Signal transmission optimization method and system for intelligent card key and OBD module

Abstract

The embodiment of the invention provides a signal transmission optimization method and system for a smart card key and an OBD module. The method comprises the following steps: acquiring an encryption control instruction sent by a mobile terminal through a Bluetooth low energy consumption protocol; the encrypted control instruction is decrypted and verified through an OBD module installed on a vehicle to obtain an effective control instruction, and a low-frequency signal corresponding to the effective control instruction is generated; a low-frequency signal is converted into a radio-frequency signal by adopting a self-adaptive frequency hopping technology, and the radio-frequency signal is sent to an intelligent card key through an OBD module, so that the intelligent card key is triggered to receive and decode the radio-frequency signal, and corresponding vehicle control operation is executed; after the vehicle control operation is completed, feedback information returned by the intelligent card key through the high-frequency signal is obtained through the OBD module, and after the correctness of the feedback information is verified, the internal state of the vehicle is updated, and a final operation result is fed back to the mobile terminal. According to the technical scheme provided by the embodiment of the invention, the safety and reliability of remote vehicle control are ensured.

Description

Technical Field

[0001] This application relates to the field of signal transmission optimization technology between smart card keys and vehicle OBD modules, and particularly to a method and system for optimizing signal transmission between smart card keys and OBD modules. Background Technology

[0002] With the rapid development of vehicle-to-everything (V2X) and intelligent transportation systems, the demand for remote vehicle control functions is increasing. Users want to be able to send encrypted control commands via mobile terminals (such as smartphones or tablets) using the Bluetooth Low Energy protocol to remotely unlock or start their vehicles. To ensure the security and reliability of these commands, a system is needed that can efficiently process and verify encrypted control commands, while ensuring the integrity of the data and the authenticity of its source during command transmission.

[0003] Currently, various vehicle remote control systems exist on the market, which typically rely on a wireless connection between the mobile device and the vehicle to send control commands. Existing OBD modules can receive control commands from mobile terminals via Bluetooth, Wi-Fi, or other communication methods and perform preliminary verification of these commands using simple encryption methods. However, most existing systems lack sophisticated security measures for command decryption, verification, and signal conversion, making them vulnerable to man-in-the-middle attacks, replay attacks, and other forms of security threats.

[0004] Traditional encryption algorithms and authentication mechanisms may be insufficient to withstand the challenges of modern hacking techniques. For example, some systems employ only basic hash functions and symmetric encryption, which may compromise data integrity and weaken timestamp checks, allowing old commands to be reused. Furthermore, the signal conversion process from the OBD module to the smart card key is more susceptible to interference or eavesdropping if the frequency remains constant. Finally, the lack of an effective verification mechanism in the feedback verification stage may lead to the acceptance of false or tampered feedback, affecting the accuracy of vehicle internal status updates. Summary of the Invention

[0005] This application provides a method and system for optimizing signal transmission between a smart card key and an OBD module, in order to solve the problem of insufficient security and reliability in the transmission of vehicle control commands in the prior art.

[0006] In a first aspect, embodiments of this application provide a method for optimizing signal transmission between a smart card key and an OBD module, including: The encrypted control command sent by the mobile terminal via Bluetooth Low Energy protocol is obtained. The encrypted control command includes a serial number generated by the mobile terminal and vehicle identification information. The control command is a command used to control the unlocking or starting of the vehicle. The encrypted control command is decrypted and verified using an OBD module installed in the vehicle to obtain a valid control command, and a corresponding low-frequency signal is generated. The process of decrypting and verifying the encrypted control command includes: using a pre-shared secret key to execute an AES-256 symmetric encryption algorithm to decrypt the encrypted control command to obtain the original control command; applying an improved hash message authentication code algorithm to verify the data integrity of the original control command; checking the timestamp of the original control command; and using an elliptic curve cryptography-based authentication mechanism to confirm the authenticity of the source of the original control command. The low-frequency signal is used to transmit the valid control command. An adaptive frequency hopping technology is used to convert the low-frequency signal into a radio frequency signal and send it to the smart card key through the OBD module, so as to trigger the smart card key to receive and decode the radio frequency signal and execute the corresponding vehicle control operation; the smart card key executes the corresponding vehicle control operation, including converting the radio frequency signal into a high-frequency signal and sending it to the vehicle so that the vehicle executes the effective control command; After completing the vehicle control operation, the OBD module obtains the feedback information transmitted back by the smart card key using a high-frequency signal. After verifying the correctness of the feedback information, the vehicle's internal status is updated and the final operation result is fed back to the mobile terminal. The feedback information includes the operation result status, serial number, timestamp, status information of the smart card key, and a checksum calculated by SHA-3. The high-frequency signal is used to quickly transmit the feedback information and confirm its validity and completeness. The process by which the OBD module verifies the correctness of the feedback information includes: performing a verification process on the received high-frequency signal, wherein the verification process includes at least comparing the serial number, verifying the freshness of the timestamp, and checking the consistency of the checksum, to ensure the correctness of the feedback information.

[0007] Optionally, it also includes: The control commands transmitted between the mobile terminal and the OBD module are encrypted using an asymmetric RSA-OAEP padding scheme and a symmetric AES-GCM mode. A public-key cryptography-based authentication mechanism combined with a dynamic challenge-response protocol is used to ensure the secure communication between the OBD module and the smart card key. By employing anti-replay mechanisms and spectrum-spread-based anti-interference technology, stable communication between the OBD module and the smart card key is maintained even in the presence of strong interference sources. A dynamic frequency selection mechanism is implemented to automatically switch the signal frequency according to environmental interference. Combined with an automatic retransmission and confirmation mechanism, this ensures that the radio frequency signal can be sent to the smart card key and that the high-frequency signal sent by the smart card key can be successfully acquired.

[0008] Optionally, the step of decrypting and verifying the encrypted control command through an OBD module installed in the vehicle to obtain a valid control command and generating a low-frequency signal corresponding to the valid control command includes: The OBD module installed in the vehicle receives encrypted control commands from the mobile terminal, performs preliminary verification on the data packets carried by the encrypted control commands, including length and format verification, and executes the AES-256 symmetric encryption algorithm using a pre-shared secret key to decrypt the encrypted control commands and recover the original control commands. During the decryption process, an initialization vector is applied to ensure the one-time nature of each decryption and prevent the reuse of the same key stream. An improved hash message authentication code algorithm is applied to verify the data integrity of the original control command; If the original control command is confirmed to have data integrity, the OBD module compares the current time with the timestamp of the received encrypted control command to determine whether the encrypted control command has expired or is abnormally delayed. If there is no expiration or abnormal delay, an identity authentication mechanism based on elliptic curve cryptography is used. The OBD module uses the corresponding public key to verify the digital signature carried in the original control command to confirm that the original control command originated from the mobile terminal. The digital signature is generated by the mobile terminal using its private key. If it is confirmed that the original control command originates from the mobile terminal, the original control command is taken as a valid control command, and a corresponding low-frequency signal is generated; the low-frequency signal is used to transmit the valid control command to the smart card key, so that the smart card key triggers the corresponding vehicle control operation.

[0009] Optionally, the application of an improved hash message authentication code algorithm to verify the data integrity of the original control command includes: The latest version of the secret key is determined from the predefined secret key shared between the OBD module and the mobile terminal; The first message authentication code value is extracted from the data packet. A message body is constructed based on the first message authentication code value and the content contained in the data packet. The message body is consistent with the message body constructed by the mobile terminal and a unique session identifier is embedded. Using a randomized nonlinear transformation step, randomly generated salt values ​​are appended before and after the message body to generate a preprocessed message body. The OBD module then calculates the second message authentication code value based on the improved hash message authentication code algorithm, combined with the preprocessed message body and the latest version of the secret key. The first message authentication code value and the second message authentication code value are compared bit by bit. If they match completely, it is confirmed that the data packet carried by the original control command has not been tampered with during transmission and has data integrity. If they do not match completely, it is confirmed that the data packet carried by the original control command has been tampered with or damaged during transmission. The original control command is rejected and the corresponding security response mechanism is triggered.

[0010] Optionally, after completing the vehicle control operation, the step of obtaining feedback information transmitted back by the smart card key using a high-frequency signal through the OBD module, and after verifying the correctness of the feedback information, updating the vehicle's internal status and feeding back the final operation result to the mobile terminal, includes: Using a predefined receiving mechanism, the OBD module acquires the high-frequency signal sent by the smart card key and extracts feedback information from the high-frequency signal. The feedback information includes the operation result status, serial number, timestamp, status information of the smart card key, and a checksum calculated by SHA-3. Determine whether the serial number in the feedback information is consistent with the serial number carried in the radio frequency signal when the OBD module sends the radio frequency signal to the smart card key. If not, refuse to accept the feedback information. If so, the freshness of the timestamp is verified by comparing the time difference between the timestamp of the OBD module receiving the feedback information and the timestamp of the smart card key generating the feedback information. If the time difference is greater than the preset threshold, the feedback information is rejected. If the time difference is less than or equal to a preset threshold, the SHA-3 algorithm is applied to recalculate the checksum based on the feedback information, and the recalculated checksum is compared bit by bit with the checksum extracted from the feedback information to check whether the checksums are consistent; if not, the feedback information is rejected. If so, update the vehicle's internal status, record the latest vehicle unlock or start event, update the vehicle security log, and generate an updated vehicle internal status. Using Bluetooth Low Energy protocol, feed back the updated vehicle internal status and operation results to the mobile terminal so that the mobile terminal can generate and display the final operation result.

