Unauthorized signal detection device, vehicle, and unauthorized signal detection method

Abstract

To provide a fraudulent signal detection device and a fraudulent signal detection method for detecting that a fraudulent signal is input to a communication network where signals are expected to be input at a predetermined period.SOLUTION: In a vehicle, a fraudulent signal detection device (ECU 110) includes a measurement unit that measures a time interval between a plurality of consecutive signals input to a communication network in chronological order, and a determination unit that determines that a conflict has occurred when a second signal is transmitted, and determines that the second signal is a mediated normal signal if a time interval between a first signal and the second signal that should be transmitted at the time interval is longer than the time interval, and a signal interval between the second signal and a signal input immediately before is equal to or less than a predetermined interval.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an unauthorized signal detection device, a vehicle, and an unauthorized signal detection method. [Background technology]

[0002] Patent Documents 1 and 2 disclose techniques for detecting unauthorized signals input into a communication network. [Prior art document] [Patent documents] Patent Document 1: JP 2021-136631 A Patent Document 2: JP 2021-064921 A Summary of the Invention [Problem to be solved by the invention]

[0003] However, there is a problem in detecting signals that are illegally input into a communication network more appropriately. The present application aims to solve the above problem by improving safety. This will ultimately contribute to further improving traffic safety and the development of a sustainable transportation system. [Means for solving the problem]

[0004] A first aspect of the present invention provides an unauthorized signal detection device that detects the input of an unauthorized signal into a communication network where signals are expected to be input at a predetermined cycle. The unauthorized signal detection device includes a measurement unit that chronologically measures the time intervals between multiple consecutive signals input into the communication network, and a determination unit that determines that a contention has occurred when transmitting the second signal if the time interval between a first signal and a second signal that should be transmitted at the cycle is longer than the cycle and the signal interval between the second signal and the signal input immediately before is equal to or shorter than the predetermined interval, and determines that the second signal is an arbitrated normal signal.

[0005] A second aspect of the present invention provides an unauthorized signal detection device that detects the input of an unauthorized signal to a communication network in which signals are expected to be input at a predetermined cycle. The unauthorized signal detection device includes a measurement unit that chronologically measures the time intervals between multiple consecutive signals input to the communication network, and a determination unit that, when the time interval between a first signal and a second signal that should be transmitted at the cycle is longer than the cycle and the time interval between the signal immediately preceding the second signal and the second signal is equal to or greater than a first threshold and equal to or less than a second threshold, determines that a contention has occurred when transmitting the second signal and determines that the second signal is an arbitrated normal signal.

[0006] In any of the above-mentioned fraudulent signal detection devices, the judgment unit may determine that the conflict has occurred when the time interval between the first signal and the second signal to be transmitted at the period is longer than the period, and the difference between the reception timing determined from the input timing and signal length of the signal immediately preceding the second signal and the input timing of the second signal is a predetermined minimum time interval that should be left between successive signals.

[0007] In any of the above-mentioned fraudulent signal detection devices, the judgment unit may judge that the second signal is not a normal signal if the time interval between the first signal and the second signal is longer than the period and the signal length between the second signal and the signal input immediately before is less than a predetermined length, and may determine whether the second signal is a fraudulent signal based on information contained in the second signal and other signals input to the communication network.

[0008] In any of the above-mentioned fraudulent signal detection devices, the judgment unit may judge that the second signal is not a normal signal if the time interval between the first signal and the second signal is longer than the period and the time interval between the reception timing of the signal immediately preceding the second signal and the input timing of the second signal exceeds the second threshold, and may determine whether the second signal is a fraudulent signal based on information contained in the second signal and other signals input to the communication network.

[0009] In any of the unauthorized signal detection devices described above, the measurement section may detect, as the time interval between the plurality of signals, the time interval between the timings at which input of each of the plurality of signals is completed.

[0010] In any of the unauthorized signal detection devices described above, the measurement section may detect, as the time interval between the plurality of signals, the time interval between timings at which input of each of the plurality of signals starts.

