Apparatus and method for differentiating relay / playback signals in smart keyless entry system

Abstract

A method of operating a smart keyless entry (PKE) system of a vehicle includes generating and transmitting a first signal including a first random number and a first timestamp value to a smart key, receiving a second signal including a second hash value and a second timestamp value from the smart key, generating a third timestamp value, and transmitting the third timestamp value to the smart key. Comparing a first difference between the second timestamp value and the first timestamp value with a first threshold value for determining whether a relay signal has occurred, comparing a second difference between the third timestamp value and the second timestamp value with a second threshold value for determining whether a relay signal and / or a playback signal has occurred, and comparing the first hash value based on the first timestamp with the second hash value to determine whether to allow the vehicle to open and close the door and start.

Description

Technical Field

[0001] The present disclosure relates to a passive keyless entry (PKE) system for a vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Keyless Entry (PKE) technology is designed to increase user convenience by enabling the user's smart key and the vehicle's PKE system to communicate, enabling the vehicle to be opened and / or started by verifying the proximity of the smart key to the vehicle without the driver having to directly operate the PKE device.

[0004] The vehicle and the smart key can communicate with each other using two different channel signals. For example, the vehicle can use a low frequency (LF) signal with a short range of two to three meters, and the smart key can use an ultra-high frequency (UHF) signal with a range of about 20 to 50 meters to remotely control the vehicle. The PKE system of the vehicle periodically sends an LF signal (for confirming the existence of the smart key and / or as a wake-up signal) to the surrounding of the vehicle, and the LF signal is received by the smart key, which responds to the received LF signal for wake-up and sends a UHF signal (for confirming the existence of the smart key) to the vehicle. In the case of confirming the existence of the smart key, the PKE system of the vehicle sends the LF signal including the query information back to the smart key, and the smart key sends a UHF signal including the response information in response to the query to the vehicle. If the received response information is verified, the PKE system of the vehicle performs vehicle control, such as switching doors, starting the vehicle, etc.

[0005] Such a PKE system may be vulnerable to relay attacks or replay attacks. In the case where the user's smart key and vehicle are far apart, a relay attack may occur when two signal repeaters are used to amplify and forward the signals from the vehicle and the smart key respectively. The replay attack strategy involves an attacker eavesdropping on and storing a valid signal when it is transmitted, and then transmitting the signal as if it were a legitimate smart key. Since a replay attack sends the original data in the same way it was originally sent and received, an attacker can use encrypted data for attacks even without decrypting it.

[0006] In such a relay attack or playback attack, the vehicle cannot determine whether the response signal sent by the smart key in response to the query actually comes from a legitimate smart key, causing the authentication process of the PKE system to fail. Summary of the invention

[0007] Embodiments of the present disclosure relate to an apparatus and method for distinguishing a relay signal from a playback signal in a keyless entry (PKE) system.

[0008] Embodiments of the present disclosure provide an apparatus and method for accurately distinguishing a normal signal from a relay / playback signal in a PKE system.

[0009] Embodiments of the present disclosure provide an apparatus and method for preventing a driver's vehicle from being stolen and items in the vehicle from being stolen and providing convenience to the driver.

[0010] The advantages of the embodiments of the present disclosure are not limited to those specifically described above, and the above advantages and other advantages that can be achieved by the embodiments of the present disclosure can be clearly understood by those skilled in the art from the following detailed description.

[0011] An embodiment of the present disclosure provides a method for distinguishing between a relay signal and a playback signal in a smart keyless entry (PKE) system, comprising: generating a first signal including a first random number and a first timestamp value and sending it to a smart key, receiving a second signal including a hash value and a second timestamp value from the smart key, generating a third timestamp value, comparing a difference between the second timestamp value and the first timestamp value with a first threshold, and determining that a relay signal has occurred when the difference between the second timestamp value and the first timestamp value is equal to or greater than the first threshold.