[0011] Optionally, the step of encrypting the control commands transmitted between the mobile terminal and the OBD module using the asymmetric RSA-OAEP padding scheme and the symmetric AES-GCM mode includes: using the asymmetric RSA-OAEP padding scheme, generating a one-time session key using the private key of the mobile terminal, and encrypting the one-time session key using the public key of the OBD module to generate an encrypted session key; using the symmetric AES-GCM mode, encrypting the control commands using the encrypted session key by the mobile terminal to generate encrypted control commands and simultaneously generating an authentication tag, and sending the encrypted control commands along with the authentication tag to the OBD module; The method of employing a public-key cryptography-based authentication mechanism combined with a dynamic challenge-response protocol to ensure secure communication between the OBD module and the smart card key includes: when the OBD module receives an encrypted control command, it decrypts the session key using its own private key, decrypts the encrypted control command using the decrypted session key, verifies the authentication tag, and after decryption and verification, the OBD module generates a random number as a challenge value and sends the challenge value to the smart card key. Upon receiving the challenge value, the smart card key signs or encrypts the challenge value using a pre-shared secret key or its own private key, and sends the processing result back to the OBD module. The OBD module then verifies the processing result returned by the smart card key. If the verification is successful, the smart card key's identity is confirmed as legitimate, and continued communication is allowed. An anti-replay mechanism is applied to maintain stable communication between the OBD module and the smart card key in the presence of strong interference sources. This includes: when the OBD module communicates with the smart card key, or when the mobile terminal communicates with the OBD module, the mobile terminal or the OBD module generates a serial number and includes this serial number in a control command. Upon receiving a corresponding signal, the OBD module or the smart card key checks whether the serial number already exists in the locally stored historical record. If not, it accepts the corresponding signal and updates the historical record; otherwise, it rejects the corresponding signal and confirms it as a replay attack. The corresponding signal includes encrypted control commands, low-frequency signals, or high-frequency signals. Anti-interference technology based on spectrum spread maintains stable communication between the OBD module and the smart card key in the presence of strong interference sources. It includes: direct sequence spread spectrum technology in anti-interference technology based on spectrum spread, which spreads the information contained in the signal to a preset bandwidth before sending the corresponding signal, and frequency hopping spread spectrum technology in anti-interference technology based on spectrum spread to switch different frequencies of the corresponding signal to avoid staying on the same interfered frequency and improve communication reliability. The implementation of the dynamic frequency selection mechanism automatically switches the signal frequency based on environmental interference conditions. Combined with an automatic retransmission and acknowledgment mechanism, it ensures that the radio frequency signal can be sent to the smart card key and that the high-frequency signal sent by the smart card key can be successfully acquired. This includes: The OBD module monitors the current wireless environment in real time, assesses the interference intensity on each frequency, and automatically selects the optimal frequency for transmitting radio frequency signals based on the monitoring results. Combined with an automatic retransmission mechanism, if the first transmission fails, the radio frequency signal is automatically retransmitted until successful. An acknowledgment mechanism is adopted: when the smart card key receives the radio frequency signal, it sends feedback information to the OBD module via a high-frequency signal to ensure that the OBD module knows that the radio frequency signal has been correctly received.

[0012] Optionally, the application of the improved hash message authentication code algorithm verifies the data integrity of the original control command, including: The latest version of the secret key is determined from the predefined secret key shared between the OBD module and the mobile terminal, according to a dynamic key rotation mechanism. ;in, ,in Indicates the current timestamp. It is the latest version of the secret key selected based on the timestamp; Extract the attached first message authentication code value from the data packet. The message body is constructed based on the first message authentication code value and the content contained in the data packet. The message body should be completely identical to the message body constructed by the mobile terminal, and should embed a unique session identifier (SID); wherein, the message body Where Data represents other content in the data packet. Indicates a connection operation; ,in It is a pre-generated session ID. It is the current timestamp. It is a function that combines a timestamp with a session ID; By employing a randomized nonlinear transformation step, randomly generated salt values ​​are appended before and after the message body to generate a preprocessed message body. ;in, ,in , , and These are functions used to generate the salt values ​​before and after the salt. It is a random number; The OBD module is based on an improved hash message authentication code algorithm, combined with a preprocessed message body. and the latest version of the secret key Calculate the second message authentication code value ;in, ,in It is a hash message authentication code function based on SHA-256. It is the SHA-256 hash function. It is a weighting coefficient representing the impact of message freshness; weighting coefficient Defined as: ,in It is the time difference between the current time and the message generation time. It is a predetermined time constant. It is a parameter that adjusts the rate of exponential decay to increase sensitivity to freshness; The first message authentication code value and the second message authentication code value Perform a character-by-character comparison; like If so, it is confirmed that the data packet carried by the original control command has not been tampered with during transmission and has data integrity; if If the original control command is confirmed to have been tampered with or damaged during transmission, the original control command will be rejected, and a corresponding security response mechanism will be triggered.

[0013] Secondly, embodiments of this application provide a signal transmission optimization system for a smart card key and an OBD module, comprising: The acquisition module is used to acquire encrypted control commands sent by the mobile terminal via Bluetooth Low Energy protocol. The encrypted control commands include a one-time session key generated by the mobile terminal and vehicle identification information. The control commands are commands used to control the unlocking or starting of the vehicle. A generation module is used to decrypt and verify the encrypted control command through an OBD module installed in the vehicle to obtain a valid control command, and to generate a low-frequency signal corresponding to the valid control command. The process of decrypting and verifying the encrypted control command includes: using a pre-shared secret key to execute an AES-256 symmetric encryption algorithm to decrypt the encrypted control command to obtain the original control command; applying an improved hash message authentication code algorithm to verify the data integrity of the original control command; checking the timestamp of the original control command; and using an elliptic curve cryptography-based authentication mechanism to confirm the authenticity of the source of the original control command. The low-frequency signal is used to transmit the valid control command. The execution module is used to convert the low-frequency signal into a radio frequency signal using adaptive frequency hopping technology and send it to the smart card key through the OBD module, so as to trigger the smart card key to receive and decode the radio frequency signal and execute the corresponding vehicle control operation. The processing module is used to obtain feedback information transmitted back by the smart card key using a high-frequency signal through the OBD module after completing the vehicle control operation, and after verifying the correctness of the feedback information, update the internal status of the vehicle and send the final operation result back to the mobile terminal; the feedback information includes the operation result status, serial number, timestamp, status information of the smart card key, and a checksum calculated by SHA-3; the high-frequency signal is used to quickly transmit the feedback information and confirm the validity and completeness of the feedback information; The process by which the OBD module verifies the correctness of the feedback information includes: performing a verification process on the received high-frequency signal, wherein the verification process includes at least comparing the serial number, verifying the freshness of the timestamp, and checking the consistency of the checksum, to ensure the correctness of the feedback information.

[0014] Thirdly, embodiments of this application provide a computing device, including a processing component and a storage component; the storage component stores one or more computer instructions; the one or more computer instructions are to be invoked and executed by the processing component to implement the signal transmission optimization method between a smart card key and an OBD module as described in the first aspect above.

[0015] Fourthly, embodiments of this application provide a computer storage medium storing a computer program, which, when executed by a computer, implements a signal transmission optimization method between a smart card key and an OBD module as described in the first aspect.

[0016] In this embodiment, an encrypted control command sent by a mobile terminal via Bluetooth Low Energy is obtained. The encrypted control command includes a serial number generated by the mobile terminal and vehicle identification information. The control command refers to an instruction used to control the unlocking or starting of the vehicle. An OBD module installed in the vehicle decrypts and verifies the encrypted control command to obtain a valid control command and generates a corresponding low-frequency signal for the valid control command. The process of decrypting and verifying the encrypted control command includes: using a pre-shared secret key to execute an AES-256 symmetric encryption algorithm to decrypt the encrypted control command to obtain the original control command, and applying an improved hash elimination algorithm. The authentication code algorithm verifies the data integrity of the original control command, checks the timestamp of the original control command, and confirms the authenticity of the source of the original control command using an identity authentication mechanism based on elliptic curve cryptography; the low-frequency signal is used to transmit the valid control command; an adaptive frequency hopping technology is used to convert the low-frequency signal into a radio frequency signal and send it to the smart card key through the OBD module to trigger the smart card key to receive and decode the radio frequency signal and execute the corresponding vehicle control operation; the smart card key executes the corresponding vehicle control operation by converting the radio frequency signal into a high-frequency signal and sending it to the vehicle so that the vehicle executes the valid control command; After completing the vehicle control operation, the OBD module obtains feedback information transmitted back by the smart card key using a high-frequency signal. After verifying the correctness of the feedback information, the internal status of the vehicle is updated and the final operation result is fed back to the mobile terminal. The feedback information includes the operation result status, serial number, timestamp, status information of the smart card key, and a checksum calculated by SHA-3. The high-frequency signal is used to quickly transmit the feedback information and confirm its validity and completeness. The process by which the OBD module verifies the correctness of the feedback information includes: performing a verification process on the received high-frequency signal, wherein the verification process includes at least comparing the serial number, verifying the freshness of the timestamp, and checking the consistency of the checksum to ensure the correctness of the feedback information.

[0017] The technical solution of this application has the following beneficial effects: This application employs the AES-256 symmetric encryption algorithm, an improved hash message authentication code algorithm, and an identity authentication mechanism based on elliptic curve cryptography to effectively prevent unauthorized access and data tampering, ensuring the authenticity and integrity of the control command source. Through rigorous decryption and verification operations, including timestamp checks and serial number comparisons, it ensures that only the latest and valid control commands can be executed, avoiding the risk of replay attacks. The introduction of adaptive frequency hopping technology not only improves the efficiency of low-frequency to radio-frequency signal conversion but also enhances the signal's anti-interference capability in complex electromagnetic environments, ensuring stable command transmission. High-frequency signals are used to achieve rapid feedback information transmission, and SHA-3 checksums ensure the validity and integrity of the feedback information, enabling the vehicle to update its internal status in a timely manner and provide accurate operation result feedback to the user terminal. The entire process is highly automated, reducing user waiting time and operation steps, while increasing the sense of security and trust in remotely controlling the vehicle, thus providing users with a more convenient and secure user experience.

[0018] Furthermore, this embodiment of the application also receives and preliminarily verifies the data packet of encrypted control command from the mobile terminal through the OBD module on the vehicle, including checks on length and format. After the preliminary verification is passed, the AES-256 symmetric encryption algorithm is used to decrypt the original control command using a pre-shared secret key and initialization vector to recover the original control command, and an improved hash message authentication code algorithm is applied to verify data integrity. Subsequently, the current time and the received timestamp are compared to determine whether the command has expired or is delayed. Then, an identity authentication mechanism based on elliptic curve cryptography is used to verify the authenticity of the digital signature confirmation source. Finally, the verified original control command is used as a valid control command to generate a low-frequency signal for transmission to the smart card key to trigger vehicle control operation.

[0019] The above methods enhance the security and reliability of the vehicle control system. Through multi-stage verification of encrypted control commands—from initial data packet validation to complex encryption and decryption processes, timestamp freshness checks, and elliptic curve cryptography-based authentication—it ensures that only genuine and up-to-date control commands are recognized as valid. Simultaneously, the AES-256 symmetric encryption algorithm combined with an initialization vector prevents duplicate attacks, while an improved hash message authentication code algorithm further guarantees the integrity and tamper-proof nature of commands during data transmission. This method not only strengthens the security barrier of remote vehicle control but also optimizes the signal conversion process between the smart card key and the OBD module, achieving stable and rapid command transmission and feedback, thereby improving the user experience and increasing user trust in the system's security.