[0011] A third aspect of the present invention provides an unauthorized signal detection device that detects the input of an unauthorized signal into a communication network in which signals are expected to be input at a predetermined cycle. The unauthorized signal detection device includes a measurement unit that measures the time interval between the timing at which each of a plurality of signals input into the communication network is completed, and a determination unit that determines that a contention has occurred when transmitting the second signal if the time interval between a first signal and a second signal that should be transmitted at the cycle is longer than the cycle and the interval between the signal immediately preceding the second signal and the second signal is equal to or shorter than the predetermined interval, and determines that the second signal is an arbitrated normal signal.

[0012] A fourth aspect of the present invention provides an unauthorized signal detection device. The unauthorized signal detection device detects input of an unauthorized signal into a communication network where signals are expected to be input at a predetermined cycle. The unauthorized signal detection device includes: a measurement unit that measures the time interval between the timing at which each of a plurality of signals input into the communication network is completed; and a determination unit that determines that a contention has occurred when transmitting the second signal if the time interval between a first signal and a second signal that should be transmitted at the cycle is longer than the cycle and the time interval between the signal immediately preceding the second signal and the second signal is equal to or greater than a first threshold and equal to or less than a second threshold, the first threshold being determined based on the signal length of the second signal, and determines that the second signal is an arbitrated normal signal.

[0013] In a fifth aspect of the present invention, there is provided a vehicle, the vehicle including any one of the unauthorized signal detection devices described above.

[0014] A sixth aspect of the present invention provides an unauthorized signal detection method for detecting input of an unauthorized signal into a communication network in which signals are expected to be input at a predetermined cycle. The unauthorized signal detection method includes the steps of: measuring, in time series, time intervals between a plurality of consecutive signals input into the communication network; and, when the time interval between a first signal and a second signal that should be transmitted at the cycle is longer than the cycle and the signal interval between the second signal and the signal input immediately before is equal to or shorter than the predetermined interval, determining that a contention has occurred when transmitting the second signal and determining that the second signal is an arbitrated normal signal.

[0015] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also constitute inventions. [Brief explanation of the drawings]

[0016] [Figure 1] 1 conceptually illustrates a system configuration of a vehicle 10 in one embodiment. [Figure 2] 2 is a block diagram illustrating a schematic functional configuration of an ECU 100. FIG. [Figure 3] Illustrates a state in which signal 330 is delayed from its periodic input timing due to contention with other signals. [Figure 4] Illustrates a state in which signal 430 is delayed from its periodic input timing without contention with other signals. [Figure 5] 10 is a flowchart illustrating an improper signal detection method executed by the ECU 110. [Figure 6] An example of a computer 2000 is shown. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0018] 1 conceptually illustrates a system configuration of a vehicle 10 according to an embodiment. The vehicle 10 includes a system 20. The system 20 includes a plurality of ECUs (electronic control units) including an ECU 100, an ECU 110, an ECU 111, an ECU 120, and an ECU 121. The ECUs included in the vehicle 10 include ECUs for controlling devices that directly affect the running of the vehicle 10, such as an engine, a transmission, and a steering device. The ECUs included in the vehicle 10 include ECUs for controlling devices that do not directly affect the running of the vehicle 10, such as an air conditioner and a navigation device. The ECUs 100, the ECU 110, the ECU 111, the ECU 120, and the ECU 121 are examples of in-vehicle devices.

[0019] The ECUs provided in the vehicle 10 communicate with each other via controller area network (CAN) communication. The ECUs provided in the vehicle 10 are connected to each other so that they can communicate with each other via multiple CAN communication networks 180. The ECU 100 functions as a gateway that relays communication between the multiple CAN communication networks 180. The CAN communication network 180 is an example of a communication network in which a signal is expected to be input at a predetermined period. The ECU 100 has a function of detecting that an unauthorized signal has been input to the CAN communication network 180.

[0020] 2 is a block diagram showing a schematic functional configuration of the ECU 100. The ECU 100 includes a processing unit 200 and a storage unit 280. The ECU 100 performs processing to determine whether or not a so-called spoofing attack has occurred, in which a third party transmits an unauthorized signal to the CAN communication network 180 while masquerading as an ECU included in the vehicle 10.

[0021] The processing unit 200 may be implemented by a processor such as a CPU that performs arithmetic processing. The storage unit 280 may include a non-volatile storage medium such as a flash memory, or a volatile storage medium such as a random access memory. The ECU 100 may be configured to include a computer. The ECU 100 executes various controls by the processing unit 200 operating in accordance with programs stored in the non-volatile storage medium.

