JP6960482B2 - Communication master and wireless communication system - Google Patents

Description

The present invention relates to, for example, a wireless communication system that executes control on the vehicle side based on a wireless signal from a portable device to a vehicle.

Conventionally, as one of the wireless communication systems in a vehicle, a so-called remote keyless entry system (RKE system), which can lock or unlock a vehicle door by operating a switch provided on a portable device, is well known. ..

As an example of the RKE system, for example, in the one disclosed in Patent Document 1, the radio signal (key signal) transmitted by the switch operation of the portable device includes a rolling code that changes every time the switch operation of the portable device is performed. When the matching of the key signal including the rolling code is established on the vehicle side, the lock or unlock control of the vehicle door is executed. As a result, after the vehicle side control (for example, unlocking the vehicle door) is executed by the key signal transmitted from the portable device, even if the key signal is intercepted by a third party, the key signal is intercepted. The key signal does not unlock the vehicle door.

JP-A-2007-224663

In a wireless communication system as described above, although the key signal transmitted from a legitimate portable device includes a rolling code, for example, when a third party transmits an illegal wireless signal in a round-robin manner, the illegal wireless signal is transmitted. Accidentally matched the key signal from the legitimate portable device, and there was a risk that the vehicle door would be unlocked. As a countermeasure, it is conceivable to increase the number of bits of the key signal to reduce the probability that an invalid radio signal from a third party matches the key signal, but as the number of bits increases, memory pressure and processing time increase. Etc. occur.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a wireless communication system capable of improving the security level while suppressing the number of bits of a wireless signal transmitted from a portable device. To do.

A wireless communication system that solves the above problems is a wireless communication system including a control means that executes control of an on-board device of the communication master based on a wireless signal transmitted from a portable device to the communication master, and the control means. Shifts to a warning state based on the determination that the communication master has received an illegal radio signal that was not transmitted from a legitimate mobile device. The on-board device is controlled on the condition that the process until the collation is established is performed a plurality of times.

According to this configuration, for example, when a third party transmits an illegal radio signal by brute force, the control means is shifted to the alert state on the communication master side. Then, in the alert state of the control means, the verification of the illegal radio signal transmitted by a third party in a brute force manner is established multiple times to execute the control on the communication master side (radio signal from a legitimate portable device (hereinafter referred to as “radio signal”). It is required to match (called a normal signal). Therefore, it is possible to reduce the probability that the control on the communication master side is executed by an illegal radio signal from a third party. In this way, the security level can be improved without increasing the number of bits of the wireless signal transmitted from the portable device.

In the wireless communication system, the wireless signal transmitted from the portable device is an encrypted code and is not encrypted with an encryption code that changes each time the wireless signal is generated by the portable device. It is preferable that the invalid radio signal includes the non-encryption code and is a signal including the non-encryption code and not including the encryption code.

According to this configuration, when a third party intercepts a legitimate signal and transmits an unauthorized radio signal including an unencrypted code of the legitimate signal while changing the encryption code portion by brute force, the illegal radio signal is transmitted. On the communication master side that received the message, the control means is shifted to the alert state. That is, if the received wireless signal contains an unencrypted code of a regular signal and does not include an encrypted code, it is highly possible that the wireless signal is a signal from a malicious third party. Therefore, it is possible to more effectively shift the control means to the alert state.

In the wireless communication system, the encryption code is preferably a rolling code that encrypts data including a counter value that is incremented each time a wireless signal is generated in the portable device.

According to this configuration, the rolling code included in the normal signal can be changed each time the normal signal is generated by the portable device.
In the wireless communication system, the non-encryption code preferably includes an ID code for individual identification of the portable device.

According to this configuration, since the ID code included in the regular signal is an unencrypted code, it can contribute to speeding up the signal matching process.

According to the wireless communication system of the present invention, it is possible to improve the security level while suppressing the number of bits of the wireless signal transmitted from the portable device.

The block diagram which shows the schematic structure of the wireless communication system of embodiment. The flowchart which shows the processing by the vehicle ECU of the same form. The flowchart which shows the processing by the vehicle ECU of the same form. The flowchart which shows the processing by the vehicle ECU of another example.

