounted. The behavior information is typically information representing at least one of the motion, posture, position, control state, and the like of the device. For example, at least one of acceleration, speed, position, and orientation can be adopted as the behavior information. Corresponding to each, an acceleration sensor, a speed sensor, a position information acquisition unit, and a gyro sensor can be adopted as the behavior information acquisition unit. In addition, as behavior information, control information of a device in which the wireless communication device according to the present invention is mounted can be adopted. Since the wireless communication apparatus according to the present invention is preferably mounted on a vehicle, information indicating the state of vehicle equipment such as an engine, an accelerator, a brake, and a steering can be adopted as control information. The behavior information acquisition unit may acquire such vehicle control information from a vehicle control device that controls the vehicle by communication.

  In the wireless communication device of the present invention, when message transmission from the transmission means is requested, the determination means determines whether the history matches the behavior of the vehicle based on the behavior information history for the most recent predetermined period. The message transmission by the transmission means can be permitted only when they match. In this way, it can be determined whether or not the vehicle behavior is matched based on the latest history information, and the determination process can be omitted when message transmission is not performed. However, the determination unit may periodically determine whether the history of behavior information matches the behavior of the vehicle, and the transmission unit may determine whether to perform message transmission based on the latest determination result. Absent. With this configuration, it is not necessary to perform the determination process every time a message is transmitted, and thus the processing load of the determination process can be reduced.

  As the determination means in the present invention, a discriminator machine-learned in advance using behavior information representing the behavior of the vehicle can be employed. The discriminator outputs whether or not the history of the inputted behavior information matches the behavior of the vehicle, or the probability that it is the behavior of the vehicle. However, the determination unit may be other than a discriminator using machine learning. For example, the determination unit may perform rule-based determination for determining whether or not a predetermined condition is satisfied.

  The wireless communication apparatus of the present invention preferably further comprises an encryption processing means for encrypting the message with a pre-stored encryption key, and the transmission means preferably transmits the message encrypted by the encryption processing means. . The encryption method is not particularly limited, and may be a public key encryption method or a common key encryption method. By encrypting the message transmission, it is possible to prevent spoofing and message tampering by an attacker or to conceal the message contents.

  Moreover, it is preferable that the behavior information acquisition unit, behavior information storage unit, determination unit, and transmission unit of the wireless communication device of the present invention are all configured by a tamper resistant device. By configuring these elements with a tamper resistant device, it is possible to prevent an attack that alters the information content or alters the processing content. Note that each of the above-described means may be configured by one tamper resistant device or a plurality of tamper resistant devices. When configured with a plurality of tamper resistant devices, it is preferable to prevent unauthorized information from being input by, for example, encrypting communication between the devices.

The present invention can also be understood as a wireless communication apparatus including at least a part of the above-described means. The present invention can also be understood as a vehicle equipped with the above-described wireless communication device. The present invention can also be understood as a wireless communication method that executes at least a part of the above processing. The present invention can also be understood as a computer program for causing a computer to execute this method, or a computer-readable storage medium in which this computer program is stored non-temporarily. Each of the above means and processes can be combined with each other as much as possible to constitute the present invention.

  According to the present invention, it is possible to prevent an attacker from impersonating a vehicle and sending a message.

It is a figure which shows the structure of the radio | wireless communication apparatus concerning embodiment. It is a flowchart which shows the flow of the process at the time of transmission of the radio | wireless communication apparatus concerning embodiment. It is a figure which shows the structure of the radio | wireless communication apparatus concerning a modification.

[Constitution]
An embodiment of the present invention is a wireless communication device that is mounted on a vehicle and used for communication with another vehicle or a roadside communication device. FIG. 1A illustrates an example in which a message is transmitted from the wireless communication device 10 mounted on the vehicle 1 to the wireless communication device 20 mounted on the vehicle 2. A functional block of the transmitting-side radio communication device 10 is shown in FIG. 1B, and a functional block of the receiving-side radio communication device 20 is shown in FIG. 1C. In the following description, it is assumed that the wireless communication devices 10 and 20 have only a transmission function and a reception function, respectively, but it is general that both of the wireless communication devices 10 and 20 have both a transmission function and a reception function. is there.

