JP2018119380A - Signal processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal processing device to improve security.SOLUTION: A signal processing device includes: a receiver receiving a first signal including first data exhibiting random numbers from a vehicle; and a transmitter which when a second signal including second data exhibiting a response to the first signal and being generated by encrypting the first data to exhibit random numbers is transmitted from a key to the vehicle, transmits a third signal to a vehicle including third data which have different bit numbers from the second data at an overlapped timing with a timing of transmitting bits configuring the second data.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a signal processing device.

  In a smart key system, a technique is known in which a signal transmitted and received between a vehicle and a vehicle key is intercepted and data such as ID (Identification) is acquired using a repeater.

  Therefore, for the impersonation, the control system determines whether the response signal from the key to the WAKE signal is a response to the WAKE signal transmitted first or a response to the WAKE signal transmitted second and later. Thus, a technique for preventing damage caused by impersonation is known (see, for example, Patent Document 1).

JP 2012-62651 A

  However, in the conventional technology as described above, there are cases where impersonation is possible by a repeater. Therefore, the door of the vehicle can be opened and closed, or the engine of the vehicle can be operated, and security may not be sufficient.

  Accordingly, an object of the present invention is to provide a signal processing device that can improve security.

  According to one aspect, the signal processing device is configured to receive a first signal including first data indicating a random number from a vehicle, a response to the first signal, and encrypt the first data. When the generated second signal including the second data indicating the random number is transmitted from the key to the vehicle, the second data is transmitted at a timing overlapping with the timing at which the bits configuring the second data are transmitted. And a transmission unit that transmits a third signal including third data having a different number of bits to the vehicle.

  The signal processing device can receive the first signal transmitted from the vehicle to the key by the receiving unit. Next, the key encrypts the first data included in the first signal to generate second data, and transmits the second signal including the second data to the vehicle as a response to the first signal. At this time, if the second data is read by the repeater, it may not be desirable in terms of security. Therefore, the signal processing device transmits the third signal including the third data to the vehicle at a timing overlapping with the timing at which the bits constituting the second data are transmitted by the transmission unit. In this case, the repeater cannot read a part of the second data due to the interference by the third data. Therefore, the signal processing device can prevent the second data from being read by the repeater and improve the security.

  A signal processing apparatus capable of improving security can be provided.

It is a block diagram which shows the example of whole structure using the signal processing apparatus which concerns on this embodiment, and a hardware structural example. It is a timing chart which shows an example of the signal transmitted and received between the signal processing device concerning this embodiment, vehicles, and a key. It is a flowchart which shows an example of the signal processing which the signal processing apparatus which concerns on this embodiment performs.

  Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

<Overall configuration example and hardware configuration example>
FIG. 1 is a block diagram illustrating an overall configuration example and a hardware configuration example using the signal processing apparatus according to the present embodiment. Hereinafter, as illustrated, an example in which data is transmitted and received by a signal between the vehicle 10 and the key 20 for the vehicle 10 will be described.

  Further, in this example, it is assumed that there is a repeater 30 that relays a signal transmitted and received between the vehicle 10 and the key 20 and analyzes the signal to be relayed to perform unauthorized access. As shown in the figure, the repeater 30 relays the signal transmitted from the vehicle 10 and transmits the received signal to the key 20 or the like.

  The vehicle 10 has a hardware configuration including, for example, an ECU (Engine Control Unit) 11, a transmitter 12, a receiver 13, a storage device 14, a door 15, an engine start button 16, and the like.

  The ECU 11 is an example of an arithmetic device and a control device.

  The transmitter 12 transmits a signal indicating predetermined data to an external device such as the key 20. For example, the transmitter 12 is a processing IC (Integrated Circuit), an antenna, or the like. The transmitter 12 uses, for example, LF (low frequency) radio waves.

  The receiver 13 receives a signal transmitted from an external device. For example, the receiver 13 is a processing IC and an antenna.

  The storage device 14 is, for example, a memory. That is, the storage device 14 is a device that stores data such as ID data that can identify the vehicle 10 or that is used for communication or the like.

  The door 15 is configured to include, for example, a lock mechanism 151, a touch sensor 152, and a lock button 153. When the driver touches the touch sensor 152, the driver can operate the door 15. Further, when the lock button 153 is operated, the driver can lock the door 15 so as not to open the lock mechanism 151 or release the lock so as to open the door 15.

  The engine start button 16 is an interface for operating the engine of the vehicle 10.

  The key 20 has a hardware configuration including, for example, a receiver 21, a transmitter 22, a processing IC 23, a storage device 24, a battery 25, and the like.

  The receiver 21 receives a signal transmitted from an external device such as the vehicle 10. For example, the receiver 21 is a processing IC and an antenna.