Hereinafter, an embodiment of the wireless communication system will be described.
As shown in FIG. 1, in the wireless communication system of the present embodiment, the vehicle is based on the operation (for example, pressing operation) of the lock switch 11 or the unlock switch 12 of the portable device 10 (remote key) at the peripheral position of the vehicle 20. The door is locked or unlocked by the door lock mechanism 21 provided on the door (not shown) of the 20th door. In this embodiment, the vehicle 20 corresponds to the communication master.

The portable device 10 includes the lock switch 11, the unlock switch 12, the portable device ECU 13, and a transmission device 14 for transmitting a collation signal Sv (wireless signal). Based on the operation of the lock switch 11 or the unlock switch 12, the portable device ECU 13 comprehensively controls the generation of the collation signal Sv and the transmission of the collation signal Sv through the transmission device 14.

On the other hand, the vehicle 20 is provided with a receiving device 22 for receiving the collation signal Sv transmitted from the portable device 10, a vehicle ECU 23, and the door lock mechanism 21 which is driven and controlled by the vehicle ECU 23. The collation signal Sv received through the receiving device 22 is input to the vehicle ECU 23. Then, the vehicle ECU 23 locks or unlocks the door through the door lock mechanism 21 based on the input verification signal Sv.

Next, the collation signal Sv generated and transmitted by the portable device ECU 13 based on the operation of the lock switch 11 or the unlock switch 12 will be described.
In the present embodiment, the collation signal Sv generated by the portable device ECU 13 includes four data (ID code Cid, switch code SW, portable device side operation count value Nm, and rolling code RC).

The ID code Cid is a code for individual identification of the portable device 10. The ID code Cid is stored in advance in the memory 15 of the portable device ECU 13.
The switch code SW is a code corresponding to each of the switches 11 and 12, and is a code that changes depending on whether the lock switch 11 is operated or the unlock switch 12 is operated.

The operation count value Nm on the portable device side is the number of operations of the lock switch 11 and the unlock switch 12 (the total number of operations of the switches 11 and 12 or the number of operations of each of the switches 11 and 12). In the present embodiment, the portable device ECU 13 counts the total number of operations of the lock switch 11 and the unlock switch 12, and the count value (portable device side operation count value Nm) is stored in the memory 15.

The rolling code RC is a code generated by encrypting the above-mentioned switch code SW and the operation count value Nm on the portable device side with an encryption key stored in the memory 15. That is, when the lock switch 11 or the unlock switch 12 is operated, the portable device ECU 13 operates the switch code SW and the portable device side according to the switch operation (whether the lock switch 11 is operated or the unlock switch 12 is operated). A rolling code RC is obtained by encrypting the count value Nm and extracting data having a predetermined number of bits from the encrypted data based on a predetermined rule. In this way, since the data on which the rolling code RC is based includes the portable device side operation count value Nm indicating the number of operations of the switches 11 and 12, the rolling code RC changes every time the switch is operated. It has become. The larger the number of bits of the rolling code RC, the higher the security, but on the other hand, it causes memory pressure and an increase in communication time. Therefore, it is desirable to set the number of bits as small as possible within the range where security can be ensured. ..

As described above, among the data included in the collation signal Sv, the ID code Cid, the switch code SW, and the operation count value Nm on the portable device side are unencrypted raw data, and the rolling code RC is encrypted data. ing.

Next, the authentication process (operation execution process of the door lock mechanism 21) by the vehicle ECU 23 will be described with reference to FIGS. 2 and 3. This process is repeatedly executed at a predetermined cycle.
As shown in FIG. 2, in step S1, it is monitored whether or not the radio signal is received via the receiving device 22. Here, when it is determined that the wireless signal has been received (step S1: YES), it is determined whether or not the received wireless signal includes the ID code Cid (step S2). The ID code Cid is stored in the memory 24 of the vehicle ECU 23.

If it is determined in step S2 that the received wireless signal includes the ID code Cid (step S2: YES), the portable device side operation count value Nm included in the received wireless signal is stored in the memory. It is determined whether or not it matches the vehicle-side count value Nc stored in 24 (step S3). On the other hand, if it is determined that the received radio signal does not include the ID code Cid (step S2: NO), the process returns to step S1.

In step S3, if it is determined that the portable device side operation count value Nm included in the received wireless signal matches the vehicle side count value Nc (step S3: YES), whether or not the warning flag is set. Is determined (step S4). At this time, when the value of the warning flag stored in the memory 24 is "1", the vehicle ECU 23 determines that the warning flag is in the set state, and when the value of the warning flag is "0". , Judge that the alert flag is in the reset state.

