Agricultural machinery T-Box anti-disassembly method based on encryption algorithm

Abstract

The invention relates to the technical field of vehicle networking safety, in particular to an agricultural machinery T-Box anti-disassembly method based on an elliptic curve encryption algorithm, which comprises the following steps: a T-Box acquires and synchronizes time information to an ECU (Electronic Control Unit); the ECU generates a random number Challenge and initiates handshake verification after the device is started; the T-Box dynamically selects a private key based on a time factor and transforms the Challenge to generate a temporary public key, and generates a signature response by using an elliptic curve encryption algorithm; and the ECU performs independent signature verification according to the same time factor and rule, and controls the operation state of the equipment according to a verification result. According to the method, the time factor is combined with the random number, so that the key depended by each authentication is temporarily effective and unique, replay attack and data tampering can be effectively resisted, the difficulty of stealing and multiplexing key information by an attacker is remarkably increased, and the authentication efficiency is improved. Therefore, more active and reliable anti-disassembly protection is provided for equipment in a complex outdoor operation environment, and the asset safety of manufacturers is practically guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Internet of Vehicles security, in particular to an agricultural machinery T-Box anti-disassembly method based on an encryption algorithm. BACKGROUND

[0002] In the current agricultural machinery industry, manufacturers generally use installment payment mode to sell high-value equipment such as large tractors and combine harvesters. In order to protect the safety of assets and realize remote management of the running state of the equipment, the manufacturer usually integrates a T-Box (Telematics Box, remote information processing control unit) in the equipment, and through real-time communication with the vehicle ECU (Electronic Control Unit, vehicle engine controller), realizes the collection and monitoring of equipment position, working condition and other data. This technical means not only improves the fine level of after-sales service, but also provides an important risk control basis for manufacturers.

[0003] However, with the increasing intelligence of agricultural machinery, the security vulnerability of the equipment communication link gradually appears, although the communication mechanism of T-Box and ECU is relatively mature in function, but its security protection ability still has the following obvious shortcomings:

[0004] 1) The existing communication protocol relies on software-level encryption means, and some algorithms still follow the early standards, which are difficult to resist current common replay attacks, data tampering and other malicious behaviors;

[0005] 2) The T-Box hardware lacks physical-level protection for key storage and operation, so that critical information is easy to be stolen or tampered with;

[0006] 3) The working environment of agricultural machinery is mostly open-air scene, and the wireless communication link is easy to be disturbed or eavesdropped, which further aggravates the risk of data leakage and unauthorized control of the equipment.

[0007] These shortcomings seriously restrict the asset security protection ability of manufacturers under the installment payment mode. SUMMARY

[0008] In order to solve the above technical problems, the present application provides a technical scheme of an agricultural machinery T-Box anti-disassembly method based on an encryption algorithm.

[0009] The technical problems solved by the present application can be realized by using the following technical scheme:

[0010] An agricultural machinery T-Box anti-disassembly method based on an encryption algorithm, comprising:

[0011] Step S1, the vehicle Internet of Things terminal T-Box acquires current time information, and sends the current time information to the vehicle engine controller ECU;

[0012] Step S2, the vehicle-mounted IoT terminal T-Box receives a random number Challenge from the vehicle engine controller ECU;

[0013] Step S3, the vehicle-mounted IoT terminal T-Box selects a current private key K1 from a key pool based on a time factor M in the current time information through a preset private key selection rule;

[0014] Step S4, the vehicle-mounted IoT terminal T-Box processes the random number Challenge to generate a temporary public key K2 based on a time factor M in the current time information through a preset public key processing rule;

[0015] Step S5, the vehicle-mounted IoT terminal T-Box encrypts the temporary public key K2 through an encryption algorithm based on the current private key K1 to generate an encryption result;

[0016] Step S6, the encryption result is sent to the vehicle engine controller ECU for verification by the vehicle engine controller ECU.

[0017] Preferably, it further comprises:

[0018] The vehicle engine controller ECU receives current time information from the vehicle-mounted IoT terminal T-Box and calibrates the local time based on the current time information;

[0019] After the device is started, the vehicle engine controller ECU generates a random number Challenge and sends the random number Challenge to the vehicle-mounted IoT terminal T-Box to initiate a handshake verification request;

[0020] The vehicle engine controller ECU receives the encryption result from the vehicle-mounted IoT terminal T-Box;

[0021] The vehicle engine controller ECU verifies the encryption result using a pre-stored T-Box public key K3, if the verification is successful, the device works normally, if the verification fails, the handshake verification request is initiated again after a period of time, if the verification fails for a plurality of times, the lock operation is performed to prohibit the device from starting.

[0022] Preferably, the time factor M is the minute value of the current time.