[0022] The processing unit 200 includes a measurement unit 210 and a determination unit 220. The measurement unit 210 measures the time intervals between multiple consecutive signals input to the CAN communication network 180 in chronological order. In this embodiment, the predetermined period may be referred to as a "set period." If the time interval between a first signal and a second signal to be transmitted at the set period is longer than the set period and the signal interval between the second signal and the signal input immediately before is equal to or shorter than the predetermined interval, the determination unit 220 determines that a conflict has occurred when transmitting the second signal and determines the second signal to be an arbitrated normal signal. This allows a signal delayed due to a conflict with another signal to be considered a normal signal. Therefore, when performing processing to consider a signal whose time interval between signals falls within a predetermined time range as a normal signal, the time range can be narrowed. This reduces the possibility of erroneously recognizing an incorrect signal as a normal signal.

[0023] The determination unit 220 may determine that contention has occurred when the time interval between the first signal and the second signal to be transmitted at a set period is longer than the set period, and the difference between the reception timing determined from the input timing and signal length of the signal immediately preceding the second signal and the input timing of the second signal is a predetermined minimum time interval that should be left between successive signals. The predetermined minimum time interval that should be left between successive signals is an ITM (Intermission) time.

[0024] The determination unit 220 may determine that the second signal is not normal if the time interval between the first signal and the second signal is longer than a set period and the signal length between the second signal and the signal input immediately before is shorter than a predetermined length. The determination unit 220 may then determine whether the second signal is an invalid signal based on information contained in the second signal and / or other signals input to the CAN communication network 180. For example, the determination unit 220 may determine whether the second signal can be considered a signal delayed due to contention based on the signal length contained in the signal's header information. This allows for more accurate determination of whether the second signal is an invalid signal. That is, when detecting timing based on the rear end of each signal (the timing at which the signal is completely received), the determination unit 220 determines whether the second signal is pushed out of range in relation to the first signal based on its own signal length information contained in the header of the second signal. For more accurate determination, the header information of the first signal, etc., can be used to determine whether the second signal is a normal signal pushed out of range due to the relationship between the first and second signals, or an abnormal signal that exists outside the range due to other factors.

[0025] As another method for determining whether a contention has occurred, the determination unit 220 may determine that a contention has occurred when transmitting the second signal if the time interval between the first signal and the second signal, which are to be transmitted at a set period, is longer than the set period and the time interval between the signal immediately preceding the second signal and the second signal is equal to or greater than a first threshold and equal to or less than a second threshold. For example, the second threshold may be a value determined from the sum of a predetermined minimum time interval (e.g., the ITM time) to be provided between successive signals and the signal length. The first threshold may be a value determined from the signal length. Thus, the determination unit 220 may determine that a contention has occurred when the difference between the reception timing, determined from the input timing and signal length of the signal immediately preceding the second signal, and the input timing of the second signal is equal to the predetermined minimum time interval to be provided between successive signals.

[0026] The determination unit 220 may determine that the second signal is not a normal signal if the time interval between the first signal and the second signal is longer than a set period and the time interval between the reception timing of the signal immediately preceding the second signal and the input timing of the second signal exceeds a second threshold, and may determine whether or not the second signal is an illegal signal based on information included in the second signal and other signals input to the CAN communication network 180. For example, the determination unit 220 may determine whether or not the second signal can be considered a signal delayed due to contention based on the signal length included in the signal's header information. This allows for more accurate determination of whether or not the signal is illegal.

[0027] The measuring section 210 may detect the time interval between the timings at which each of the plurality of signals starts being input as the time interval between the plurality of signals. When the time interval between the plurality of signals is determined as the timing at which the signal input starts, the determining section 220 may determine whether or not contention has occurred by taking into account the signal length of the signal immediately preceding the second signal.