If it is determined in step S4 that the warning flag is not set (reset state) (step S4: NO), it is determined whether or not the rolling code RC included in the received radio signal is correct. (Step S5). Here, the vehicle ECU 23 encrypts the vehicle side count value Nc (or the portable device side operation count value Nm included in the received wireless signal) and the switch code SW included in the received wireless signal. When the data of a predetermined number of bits extracted from the encrypted data based on the predetermined rule and the rolling code RC included in the received radio signal match, the rolling code RC Is correct.

In step S5, it is determined that the rolling code RC included in the received wireless signal is correct, so that the received wireless signal is a collation signal Sv (regular signal) transmitted from the legitimate portable device 10. Judged. That is, the collation of the collation signal Sv transmitted from the portable device 10 is established.

In step S5, in the process after it is determined that the rolling code RC included in the received radio signal is correct (that is, after the radio signal verification is established in the reset state of the warning flag), the vehicle side is in step S6. The count value Nc is incremented (Nc ← Nc + 1), and the operation of the door lock mechanism 21 is executed in the following step S7. In step S7, the door lock mechanism 21 unlocks or locks the door based on the switch code SW included in the received wireless signal.

As described above, when the verification signal Sv from the legitimate portable device 10 is input to the vehicle ECU 23 in the reset state of the warning flag, the door lock mechanism 21 is activated by one verification establishment. ing.

On the other hand, if it is determined in step S5 that the rolling code RC included in the received radio signal is incorrect (step S5: NO), the warning flag is set in step S8 (that is, the warning flag is set. The value is set to "1"). Then, after the process of step S8 (setting of the warning flag), the authentication process of the radio signal is completed. That is, if it is determined through steps S2 and S3 that the ID code Cid of the wireless signal and the operation count value Nm on the portable device side are correct, and if it is determined in step S5 that the rolling code RC of the wireless signal is incorrect, the verification fails. The door lock mechanism 21 does not operate and the warning flag is set.

Here, when it is determined that the ID code Cid and the operation count value Nm on the portable device side are correct through steps S2 and S3 in the alert flag set state, that is, it is determined that the alert flag is set in step S4. In that case, the process proceeds to step S10. In this step S10, it is determined whether or not the rolling code RC included in the received radio signal is correct by the same process as in step S5. Then, when it is determined that the rolling code RC included in the received radio signal is incorrect (step S10: NO), the collation fails and the process proceeds to step S8, that is, the door lock mechanism 21 does not operate. And the alert flag is set.

On the other hand, if it is determined in step S10 that the rolling code RC included in the received wireless signal is correct (step S10: YES), in the following step S11, 1 is added to the portable device side operation count value Nm. The value is temporarily stored (that is, Nm + 1 is stored as a temporary count value Nt). If YES is determined in step S10, it means that the received radio signal is collated in the alert flag set state. However, in the alert flag set state, if the collation is established only once, the door lock mechanism is established. The operation of 21 is not executed.

As shown in FIG. 3, in step S21 following step S11, it is monitored whether or not the radio signal is received via the receiving device 22 in the same manner as in step S1. Here, when it is determined that the wireless signal has been received (step S21: YES), it is determined whether or not the received wireless signal includes the ID code Cid (step S22).

In step S22, when it is determined that the wireless signal received in step S21 contains the ID code Cid (step S22: YES), the portable device side operation count value Nm included in the received wireless signal. Is determined to match the provisional count value Nt saved in step S11 (step S23). On the other hand, if it is determined that the received radio signal does not include the ID code Cid (step S22: NO), the process returns to step S21.

In step S23, when it is determined that the operation count value Nm on the portable device side included in the wireless signal received in step S21 matches the provisional count value Nt (step S23: YES), it is included in the received wireless signal. It is determined whether or not the rolling code RC is correct (step S24). In this step S24, the same process as in step S5 is executed. That is, here, the vehicle ECU 23 encrypts the provisional count value Nt (or the portable device side operation count value Nm included in the received wireless signal) and the switch code SW included in the received wireless signal. When the data of a predetermined number of bits extracted from the encrypted data based on the predetermined rule and the rolling code RC included in the received radio signal match, this rolling code is used. Judge that RC is correct. Here, when it is determined that the rolling code RC included in the received radio signal is correct (step S24: YES), the second collation is established in the alert flag set state.