[0020] These or other aspects of this application will become more apparent in the following description of the embodiments. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This application provides a flowchart illustrating a method for optimizing signal transmission between a smart card key and an OBD module. Figure 2 This application provides a schematic diagram illustrating the signal transmission between a smart card key and an OBD module. Figure 3 This invention provides a schematic diagram of the signal transmission optimization system for a smart card key and an OBD module. Figure 4 A schematic diagram of the structure of a computing device provided in this application is shown. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0024] In some of the processes described in the specification, claims, and accompanying drawings of this application, multiple operations appearing in a specific order are included. However, it should be clearly understood that these operations may not be executed in the order they appear herein, or may be executed in parallel. The operation numbers, such as 101, 102, etc., are merely used to distinguish different operations and do not themselves represent any execution order. Furthermore, these processes may include more or fewer operations, and these operations may be executed sequentially or in parallel. It should be noted that the descriptions such as "first," "second," etc., in this document are used to distinguish different messages, devices, modules, etc., and do not represent a chronological order, nor do they limit "first" and "second" to different types.

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Figure 1 This application provides a flowchart of a method for optimizing signal transmission between a smart card key and an OBD module, as shown in the embodiments of this application. Figure 1 As shown, the method includes: Step 101: Obtain the encrypted control command sent by the mobile terminal via Bluetooth Low Energy protocol; In this step, the encrypted control command includes a serial number generated by the mobile terminal and vehicle identification information. The control command refers to the command used to control the unlocking or starting of the vehicle. In practice, when users want to remotely control their vehicles, they can create a control command containing the necessary parameters via a mobile application and encrypt it using a pre-set security algorithm. This encrypted control command is then transmitted to the OBD module near the vehicle via the BLE protocol, ensuring a stable connection even in low-signal conditions.

[0027] For example, in a typical smart home system, a user can lock the garage door and car simultaneously via a mobile app before leaving home. When the user presses the "lock car" button, the app generates an encrypted control command containing the aforementioned information and sends this command to the vehicle parked at the front door using BLE. Due to BLE's low power consumption, this interaction will not significantly affect the phone's battery life.

[0028] Step 102: Decrypt and verify the encrypted control command using the OBD module installed on the vehicle to obtain a valid control command and generate a low-frequency signal corresponding to the valid control command. In this step, the process of decrypting and verifying the encrypted control command includes: using a pre-shared secret key to execute the AES-256 symmetric encryption algorithm to decrypt the encrypted control command to obtain the original control command; applying an improved hash message authentication code algorithm to verify the data integrity of the original control command; checking the timestamp of the original control command; and using an identity authentication mechanism based on elliptic curve cryptography to confirm the authenticity of the source of the original control command; the low-frequency signal is used to transmit the valid control command. In practice, the OBD module first performs preliminary verification on the received data packets, such as length and format checks, to ensure the data packets are complete and error-free. Next, it uses AES-256 and an initialization vector to decrypt the encrypted control commands and recover the original control commands. Then, it verifies that the data has not been tampered with using HMAC, compares the current time and timestamp to determine if the command has expired, and finally verifies the digital signature using ECC to ensure that the command indeed originated from the user's mobile device.

[0029] For example, continuing the previous example, when the vehicle receives a lock command, the OBD module begins processing it. It first checks if the data packet conforms to the expected format, then decrypts the command using a pre-agreed secret key and IV, then uses HMAC to ensure the command content hasn't been tampered with, verifies the command is recently issued using a timestamp, and finally verifies the user's identity using ECC. Only when all these checks pass is it considered a valid control command.

[0030] Step 103: Using adaptive frequency hopping technology, the low-frequency signal is converted into a radio frequency signal and sent to the smart card key through the OBD module to trigger the smart card key to receive and decode the radio frequency signal and execute the corresponding vehicle control operation; the smart card key executes the corresponding vehicle control operation by converting the radio frequency signal into a high-frequency signal and sending it to the vehicle so that the vehicle executes the valid control command; In this step, the smart card key performs the corresponding vehicle control operation, including converting the radio frequency signal into a high frequency signal and sending it to the vehicle so that the vehicle can execute the valid control command. In practice, once a valid control command is confirmed, the OBD module generates a corresponding low-frequency signal, which is then converted into a radio frequency (RF) signal using FHSS technology. This process not only enhances the signal's anti-interference performance but also allows the smart card key to accurately receive and decode the RF signal, thereby performing operations such as unlocking or starting the vehicle. The smart card key also converts the RF signal into a high-frequency signal and sends it back to the vehicle to complete the actual control operation.

[0031] For example, in the garage door scenario, once the OBD module completes all verification, it generates a low-frequency signal and converts it into a radio frequency signal using FHSS technology, sending it to the smart card key. Upon receiving the signal, the smart card key immediately decodes it and executes the lock command, simultaneously converting the result into a high-frequency signal to feed back to the vehicle, ensuring that the doors and engine are correctly locked.

[0032] Step 104: After completing the vehicle control operation, the OBD module obtains the feedback information transmitted back by the smart card key using a high-frequency signal, and after verifying the correctness of the feedback information, updates the internal status of the vehicle and sends the final operation result back to the mobile terminal. In this step, the feedback information includes the operation result status, serial number, timestamp, status information of the smart card key, and a checksum calculated by SHA-3; the high-frequency signal is used to quickly transmit the feedback information and confirm its validity and completeness; wherein, the process by which the OBD module verifies the correctness of the feedback information includes: performing a verification process on the received high-frequency signal, wherein the verification process includes at least comparing the serial number, verifying the freshness of the timestamp, and checking the consistency of the checksum to ensure the correctness of the feedback information.

[0033] In practice, after the smart card key completes the control operation, it generates a feedback data packet containing the aforementioned information and quickly transmits it back to the OBD module via a high-frequency signal. Upon receiving the packet, the OBD module rigorously verifies the feedback information, including serial number comparison, timestamp freshness check, and checksum consistency verification. Once the feedback information is confirmed to be correct, the OBD module updates the vehicle's internal records and notifies the mobile terminal that the operation has been completed via network connection.

[0034] For example, in the scenario of locking a car in a garage, after the smart card key completes the locking operation, it immediately converts the successful operation feedback information into a high-frequency signal and sends it to the OBD module. After receiving this information, the OBD module carefully verifies its correctness, updates the vehicle status after ensuring everything is normal, and notifies the user's mobile application via the Internet, informing the user that their car has been securely locked.

[0035] Through the coordinated operation of the above four steps, this application provides a highly secure and reliable signal transmission method between a smart card key and an OBD module. This method not only enhances the security of vehicle control commands, preventing unauthorized access and potential attacks, but also optimizes the signal transmission process, ensuring efficient delivery of commands and feedback information. Furthermore, it improves the user experience, allowing users to conveniently and quickly control their vehicles from anywhere, while providing users with a high degree of trust in the system's security. The overall solution effectively addresses the security vulnerabilities and service response delays present in existing technologies, providing strong support for the development of modern vehicle networking.

[0036] The following will combine Figure 1 and Figure 2 To further explain the above solution, in order to address the security issues in the transmission of control commands between the mobile terminal and the OBD module in the prior art, some embodiments of the method further include: The control commands transmitted between the mobile terminal and the OBD module are encrypted using an asymmetric RSA-OAEP padding scheme and a symmetric AES-GCM mode. The encryption of the control commands between the mobile terminal and the OBD module using the asymmetric RSA-OAEP padding scheme and the symmetric AES-GCM mode includes: generating a one-time session key using the private key of the mobile terminal using the asymmetric RSA-OAEP padding scheme, encrypting the one-time session key using the public key of the OBD module to generate an encrypted session key; and encrypting the control commands using the encrypted session key via the mobile terminal using the symmetric AES-GCM mode to generate encrypted control commands and simultaneously generate an authentication tag, and sending the encrypted control commands along with the authentication tag to the OBD module.

[0037] In this embodiment, the asymmetric RSA-OAEP padding scheme is an encryption method for generating one-time session keys. The session key is generated using the mobile terminal's private key and encrypted with the OBD module's public key. This ensures that only the OBD module possessing the corresponding private key can decrypt and use the session key, enhancing the security of key exchange. The symmetric AES-GCM encryption mode not only provides robust data encryption but also generates an authentication tag during encryption to verify the integrity and authenticity of the data's origin, thus guaranteeing the secure transmission of control commands. The one-time session key is a temporarily generated key used for a single communication session. It improves security because even if an attacker intercepts a communication, they cannot use the same keystream for subsequent attacks. The encrypted session key is a one-time session key encrypted using an asymmetric encryption algorithm, ensuring that only the target device can decrypt and use it. The authentication tag, generated using the AES-GCM mode, is attached after the encrypted control command to verify the integrity and authenticity of the data's origin.

[0038] In this embodiment, when a user wants to remotely control a vehicle, the mobile terminal first generates a random one-time session key using the asymmetric RSA-OAEP padding scheme, and then encrypts this session key using the public key of the OBD module to generate an encrypted session key. Next, the mobile terminal uses this encrypted session key and the symmetric AES-GCM mode to encrypt the actual control commands, while simultaneously generating an authentication tag to ensure data integrity and authenticity. The encrypted control commands, along with the authentication tag, are encapsulated into a data packet and sent to the OBD module via Bluetooth Low Energy. Upon receiving the data packet, the OBD module uses its private key to decrypt the one-time session key, then uses the decrypted session key to decrypt the control commands, and verifies the authentication tag to confirm that the commands have not been tampered with and indeed originate from a legitimate mobile device. This method not only ensures the secure transmission of control commands, preventing man-in-the-middle attacks and replay attacks, but also improves the overall system security and reliability, allowing users to confidently perform remote vehicle control operations. Furthermore, since the AES-GCM mode provides efficient data encryption and authentication functions, it can achieve rapid response without affecting the user experience, further enhancing the system's practicality.

[0039] To address the insufficient security of communication between the OBD module and the smart card key in existing technologies, some embodiments further include: employing a public-key cryptography-based authentication mechanism combined with a dynamic challenge-response protocol to ensure secure communication between the OBD module and the smart card key. This secure communication includes: when the OBD module receives an encryption control command, it decrypts the session key using its own private key, then decrypts the encryption control command using the decrypted session key, verifies the authentication tag, and after decryption and verification, generates a random number as a challenge value and sends it to the smart card key. Upon receiving the challenge value, the smart card key signs or encrypts the challenge value using a pre-shared secret key or its own private key, and sends the result back to the OBD module. The OBD module then verifies the result returned by the smart card key. If the verification is successful, the smart card key's identity is confirmed as legitimate, and continued communication is permitted.

[0040] In this embodiment, the public-key cryptography-based authentication mechanism is a method of identity verification using asymmetric encryption algorithms. Each device has a public and private key pair, where the public key can be made public, while the private key must be kept secret. The sender uses the receiver's public key to encrypt information, and only the receiver with the corresponding private key can decrypt the information, thus ensuring the confidentiality of the information and the authenticity of its source. The dynamic challenge-response protocol is a two-way authentication method that sends a randomly generated challenge value to the other party, requiring the other party to process the challenge value in a specific way and then return the result. The receiver verifies the returned result to confirm the legitimacy of the other party's identity. This method not only prevents replay attacks but also ensures the uniqueness of each communication. The challenge value is a value randomly generated by the OBD module to test the authenticity and current state of the smart card key. It is one-time use, ensuring a different verification process for each communication. Signing or encryption processing is the process by which the smart card key processes the challenge value after receiving it, using a pre-shared secret key or its own private key. This can be a digital signature or encryption operation, the purpose of which is to prove that the smart card key possesses the correct key and can correctly respond to the challenge. The processing result is the data that the smart card key calculates based on the challenge value and sends back to the OBD module to verify the identity and legitimacy of the smart card key.