[0028] The measuring unit 210 may detect the time interval between the timings at which input of each of the multiple signals is completed as the time interval between the multiple signals. In this case, the determining unit 220 may determine that a contention has occurred when transmitting the second signal if the time interval between the first signal and the second signal that should be transmitted at a set period is longer than the set period and the time interval between the signal immediately preceding the second signal and the second signal is equal to or shorter than a predetermined interval, and may determine that the second signal is an arbitrated normal signal. As another method for determining whether a contention has occurred, the determining unit 220 may determine that a contention has occurred when transmitting the second signal if the time interval between the first signal and the second signal that should be transmitted at a set period is longer than the set period and the time interval between the signal immediately preceding the second signal and the second signal is equal to or greater than a first threshold and equal to or smaller than a second threshold determined based on the signal length of the second signal. When the signal input completion timing is determined as the time interval between the multiple signals, the determining unit 220 may determine whether a contention has occurred by taking into account the signal length of the second signal. By adopting a configuration in which the timing of signal input completion is the time interval between multiple signals, there is no need to obtain the signal length from the header information of the previous signal to determine whether a conflict has occurred when transmitting the second signal, and the determination can be made by taking into account the signal length from the header information of the second signal itself.

[0029] 3 is a schematic diagram illustrating a state in which signal 330 is delayed from its periodic input timing due to contention with other signals. In FIG. 3, signals 310, 320, and 330 are signals that are input consecutively to CAN communication network 180. In this embodiment, signals transmitted through CAN communication network 180 may not be shown on a fixed time scale for ease of understanding.

[0030] Signal 310 is a signal that begins being input to CAN communication network 180 at time t1 and ends being input to CAN communication network 180 at time t2. Signal 320 is a signal that begins being input to CAN communication network 180 at time t3 and ends being input to CAN communication network 180 at time t5. Signal 320 is a signal that begins being input to CAN communication network 180 at time t6 and ends being input to CAN communication network 180 at time t7.

[0031] 3, signals 310 and 330 are signals belonging to a group of signals input to CAN communication network 180 at a predetermined cycle. Signals 310 and 330 are assumed to have the same CAN ID. Signal 330 is a signal that is delayed due to contention with signal 320. In this embodiment, the CAN ID of signal 320 is assumed to be different from the CAN IDs of signals 310 and 330, and the fraudulent signal detection process executed by ECU 110 will be described. However, similar processing can be applied even when the CAN ID of signal 320 is the same as the CAN IDs of signals 310 and 330.

[0032] For example, signal 330 starts being input to the CAN communication network 180 at the same time as signal 320, resulting in a communication conflict. As a result, signal 330 starts being input to the CAN communication network 180 at time t5, after input of signal 320 to the CAN communication network 180 has ended. In another example, signal 330 is a signal that should start being input during the period in which signal 320 is input to the CAN communication network 180, and waits for input of signal 320 to end and the bus to enter an idle state, and starts being input to the CAN communication network 180 after time t5. When signal 330 is input to the CAN communication network 180, the bus enters an idle state after the end of an ITM (Intermission) for 3 bits after input of the data frame of signal 320 to the CAN communication network 180 has ended. Therefore, signal 330, which has competed with signal 320, may start being input to the CAN communication network 180 at time t6, after the time from time t5 until the ITM ends. The time interval corresponding to ITM is an example of a predetermined minimum time interval that should be provided between successive signals.

[0033] Therefore, when the time interval between time t6 and time t3 matches the sum of the signal length and ITM of signal 320, determination unit 220 can determine that signal 330 has been delayed due to contention with signal 320. Therefore, determination unit 220 determines that signal 330 is a normal signal.

[0034] In this way, the judgment unit 220 can judge that the signal 330 is a normal signal when the interval between time t5 and time t6 calculated from the timing at which the input of the signal 320 to the CAN communication network 180 began and the signal length of the signal 320 matches the ITM.

[0035] Here, when the signal length of signal 320 is longer than a predetermined length, the determination unit 220 may determine that signal 330 has been delayed due to contention with signal 320, and may determine that signal 330 is a normal signal. In this way, the determination unit 220 may determine that signal 330 has been delayed due to contention with signal 320 when the signal length of signal 320 immediately preceding signal 330 is longer. Alternatively, the determination unit 220 may determine that signal 330 has been delayed due to contention with signal 320 when the time interval between time t6 and time t3 is equal to or greater than the sum of the signal length and the ITM and equal to or less than the sum of the signal length, the ITM, and a predetermined margin. Alternatively, the determination unit 220 may determine that signal 330 has been delayed due to contention with signal 320 when the time interval between time t6 and time t3 is equal to or greater than the signal length and equal to or less than the sum of the signal length, the ITM, and a predetermined margin.