[0012] An embodiment of the present disclosure provides a device for distinguishing between a relay signal and a playback signal in a smart keyless entry (PKE) system, which includes a memory configured to store commands and a processor, the processor being configured to: generate a first signal including a first random number and a first timestamp value and send it to a smart key, receive a second signal including a hash value and a second timestamp value from the smart key, generate a third timestamp value, compare the difference between the second timestamp value and the first timestamp value with a first threshold, and when the difference between the second timestamp value and the first timestamp value is equal to or greater than the first threshold, determine that a relay signal has occurred. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figures 1A to 1C is a schematic diagram of an authentication process between a smart key and a PKE system according to an embodiment of the present disclosure.

[0014] Figure 2 is a block diagram of a smart key according to an embodiment of the present disclosure.

[0015] Figure 3 is a block diagram of a PKE system according to an embodiment of the present disclosure.

[0016] Figure 4 is a flowchart of operations of a smart key and a PKE system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, similar reference numerals may refer to similar elements even though these elements may be shown in different drawings. In addition, for the purpose of clarity and brevity, when it is considered that a detailed description of related known parts and functions may obscure the subject matter of the present disclosure, a detailed description thereof is not included in the following description of the embodiments.

[0018] Various ordinal numbers or letter codes, such as "first", "second", "A", "B", "(a)" and "(b)", etc., may be used only as prefixes to distinguish one component from another, but do not mean or imply the substance, order or sequence of the components. Throughout the specification, when a part "includes" or "comprises" a component, the part is intended to allow other components to be included as well, without excluding other components, unless otherwise stated. Terms such as "unit", "module", etc. may refer to a unit in which at least one function or operation is processed, and they may be implemented by hardware, software or a combination thereof.

[0019] Embodiments of the present disclosure relate to devices and methods for defending against relay and playback attacks when a car door is opened with a smart key. In this article, a smart key may refer to a PKE device carried by a user and linked to a PKE system, and may be a dedicated device for PKE services, such as a key fob, or a mobile device running a PKE application. Embodiments of the present disclosure may utilize hash values ​​and information about the time required to generate a hash for authentication between a PKE system and a smart key to distinguish relay / playback signals from legitimate signals. Embodiments of the present disclosure may support mutual authentication by using a key-based hash, and may support phased checking by dividing into processing intervals and verifying the time required for the related processing, rather than the total processing time.

[0020] Figures 1A to 1C is a schematic diagram of an authentication process between a smart key and a PKE system according to an embodiment of the present disclosure.

[0021] Figure 1A An example PKE system is shown.

[0022] The PKE system may be installed on a vehicle and may control access and activation, such as unlocking or starting the vehicle.

[0023] The PKE system of the vehicle can periodically send LF signals to the surrounding of the vehicle. The smart key that receives the LF signal can wake up and send a UHF (ultra-high frequency) signal to the PKE system of the vehicle as a response signal to the received LF signal.

[0024] When the smart key is confirmed to exist based on the UHF signal, the PKE system can send a LF signal including the query information back to the smart key, and then the smart key can send a UHF signal including the response information corresponding to the query to the vehicle's PKE system. When the received response information is correctly verified, the vehicle's PKE system can decide to authorize the door opening and closing and starting. In this example case, there will be no delay between the PKE system and the smart key.

[0025] Figure 1B Another example PKE system is shown.

[0026] Figure 1B An attack device is shown that can intercept LF signals at a short distance and perform amplification or frequency band conversion to extend the signal range of the LF signal. As a result, since the smart key cannot transmit the UHF signal to the PKE system at the correct time, the PKE system may have difficulty parsing the UHF signal and checking the time delay condition to determine whether the door opening and closing and starting are authorized.

[0027] Figure 1C Yet another example PKE system is shown.

[0028] A playback attack device can be used to retrieve and resend a previously received smart key signal at a later time. As a result, it may be difficult for the PKE system to parse the UHF signal and check the time delay condition to determine whether the door opening and closing and starting are authorized.

[0029] Figure 2 is a block diagram of a smart key 200 according to an embodiment of the present disclosure.