[0041] In this embodiment, when the OBD module receives the encrypted control command sent by the mobile terminal, it first decrypts the session key using its own private key, and then decrypts the encrypted control command using the decrypted session key. Simultaneously, it verifies the attached authentication tag to ensure data integrity and the authenticity of the source. If decryption and verification are successful, the OBD module generates a random number as a challenge value and sends this challenge value to the smart card key. Upon receiving the challenge value, the smart card key signs or encrypts the challenge value using a pre-shared secret key or its own private key, and sends the processing result back to the OBD module. The OBD module receives the processing result and verifies it to check if it meets expectations. If the verification passes, the smart card key's identity is confirmed as legitimate, and communication is allowed to continue; otherwise, further communication is rejected, and the corresponding security response mechanism is triggered. This method not only enhances communication security but also effectively prevents replay attacks and other potential security threats, ensuring the reliability and authenticity of communication between the OBD module and the smart card key.

[0042] To address the security risks of unstable communication and replay attacks in existing technologies under strong interference environments, some embodiments of the method further include: applying anti-replay mechanisms and spectrum spread-based anti-interference technology to maintain stable communication between the OBD module and the smart card key in the presence of strong interference sources.

[0043] The application of an anti-replay mechanism to maintain stable communication between the OBD module and the smart card key in the presence of strong interference sources includes: when the OBD module communicates with the smart card key, or when the mobile terminal communicates with the OBD module, the mobile terminal or the OBD module generates a serial number and includes the serial number in a control command. Upon receiving a corresponding signal, the OBD module or the smart card key checks whether the serial number already exists in the locally stored historical record. If not, it accepts the corresponding signal and updates the historical record; otherwise, it rejects the corresponding signal and confirms it as a replay attack. The corresponding signal includes encrypted control commands, low-frequency signals, or high-frequency signals.

[0044] Among them, the anti-interference technology based on spectrum spread maintains stable communication between the OBD module and the smart card key in the presence of strong interference sources. It includes: direct sequence spread spectrum technology in the anti-interference technology based on spectrum spread, which spreads the information contained in the signal to a preset bandwidth before sending the corresponding signal, and uses frequency hopping spread spectrum technology in the anti-interference technology based on spectrum spread to switch different frequencies of the corresponding signal to avoid staying on the same interfered frequency and improve communication reliability.

[0045] In this embodiment, the anti-replay mechanism is a security measure to prevent attackers from deceiving the system by intercepting and retransmitting old messages. It avoids replay attacks by assigning a unique sequence number to each communication and checking the receiver's history to ensure each message is new. The sequence number is a unique identifier generated by the mobile terminal or OBD module and included in the control commands. After receiving a signal, the receiver checks if the sequence number already exists in the locally stored history. If it does not exist, the signal is accepted and the history is updated; otherwise, the signal is rejected, and a replay attack is confirmed. Anti-interference techniques for spectrum spreading include direct sequence spread spectrum (DSS) and frequency hopping spread spectrum. These techniques expand the signal information to a wider frequency band or frequently switch frequencies, making the signal less susceptible to interference at specific frequencies, thus improving communication reliability and robustness. DSS expands the information contained in the signal to a preset width of frequency band before transmission, increasing signal redundancy so that even if some frequency bands are interfered with, the entire signal can still be correctly decoded. Frequency hopping spread spectrum technology transmits signals by rapidly switching between different frequencies, avoiding the need to stay on the same interfered frequency, thus further enhancing the reliability of communication.

[0046] In this embodiment, to ensure the stability and security of communication between the OBD module and the smart card key in a complex electromagnetic environment, two key technologies are employed: an anti-replay mechanism and an anti-interference technology based on spectrum spread.

[0047] First, regarding the anti-replay mechanism, when the OBD module communicates with the smart card key, or when the mobile terminal communicates with the OBD module, the system generates a unique serial number and includes it in all transmitted signals. Whenever the OBD module or smart card key receives a signal, it checks if the serial number already exists in the locally stored history. If the serial number is new, the signal is accepted and the history is updated; if the serial number is duplicated, the signal is rejected and marked as a potential replay attack. This method effectively prevents attackers from launching replay attacks using old messages, ensuring communication security.

[0048] Secondly, regarding anti-interference techniques for spectrum spreading, this embodiment employs direct sequence spread spectrum (DSSS) and frequency hopping spread spectrum (FSS) techniques. Before transmitting the signal, the information is spread across a wider frequency band, which not only increases signal redundancy but also enables the signal to better resist interference from local frequency bands. Furthermore, by continuously switching between different frequencies, the system avoids remaining on the same interfered frequency for extended periods, significantly improving communication reliability and stability. This combined approach effectively solves the communication quality problem under strong interference environments, ensuring continuous and stable communication between the OBD module and the smart card key.

[0049] By combining these two technologies, this embodiment not only significantly improves the security and reliability of communication, but also optimizes performance in complex electromagnetic environments, providing users with a safer and more efficient remote vehicle control system.

[0050] To address the issue of unstable signal transmission caused by environmental interference in wireless communication, some embodiments of the method further include: implementing a dynamic frequency selection mechanism to automatically switch signal frequencies based on environmental interference conditions, combined with an automatic retransmission and acknowledgment mechanism, to ensure that the radio frequency signal can be sent to the smart card key and that the high-frequency signal sent by the smart card key can be successfully acquired. The implementation of the dynamic frequency selection mechanism, which automatically switches signal frequencies based on environmental interference conditions and combines an automatic retransmission and acknowledgment mechanism to ensure that the radio frequency signal can be sent to the smart card key and that the high-frequency signal sent by the smart card key can be successfully acquired, includes: real-time monitoring of the current wireless environment by the OBD module, evaluating the interference intensity at each frequency, automatically selecting the optimal frequency for transmitting the radio frequency signal based on the monitoring results, and, combined with the automatic retransmission mechanism, automatically retransmitting the radio frequency signal if the first transmission fails (e.g., due to interference causing loss or damage) until successful; and employing an acknowledgment mechanism, whereby, after the smart card key receives the radio frequency signal, it sends feedback information to the OBD module via a high-frequency signal to ensure that the OBD module knows that the radio frequency signal has been correctly received.

[0051] In this embodiment, the Dynamic Frequency Selection (DFS) mechanism is a technology that assesses the interference intensity of each frequency in real time based on the current wireless environment and automatically selects the optimal frequency for transmitting radio frequency signals. It improves communication success rate by monitoring and analyzing the surrounding electromagnetic environment to ensure the selected frequency has the lowest interference level. Interference intensity assessment involves the OBD module continuously monitoring the signal quality of different frequencies, measuring the noise level and the impact of other potential interference sources at each frequency to determine which frequency is best suited for current communication needs. Optimal frequency selection, based on the interference intensity assessment results, selects the frequency with the least interference and the highest signal-to-noise ratio as the preferred frequency for current communication, ensuring the reliability and efficiency of data transmission. The automatic retransmission mechanism automatically retransmits the radio frequency signal when the initial transmission fails (e.g., due to loss or damage caused by interference) until successful. This mechanism compensates for transmission failures caused by brief interference or other temporary problems. The confirmation mechanism involves the smart card key sending feedback information to the OBD module via a high-frequency signal after receiving the radio frequency signal, informing it that the signal has been correctly received. This step ensures the integrity of the communication link and provides two-way verification.

[0052] In this embodiment of the application, in the intelligent vehicle control system, to ensure stable and reliable transmission of radio frequency signals from the OBD module to the smart card key, the OBD module first monitors the current wireless environment in real time and assesses the interference intensity on each frequency. Based on these monitoring results, the OBD module automatically selects the frequency with the least interference to transmit the radio frequency signal. If the initial transmission fails due to environmental interference, the OBD module will automatically retransmit the radio frequency signal until successful. Once the smart card key receives the radio frequency signal, it immediately sends an acknowledgment message back to the OBD module via a high-frequency signal, notifying it that the signal has been correctly received. This method not only improves the reliability of communication but also enhances the system's anti-interference capability, ensuring stable communication even in complex electromagnetic environments. Furthermore, the combined use of the automatic retransmission mechanism and the acknowledgment mechanism further improves the accuracy and efficiency of communication, allowing users to confidently perform remote vehicle control operations.

[0053] To address the issue of insufficient data integrity verification during control command transmission in existing technologies, in some embodiments, step 102 involves using an OBD module installed in the vehicle to decrypt and verify the encrypted control command to obtain a valid control command, and generating a corresponding low-frequency signal for the valid control command. This includes: The OBD module installed in the vehicle receives encrypted control commands from a mobile terminal. It performs preliminary verification on the data packets carried by the encrypted control commands, including length and format checks. After passing the preliminary verification, it uses a pre-shared secret key to execute the AES-256 symmetric encryption algorithm to decrypt the encrypted control commands and recover the original control commands. During the decryption process, an initialization vector is applied to ensure the one-time nature of each decryption, preventing the reuse of the same keystream. An improved hash message authentication code algorithm is applied to verify the data integrity of the original control commands. If the original control commands are determined to be data intact, the OBD module compares the current time with the received encrypted data. The timestamp of the encrypted control command is used to determine whether the encrypted control command has expired or is abnormally delayed. If it has not expired or is abnormally delayed, an identity authentication mechanism based on elliptic curve cryptography is used. The OBD module uses the corresponding public key to verify the digital signature carried in the original control command to confirm that the original control command originates from the mobile terminal. The digital signature is generated by the mobile terminal using its private key. If the original control command is confirmed to originate from the mobile terminal, the original control command is considered a valid control command, and a corresponding low-frequency signal is generated. The low-frequency signal is used to transmit the valid control command to the smart card key so that the smart card key triggers the corresponding vehicle control operation.

[0054] Optionally, the improved hash message authentication code algorithm is used to verify the data integrity of the original control command, including: determining the latest version of the secret key from a predefined secret key shared by the OBD module and the mobile terminal; separating the attached first message authentication code value from the data packet; constructing a message body based on the first message authentication code value and the content contained in the data packet, wherein the message body is consistent with the message body constructed by the mobile terminal and embeds a unique session identifier; using a randomized nonlinear transformation step, appending randomly generated salt values ​​before and after the message body to generate a preprocessed message body; and having the OBD module calculate a second message authentication code value based on the improved hash message authentication code algorithm, combined with the preprocessed message body and the latest version of the secret key; comparing the first message authentication code value and the second message authentication code value bit by bit; if they match completely, it is confirmed that the data packet carried by the original control command has not been tampered with during transmission and has data integrity; if they do not match completely, it is confirmed that the data packet carried by the original control command has been tampered with or damaged during transmission, the original control command is rejected, and a corresponding security response mechanism is triggered.