[0036] 4 shows a schematic diagram of a state in which signal 430 is delayed from its periodic input timing without conflict with other signals. Assume that signals 310 and 430 contain the same CAN ID. Unlike in FIG. 3, signal 430 is a delayed signal without conflict with signal 320.

[0037] 4, signal 430 starts being input to CAN communication network 180 at time t9, which is after time t6. Because the time interval between time t9 and time t3 is longer than the sum of the signal length of signal 320 and the ITM, determination unit 220 can determine that signal 430 has been delayed without being due to contention with signal 320. Therefore, determination unit 220 determines that signal 430 is an invalid signal.

[0038] In other words, the judgment unit 220 can judge that the signal 330 is a normal signal if the interval between time t5 and time t9 calculated from the timing at which the input of the signal 320 to the CAN communication network 180 began and the signal length of the signal 320 is longer than ITM.

[0039] In the examples of FIGS. 3 and 4 , the measurement unit 210 mainly measures the time interval between the start times of signal input to the CAN communication network 180 as the time interval between successive signals. However, the measurement unit 210 may also measure the time interval between the end times of signal input to the CAN communication network 180 as the time interval between successive signals. For example, in the example shown in FIG. 3 , the determination unit 220 may determine that the signal 330 was delayed due to contention with the signal 320 because the time interval between time t7 and time t5 is equal to the sum of the signal length and ITM of the signal 330. As a result, the determination unit 220 may determine that the signal 330 is normal. In the example shown in FIG. 4 , the determination unit 220 may determine that the signal 330 was delayed not due to contention with the signal 320 because the time interval between time t10 and time t5 is longer than the sum of the signal length and ITM of the signal 320. Therefore, the determining section 220 may determine that the signal 430 is an invalid signal.

[0040] 5 is a flowchart illustrating an improper signal detection method executed by the ECU 110. The process of the flowchart in FIG. 5 can be executed each time a signal is detected on the CAN communication network 180.

[0041] When a signal is detected, in S502, the measurement unit 210 measures the time interval between successive signals. As described above, the time interval may be calculated from the time when the successive signals are input, or may be calculated from the time when the input of the successive signals ends.

[0042] In S504, the determination unit 220 determines whether or not a signal that should be periodically input to the CAN communication network 180 is delayed from the input time predicted from the period, based on the time interval measured by the measurement unit 210. For example, in FIG. 3, the determination unit 220 may determine whether or not the time interval between the signal 310 and the signal 330 is longer than the time calculated based on the period.

[0043] If it is determined in S504 that the signal to be periodically input to CAN communication network 180 is not delayed from the input time predicted from the period, the process proceeds to S508. On the other hand, if it is determined in S504 that the signal to be periodically input to CAN communication network 180 is delayed from the input time predicted from the period, the process proceeds to S506.

[0044] In S506, the determination unit 220 determines whether a signal that should be periodically input to the CAN communication network 180 has been delayed due to contention. For example, as described with reference to FIGS. 3 and 4 , the determination unit 220 determines whether a signal that should be periodically input has been delayed due to contention based on the time interval between successive signals, the signal length, and the time corresponding to the output of the ITM. If it is determined that the signal that should be periodically input has been delayed due to contention, in S508, the determination unit 220 determines that the delayed signal is a normal signal. On the other hand, if it is determined that the signal that should be periodically input has not been delayed due to contention, in S510, the determination unit 220 determines that the delayed signal is an invalid signal. Here, the determination unit 220 may determine whether a signal has been delayed due to contention with another signal during transmission based on information included in the header or data field of the signal to be determined and / or the signal input to the CAN communication network 180 before the signal to be determined.

[0045] As described above, according to the system 20, even if a signal that should be periodically input to the CAN communication network 180 is input to the CAN communication network 180 with a delay, if it is determined that the signal is delayed due to communication arbitration or bus idle waiting, the signal can be determined to be a normal signal. This reduces the possibility of erroneously determining that a signal delayed simply due to communication arbitration or bus idle waiting is an invalid signal. In addition, a signal delayed without being due to communication arbitration or bus idle waiting can be determined to be an invalid signal.