[0030] The smart key 200 according to at least one embodiment of the present disclosure may include a signal receiving unit 202 , a signal parsing unit 204 , a real-time clock handling unit 206 , a signal generating unit 208 , a signal sending unit 210 , a random number generating unit 212 , a hardware security module (HSM) 214 , and the like.

[0031] The signal receiving unit 202 may receive a LF signal transmitted by a PKE system. The PKE system may refer to a smart key system in a vehicle.

[0032] The signal parsing unit 204 can digitize the signal and extract the received visual data and random number data. When using encryption / decryption for communication, the HSM 214 can be used. The HSM 214 can be accommodated in the smart key 200 in the form of a chip and can prevent unauthorized physical access to the internal storage information.

[0033] The real-time clock processing unit 206 may generate time information by adjusting the time of the real-time clock built into the smart key 200 to the time of the received signal, and transmit the generated time information to the signal generating unit 208 .

[0034] The random number generation unit 212 may generate a random number and transmit the random number to the signal generation unit 208 .

[0035] The signal generation unit 208 can convert the data contained in the response data into a UHF signal using the random number generated by the random number generation unit 212 and the time information generated by the real-time clock handling unit 206 as a basis, and thereby generate a response UHF signal. HSM encryption can be applied to the response UHF signal.

[0036] The signal transmitting section 210 may transmit the response UHF signal from the signal generating section 208 to the PKE system.

[0037] Figure 3 is a block diagram of a PKE system 300 according to an embodiment of the present disclosure.

[0038] According to at least one embodiment of the present disclosure, the PKE system 300 may include a real-time clock handling unit 302, a random number generation unit 304, a storage unit 306, a signal generation unit 308, a signal sending unit 310, a signal receiving unit 312, a signal parsing unit 314, an authentication unit 316, a body control unit 318, an engine control unit 320, an HSM 322, and the like.

[0039] The real time clock handling part 302 may measure the current time and send it to the signal generating part 308 .

[0040] The random number generator 304 may generate a random number and transmit it to the signal generator 308. The random number generator 304 may use the HSM 322 when generating the random number.

[0041] The storage unit 306 may store the time measured by the real time clock handling unit 302 .

[0042] The signal generation section 308 may receive the random number generated by the random number generation section 304 and the time data measured by the real time clock handling section 302 to generate challenge data, and may convert the challenge data into a LF signal. The data may be encrypted by the HSM 322 before conversion.

[0043] The signal transmitting unit 310 may transmit the LF signal generated by the signal generating unit 308 to the smart key 200 .

[0044] The signal receiving unit 312 may receive a response UHF signal from the smart key 200. The response UHF signal may be referred to as a UHF signal or a response signal.

[0045] The signal parsing unit 314 may convert the response UHF signal into digital data during the decryption process, and may extract the visual data and random number data contained in the response signal. The signal parsing unit 314 may utilize the HSM 322 to perform the decryption process.

[0046] The authentication unit 316 can check the random number and the visual data, and according to the check result, can authorize the body control unit 318 and the engine control unit 320 to open and close the door (access) and start. The check result can be displayed on the liquid crystal display (LCD) of the system to inform the user.

[0047] The vehicle body control unit 318 can control the opening and closing of the vehicle doors according to the inspection result of the authentication unit 316 .

[0048] The engine control unit 320 may control the vehicle to start according to the inspection result of the authentication unit 316 .

[0049] Figure 4 is a flowchart of operations of a smart key and a PKE system according to an embodiment of the present disclosure.

[0050] In operation S402, the PKE system may wait for a period of time for the LF signal to be transmitted.

[0051] In operation S404, the PKE system may generate a seed random number (N A ) and store it in the storage unit.

[0052] In operation S406, the PKE system may use an internal real time clock (RTC) to check the current time (T A ) and store it in the storage unit.

[0053] In operation S410, the PKE system may generate a random number (N A ) and timestamp (T A ) and sends it to the outside. Before generating the LF signal, the PKE system can use the pre-shared symmetric key to selectively perform an HSM-based encryption operation in operation S408.