Then, in step S24, in the process after it is determined that the rolling code RC included in the received radio signal is correct (that is, after the second collation is established in the alert flag set state), step S25 Resets the alert flag (that is, the value of the alert flag is set to "0").

After that, in step S26, the value obtained by adding 1 to the provisional count value Nt is overwritten as the vehicle side count value Nc (Nc ← Nt + 1), and in the following step S27, the operation of the door lock mechanism 21 is executed. In step S27, the door lock mechanism 21 unlocks or locks the door based on the switch code SW included in the radio signal received in step S21.

On the other hand, in step S23 described above, if it is determined that the operation count value Nm on the portable device side included in the radio signal received in step S21 does not match the provisional count value Nt (step S23: NO), the collation It becomes unsuccessful and the warning flag is set (step S28). Further, in step S24 described above, even if it is determined that the rolling code RC included in the radio signal received in step S21 is incorrect (step S24: NO), the verification is not established and the warning flag is set (step S24: NO). Step S28). Then, after the process of step S28 (setting of the warning flag), the authentication process of the radio signal is completed.

Further, in the present embodiment, when it is determined in step S3 that the operation count value Nm on the portable device side included in the received wireless signal does not match the count value Nc on the vehicle side (step S3: NO). It is determined whether or not the operation count value Nm on the portable device side is larger than the count value Nc on the vehicle side (step S30). Here, when it is determined that the operation count value Nm on the portable device side is equal to or less than the count value Nc on the vehicle side (step S30: NO), the process proceeds to step S8. On the other hand, if it is determined in step S30 that the operation count value Nm on the portable device side is larger than the count value Nc on the vehicle side (step S30: YES), the process proceeds to step S10.

By providing the process of step S30, the switches 11 and 12 are operated (so-called empty operation) in a situation where wireless communication cannot be established, such as when the portable device 10 is far away from the vehicle 20. , It becomes effective when the operation count value Nm on the portable device side is incremented while the count value Nc on the vehicle side remains as it is.

That is, when the collation signal Sv based on the operation of the switches 11 and 12 after the empty operation is received on the vehicle 20 side (step S1: YES), YES in step S2, NO in step S3, YES in step S30, and so on. , It is determined as YES in step S10. Then, in the following step S11, the value obtained by adding 1 to the operation count value Nm on the portable device side is saved as the provisional count value Nt. After that, when the vehicle 20 side receives the collation signal Sv transmitted by the operation of the switches 11 and 12 that do not sandwich the empty operation (step S21: YES), the collation of the collation signal Sv is established by the processing of steps S22 to S24. , The operation of the door lock mechanism 21 is executed (step S27). Further, in step S26, since the value obtained by adding 1 to the provisional count value Nt is overwritten as the vehicle side count value Nc, the vehicle side count value follows the portable device side operation count value Nm incremented by the empty operation. Nc is corrected.

Next, the operation of this embodiment will be described.
The raw data included in the collation signal Sv transmitted from the portable device 10, that is, the ID code Cid, the switch code SW, and the portable device side operation count value Nm is specified by a third party, and it is difficult for the third party to identify. Consider that an illegal radio signal (illegal signal Sf) in which the rolling code RC part is changed by rounding is transmitted to the vehicle 20.

Here, first, it is assumed that the rolling code RC of the invalid signal Sf by the first trial of the brute force does not match the rolling code RC of the collation signal Sv (normal signal). Then, when the illegal signal Sf is received by the receiving device 22 in the reset state of the warning flag, it is determined as NO in the above step S5, and the warning flag is set in the subsequent step S8. After that, the authentication process of the illegal signal Sf is completed without executing the operation of the door lock mechanism 21.

After that, if the invalid signal Sf from the second and subsequent trials accidentally matches the collation signal Sv (normal signal) (collation is established) (step S10: YES), the process proceeds to the process of step S11 and subsequent steps. That is, in the alert flag set state, the operation of the door lock mechanism 21 is not executed only once the verification of the invalid signal Sf is established. Then, if the rolling code RC of the illegal signal Sf transmitted next does not match the rolling code RC of the collation signal Sv (regular signal) (step S24: NO), the warning flag is set in the following step S28 (warning flag). The set state is maintained), and the authentication process of the invalid signal Sf is completed without executing the operation of the door lock mechanism 21. That is, when the illegal signal Sf to be transmitted next is received, the process proceeds to the process of step S2, so that the operation execution process of the door lock mechanism 21 (step S27) is performed while the warning flag is set. It is necessary that the illegal signal Sf tried by brute force is collated twice in a row. As a result, the probability that the door lock mechanism 21 is operated by the illegal signal Sf is reduced.