[0046] In the embodiment described above, the ECU 110 performs the process of detecting an illegal signal. However, it is also possible to adopt a configuration in which another ECU, including the ECU 100, performs the process of detecting an illegal signal.

[0047] 6 shows an example of a computer 2000 in which multiple embodiments of the present invention may be embodied in whole or in part. A program installed on the computer 2000 may cause the computer 2000 to function as a system or each part of a system, such as the system 20 according to an embodiment, or an apparatus or each part of the apparatus, such as the ECU 110, to perform operations associated with the system or each part of the system or the apparatus or each part of the apparatus, and / or to perform a process or steps of the process according to an embodiment. Such a program may be executed by the CPU 2012 to cause the computer 2000 to perform specific operations associated with some or all of the processing procedures and blocks of the block diagrams described herein.

[0048] The computer 2000 according to this embodiment includes a CPU 2012 and a RAM 2014, which are interconnected by a host controller 2010. The computer 2000 also includes a ROM 2026, a flash memory 2024, a communication interface 2022, and an input / output chip 2040. The ROM 2026, the flash memory 2024, the communication interface 2022, and the input / output chip 2040 are connected to the host controller 2010 via the input / output controller 2020.

[0049] The CPU 2012 operates according to programs stored in the ROM 2026 and RAM 2014, thereby controlling each unit.

[0050] The communication interface 2022 communicates with other electronic devices via a network. The flash memory 2024 stores programs and data used by the CPU 2012 in the computer 2000. The ROM 2026 stores a boot program and the like executed by the computer 2000 upon activation, and / or programs dependent on the hardware of the computer 2000. The input / output chip 2040 may also connect various input / output units such as a keyboard, mouse, and monitor to the input / output controller 2020 via input / output ports such as a serial port, a parallel port, a keyboard port, a mouse port, a monitor port, a USB port, an HDMI (registered trademark) port, etc.

[0051] The programs are provided via a computer-readable storage medium such as a CD-ROM, a DVD-ROM, or a memory card, or via a network. The RAM 2014, the ROM 2026, or the flash memory 2024 are examples of computer-readable storage media. The programs are installed in the flash memory 2024, the RAM 2014, or the ROM 2026 and executed by the CPU 2012. Information processing described in these programs is read by the computer 2000, and causes cooperation between the programs and the various types of hardware resources described above. An apparatus or a method may be configured by implementing operations or processing of information in accordance with the use of the computer 2000.

[0052] For example, when communication is performed between the computer 2000 and an external device, the CPU 2012 may execute a communication program loaded into the RAM 2014 and instruct the communication interface 2022 to perform communication processing based on the processing described in the communication program. Under the control of the CPU 2012, the communication interface 2022 reads transmission data stored in a transmission buffer processing area provided in a recording medium such as the RAM 2014 or flash memory 2024, transmits the read transmission data to a network, and writes received data received from the network to a reception buffer processing area or the like provided on the recording medium.

[0053] The CPU 2012 may also cause all or a necessary portion of a file or database stored on a recording medium such as the flash memory 2024 to be read into the RAM 2014, and perform various types of processing on the data on the RAM 2014. The CPU 2012 then writes the processed data back to the recording medium.

[0054] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and subjected to information processing. The CPU 2012 may perform various types of processing on data read from the RAM 2014, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described herein and specified by the instruction sequences of the programs, and write the results back to the RAM 2014. The CPU 2012 may also search for information in a file, database, etc. on the recording medium. For example, if multiple entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored on the recording medium, the CPU 2012 may search for an entry that matches a condition specified by the attribute value of the first attribute from among the multiple entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0055] The above-described programs or software modules may be stored in a computer-readable storage medium on or near the computer 2000. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as the computer-readable storage medium. The programs stored in the computer-readable storage medium may be provided to the computer 2000 via a network.

[0056] A program installed in computer 2000 and causing computer 2000 to function as ECU 110 may act on CPU 2012 or the like to cause computer 2000 to function as each unit of ECU 110. When the information processing described in these programs is read into computer 2000, it functions as each unit of ECU 110, which is a specific means formed by the software and the various hardware resources described above working together. These specific means then perform calculations or processing of information according to the intended use of computer 2000 in this embodiment, thereby constructing a specific ECU 110 according to the intended use.