  As shown in FIG. 1B, the transmission-side wireless communication device 10 includes an acceleration sensor 11a, a GPS device 11b, a sensing history storage unit 12, a message transmission unit 13, a behavior determination unit 14, a key storage unit 15, and an encryption. Unit 16 and wireless communication unit 17. These functional units of the wireless communication device 10 may be realized by a combination of a processor (MPU) and a computer program, may be realized by dedicated hardware such as an ASIC, or may be reconfigurable like an FPGA. It may be realized by a simple gate array or a combination thereof.

  The acceleration sensor 11a is typically a triaxial acceleration sensor, but may be a biaxial or uniaxial acceleration sensor. From the acceleration information obtained from the acceleration sensor 11a, the movement of the wireless communication device 10 and thus the vehicle 1 on which the wireless communication device 10 is mounted can be known. Also, speed information can be obtained by integrating acceleration information.

  The GPS device 11b acquires position information from a GPS satellite signal. The GPS device provides information on latitude, longitude, and altitude. In addition to the GPS device, a position information acquisition device that acquires position information using an arbitrary satellite positioning system such as Galileo, Hokuto, or GLONASS can be employed. In addition to satellite positioning, positioning based on radio waves from a mobile phone base station or a wireless LAN access point may be employed.

  The acceleration sensor 11 a and the GPS device 11 b are examples of sensors that acquire behavior information indicating the behavior of the wireless communication device 10. Therefore, any sensor other than the acceleration sensor 11a and the GPS device 11b can be used as long as it can acquire behavior information of the wireless communication device 10. For example, a gyro sensor (angular velocity sensor), a geomagnetic sensor, or the like can be used. In the present specification, the acceleration sensor 11a and the GPS device 11b may be collectively referred to as the sensor 11.

  The sensing history storage unit 12 is a functional unit that stores sensor information (behavior information) acquired from the sensor 11, and is configured by an arbitrary type of memory device. The sensor 11 periodically acquires sensor information and stores it in the sensing history storage unit 12. The sensing history storage unit 12 may store the measurement data of the sensor 11 as it is, may store data after filtering processing such as noise removal, or signal analysis such as Fourier analysis. Data after processing may be stored.

  The message transmission part 13 receives the request | requirement which performs communication between vehicles, and the content of the message (transmission message) which should be transmitted. When the message transmission unit 13 receives the transmission request, the message transmission unit 13 instructs the behavior determination unit 14 to determine whether or not the behavior of the wireless communication device 10 matches the behavior of the vehicle. Encrypt and send.

  The behavior determination unit 14 is a functional unit that determines whether the sensor information (behavior information) stored in the sensing history storage unit 12 matches the behavior of the vehicle. The behavior determination unit 14 is, for example, a discriminator obtained by performing machine learning using sensor information representing vehicle behavior prepared in advance and sensor information representing behavior other than the vehicle as learning data. As a machine learning technique, any technique such as a neural network, a decision tree, or a support vector machine can be adopted. The learning data may be data obtained based on actual measurement, or data generated by simulation. In the present embodiment, the behavior determination unit 14 is intended to classify behavior information into vehicles and other behaviors, but it is to determine whether the behavior of an automobile with four or more wheels is included in the vehicle, You may comprise so that the behavior of a motorcycle, a motorbike, etc. may not pass determination. What kind of behavior should be identified may be determined according to requirements required in actual operation.

  In addition, the behavior determination part 14 can also employ | adopt structures other than the discriminator based on machine learning. For example, the behavior determination unit 14 may be configured to perform rule-based processing for determining whether or not a predetermined rule is satisfied. Alternatively, a final determination result may be obtained by combining rule-based determination and determination by a discriminator.

  The key storage unit 15 is a functional unit that stores an encryption key used for encryption during wireless communication with a communication partner. In this embodiment, a public key cryptosystem is adopted, and the secret key and the public key of the wireless communication device 10 and the public key of the wireless communication device 20 are stored in the key storage unit 15.

  The encryption unit 16 encrypts the transmission message. In the present embodiment, in order to prevent spoofing, the transmission message is encrypted with the secret key of the wireless communication device 10. On the receiving side, it is possible to confirm that the sender of the message is the wireless communication device 10 by decrypting with the public key of the wireless communication device 10. In order to conceal the content of the transmission message, the transmission message may be encrypted using the public key of the communication partner (in this case, the wireless communication device 20).