[0055] In this embodiment, within the intelligent vehicle control system, to ensure that encrypted control commands sent from the mobile terminal to the OBD module are not tampered with or corrupted, an improved Hash-based Message Authentication Code (HMAC) algorithm is used to verify the data integrity of the original control commands. This process involves determining the latest version of the secret key using a predefined and shared secret key; extracting the attached first Message Authentication Code (MAC) value from the received data packet; and constructing a message body consistent with the message body constructed by the mobile terminal based on this MAC value and the data packet content, embedding a unique session identifier. To further enhance security, a randomized nonlinear transformation is used to append randomly generated salt values ​​before and after the message body, generating a pre-processed message body. Finally, the OBD module calculates a second MAC value based on the improved HMAC algorithm, combining the pre-processed message body and the latest version of the secret key, and compares the first MAC value with the second MAC value bit by bit to confirm whether the data packet has maintained its original state.

[0056] In this embodiment, when the OBD module receives an encrypted control command, it first performs a preliminary check on the data packet, including length and format checks, to ensure the data packet structure is correct. Then, it uses a pre-shared secret key to execute the AES-256 symmetric encryption algorithm to decrypt the encrypted control command, and applies an initialization vector to ensure the one-time nature of each decryption. Next, the OBD module applies an improved HMAC algorithm to verify the data integrity of the original control command. Specifically, it recalculates a MAC value based on the latest secret key and compares it with the received MAC value. If the two MAC values ​​match perfectly, it indicates that the data packet has not been tampered with; if they do not match, it is considered that the data packet has been tampered with or corrupted. In this case, the OBD module will refuse to accept the command and trigger the corresponding security response mechanism. Furthermore, the OBD module will check the timestamp to determine the freshness of the command and use an elliptic curve cryptography-based authentication mechanism to verify the digital signature to confirm that the command indeed originates from the mobile terminal. Once all verifications pass, the original control command is considered valid and converted into a low-frequency signal to trigger the smart card key to perform the corresponding vehicle control operation.

[0057] Here is a specific example: In a smart home system, a user wants to remotely unlock their car parked outside their home. They create an encrypted control command via a mobile app, containing a serial number, timestamp, and vehicle identification information. This command is sent to the vehicle's OBD module via Bluetooth Low Energy. Upon receiving the command, the OBD module first performs preliminary length and format checks, then decrypts the command using a pre-shared secret key and initialization vector to recover the original control command. Next, the OBD module verifies data integrity using an improved HMAC algorithm. It recalculates a MAC value based on the latest version of the secret key and compares it bit-by-bit with the first MAC value extracted from the data packet. Since the two match perfectly, the OBD module confirms that the data packet has not been tampered with. Next, it checks the timestamp, finding the command to be fresh, and verifies the digital signature using elliptic curve cryptography, confirming that the command indeed originated from the user's mobile phone. Finally, the OBD module treats the original control command as a valid control command, generating a corresponding low-frequency signal and sending it to the smart card key, triggering the vehicle unlocking operation. This process not only ensures the security and reliability of the command but also improves the user experience, allowing users to confidently control their vehicles remotely.

[0058] To address the issue of insufficient feedback information verification in existing technologies, in some embodiments, step 104, after completing the vehicle control operation, involves obtaining feedback information transmitted back by the smart card key using a high-frequency signal via the OBD module, verifying the correctness of the feedback information, updating the vehicle's internal state, and feeding back the final operation result to the mobile terminal. This includes: Using a predefined receiving mechanism, the OBD module acquires the high-frequency signal sent by the smart card key and extracts feedback information from it. This feedback information includes the operation result status, serial number, timestamp, the smart card key's status information, and a checksum calculated using SHA-3. The system determines whether the serial number in the feedback information matches the serial number carried in the radio frequency signal sent by the OBD module to the smart card key. If not, the feedback information is rejected. If it matches, the system verifies the time difference between the timestamp of the feedback information received by the OBD module and the timestamp of the feedback information generated by the smart card key, ensuring the time difference is less than a preset threshold. If the time difference between the time difference and the time difference is greater than a preset threshold, the feedback information is rejected. If the time difference is less than or equal to the preset threshold, the SHA-3 algorithm is applied to recalculate the checksum based on the feedback information. The recalculated checksum is then compared bit by bit with the checksum extracted from the feedback information to check if they match. If they do not match, the feedback information is rejected. If they do match, the vehicle's internal state is updated, the latest vehicle unlocking or starting event is recorded, the vehicle security log is updated, and an updated vehicle internal state is generated. Using Bluetooth Low Energy protocol, the updated vehicle internal state and operation results are fed back to the mobile terminal so that the mobile terminal can generate and display the final operation result.

[0059] In this embodiment, to ensure the authenticity and integrity of the feedback information received from the smart card key, a strict receiving mechanism and multiple verification processes are introduced. The feedback information includes the operation result status, serial number, timestamp, smart card key status information, and a checksum calculated by the SHA-3 algorithm. The serial number is used to match the serial number in the radio frequency signal previously sent to the smart card key to prevent replay attacks; the timestamp is used to verify the freshness of the feedback information, ensuring that it is not expired or delayed; and the checksum is used to check whether the feedback information has maintained its original state during transmission and has not been tampered with.

[0060] In this embodiment, after the vehicle control operation is completed, the smart card key sends feedback information containing the above information back to the OBD module via a high-frequency signal. Upon receiving the high-frequency signal, the OBD module first extracts the feedback information. Then, it checks whether the serial number in the feedback information matches the serial number in the radio frequency signal previously sent to the smart card key. If they do not match, the feedback information is rejected. Next, the OBD module compares the time difference between the timestamp of the received feedback information and the timestamp of the smart card key generating the feedback information to verify the freshness of the timestamp. If the time difference exceeds a preset threshold, the feedback information is also rejected. Finally, the OBD module uses the SHA-3 algorithm to recalculate the checksum based on the feedback information and compares it bit by bit with the checksum carried in the feedback information. If they match perfectly, it indicates that the feedback information has not been tampered with. The OBD module updates the vehicle's internal state, records the latest vehicle unlocking or starting event, updates the vehicle security log, and generates an updated vehicle internal state. Subsequently, the OBD module uses the Bluetooth Low Energy protocol to feed back the updated vehicle internal state and operation results to the mobile terminal, enabling the mobile terminal to generate and display the final operation result.

[0061] The following is a specific example: In a smart home system, a user remotely locks their car parked outside their home via a mobile app. After the lock command is executed, the smart key packages the operation result status, serial number, timestamp, its own status information, and SHA-3 checksum into a feedback message and sends it back to the OBD module via a high-frequency signal. Upon receiving the high-frequency signal, the OBD module first extracts the feedback message and checks if the serial number matches the serial number in the previously sent radio frequency signal. Assuming a match, the OBD module then compares the timestamps; if the time difference is less than a preset threshold, the feedback message is fresh. Next, it recalculates the checksum using the SHA-3 algorithm and compares it bit-by-bit with the checksum in the feedback message, confirming a perfect match. Therefore, the OBD module considers the feedback message valid, updates the vehicle's internal status, records the new lock event, and updates the vehicle's security log. Finally, the OBD module sends the updated vehicle status and a successful lock message to the user's mobile app via the BLE protocol. The user sees a "Lock successful" notification on the app. This entire process not only ensures communication security and reliability but also enhances the user experience, allowing the user to monitor vehicle status changes in real time.

[0062] To address the security shortcomings in the transmission of control commands between mobile terminals and OBD modules in existing technologies, some embodiments employ an asymmetric RSA-OAEP padding scheme and a symmetric AES-GCM mode to encrypt the control commands transmitted between the mobile terminal and the OBD module. This includes: using the asymmetric RSA-OAEP padding scheme, generating a one-time session key using the mobile terminal's private key, and encrypting the one-time session key using the OBD module's public key to generate an encrypted session key; using the symmetric AES-GCM mode, encrypting the control commands using the encrypted session key via the mobile terminal to generate encrypted control commands and simultaneously generating an authentication tag, and sending the encrypted control commands along with the authentication tag to the OBD module. For example, a user creates a vehicle unlock command via a mobile app. The app uses asymmetric RSA-OAEP to generate and encrypt a one-time session key, then encrypts the command using AES-GCM mode and generates an authentication tag. The encrypted command and tag are sent to the OBD module via BLE. After decrypting the session key, the OBD module decrypts the control command and verifies the authentication tag, confirming that the command has not been tampered with and originates from a legitimate mobile device. This method ensures the security and reliability of remote vehicle control.

[0063] The method of employing a public-key cryptography-based authentication mechanism combined with a dynamic challenge-response protocol to ensure secure communication between the OBD module and the smart card key includes: when the OBD module receives an encrypted control command, it decrypts the session key using its own private key, decrypts the encrypted control command using the decrypted session key, verifies the authentication tag, and after decryption and verification, the OBD module generates a random number as a challenge value and sends the challenge value to the smart card key. Upon receiving the challenge value, the smart card key signs or encrypts the challenge value using a pre-shared secret key or its own private key, and sends the processing result back to the OBD module. The OBD module then verifies the processing result returned by the smart card key. If the verification is successful, the smart card key's identity is confirmed as legitimate, and continued communication is allowed. For example, in an intelligent vehicle control system, after the OBD module decrypts the encrypted control commands and verifies the authentication tag, it generates a random challenge value and sends it to the smart card key. Upon receiving the challenge value, the smart card key signs or encrypts it using a pre-shared secret key or its own private key and sends the result back. The OBD module verifies the result; if the verification is successful, it confirms the smart card key's legitimacy and allows subsequent vehicle control operations. This process prevents unauthorized device access and ensures the security and reliability of communication.

[0064] An anti-replay mechanism is applied to maintain stable communication between the OBD module and the smart card key in the presence of strong interference sources. This includes: when the OBD module communicates with the smart card key, or when the mobile terminal communicates with the OBD module, the mobile terminal or the OBD module generates a serial number and includes this serial number in a control command. Upon receiving a corresponding signal, the OBD module or the smart card key checks whether the serial number already exists in the locally stored historical record. If not, it accepts the corresponding signal and updates the historical record; otherwise, it rejects the corresponding signal and confirms it as a replay attack. The corresponding signal includes encrypted control commands, low-frequency signals, or high-frequency signals. For example, in an intelligent vehicle control system, when a user sends an unlock command via a mobile app, the app generates a unique serial number and embeds it into the command. Upon receiving the command, the OBD module checks if this serial number has already been stored locally. If not, the command is considered valid, the corresponding operation is performed, and the serial number is recorded; if it already exists, the command is rejected to prevent replay attacks. This method ensures the uniqueness of each communication, enhancing system security.