[0054] In operation S412 , the smart key may receive a challenge signal transmitted by the PKE.

[0055] In operation S414 , the smart key may decrypt the received challenge signal using the HSM.

[0056] In operation S416, the smart key may update the time of the real-time clock in the smart key to the timestamp value (T A ).

[0057] In operation S418, the smart key may store the random number (N B ).

[0058] In operation S420, the smart key may check the current time (T B ) and calculate N B The hash value (H B ). Calculate the hash value (H B ) can use a shared key (K S ). In an embodiment of the present disclosure, a shared key may be used for hash calculation, and a shared symmetric key may be used for encryption using an HSM.

[0059] In operation S424, the smart key may generate a time stamp including a current time stamp (T B ) and hash (H B ) before generating the UHF signal, in operation S422, the smart key may selectively perform an HSM-based encryption operation using a pre-shared symmetric key.

[0060] In operation S426 , the smart key may transmit the generated response signal (UHF signal) to the outside.

[0061] In operation S428 , the PKE system may receive a response signal from the smart key.

[0062] In operation S430, the PKE system may use the HSM to decrypt the received response signal.

[0063] In operation S432, the PKE system may determine the current time (T C ). In other words, the PKE system can generate a timestamp.

[0064] In operation S434, the PKE system may calculate |T B -T A |, which can represent the time required for the smart key to receive the query signal and send the response signal, and can determine |T B -T AIs it less than a predetermined threshold (Th 1 Operation S434 may be, for example, an operation for determining that a playback attack delay occurs.

[0065] If |T B -T A | is less than a set or predetermined threshold (Th 1 ), then in operation S436, the PKE system can calculate |T C -T B |, which can represent the time between the smart key sending the response signal and the PKE system receiving the response signal, and can determine |T C -T B |Is it less than a set or predetermined threshold (Th 2 Operation S436 may be, for example, an operation for determining a delay in the occurrence of a relay / replay attack.

[0066] If |T C -T B | is less than a set or predetermined threshold (Th 2 ), then in operation S438, the PKE system may convert the hash (H B ) and random number (N A )'s hash (H A ) for comparison.

[0067] The shared key that the PKE system and the smart key can share can be used to calculate H A .

[0068] In operation S440, if H B and H A If they are equal, the authentication is successful and the PKE system allows the door to be opened, closed and started.

[0069] However, if in operation S434, |T B -T A Greater than or equal to a set or predetermined threshold (Th 1 ), or in operation S436, |T C -T B Greater than or equal to a set or predetermined threshold (Th 2 ), or in operation S438, H B and H A If they are not equal, the authentication fails in operation S442, and the PKE system prohibits door opening and closing and startup.

[0070] The embodiments of the present disclosure can utilize time synchronization, signal processing time within the smart key, communication link delay time, etc. to perform attack detection, thereby shortening the time required to distinguish between legitimate signals and relay / playback signals.

[0071] The embodiments of the present disclosure can determine whether an attacking device is used and whether a signal is recovered, while ensuring the confidentiality of the signal.

[0072] The embodiments of the present disclosure can implement phased inspection through segmented comparison verification, such as Figure 4 Operations S434 to S438 are performed to prevent playback attacks and relay attacks.

[0073] Although the above-mentioned figures present the corresponding operations as being performed in sequence, they are only used to illustrate the technical ideas of the embodiments of the present disclosure. Therefore, without departing from the essence of the embodiments of the present disclosure, ordinary technicians in the relevant field can change the order of operations shown in the figures or perform one or more operations in parallel, and combine various modifications, additions and substitutions when practicing the embodiments of the present disclosure, so the operations in the figures are not limited to the time sequence shown.

[0074] Figure 4 The operations shown may be implemented as computer-readable code on a computer-readable recording medium. The computer-readable recording medium may include any type of recording device on which data readable by a computer system may be recorded. Examples of computer-readable recording media include non-transitory media such as ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. In addition, the computer-readable recording medium may be distributed in computer systems connected via a network, where the computer-readable code may be stored and executed in a distributed manner.