  The wireless communication unit 17 transmits the transmission message encrypted by the encryption unit 16. Any wireless communication system may be used, and any wireless LAN (IEEE 802.11), IEEE 802.20, IEEE 802.16, DSRC, etc. may be employed.

  In addition, it is preferable that each said function part of the radio | wireless communication apparatus 10 is comprised with a tamper resistant apparatus. By tamper resistance, it is physically safe, and it becomes impossible or very difficult to modify or obtain the processing contents of each functional unit and stored information from the outside.

Next, the configuration of the wireless communication device 20 mounted on the receiving vehicle 2 will be described. As illustrated in FIG. 2C, the wireless communication device 20 includes functional units such as a wireless communication unit 21, a key storage unit 22, an encryption unit 23, and a message reception unit 24. These functional units of the wireless communication device 20 may be realized by a combination of a processor (MPU) and a computer program, may be realized by dedicated hardware such as an ASIC, or may be reconfigurable like an FPGA. It may be realized by a simple gate array or a combination thereof.

  The wireless communication unit 21 receives wireless communication from the wireless communication device 10. As the wireless communication method of the wireless communication unit 21, the same method as that of the wireless communication device 10 is adopted. The key storage unit 22 stores the secret key and public key of the wireless communication device 20 and the public key of the wireless communication device 10. The encryption unit 23 decrypts the encrypted transmission message transmitted from the wireless communication device 10 using the public key of the wireless communication device 10 stored in the key storage unit 22. The decrypted transmission message is sent to a message processing unit (not shown) via the message receiving unit 24.

[processing]
Next, processing performed at the time of transmission in the wireless communication apparatus 10 on the transmission side will be described with reference to the flowchart of FIG. Although not described in the flowchart, the acceleration sensor 11a and the GPS device 11b periodically acquire sensor information and store it as a history in the sensing history storage unit 12.

  First, the message transmission unit 13 receives a request for requesting message transmission and the content of the message to be transmitted (S1). When the message transmission unit 13 receives the transmission request, the history of the sensor information (acceleration information and position information in this embodiment) stored in the sensing history storage unit 12 becomes the behavior of the vehicle. Instructs to determine if they match. The behavior determination unit 14 acquires sensor information of the latest predetermined period from the sensor information stored in the sensing history storage unit 12, and determines whether the sensor information matches the behavior of the vehicle using a discriminator. (S2).

  When it is determined that the sensor information stored in the sensing history storage unit 12 matches the behavior of the vehicle (S3-YES), message transmission is permitted. Specifically, the encryption unit 16 performs an encryption process of the transmission message using the secret key of the wireless communication device 10 (S4), and the encrypted message is transmitted from the wireless communication unit 17 (S5). .

  On the other hand, when it is determined that the sensor information stored in the sensing history storage unit 12 does not match the behavior of the vehicle (S3-NO), the transmission message is discarded (S6) and the message transmission process is not performed.

[Advantageous Effects of Embodiment]
According to the present embodiment, a message can be transmitted only when the wireless communication device 10 is mounted on a vehicle. Therefore, even if the attacker removes the wireless communication device 10 from the vehicle and installs it on the road or the like and transmits a message to the surrounding vehicle for the purpose of attack, such a message is not transmitted and the attack is not performed. Can be prevented. By adopting authentication using an encryption key, the receiving side can determine whether or not the information is transmitted from the wireless communication device 10, but only by removing the wireless communication device 10 as described above and using it for an attack. Cannot detect the case. As in the present embodiment, such an attack can be prevented by setting the message transmission condition to match the behavior of the vehicle.

In addition, since each functional unit of the wireless communication device 10 is configured by a tamper-resistant device, an attacker can change the sensor information stored in the sensing history storage unit 12 to replace the sensor information that represents the behavior of the vehicle. Further, an attack that causes a message to be transmitted with a false determination result by the behavior determination unit 14 cannot be performed. Also, message tampering and forgery are impossible because the encryption key cannot be extracted. Therefore, in vehicle-to-vehicle communication, it is possible to prevent an attack of impersonating a vehicle and transmitting a message.

[Modification]
The above description exemplifies the embodiment of the present invention. The present invention should not be construed as being limited to the above embodiment, and various modifications can be made within the scope of the technical idea of the present invention. Deformation is possible.