[0065] Anti-interference technology based on spectrum spread maintains stable communication between the OBD module and the smart card key in the presence of strong interference sources. It includes: direct sequence spread spectrum technology in anti-interference technology based on spectrum spread, which spreads the information contained in the signal to a preset bandwidth before sending the corresponding signal, and frequency hopping spread spectrum technology in anti-interference technology based on spectrum spread to switch different frequencies of the corresponding signal to avoid staying on the same interfered frequency and improve communication reliability. For example, in a busy urban environment, to ensure uninterrupted communication of the vehicle control system, the OBD module uses direct sequence spread spectrum (DSS) technology to extend the signal information to a wider frequency band, and then employs frequency hopping spread spectrum technology to rapidly switch frequencies during transmission. When the smart card key receives the signal, it can accurately decode and respond. Even if some frequencies are interfered with, the system can continue to communicate using unaffected frequencies, ensuring the stability and accuracy of command transmission. This method effectively improves communication quality in complex electromagnetic environments.

[0066] The dynamic frequency selection mechanism automatically switches signal frequencies based on environmental interference, and combined with an automatic retransmission and acknowledgment mechanism, ensures that the radio frequency signal can be sent to the smart card key and that the high-frequency signal sent by the smart card key can be successfully acquired. This includes: real-time monitoring of the current wireless environment by the OBD module, assessing the interference intensity on each frequency, automatically selecting the optimal frequency for transmitting the radio frequency signal based on the monitoring results, and, combined with the automatic retransmission mechanism, automatically retransmitting the radio frequency signal if the first transmission fails (e.g., due to interference causing loss or damage); and employing an acknowledgment mechanism, when the smart card key receives the radio frequency signal, it sends feedback information to the OBD module via a high-frequency signal to ensure that the OBD module knows that the radio frequency signal has been correctly received.

[0067] For example, in a busy city parking lot, the OBD module monitors the wireless environment in real time and detects severe interference on certain frequencies. Based on the monitoring results, it automatically selects the frequency with the least interference to send radio frequency signals to the smart card key. If the initial transmission fails, the OBD module will automatically retransmit until successful. Upon receiving the signal, the smart card key immediately sends an acknowledgment message back to the OBD module via a high-frequency signal, ensuring the OBD module knows the signal has been correctly received. This method ensures stable and reliable communication even in complex electromagnetic environments.

[0068] In this embodiment, the asymmetric RSA-OAEP padding scheme represents an encryption method for generating one-time session keys. The session key is generated using the mobile terminal's private key and encrypted using the OBD module's public key. This ensures that only the OBD module with the corresponding private key can decrypt and use the session key, enhancing the security of key exchange. The symmetric AES-GCM encryption mode not only provides robust data encryption but also generates an authentication tag during encryption to verify data integrity and authenticity, thus guaranteeing the secure transmission of control commands. The public-key cryptography-based authentication mechanism combined with a dynamic challenge-response protocol verifies the legitimacy of the smart card key. After receiving the encrypted control command, the OBD module decrypts the session key and verifies the authentication tag, then sends a random number as a challenge value to the smart card key. The smart card key needs to sign or encrypt this challenge value using a pre-shared secret key or its own private key and send the result back to the OBD module for verification. The anti-replay mechanism means that a new sequence number is generated for each communication and included in the control command. Upon receiving a signal, the receiving end (OBD module or smart card key) checks if the serial number already exists in the locally stored history to prevent the reuse of old commands. The spectrum spreading anti-interference technology employs direct sequence spread spectrum and frequency hopping spread spectrum techniques to extend the signal information over a wider frequency band and continuously switch frequencies to avoid remaining on the same interfered frequency, thus improving communication robustness and reliability. The dynamic frequency selection mechanism means that the OBD module monitors the wireless environment in real time, assesses the interference intensity on each frequency, and automatically selects the optimal frequency for transmitting the radio frequency signal based on this information. If the initial transmission fails, it automatically retransmits until successful. Furthermore, an acknowledgment mechanism is employed to ensure that the smart card key correctly receives the radio frequency signal.

[0069] In this embodiment, when a user wants to remotely control a vehicle, the mobile terminal first generates a one-time session key using an asymmetric RSA-OAEP padding scheme and encrypts the session key with the OBD module's public key. Next, it uses this encrypted session key and a symmetric AES-GCM mode to encrypt the actual control commands and generate an authentication tag to ensure data integrity and authenticity. The encrypted control commands, along with the authentication tag, are sent to the OBD module. Upon receiving the authentication tag, the OBD module decrypts the session key using its private key and then decrypts the control commands using the decrypted session key, while simultaneously verifying the authentication tag. If the verification passes, the OBD module continues with subsequent operations and verifies the legitimacy of the smart card key's identity using a dynamic challenge-response protocol. Throughout the process, to prevent replay attacks, a new serial number is assigned each time, and to combat interference, spectrum spreading technology and a dynamic frequency selection mechanism are employed to ensure stable communication even in complex electromagnetic environments. Finally, the OBD module confirms whether the smart card key has correctly received the radio frequency signal using a high-frequency signal, ensuring the integrity of the communication link.

[0070] This application recognizes that existing methods for verifying data integrity typically rely on static keys and simple hash algorithms, which are ill-suited to complex network attacks and the demands of long-term security maintenance. To improve the security of control command transmission in intelligent vehicle control systems and ensure that data is not tampered with or corrupted during transmission, a new alternative solution is proposed, which includes: The application uses an improved hash message authentication code algorithm to verify the data integrity of the original control command, including: The latest version of the secret key is determined from the predefined secret key shared between the OBD module and the mobile terminal, according to a dynamic key rotation mechanism. ;in, ,in Indicates the current timestamp. It is the latest version of the secret key selected based on the timestamp; The following is a detailed explanation of each parameter: This represents the latest version of the secret key. This is a crucial parameter used for encrypting and decrypting communication data, ensuring the security of data transmission. It is determined through a dynamic key rotation mechanism. Each time secure communication is required, the system selects the latest secret key version based on the current timestamp.

[0071] This function represents the latest version of the secret key selected based on the timestamp. It is a mapping function that maps the current timestamp to the latest secret key within the corresponding time period. To prevent security risks arising from the long-term use of the same key, a dynamic key rotation mechanism can be used to periodically update the key, ensuring that the system's security is not compromised due to key leakage. A key update cycle (e.g., quarterly or monthly) is pre-set, and a new secret key is generated at the beginning of each cycle and stored in a secure location. When data integrity verification is required, the latest key version corresponding to the current timestamp is selected.

[0072] This represents the current timestamp. It's a numerical value indicating the current time, typically given in Unix time (the number of seconds since January 1, 1970). Timestamps are introduced to ensure that the key used in each communication is up-to-date, thus preventing replay attacks (i.e., an attacker intercepting and resending old messages). By combining timestamps with key selection, it ensures that even if an attacker obtains an old key, they cannot use it to crack current communications. The current time is obtained from the system clock and converted to Unix timestamp format.

[0073] Extract the attached first message authentication code value from the data packet. The message body is constructed based on the first message authentication code value and the content contained in the data packet. The message body should be completely identical to the message body constructed by the mobile terminal, and should embed a unique session identifier (SID); wherein, the message body Where Data represents other content in the data packet. Indicates a connection operation; ,in It is a pre-generated session ID. It is a function that combines a timestamp with a session ID; The following is a detailed explanation of each parameter: The message body is the complete message composed of the data packet content and a session identifier, used for subsequent hash calculations and integrity verification. It is designed to construct a message body containing all necessary information, ensuring the original data is fully represented during transmission and its integrity can be verified using a hash algorithm.

[0074] The Data section represents the rest of the data packet. This part contains the specific parameters of the control commands and other relevant information.

[0075] - Acquisition method: Extracted from received data packets, typically including operation type (e.g., unlock, start), vehicle identification information, etc. The design aims to ensure that all control command details are incorporated into the message body for complete hash calculation and verification.

[0076] This represents the concatenation operator. It is used to join two different parts into a single string or byte sequence. Its design aims to provide a simple and efficient way to combine different parts of information, ensuring the structural consistency and predictability of the message body, and facilitating subsequent processing.

[0077] SID stands for Session Identifier. It is a unique identifier used to distinguish different communication sessions. The design aims to prevent replay attacks and ensure the uniqueness of each session by combining the session ID and timestamp to generate a unique identifier.

[0078] SessionID represents a pre-generated session ID. This is a unique identifier generated at the start of each communication session. It is generated when a new communication session is established, and is typically a unique value generated by a random number or pseudo-random number generator. The design purpose is to ensure that each communication session has a unique identifier, preventing data from different sessions from being confused.

[0079] This function combines a timestamp with a session ID. It is responsible for combining the two into a unique session identifier. The design aims to combine the timestamp and session ID through specific mathematical or logical operations to generate a unique identifier that cannot be easily guessed, thus further enhancing the system's security.

[0080] By employing a randomized nonlinear transformation step, randomly generated salt values ​​are appended before and after the message body to generate a preprocessed message body. ;in, ,in , , and These are functions used to generate the salt values ​​before and after the salt. It is a random number; The following is a detailed explanation of each parameter: This indicates a preprocessed message body. This is in contrast to the original message body. A new message body has been added to enhance security, incorporating a random salt value. The design aims to prevent rainbow table attacks and other attacks based on pre-computed hash values ​​by adding salt values ​​before and after the message body, ensuring that each generated message body is unique.

[0081] Indicates the pre-salt value. This is a random string or byte sequence appended to the beginning of the message body. Timestamp Obtain the current time from the system clock and convert it to Unix timestamp format. (Random number) Generate using a secure random number generator. (Function) It could be a simple join operation or a more complex hash function that combines a timestamp and a random number to generate a unique pre-salt. The design purpose is to use the pre-salt to increase the complexity and uniqueness of the message body, ensuring that even identical messages are not unique. Different things will happen at different times. This prevents replay attacks.

[0082] This represents the original message body. It's the complete message composed of the data packet content and the session identifier. Built according to the previous steps, it contains all necessary control command information and the session identifier. The design aims to ensure that all control command details are included in the message body for complete hash calculation and verification.

[0083] The "Salt" directive indicates a post-salt value. This is a random string or byte sequence appended to the message body. It's designed to further enhance the complexity and uniqueness of the message body, making it difficult for attackers to guess the content of the original message body through pattern analysis.