[0075] In addition, the components of the embodiments of the present disclosure can utilize integrated circuit structures, such as memory, processor, logic circuit, lookup table, etc. These integrated circuit structures can perform each function described herein under the control of one or more microprocessors or other control devices. In addition, the components of the embodiments of the present disclosure can be specifically implemented by a part of program or code, which includes one or more executable instructions for performing a specific logical function, and can be performed by one or more microprocessors or other control devices. The components of the embodiments of the present disclosure can include or be implemented by a central processing unit (CPU), a microprocessor, etc. that performs its corresponding function. The components of the embodiments of the present disclosure can store instructions executed by one or more processors in one or more memories.

[0076] The embodiments of the present disclosure can accurately distinguish relay signals in a PKE system.

[0077] The embodiments of the present disclosure can prevent the driver's vehicle from being stolen and the items in the vehicle from being stolen, and provide convenience for the driver.

[0078] The embodiments of the present disclosure can implement phased inspection through segmented comparison verification to accurately distinguish relay signals.

[0079] The embodiments of the present disclosure can accurately distinguish between relay signals and replay signals to defend against both relay attacks and replay attacks.

[0080] The advantages and functions of the embodiments of the present disclosure are not limited to the above advantages and functions, and other unmentioned advantages and functions can be clearly understood by those skilled in the art from the above description.

[0081] Although the exemplary embodiments of the present disclosure are described for illustrative purposes, it will be understood that those skilled in the art may make various modifications, additions and substitutions without departing from the concept and scope of the present disclosure. Therefore, for the sake of brevity and clarity, some exemplary embodiments of the present disclosure are described. The scope of the technical ideas of the embodiments of the present disclosure are not limited by the diagrams. Therefore, it will be understood by those skilled in the art that the scope of the present disclosure is not limited by the embodiments specifically described above, but is defined by the attached claims and their equivalents.

Claims

1. A method for operating a smart keyless entry (PKE) system of a vehicle, the method comprising the following steps: generating a first signal including a first random number and a first timestamp value; sending the first signal to a smart key; receiving a second signal including a second hash value and a second timestamp value from the smart key; comparing a first difference between the second timestamp value and the first timestamp value with a first threshold; as well as In response to the first difference between the second timestamp value and the first timestamp value being equal to or greater than the first threshold, it is determined that a relay signal has occurred.

2. The method according to claim 1, wherein: The first difference between the second timestamp value and the first timestamp value represents a first sum of a first time required for the smart key to receive the first signal from the PKE system and a second time required for the smart key to send the second signal to the PKE system.

3. The method according to claim 1, further comprising the steps of: upon receiving the second signal, generating a third timestamp value; as well as In response to the first difference between the second timestamp value and the first timestamp value being less than the first threshold, the second difference between the third timestamp value and the second timestamp value is compared with the second threshold, and in response to the second difference between the third timestamp value and the second timestamp value being equal to or greater than the second threshold, it is determined that one or both of the relay signal and the playback signal have occurred.

4. The method according to claim 3, wherein: The second difference between the third timestamp value and the second timestamp value represents a second sum of a second time required for the smart key to send the second signal to the PKE system and a third time required for the PKE system to receive the second signal.

5. The method according to claim 3, further comprising the steps of: Based on the first random number, generate a first hash value; In response to the second difference between the third timestamp value and the second timestamp value being less than the second threshold, the first hash value is compared with the second hash value included in the second signal, and in response to the first hash value based on the first random number being equal to the second hash value included in the second signal, the door opening and closing and starting of the vehicle are allowed.

6. The method according to claim 5, further comprising: In response to the first hash value based on the first random number being not equal to the second hash value included in the second signal, door opening and closing and starting of the vehicle are prohibited.

7. The method according to claim 1, wherein: The first signal comprises a low frequency signal, and the second signal comprises an ultra-high frequency signal.