  In the above description, it is determined whether the behavior of the wireless communication device matches the behavior of the vehicle based on acceleration information, position information, etc., but in order to determine whether the behavior is a vehicle behavior, other than sensor information It is also possible to use this information. For example, as shown in FIG. 3, the wireless communication device 10 may be provided with a control information acquisition unit 18, and the control information acquisition unit 18 may acquire vehicle control information from the vehicle control device 30. The vehicle control device 30 is a device that transmits a control command to an engine, a steering, a brake, and the like and acquires information representing these states. The control information acquisition unit 18 acquires a control command transmitted by the vehicle control device 30 and information indicating a control state, and stores the control command in the control information history storage unit 19. In this example, the behavior determination unit 14 determines whether or not the vehicle behavior is based on the control information. With such a configuration, the same effect as in the above embodiment can be obtained.

  In addition, when employ | adopting the above structures, it is desirable to comprise so that the control information acquisition part 18 may not acquire false control information accidentally. For that purpose, it is desirable that the vehicle control device 30 is constituted by a tamper-proof device and that communication between the vehicle control device 30 and the control information acquisition unit 18 is encrypted to prevent message tampering and spoofing.

  In the above description, each functional unit of the wireless communication device 10 has been described as being configured by one tamper resistant device, but may be configured by a plurality of tamper resistant devices to encrypt communication between the devices. I do not care.

  In the above description, after receiving a message transmission request, transmission is performed after determining whether the history of behavior matches the behavior of the vehicle, but the processing order may be other than this. For example, the determination unit may periodically determine whether the history of the behavior information matches the behavior of the vehicle. When a message transmission request is received, if the latest behavior determination result matches the vehicle behavior, the requested message may be transmitted. In this way, the determination process does not have to be performed every time the message is transmitted, so that the transmission can be performed immediately after receiving the message transmission request.

  In the above description, the wireless communication device 10 has been described as having only a transmission function. However, the wireless communication device 20 also has a reception function, so that messages can be transmitted and received. In the above description, the communication partner of the wireless communication device 10 is the in-vehicle wireless communication device 20, but the communication partner may be a roadside communication device or any other wireless communication device.

10: Wireless communication device 11a: Acceleration sensor 11b: GPS device 12: Sensing history storage unit 13: Message transmission unit 14: Behavior determination unit 16: Encryption unit 17: Wireless communication unit

Claims (8)

Behavior information acquisition means for acquiring behavior information;
Behavior information storage means for storing a history of behavior information acquired from the behavior information acquisition means;
Determination means for determining whether or not the history of the behavior information stored in the behavior information storage means matches the behavior of the vehicle;
A transmission unit that transmits a message only when the determination unit determines that the history of the behavior information matches the behavior of the vehicle;
A wireless communication device. The behavior information is acceleration information or position information,
The behavior information acquisition means is an acceleration sensor or position information acquisition means.
The wireless communication apparatus according to claim 1. The behavior information is vehicle control information,
The behavior information acquisition means acquires vehicle control information by communication from a vehicle control device.
The wireless communication apparatus according to claim 1. The determination unit determines whether or not the history of behavior information for the most recent predetermined period matches the behavior of the vehicle when message transmission by the transmission unit is requested,
The radio | wireless communication apparatus of any one of Claim 1 to 3. The determination means is a discriminator machine-learned based on behavior information representing the behavior of the vehicle.
The radio | wireless communication apparatus of any one of Claim 1 to 4. It further comprises cryptographic processing means for encrypting the message with a pre-stored cryptographic key,
The transmission means transmits the message encrypted by the encryption processing means;
The radio | wireless communication apparatus of any one of Claim 1 to 5. The behavior information acquisition unit, the behavior information storage unit, the determination unit, and the transmission unit are all configured by a tamper resistant device.
The wireless communication apparatus according to any one of claims 1 to 6. A wireless communication method performed by a wireless communication device,
Acquiring behavior information and storing the history of the behavior information in the behavior information storage means;
Determining whether the history of behavior information stored in the behavior information storage means matches the behavior of the vehicle;
When it is determined that the history of the behavior information matches the behavior of the vehicle, sending a message;
A wireless communication method.

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