[0084] The OBD module is based on an improved hash message authentication code algorithm, combined with a preprocessed message body. and the latest version of the secret key Calculate the second message authentication code value ;in, ,in It is a hash message authentication code function based on SHA-256. It is the SHA-256 hash function. It is a weighting coefficient representing the impact of message freshness; weighting coefficient Defined as: ,in It is the time difference between the current time and the message generation time. It is a predetermined time constant. It is a parameter that adjusts the rate of exponential decay to increase sensitivity to freshness; The following is a detailed explanation of each parameter: This represents the second message authentication code value. This value is calculated using a modified Hash Message Authentication Code (HMAC) algorithm and is used to verify the integrity of the message body and the authenticity of its origin. Its design aims to ensure that received messages have not been tampered with and indeed originate from the intended sender.

[0085] HMAC stands for Hash Message Authentication Code Function. It's a security mechanism based on hash functions, combined with a secret key, to encrypt and verify messages. Its design aims to provide a robust method for verifying message integrity and origin, preventing man-in-the-middle attacks and other forms of data tampering.

[0086] This represents the latest version of the secret key. This is a crucial parameter used for encrypting and decrypting communication data, ensuring the security of data transmission. A dynamic key rotation mechanism selects the latest secret key version based on the current time. The design aims to periodically update the key to prevent security risks arising from the long-term use of the same key.

[0087] This represents a weighting coefficient. It reflects the impact of message freshness and is adjusted based on the time difference between the current time and the message generation time. The design purpose is to introduce a weighting coefficient to assess message freshness, thereby preventing replay attacks and ensuring that only the newest and most relevant messages are accepted.

[0088] H stands for SHA-256 hash function. This is a commonly used one-way hash function that maps messages of arbitrary length to fixed-length hash values. Its design aims to provide an irreversible way to convert messages into fixed-length digests, ensuring message integrity.

[0089] The first message authentication code value and the second message authentication code value Perform a character-by-character comparison; like If so, it is confirmed that the data packet carried by the original control command has not been tampered with during transmission and has data integrity; if If the original control command is confirmed to have been tampered with or damaged during transmission, the original control command will be rejected, and a corresponding security response mechanism will be triggered.

[0090] The following is a specific example: In the field of intelligent vehicle control, to ensure that control commands sent from a mobile terminal to the OBD module are not tampered with or damaged during transmission, this application proposes an embodiment of an improved Hash Message Authentication Code (HMAC) algorithm for verifying data integrity. When a user sends control commands for a drilling vehicle via a mobile terminal, the OBD module first determines the latest version of the secret key according to a predefined dynamic key rotation mechanism. The key is selected based on the current time. Then, the OBD module extracts the accompanying first message authentication code value from the received data packet. Based on this, a message body containing data content and other information is constructed. A unique session identifier is embedded within it. ,Should This is generated by combining a pre-generated session ID with the current timestamp. Next, to enhance security, the OBD module appends randomly generated salt values ​​to the beginning and end of the message body, generating a pre-processed message body. Subsequently, the OBD module uses an improved HMAC algorithm combined with a preprocessed message body. and the latest version of the secret key Calculate the second message authentication code value In this process, a weighting coefficient is introduced. It reflects the impact of message freshness and is adjusted based on the time difference between the current time and the message generation time. Finally, the OBD module will use the first message authentication code value. and the calculated second message authentication code value A bit-by-bit comparison is performed. If the two match perfectly, it confirms that the data packet carried by the original control command has not been tampered with during transmission and possesses data integrity; otherwise, if they do not match, it is assumed that the data packet has been tampered with or corrupted, the system refuses to accept the command, and triggers the corresponding security response mechanism. This method not only enhances the security of data transmission but also effectively prevents replay attacks, ensuring the reliability and security of communication in the remote vehicle control system.

[0091] Figure 3 This application provides a schematic diagram of the signal transmission optimization device (or system) for a smart card key and an OBD module, as shown in the embodiment. Figure 3 As shown, the device includes: The acquisition module 21 is used to acquire encrypted control instructions sent by the mobile terminal via Bluetooth Low Energy protocol. The encrypted control instructions include a one-time session key generated by the mobile terminal and vehicle identification information. The control instructions are instructions used to control the unlocking or starting of the vehicle. The generation module 22 is used to decrypt and verify the encrypted control command through an OBD module installed in the vehicle to obtain a valid control command, and to generate a low-frequency signal corresponding to the valid control command. The process of decrypting and verifying the encrypted control command includes: using a pre-shared secret key to execute an AES-256 symmetric encryption algorithm to decrypt the encrypted control command to obtain the original control command; applying an improved hash message authentication code algorithm to verify the data integrity of the original control command; checking the timestamp of the original control command; and using an elliptic curve cryptography-based authentication mechanism to confirm the authenticity of the source of the original control command. The low-frequency signal is used to transmit the valid control command. The execution module 23 is used to convert the low-frequency signal into a radio frequency signal using adaptive frequency hopping technology and send it to the smart card key through the OBD module, so as to trigger the smart card key to receive and decode the radio frequency signal and execute the corresponding vehicle control operation. Processing module 24 is used to obtain feedback information transmitted back by the smart card key using a high-frequency signal through the OBD module after completing the vehicle control operation, and after verifying the correctness of the feedback information, update the internal status of the vehicle and send the final operation result back to the mobile terminal; the feedback information includes the operation result status, serial number, timestamp, status information of the smart card key, and a checksum calculated by SHA-3; the high-frequency signal is used to quickly transmit the feedback information and confirm the validity and completeness of the feedback information; The process by which the OBD module verifies the correctness of the feedback information includes: performing a verification process on the received high-frequency signal, wherein the verification process includes at least comparing the serial number, verifying the freshness of the timestamp, and checking the consistency of the checksum, to ensure the correctness of the feedback information.

[0092] Figure 3 The aforementioned signal transmission optimization device between the smart card key and the OBD module can perform... Figure 1 The implementation principle and technical effects of the signal transmission optimization method between the smart card key and the OBD module described in the illustrated embodiment will not be repeated here. The specific operation methods of each module and unit in the signal transmission optimization device between the smart card key and the OBD module in the above embodiments have been described in detail in the embodiments related to this method, and will not be elaborated upon here.

[0093] In one possible design, Figure 3 The signal transmission optimization device for the smart card key and OBD module in the illustrated embodiment can be implemented as a computing device, such as... Figure 4 As shown, the computing device may include a storage component 31 and a processing component 32; The storage component 31 stores one or more computer instructions, wherein the one or more computer instructions are invoked and executed by the processing component 32.

[0094] The processing component 32 is used for the above Figure 1 The embodiment describes a method for optimizing signal transmission between the smart card key and the OBD module.

[0095] The processing component 32 may include one or more processors to execute computer instructions to complete all or part of the steps in the above-described method. Alternatively, the processing component may be implemented as one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the above-described method.

[0096] Storage component 31 is configured to store various types of data to support operations at the terminal. The storage component can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0097] Of course, computing devices may also include other components, such as input / output interfaces, display components, communication components, etc.

[0098] Input / output interfaces provide interfaces between processing components and peripheral interface modules, which can be output devices, input devices, etc.

[0099] The communication components are configured to facilitate wired or wireless communication between computing devices and other devices.

[0100] The computing device can be a physical device or an elastic computing host provided by a cloud computing platform. In this case, the computing device can refer to a cloud server, and the aforementioned processing components, storage components, etc., can be basic server resources rented or purchased from the cloud computing platform.

[0101] This application also provides a computer storage medium storing a computer program, which, when executed by a computer, can perform the above-described functions. Figure 1 The illustrated embodiment describes a method for optimizing signal transmission between a smart card key and an OBD module.

[0102] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0103] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0104] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for signal transmission optimization of a smart card key and an OBD module, characterized by, The method comprises the following steps: obtaining an encrypted control instruction sent by a mobile terminal through a Bluetooth Low Energy protocol, wherein the encrypted control instruction contains a serial number generated by the mobile terminal and vehicle identification information, and the control instruction refers to an instruction for controlling the vehicle to be unlocked or started; decrypting and verifying the encrypted control instruction through an OBD module installed on the vehicle to obtain a valid control instruction, and generating a low-frequency signal corresponding to the valid control instruction; wherein the process of decrypting and verifying the encrypted control instruction includes: using a pre-shared secret key to execute an AES-256 symmetric encryption algorithm to decrypt the encrypted control instruction to obtain an original control instruction, and applying an improved Hash Message Authentication Code algorithm to verify the data integrity of the original control instruction, check the timestamp of the original control instruction, and confirm the authenticity of the source of the original control instruction using an identity authentication mechanism based on elliptic curve cryptography; the low-frequency signal is used to transmit the valid control instruction; using an adaptive frequency hopping technology to convert the low-frequency signal into a radio frequency signal and send it to a smart card key through the OBD module, so as to trigger the smart card key to receive and decode the radio frequency signal and execute corresponding vehicle control operations; the corresponding vehicle control operations executed by the smart card key include converting the radio frequency signal into a high-frequency signal and sending it to the vehicle to execute the valid control instruction by the vehicle; after completing the vehicle control operation, obtaining feedback information returned by the smart card key using a high-frequency signal through the OBD module, and updating the internal state of the vehicle and feeding back the final operation result to the mobile terminal after verifying the correctness of the feedback information; the feedback information includes operation result status, serial number, timestamp, state information of the smart card key, and a check code calculated by SHA-3; the high-frequency signal is used to quickly return the feedback information and confirm the validity and integrity of the feedback information; wherein the process of verifying the correctness of the feedback information by the OBD module includes executing a verification process on the received high-frequency signal, wherein the verification process at least includes comparing the serial number, verifying the freshness of the timestamp, and checking the consistency of the check code, to ensure the correctness of the feedback information.

2. The method of claim 1, wherein, Further comprising: encrypting the control instruction transmitted between the mobile terminal and the OBD module using an asymmetric RSA-OAEP padding scheme and a symmetric AES-GCM mode, and applying an identity authentication mechanism based on public key cryptography combined with a dynamic challenge-response protocol to ensure the security of communication between the OBD module and the smart card key; applying an anti-replay mechanism and an anti-interference technology based on spectrum spreading to maintain stable communication between the OBD module and the smart card key in the presence of strong interference sources; implementing a dynamic frequency selection mechanism to automatically switch the signal frequency according to the environmental interference, and combining an automatic retransmission and confirmation mechanism to ensure that the radio frequency signal can be sent to the smart card key and the high-frequency signal sent by the smart card key can be successfully obtained.