8. A smart keyless entry PKE system for a vehicle, the system comprising: a non-transitory memory configured to store computer executable code; and A processor configured to execute the code, wherein the code includes instructions to cause the processor to: generating a first signal including a first random number and a first timestamp value, sending the first signal to the smart key, receiving a second signal including a second hash value and a second timestamp value from the smart key, upon receiving the second signal, generating a third timestamp value, comparing a first difference between the second timestamp value and the first timestamp value with a first threshold, and In response to the first difference between the second timestamp value and the first timestamp value being equal to or greater than the first threshold, it is determined that a relay signal has occurred.

9. The system according to claim 8, wherein: The first difference between the second timestamp value and the first timestamp value represents a first sum of a first time required for the smart key to receive the first signal from the PKE system and a second time required for the smart key to send the second signal to the PKE system.

10. The system according to claim 8, wherein: The code includes additional commands to cause the processor to: In response to the first difference between the second timestamp value and the first timestamp value being less than the first threshold, comparing a second difference between the third timestamp value and the second timestamp value with a second threshold, and In response to the second difference between the third timestamp value and the second timestamp value being equal to or greater than the second threshold, it is determined that one or both of the relay signal and the playback signal have occurred.

11. The system according to claim 10, wherein: The second difference between the third timestamp value and the second timestamp value represents a second sum of a second time required for the smart key to send the second signal to the PKE system and a third time required for the PKE system to receive the second signal.

12. The system according to claim 10, wherein: The code includes further instructions to cause the processor to: Based on the first random number, generating a first hash value, and In response to the second difference between the third timestamp value and the second timestamp value being less than the second threshold, the first hash value is compared with the second hash value included in the second signal, and in response to the first hash value being equal to the second hash value, door opening and closing and starting of the vehicle are allowed.

13. The system according to claim 12, wherein: The code includes a prohibition command, causing the processor to: in response to the first hash value not being equal to the second hash value, prohibit opening and closing doors and starting of the vehicle.

14. The system according to claim 8, wherein: The first signal comprises a low frequency signal, and the second signal comprises an ultra-high frequency signal.

15. A method for operating a smart key for a vehicle, the method comprising the following steps: receiving a first signal including a first random number and a first timestamp value from a smart keyless entry PKE system of the vehicle; generating a second random number and a second timestamp value; as well as sending a second signal including a second hash value and the second timestamp value to the PKE system, Wherein, the PKE system is configured to: generate a third timestamp value based on receiving the second signal; compare a first difference between the second timestamp value and the first timestamp value with a first threshold; and, in response to the first difference between the second timestamp value and the first timestamp value being equal to or greater than the first threshold, determine that a relay signal has occurred.

16. The method according to claim 15, wherein: The first difference between the second timestamp value and the first timestamp value represents a first sum of a first time required for the smart key to receive the first signal from the PKE system and a second time required for the smart key to send the second signal to the PKE system.

17. The method according to claim 15, wherein: The PKE system is also configured to: in response to the first difference between the second timestamp value and the first timestamp value being less than the first threshold, compare the second difference between the third timestamp value and the second timestamp value with the second threshold, and, in response to the second difference between the third timestamp value and the second timestamp value being equal to or greater than the second threshold, determine that one or both of the relay signal and the playback signal have occurred.

18. The method according to claim 17, wherein: The second difference between the third timestamp value and the second timestamp value represents a second sum of a second time required for the smart key to send the second signal to the PKE system and a third time required for the PKE system to receive the second signal.

19. The method according to claim 17, wherein: The PKE system is configured to: generate a first hash value based on the first random number; In response to the second difference between the third timestamp value and the second timestamp value being less than the second threshold, comparing the first hash value with the second hash value included in the second signal; And, in response to the first hash value being equal to the second hash value, door opening and closing and starting of the vehicle are permitted.

20. The method according to claim 19, wherein: The PKE system is further configured to: in response to the first hash value not being equal to the second hash value, prohibit door opening and closing and starting of the vehicle.

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