[0057] Various embodiments have been described with reference to block diagrams. In the block diagrams, each block may represent (1) a stage of a process where an operation is performed or (2) a portion of an apparatus responsible for performing the operation. Particular stages and portions may be implemented by dedicated circuitry, programmable circuitry provided with computer-readable instructions stored on a computer-readable storage medium, and / or a processor provided with computer-readable instructions stored on a computer-readable storage medium. Dedicated circuitry may include digital and / or analog hardware circuitry, and may include integrated circuits (ICs) and / or discrete circuits. Programmable circuitry may include reconfigurable hardware circuitry including logical AND, logical OR, logical XOR, logical NAND, logical NOR, and other logic operations, flip-flops, registers, memory elements such as field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), and the like.

[0058] A computer-readable storage medium may include any tangible device capable of storing instructions that are executed by an appropriate device, such that the computer-readable storage medium with instructions stored thereon constitutes at least a portion of an article of manufacture containing instructions that can be executed to provide means for performing the operations specified in a process or block diagram. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disc (DVD), Blu-ray disc, memory stick, integrated circuit card, etc.

[0059] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, JAVA®, C++, etc., and conventional procedural programming languages ​​such as the “C” programming language or similar programming languages.

[0060] The computer-readable instructions may be provided to a processor or programmable circuitry of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, either locally or over a wide-area network (WAN) such as a local area network (LAN), the Internet, etc., and executed to provide means for performing the operations specified in the process steps or block diagrams described. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc.

[0061] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0062] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0063] 10 vehicles 20 Systems 100 ECU 110 ECU 111 ECU 120 ECU 121 ECU 180 CAN communication network 200 Processing section 210 Measurement Unit 220 Judgment section 280 Storage section 2000 Computer 2010 Host Controller 2012 CPU 2014 RAM 2020 Input / Output Controller 2022 Communication Interface 2024 flash memory 2026 ROM 2040 Input / Output Chip

Claims

1. 1. An unauthorized signal detection device that detects an unauthorized signal being input into a communication network in which a signal is expected to be input at a predetermined period, comprising: a measuring unit that measures the time intervals between a plurality of successive signals input to the communication network in time series; a determination unit that determines that a contention has occurred when transmitting the second signal, and determines that the second signal is an arbitrated normal signal, when a time interval between a first signal and a second signal that should be transmitted at the period is longer than the period and a signal interval between the second signal and a signal input immediately before is equal to or shorter than a predetermined interval; Equipped with The determination unit determines that the contention has occurred when the time interval between the first signal and the second signal to be transmitted in the cycle is longer than the cycle, and the difference between the reception timing determined from the input timing and signal length of the signal immediately preceding the second signal and the input timing of the second signal is a predetermined minimum time interval that should be left between successive signals. Rogue signal detection device.

2. 1. An unauthorized signal detection device that detects an unauthorized signal being input into a communication network in which a signal is expected to be input at a predetermined period, comprising: a measuring unit that measures the time intervals between a plurality of successive signals input to the communication network in time series; a determination unit that determines that a contention has occurred when transmitting the second signal and determines that the second signal is an arbitrated normal signal when a time interval between a first signal and a second signal to be transmitted at the period is longer than the period and a time interval between the signal immediately preceding the second signal and the second signal is equal to or greater than a first threshold and equal to or less than a second threshold; An unauthorized signal detection device comprising:

3. The determination unit determines that the contention has occurred when the time interval between the first signal and the second signal to be transmitted in the cycle is longer than the cycle, and the difference between the input timing of the second signal, which is determined from the input timing and signal length of the signal immediately before the second signal, is a predetermined minimum time interval that should be left between successive signals.

3. The fraudulent signal detection device according to claim 2.

4. 1. An unauthorized signal detection device that detects an unauthorized signal being input into a communication network in which a signal is expected to be input at a predetermined period, comprising: a measuring unit that measures the time intervals between a plurality of successive signals input to the communication network in time series; a determination unit that determines that a contention has occurred when transmitting the second signal, and determines that the second signal is an arbitrated normal signal, when a time interval between a first signal and a second signal that should be transmitted at the period is longer than the period and a signal interval between the second signal and a signal input immediately before is equal to or shorter than a predetermined interval; Equipped with The determination unit determines that the second signal is not a normal signal when the time interval between the first signal and the second signal is longer than the period and the length of the signal between the second signal and the signal input immediately before is shorter than a predetermined length, and determines whether the second signal is an invalid signal based on information included in the second signal and / or other signals input to the communication network. Rogue signal detection device.