  The transmitter 22 transmits a signal to an external device. For example, the transmitter 22 is a processing IC and an antenna.

  The processing IC 23 is an example of an arithmetic device and a control device.

  The storage device 24 is, for example, a memory. That is, the storage device 24 is a device that stores data such as ID data that can identify the key 20 or is used for communication or the like.

  The battery 25 is an example of a power supply device that supplies power to the device included in the key 20.

  The signal processing device 40 has a hardware configuration including, for example, a receiver 41, a transmitter 42, a processing IC 43, a storage device 44, a power supply device 45, and the like.

  The receiver 41 receives a signal transmitted from an external device such as the vehicle 10. The receiver 41 is an example of a receiving unit. For example, the receiver 41 is a processing IC and an antenna.

  The transmitter 42 transmits a signal to an external device. The transmitter 42 is an example of a transmission unit. For example, the transmitter 42 is a processing IC, an antenna, or the like.

  The processing IC 43 is an example of an arithmetic device and a control device.

  The storage device 44 is, for example, a memory. That is, the storage device 44 is a device that stores data such as ID data that can identify the signal processing device 40 or that is used for communication or the like.

  The power supply device 45 is an example of a power supply device that supplies power to a device included in the signal processing device 40. For example, the power supply device 45 is an AC adapter that converts power such as a battery or an outlet.

  The signal processing device 40 is installed, for example, in a key storage place where the keys 20 are stored.

  Note that the hardware configuration of each device is not limited to the illustrated configuration. For example, each device may further include an arithmetic device, a storage device, a control device, or an interface.

<Example of signal processing>
FIG. 2 is a timing chart illustrating an example of signals transmitted and received between the signal processing device, the vehicle, and the key according to the present embodiment. Hereinafter, a first signal SG1 as illustrated is transmitted from the vehicle 10 (see FIG. 1) to the key 20 (see FIG. 1) and the signal processing device 40 (see FIG. 1). In the following example, the first signal SG1 transmitted to the key 20 and the signal processing device 40 indicates the same data and is received by each device at the same timing.

  Then, the second signal SG <b> 2 is transmitted from the key 20 to the vehicle 10.

  Further, the third signal SG <b> 3 is transmitted from the signal processing device 40 to the vehicle 10. The third signal SG3 is a signal having the same frequency as the second signal SG2.

  First, the vehicle 10 first transmits data indicating “Preamble”, “Codevision”, and “Pattern” by the first signal SG1 (in the illustrated example, the first timing T1). Note that the data transmitted by the first signal SG1 at the first timing T1 is data notifying the device that receives the first signal SG1 that data will be transmitted from now on. Therefore, the contents of “Preamble”, “Codevision”, and “Pattern” are determined by the specifications of the vehicle 10, the key 20, the signal processing device 40, and the like.

  When the data transmitted at the first timing T1 is received, the key 20 transmits the data to be “ACK” by the second signal SG2 in order to notify the transmission side, that is, the vehicle 10, of the reception (example shown in the figure). Then, it is the second timing T2.)

  When the vehicle 10 receives the second signal SG2 including the “ACK” data from the key 20, the vehicle 10 transmits the first signal SG1 including the first data D1 to the key 20 (in the illustrated example, at the third timing T3). is there). As shown in the drawing, the vehicle 10 may transmit data such as “Preamble”, “Codeviolation”, and “Pattern” to the key 20 before sending the first data D1. At the third timing T3, head data or footer data may be further added to the first data D1, and the first signal SG1 may be transmitted.

  The first data D1 is data indicating an input, so-called “Challenge”. In this way, when data indicating “Challenge” is transmitted to the key 20, the key 20 sends a response to the input, so-called “Response”, from the first data D1 based on a preset law such as encryption. Can be generated. Then, data indicating “Response” is transmitted from the key 20 to the vehicle 10, and the vehicle 10 can authenticate the key 20 based on whether or not the “Response” is set.

  The first data D1 is data indicating a random number, for example. That is, the first data D1 is data indicating a random number generated by the ECU 11 (see FIG. 1) by executing a random number function, for example.

  Furthermore, in the following description, data generated by encrypting the first data D1 is referred to as “second data D2.” Therefore, when “Challenge” indicated by the first data D1 is a random number, “Response” indicated by the second data D2 is also a random number.

  Next, when receiving the first data D1, the key 20 responds to the first data D1, and therefore generates the second data D2, and transmits the second signal SG2 including the second data D2 to the vehicle 10. (In the example shown, it is the fourth timing T4).

  On the other hand, when the second signal SG2 including the second data D2 is transmitted from the key 20 to the vehicle 10, the signal processing device 40 is at a timing overlapping with the timing at which the bits constituting the second data D2 are transmitted. The third signal SG3 including the third data D3 is transmitted (in the illustrated example, the fifth timing T5).