3. The method of claim 1, wherein, The encrypted control instruction is decrypted and verified by the OBD module installed on the vehicle to obtain a valid control instruction, and a low-frequency signal corresponding to the valid control instruction is generated, comprising: The encrypted control instruction is received by the OBD module installed on the vehicle from the mobile terminal, the data packet carried by the encrypted control instruction is preliminarily checked, including length check and format check, and after the preliminary check is passed, the AES-256 symmetric encryption algorithm is used to perform the encryption algorithm, the encrypted control instruction is decrypted, and the original control instruction is restored; wherein, the initialization vector is applied in the decryption process to ensure the one-time characteristic of each decryption, and to prevent the reuse of the same key stream; The improved hash message authentication code algorithm is applied to verify the data integrity of the original control instruction; In the case where the original control instruction has data integrity, the OBD module compares the current time with the time stamp of the encrypted control instruction to determine whether the encrypted control instruction is expired or abnormally delayed, and in the case where there is no expiration or abnormal delay, the digital signature carried in the original control instruction is verified by the OBD module using the corresponding public key based on the elliptic curve cryptography identity authentication mechanism to confirm that the original control instruction comes from the mobile terminal; the digital signature is generated by the mobile terminal using a private key; If it is confirmed that the original control instruction comes from the mobile terminal, the original control instruction is taken as a valid control instruction, and a corresponding low-frequency signal is generated; the low-frequency signal is used to transmit the valid control instruction to the smart card key, so that the smart card key triggers the corresponding vehicle control operation.

4. The method of claim 3, wherein, The improved hash message authentication code algorithm is applied to verify the data integrity of the original control instruction, comprising: The latest version of the secret key is determined from the secret key shared in advance between the OBD module and the mobile terminal; The first message authentication code value attached in the data packet is separated, the message body is constructed based on the first message authentication code value and the content contained in the data packet, the message body is consistent with the message body constructed by the mobile terminal, and a unique session identifier is embedded; A random salt value is generated by a random nonlinear transformation step before and after the message body to generate a pretreated message body, and the OBD module calculates a second message authentication code value based on the improved hash message authentication code algorithm, the pretreated message body and the latest version of the secret key; The first message authentication code value and the second message authentication code value are compared bit by bit, if they are completely matched, it is confirmed that the data packet carried by the original control instruction has not been tampered with in the transmission process and has data integrity; if they are not completely matched, it is confirmed that the data packet carried by the original control instruction has been tampered with or damaged in the transmission process, the original control instruction is rejected, and the corresponding security response mechanism is triggered.

5. The method of claim 1, wherein, The feedback information returned by the smart card key through high frequency signal is acquired by the OBD module after the vehicle control operation is completed, and the internal state of the vehicle is updated and the final operation result is fed back to the mobile terminal after verifying the correctness of the feedback information, including: The high frequency signal sent by the smart card key is acquired by the OBD module through the pre-defined receiving mechanism, and the feedback information is separated from the high frequency signal, including operation result status, serial number, timestamp, state information of the smart card key and verification code calculated by SHA-3; Determine whether the serial number in the feedback information is consistent with the serial number carried by the radio frequency signal when the OBD module sends the radio frequency signal to the smart card key, if not, refuse to accept the feedback information; If yes, verify the freshness of the timestamp by comparing the time difference between the timestamp when the OBD module receives the feedback information and the timestamp when the smart card key generates the feedback information, if the time difference is greater than the preset threshold, refuse to accept the feedback information; If the time difference is less than or equal to the preset threshold, apply SHA-3 algorithm, calculate the verification code based on the feedback information, and compare the recalculated verification code with the verification code extracted from the feedback information bit by bit to check whether the verification codes are consistent; if not, refuse to accept the feedback information; If yes, update the internal state of the vehicle, record the latest vehicle unlocking or starting event, update the vehicle security log, and generate the updated vehicle internal state, use Bluetooth low energy protocol to feed back the updated vehicle internal state and operation result to the mobile terminal, so that the mobile terminal generates the final operation result and displays.

6. The method of claim 2, wherein, The control instructions transmitted between the mobile terminal and the OBD module are encrypted using asymmetric RSA-OAEP padding scheme and symmetric AES-GCM mode, including: using asymmetric RSA-OAEP padding scheme, generating a one-time session key through the private key of the mobile terminal, and encrypting the one-time session key using the public key of the OBD module to generate an encrypted session key; using symmetric AES-GCM mode, the mobile terminal encrypts the control instruction using the encrypted session key to generate an encrypted control instruction and an authentication tag at the same time, and sends the encrypted control instruction together with the authentication tag to the OBD module; The identity authentication mechanism based on public key cryptography is combined with a dynamic challenge-response protocol to ensure the safety of communication between the OBD module and the smart card key, including: after the OBD module receives an encrypted control instruction, the OBD module uses its own private key to decrypt a session key, uses the decrypted session key to decrypt the encrypted control instruction, and verifies the authentication tag; after decryption and verification, the OBD module generates a random number as a challenge value and sends the challenge value to the smart card key, so that the smart card key, after receiving the challenge value, uses a pre-shared secret key or its own private key to sign or encrypt the challenge value, and returns the processing result to the OBD module, so that the OBD module verifies the processing result returned by the smart card key, and if the verification is passed, the identity of the smart card key is confirmed to be legal, and the communication is allowed to continue; An anti-replay mechanism is applied to maintain the stability of communication between the OBD module and the smart card key in the presence of strong interference sources, including: when the OBD module and the smart card key communicate, or the mobile terminal and the OBD module communicate, the mobile terminal or the OBD module generates a serial number, and the serial number is included in the control instruction, so that the OBD module or the smart card key checks whether the serial number exists in the local stored history record after receiving the corresponding signal, if not, the corresponding signal is accepted and the history record is updated; otherwise, the corresponding signal is rejected and the corresponding signal is confirmed as a replay attack; the corresponding signal includes an encrypted control instruction, a low-frequency signal or a high-frequency signal; The anti-interference technology based on spectrum spreading is used to maintain the stability of communication between the OBD module and the smart card key in the presence of strong interference sources, including: in the direct sequence spread spectrum technology in the anti-interference technology based on spectrum spreading, the information contained in the signal is spread to a preset width of the frequency band before the signal is sent, and the frequency hopping spread spectrum technology in the anti-interference technology based on spectrum spreading is used to switch different frequencies of the corresponding signal to avoid staying at the same disturbed frequency, thereby improving the communication reliability; The dynamic frequency selection mechanism is implemented to automatically switch the signal frequency according to the environmental interference, and the automatic retransmission and confirmation mechanism is combined to ensure that the radio frequency signal can be sent to the smart card key and the high-frequency signal sent by the smart card key can be successfully acquired, including: The OBD module monitors the current wireless environment in real time, evaluates the interference intensity on each frequency, automatically selects the optimal frequency for sending the radio frequency signal according to the monitoring result, and combines the automatic retransmission mechanism to automatically retransmit the radio frequency signal until success if the first transmission fails; the confirmation mechanism is used, and when the smart card key receives the radio frequency signal, the smart card key sends feedback information to the OBD module through a high-frequency signal to ensure that the OBD module knows that the radio frequency signal has been correctly received.

7. The method of claim 4, wherein, The improved hash message authentication code algorithm is applied to verify the data integrity of the original control instruction, including: determining the latest version of the secret key according to a dynamic key rotation mechanism from the predefined secret key shared by the OBD module and the mobile terminal ; wherein , wherein denotes the current timestamp, is the latest version of the secret key selected according to the timestamp; separating a first message authentication code value from the data packet constructing a message body based on the first message authentication code value and the content contained in the data packet the message body should be identical to the message body constructed by the mobile terminal and embed a unique session identifier SID; wherein the message body wherein Data represents other content in the data packet, represents a connection operation; wherein is a pre-generated session ID, is a current timestamp, is a function combining the timestamp and the session ID; appending a randomly generated salt value before and after the message body using a randomised non-linear transformation step to generate a pre-processed message body ; wherein , , , and are functions for generating the before and after salt values respectively, is a random number; The OBD module calculates a second message authentication code value based on an improved hash message authentication code algorithm in combination with the pre-processed message body and the latest version of the secret key ; wherein, wherein is a hash message authentication code function based on SHA-256, is a SHA-256 hash function, is a weight coefficient representing the freshness influence of the message; the weight coefficient is defined as: wherein is the time difference between the current time and the message generation time, is a predetermined time constant, is a parameter adjusting the exponential decay rate to increase the sensitivity to freshness;​ comparing the first message authentication code value and the second message authentication code value bit by bit; If , it is confirmed that the data packet carried by the original control instruction is not tampered in the transmission process, and has data integrity; if , it is confirmed that the data packet carried by the original control instruction has been tampered or damaged in the transmission process, the original control instruction is rejected, and the corresponding security response mechanism is triggered.

8. A system for signal transmission optimization of a smart card key and an OBD module, characterized by, including: An acquisition module is configured to acquire an encrypted control instruction sent by a mobile terminal through a Bluetooth Low Energy protocol, the encrypted control instruction containing a one-time session key generated by the mobile terminal and vehicle identification information, the control instruction being an instruction for controlling vehicle unlocking or starting; An generation module is configured to decrypt and verify the encrypted control instruction through an OBD module installed on a vehicle to obtain a valid control instruction and generate a low-frequency signal corresponding to the valid control instruction; the process of decrypting and verifying the encrypted control instruction includes: using a pre-shared secret key to perform AES-256 symmetric encryption algorithm to decrypt the encrypted control instruction to obtain an original control instruction, and applying an improved Hash Message Authentication Code algorithm to verify data integrity of the original control instruction, check a timestamp of the original control instruction, and confirm authenticity of a source of the original control instruction by using an identity authentication mechanism based on elliptic curve cryptography; the low-frequency signal is used to transmit the valid control instruction; An execution module is configured to convert the low-frequency signal into a radio frequency signal by using an adaptive frequency hopping technology and send the radio frequency signal to a smart card key through the OBD module, so as to trigger the smart card key to receive and decode the radio frequency signal and perform a corresponding vehicle control operation; A processing module is configured to acquire feedback information returned by the smart card key through a high-frequency signal through the OBD module after completing the vehicle control operation, and update an internal state of the vehicle and feed back a final operation result to the mobile terminal after verifying correctness of the feedback information; the feedback information includes an operation result state, a serial number, a timestamp, state information of the smart card key, and a check code calculated by SHA-3; the high-frequency signal is used to quickly return the feedback information and confirm validity and integrity of the feedback information; The OBD module verifies correctness of the feedback information by performing a verification process on the received high-frequency signal, wherein the verification process at least includes comparing the serial number, verifying freshness of the timestamp, and checking consistency of the check code, to ensure correctness of the feedback information.

9. A computing device, comprising: A processing component and a storage component are included; the storage component stores one or more computer instructions; the one or more computer instructions are used to be called and executed by the processing component to implement the signal transmission optimization method of the smart card key and the OBD module according to any one of claims 1-7.

10. A computer storage medium, characterized in that, A computer program is stored, and when the computer program is executed by a computer, the signal transmission optimization method of the smart card key and the OBD module according to any one of claims 1-7 is implemented.

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