5. The determination unit determines that the second signal is not a normal signal when the time interval between the first signal and the second signal is longer than the period and the time interval between the reception timing of a signal immediately before the second signal and the input timing of the second signal exceeds the second threshold, and determines whether the second signal is an unauthorized signal based on information included in the second signal and / or other signals input to the communication network.

3. The fraudulent signal detection device according to claim 2.

6. The measurement unit detects a time interval between timings at which input of each of the plurality of signals is completed as a time interval between the plurality of signals.

3. The fraudulent signal detection device according to claim 2.

7. The measurement unit detects a time interval between timings at which input of each of the plurality of signals starts as a time interval between the plurality of signals.

3. The fraudulent signal detection device according to claim 2.

8. 1. An unauthorized signal detection device that detects an unauthorized signal being input into a communication network in which a signal is expected to be input at a predetermined period, comprising: a measuring unit that measures a time interval between timings at which input of each of a plurality of signals to the communication network is completed; a determination unit that determines that a contention has occurred when transmitting the second signal and determines that the second signal is an arbitrated normal signal, when a time interval between a first signal and a second signal that should be transmitted at the period is longer than the period and a time interval between the signal immediately preceding the second signal and the second signal is equal to or greater than a first threshold and equal to or less than a second threshold determined based on a signal length of the second signal; An unauthorized signal detection device comprising:

9. A vehicle equipped with the unauthorized signal detection device according to claim 1 or 2.

10. 1. A method for detecting an unauthorized signal input into a communication network in which a signal is expected to be input at a predetermined period, comprising: a step in which a measurement unit included in the unauthorized signal detection device measures time intervals between a plurality of consecutive signals input to the communication network in a time series manner; a determining step in which a determining unit included in the unauthorized signal detection device determines that a conflict has occurred when transmitting the second signal, and determines that the second signal is an arbitrated normal signal, when a time interval between a first signal and a second signal to be transmitted at the period is longer than the period and a signal interval between the second signal and a signal input immediately before is equal to or shorter than a predetermined interval; Equipped with The determination step determines that the contention has occurred when the time interval between the first signal and the second signal to be transmitted in the period is longer than the period, and the difference between the reception timing of the second signal, determined from the input timing and signal length of the signal immediately preceding the second signal, and the input timing of the second signal is a predetermined minimum time interval that should be left between successive signals. False signal detection methods.

11. 1. A method for detecting an unauthorized signal input into a communication network in which a signal is expected to be input at a predetermined period, comprising: a step in which a measurement unit included in the unauthorized signal detection device measures time intervals between a plurality of consecutive signals input to the communication network in a time series manner; a determination unit included in the unauthorized signal detection device determining that a contention has occurred when transmitting the second signal when a time interval between a first signal and a second signal to be transmitted at the period is longer than the period and a time interval between a signal immediately preceding the second signal and the second signal is equal to or greater than a first threshold value and equal to or less than a second threshold value, and determining that the second signal is an arbitrated normal signal; 1. A method for detecting an unauthorized signal, comprising:

12. 1. A method for detecting an unauthorized signal input into a communication network in which a signal is expected to be input at a predetermined period, comprising: a step in which a measurement unit included in the unauthorized signal detection device measures time intervals between a plurality of consecutive signals input to the communication network in a time series manner; a determining step in which a determining unit included in the unauthorized signal detection device determines that a conflict has occurred when transmitting the second signal, and determines that the second signal is an arbitrated normal signal, when a time interval between a first signal and a second signal to be transmitted at the period is longer than the period and a signal interval between the second signal and a signal input immediately before is equal to or shorter than a predetermined interval; Equipped with The determining step determines that the second signal is not a normal signal if the time interval between the first signal and the second signal is longer than the period and the length of the signal between the second signal and the immediately preceding signal is less than a predetermined length, and determines whether the second signal is an invalid signal based on information included in the second signal and / or other signals input to the communication network. False signal detection methods.

Images