  Note that the timing at which the third signal SG3 including the third data D3 is transmitted may be during the transmission of the bit BT constituting the second data D2 (in the illustrated example, the transmission period TN). .

  Like the fifth timing T5, the third signal SG3 is transmitted so that the third data D3 overlaps at the timing at which the bit BT constituting the second data D2 is transmitted. If it does in this way, even if the repeater 30 receives 2nd signal SG2 containing the 2nd data D2, it is difficult to read the data of the bit BT part.

  The third data D3 is, for example, continuous wave (CW) or data in which all the bits constituting the third data D3 are “1” (High level). Further, the third data D3 has a bit number different from that of the second data D2, as illustrated. In this way, the signal processing device 40 can prevent the repeater 30 from reading the bit BT that is part of the second data D2.

  As shown in the figure, it is desirable that the third signal SG3 does not transmit data except during the transmission period TN. The third signal SG3 is often a signal similar to noise for devices other than the signal processing device 40. Therefore, noise can be reduced by preventing data from being transmitted outside the transmission period TN by the third signal SG3.

  The third signal SG3 may also be transmitted when communicating with a vehicle different from the vehicle 10 or a vehicle of a different generation. If the vehicles are of different generations, the format of data used for communication may differ. Even in such a case, if the third signal SG3 is used, unauthorized access or the like may be prevented as shown in the figure.

  Furthermore, as the number of bits of the third data D3 is larger, more bits of the second data D2 can be crushed.

  The second data D2 may be a so-called key signal used for security or the like in a smart system or the like. Therefore, when the second data D2 is read by the repeater 30, unauthorized access or the like may be performed. Therefore, as shown in the figure, if a part of the second data D2 is not read by the third signal SG3, unauthorized access or the like can be prevented.

<Example of processing flow>
FIG. 3 is a flowchart illustrating an example of signal processing executed by the signal processing apparatus according to the present embodiment. Hereinafter, processing performed by the signal processing device 40 illustrated in FIG. 1 will be described.

  In step S01, the signal processing device 40 determines whether or not the first data is transmitted. Specifically, when “Preamble” and “Codeviolation” data are transmitted by the first signal SG1, as in the third timing T3 illustrated in FIG. 2, the signal processing device 40 receives the first signal SG1. Judged as medium.

  Next, when the signal processing device 40 determines that the first signal SG1 is being received (YES in step S01), the signal processing device 40 proceeds to step S02. On the other hand, when the signal processing device 40 determines that the first signal SG1 is not being received (NO in step S01), the signal processing device 40 repeats step S01.

  In step S02, the signal processing device 40 determines whether the signal is a signal from the vehicle and includes the first data. Specifically, when the “Pattern” data is transmitted by the first signal SG1 as in the third timing T3 illustrated in FIG. 2, the signal processing device 40 receives the signal from the vehicle based on “Pattern”. It can be determined whether it is a signal and whether the first data D1 is included. That is, “Pattern” is set with a value that can identify a predetermined vehicle and the first data D1. When the “Pattern” is a value that can be identified from the vehicle and the first data, the signal processing device 40 determines that the signal processing device 40 is a signal from the vehicle and includes the first data.

  Next, when the signal processing device 40 determines that the signal is from the vehicle and includes the first data (YES in step S02), the signal processing device 40 proceeds to step S03. On the other hand, if the signal processing device 40 determines that the signal is not a signal from the vehicle or does not include the first data (NO in step S02), the signal processing device 40 proceeds to step S01.

  In step S03, the signal processing device 40 transmits a third signal. Specifically, as shown in FIG. 2, the signal processing device 40 outputs the third signal SG3 so as to overlap with the fifth timing T5, that is, the timing at which the bit BT constituting the second data D2 is transmitted. Send.

  As described above, the signal processing device 40 transmits the third data D3 in accordance with the timing at which the key transmits the second data D2 to the vehicle. In this way, it is possible to prevent the repeater 30 (see FIG. 1) or the like from receiving the second data D2 and prevent unauthorized access.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to specific embodiment described. Therefore, various modifications or changes can be made within the scope of the gist of the present invention described in the claims.

10 vehicle 20 key 30 repeater 40 signal processing device D1 first data D2 second data D3 third data SG1 first signal SG2 second signal SG3 third signal

Claims (1)

A receiving unit for receiving a first signal including first data indicating a random number from the vehicle;
When a second signal indicating a response to the first signal and generated by encrypting the first data and including second data indicating a random number is transmitted from the key to the vehicle, the second data is A signal processing apparatus comprising: a transmission unit configured to transmit a third signal including third data having a bit number different from that of the second data to the vehicle at a timing overlapping with a timing at which the constituent bits are transmitted.

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