Next, the characteristic effects of this embodiment will be described.
(1) The vehicle ECU 23 sets a warning flag based on the determination that the vehicle 20 has received an illegal radio signal that is not transmitted from the legitimate portable device 10. Then, in the warning flag set state (warning state), the control of the door lock mechanism 21 is executed on condition that the processing from the reception of the radio signal to the establishment of the matching of the radio signal is performed a plurality of times. According to this configuration, in the state where the warning flag is set, the verification of the illegal signal Sf from the third party is established multiple times in the execution of the control on the vehicle 20 side (matches with the verification signal Sv from the regular portable device 10). Is required to do. Therefore, it is possible to reduce the probability that the control on the vehicle 20 side is executed by the illegal signal Sf from the third party. In this way, the security level can be improved without increasing the number of bits of the collation signal Sv transmitted from the portable device 10 (particularly the number of bits of the rolling code RC).

(2) The verification signal Sv transmitted from the portable device 10 is encrypted with a rolling code RC (encryption code) which is an encrypted code and changes every time a wireless signal is generated by the portable device 10. Includes the ID code Cid that is not used and the operation count value Nm on the portable device side. Then, the vehicle ECU 23 sets the warning flag based on the determination that the radio signal including the ID code Cid and the operation count value Nm on the portable device side and not including the rolling code RC has been received (step S8). That is, when the received wireless signal includes the ID code Cid and the operation count value Nm on the portable device side and does not include the rolling code RC, the wireless signal is a signal from a malicious third party. Since there is a high possibility, it is possible to shift to the set state of the alert flag more effectively.

(3) The rolling code RC as the encryption code is a code that encrypts data including the operation count value Nm on the portable device side, which is incremented each time the collation signal Sv is generated in the portable device 10. The rolling code RC included in the collation signal Sv can be changed each time the collation signal Sv is generated in 10.

(4) Since the ID code Cid is included in the collation signal Sv as raw data (unencrypted code), it can contribute to speeding up the signal collation process in the vehicle ECU 23.
(5) Among the processes of the vehicle ECU 23, when steps S1 to S7 and steps S10 are set as the first phase and steps S21 to S27 are set as the second phase, the radio received in the first phase is in the reset state of the warning flag. The operation of the door lock mechanism 21 is executed on condition that the signal matching is established (step S5: YES). On the other hand, in the alert flag set state, the process shifts to the second phase on the condition that the matching of the radio signals received in the first phase is established (step S10: YES), and then the matching of the radio signals received in the second phase is performed. The operation of the door lock mechanism 21 is executed on condition that the door lock mechanism 21 is established (step S24: YES).

Further, when it is determined that the radio signal received in the second phase is a signal including the ID code Cid and the operation count value Nm on the portable device side and does not include the rolling code RC (step S24: NO), Move to the first phase. As a result, when a third party who has specified the ID code Cid and the operation count value Nm on the portable device side transmits the illegal signal Sf, a brute force trial is performed in order for the door lock mechanism 21 to be operated. It is necessary that the illegal signal Sf is collated twice in a row (that is, in the first and second phases). Therefore, the probability that the door lock mechanism 21 is operated by the fraudulent signal Sf from a third party can be further reduced.

The above embodiment may be changed as follows.
-The processing of the vehicle ECU 23 of the above embodiment (see FIGS. 2 and 3) may be appropriately changed.
For example, as shown in FIG. 4, step S3 in the processing of the vehicle ECU 23 may be changed to step S103. In step S103, the portable device side operation count value Nm included in the received wireless signal is equal to or greater than the vehicle side count value Nc and is within a range smaller than the sum of the vehicle side count value Nc and the predetermined value p. Whether or not it is judged.

Here, if it is determined that the operation count value Nm on the portable device side is within the above range (step S103: YES), the process proceeds to step S4. On the other hand, the portable device side operation count value Nm is out of the above range (that is, the portable device side operation count value Nm is smaller than the vehicle side count value Nc, or the portable device side operation count value Nm is the vehicle side count value Nc. If it is determined (which is equal to or greater than the sum of the predetermined values p) (step S103: NO), the process proceeds to step S10. Then, in step S10, if it is determined that the rolling code RC included in the received radio signal is correct (step S10: YES), the process proceeds to step S21 through step S11.

According to this, in a situation where the switches 11 and 12 of the portable device 10 are operated empty and the operation count value Nm on the portable device side becomes larger than the count value Nc on the vehicle side, the number of empty operations is greater than the predetermined value p. If the number is small, YES is determined in step S103, and the process proceeds to step S4. In this way, by giving a range to the verification establishment of the operation count value Nm on the portable device side, the operation of the door lock mechanism 21 is executed even by the verification signal Sv transmitted after the empty operation is performed a number of times less than the predetermined value p. It is supposed to be done. In this case, instead of step S6 (Nc ← Nc + 1) in the process of the vehicle ECU 23 of the above embodiment, the process of overwriting the value obtained by adding 1 to the operation count value Nm on the portable device side as the vehicle side count value Nc (step). It is desirable to set it to S106).

Further, when the operation count value Nm on the portable device side is out of the above range, there is a high possibility that the received wireless signal is an invalid wireless signal. Therefore, if it is determined in step S103 that the operation count value Nm on the portable device side is out of the above range, the process proceeds to step S10, that is, the operation of the door lock mechanism 21 is not executed depending on the radio signal. Is desirable.

-In the process of the vehicle ECU 23 of the above embodiment, if NO is determined in step S22, the process may be changed so as to move to step S28. Further, in the process of the vehicle ECU 23 of the above embodiment, if NO is determined in step S23, the process may be changed so as to return to step S21. Further, in the process of the vehicle ECU 23 of the above embodiment, if NO is determined in step S24, the process may be changed so as to return to step S21.

-The content of the collation signal Sv from the portable device 10 is not limited to the above embodiment, and can be changed as appropriate. For example, in the above embodiment, a part of the data of the collation signal Sv is encrypted, but the present invention is not limited to this, and all the data of the collation signal Sv may be encrypted.

-In the above embodiment, when the number of determinations of NO in step S21 reaches a predetermined value (that is, when a predetermined time elapses without receiving a signal), the process may be terminated and the process may proceed to step S1. ..

-In the above embodiment, the rolling code RC is generated based on the data obtained by encrypting the switch code SW and the portable device side operation count value Nm, but the rolling code RC is not limited to this, for example, the switch code SW and the portable device side operation count. The rolling code RC may be generated based on the data obtained by encrypting the value Nm and the ID code Cid.

-In the above embodiment, an example applied to the RKE system in the vehicle 20 is shown, but the present invention is not limited to this, and can be applied to the detection of an unauthorized signal in in-vehicle communication such as CAN (controller area network). Further, it can be applied not only to the wireless communication system of the vehicle but also to the wireless communication system of the house where the entrance door is locked and unlocked through wireless communication between the lock device provided on the entrance door of the house and the portable device, for example. Is.

-The above-described embodiment and each modification may be combined as appropriate.
Next, the technical idea that can be grasped from the above embodiment and another example will be added below.
(B) A wireless communication system including a control means for executing control of an on-board device of the communication master based on a wireless signal transmitted from a portable device to the communication master.
The control means shifts from the non-alert state to the alert state based on the determination that the communication master has received an illegal radio signal that is not transmitted from the legitimate portable device.
In the non-alert state, the on-board device is controlled on condition that the wireless signal received in the first phase is collated.
In the alert state, the process shifts to the second phase when the matching of the radio signals received in the first phase is established, and the control of the on-board device is executed on the condition that the matching of the radio signals received in the second phase is established. A wireless communication system characterized by this.

According to this configuration, in the non-alert state, the on-board device is controlled on the condition that the radio signal matching is established in the first phase (step S5: YES). On the other hand, in the alert state, the on-board device is controlled on the condition that the wireless signal matching is established in the second phase (step S24: YES), which is shifted in the wireless signal matching establishment (step S10: YES) in the first phase. Is executed. In other words, in the alert state, it is necessary to verify the radio signal multiple times in order to execute the control on the communication master side, so that the control on the communication master side is executed by an illegal radio signal from a third party. The probability of being done can be reduced. In this way, the security level can be improved without increasing the number of bits of the wireless signal transmitted from the portable device.

(B) The wireless signal transmitted from the portable device is an encrypted code that changes each time the wireless signal is generated by the portable device, and an unencrypted unencrypted code. Including and
A wireless communication system characterized in that, when the radio signal received in the second phase is a signal including the unencrypted code and does not include the encrypted code, the signal is shifted to the first phase.

According to this configuration, when the radio signal received in the second phase is a signal containing an unencrypted code and does not include an encrypted code (step S24: NO), the process proceeds to the first phase. As a result, when the non-encrypted code is specified by a third party and the third party sends an illegal wireless signal in which the part of the specific difficult encrypted code is brute-forced, the communication master side. In order for the control of the above to be executed, it is necessary that the verification of the invalid radio signal is continuously established in the first and second phases. Therefore, the probability that the control on the communication master side is executed by an illegal radio signal from a third party can be further reduced.

10 ... portable device, 20 ... vehicle (communication master), 21 ... door lock mechanism (mounted device), Sv ... verification signal, Cid ... ID code (unencrypted code), SW ... switch code (unencrypted code), Nm: Operation count value on the portable device side (non-encrypted code), RC: Rolling code (encrypted code).

Claims (7)

A communication master that communicates with mobile devices
A first counter whose counter value is incremented each time the received radio signal generates a radio signal, and a radio signal generator that generates a radio signal using the first counter value measured by the first counter. A control unit that determines whether or not the signal is a collation signal that is a radio signal transmitted from the portable device.
The second counter that measures the second counter value and
With
The control unit
When it is determined that the radio signal received in the non-alert state is the collation signal, the second counter value is incremented, and when it is determined that the radio signal is not the collation signal, the alert state is entered.
In the non-alert state, it is determined whether or not the received radio signal is the collation signal based on the second counter value.
In the alert state,
When it is determined based on the second counter value whether or not the received radio signal is the collation signal, and it is determined based on the second counter value that the received radio signal is the collation signal. The first value, which is a value equal to the first counter value extracted from the radio signal determined to be the collation signal, is incremented and the incremented first value is defined as a temporary counter value.
Whether or not the radio signal received after defining the temporary counter value is the collation signal is determined based on the temporary counter value, and if the received radio signal is the collation signal, the temporary counter value is determined. When the determination is made based on the above, the second value, which is a value equal to the provisional counter value, is incremented and the second value after the increment is set to the second counter value to shift to the non-alert state.
Communication master. In the communication master according to claim 1,
The wireless signal transmitted from the portable device includes an encrypted code that changes each time the wireless signal is generated by the portable device, and an unencrypted unencrypted code. And
The communication master, wherein the radio signal determined not to be the collation signal is a signal including the unencrypted code and not including the encrypted code. In the communication master according to claim 2,
The communication master is characterized in that the encryption code is a rolling code that encrypts data including the first counter value. In the communication master according to claim 2 or 3,
The non-encryption code is a communication master including an ID code for individual identification of the portable device. The control unit increments the first value and defines the first value after the increment as the temporary counter value, and defines a value obtained by adding 1 to the first value as the temporary counter. The communication master according to any one of claims 1 to 4. The control unit increments the second value and sets the second value after the increment to the second counter value, and the second counter is a value obtained by adding 1 to the second value. The communication master according to any one of claims 1 to 4, which is set to a value. A wireless communication system including a portable device and a communication master that communicates with the portable device.
The portable device
The first counter, whose counter value is incremented each time a radio signal is generated,
A radio signal generation unit that generates a radio signal using the first counter value measured by the first counter, and
With
The communication master
A control unit that determines whether or not the received wireless signal is a collation signal that is a wireless signal transmitted from the portable device.
The second counter that measures the second counter value and
With
The control unit
When it is determined that the radio signal received in the non-alert state is the collation signal, the second counter value is incremented, and when it is determined that the radio signal is not the collation signal, the alert state is entered.
In the non-alert state, it is determined whether or not the received radio signal is the collation signal based on the second counter value.
In the alert state,
When it is determined based on the second counter value whether or not the received radio signal is the collation signal, and it is determined based on the second counter value that the received radio signal is the collation signal. The first value, which is a value equal to the first counter value extracted from the radio signal determined to be the collation signal, is incremented and the incremented first value is defined as a temporary counter value.
Whether or not the radio signal received after defining the temporary counter value is the collation signal is determined based on the temporary counter value, and if the received radio signal is the collation signal, the temporary counter value is determined. When the determination is made based on the above, the second value, which is a value equal to the provisional counter value, is incremented and the second value after the increment is set to the second counter value to shift to the non-alert state.
Wireless communication system.

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