[0023] Preferably, the step S3 comprises:

[0024] Step S31, a private key index index is calculated through a private key selection function F_key(M);

[0025] Step S32, according to the private key index index, select the corresponding private key from the key pool as the current private key K1.

[0026] Preferably, the private key selection function in step S31 is:

[0027]

[0028] Wherein, K is a preset positive integer time interval constant.

[0029] Preferably, the step S4 comprises:

[0030] Step S41, determine the number of shifts shift_times based on the time factor M;

[0031] Step S42, perform a left circular shift operation on the random number Challenge for shift_times times;

[0032] Step S43, intercept the first i bytes of the data after the left circular shift as the temporary public key K2.

[0033] Preferably, the encryption algorithm in step S5 is the elliptic curve digital signature algorithm.

[0034] Preferably, the vehicle engine controller ECU uses the pre-stored T-Box public key K3 to verify the encryption result, if the verification is successful, the device works normally, if the verification fails, wait for a period of time and then initiate the handshake verification request again, if the verification fails for a plurality of times, perform the lock operation to prohibit the device from starting, including:

[0035] The vehicle engine controller ECU determines the current T-Box public key K3 according to the time factor M using the same private key selection rule as the vehicle-mounted Internet of Things terminal T-Box;

[0036] Decrypt the received encryption result using the current T-Box public key K3 to obtain the decrypted public key K2'';

[0037] The vehicle engine controller ECU processes the locally saved random number Challenge based on the time factor M using the same public key processing rule as the vehicle-mounted Internet of Things terminal T-Box to generate a local reference public key K2';

[0038] Compare the local reference public key K2' with the decrypted public key K2'' to determine whether they are consistent, if they are consistent, the verification is successful; otherwise, the verification fails, the vehicle engine controller ECU waits for a period of time and then initiates the handshake verification request again, if the verification fails for a plurality of times, perform the lock operation to prohibit the device from starting.

[0039] Preferably, in the step S1, the vehicle Internet of Things terminal T-Box obtains the current time information through the internally integrated Beidou positioning module or RTC clock circuit.

[0040] Preferably, the vehicle Internet of Things terminal T-Box and the vehicle engine controller ECU communicate through the CAN bus.

[0041] The application has the beneficial effects that: by combining the time factor with the random number, a dynamic key generation and verification process is constructed, so that the key relied on each time authentication is temporarily effective and unique, which not only can effectively resist replay attacks and data tampering, but also significantly increases the difficulty of attackers to steal and reuse the key information, thereby providing more active and reliable anti-disassembly protection for the device in the complex open operation environment, and effectively protecting the asset safety of the manufacturer. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a method flowchart of the application;

[0043] Figure 2 is a block diagram of step S3 of the application;

[0044] Figure 3 is a block diagram of step S4 of the application. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0046] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0047] The application will be further described below with reference to the drawings and specific embodiments, but not as a limitation of the application.

[0048] Reference Figure 1 , the application provides an anti-disassembly method for agricultural machinery T-Box based on encryption algorithm, comprising:

[0049] Step S1, the vehicle Internet of Things terminal T-Box obtains the current time information, and sends the current time information to the vehicle engine controller ECU;

[0050] Step S2, the vehicle-mounted IoT terminal T-Box receives a random number Challenge from the vehicle engine controller ECU;

[0051] Step S3, the vehicle-mounted IoT terminal T-Box selects a current private key K1 from a key pool based on a time factor M in the current time information through a preset private key selection rule;

[0052] Step S4, the vehicle-mounted IoT terminal T-Box processes the random number Challenge to generate a temporary public key K2 based on a time factor M in the current time information through a preset public key processing rule;

[0053] Step S5, the vehicle-mounted IoT terminal T-Box encrypts the temporary public key K2 through an encryption algorithm based on the current private key K1 to generate an encryption result;

[0054] Step S6, the encryption result is sent to the ECU for verification by the vehicle engine controller ECU.

[0055] Further comprising:

[0056] The vehicle engine controller ECU receives current time information from the vehicle-mounted IoT terminal T-Box and calibrates the local time based on the current time information;

[0057] After the device is started, the vehicle engine controller ECU generates a random number Challenge and sends the random number Challenge to the vehicle-mounted IoT terminal T-Box to initiate a handshake verification request;

[0058] The vehicle engine controller ECU receives the encryption result from the vehicle-mounted IoT terminal T-Box;

[0059] The vehicle engine controller ECU verifies the encryption result using a pre-stored T-Box public key K3, if the verification is successful, the device works normally, if the verification fails, the device waits for a period of time and initiates the handshake verification request again, if the verification fails for a plurality of times, the device performs a lock operation to prohibit the device from starting.

[0060] The time factor M is the minute value of the current time.

[0061] Specifically, in the embodiments of the present application, in order to solve the problems of being vulnerable to replay attacks, data tampering and key theft caused by using static keys and fixed communication modes in the prior art, a key selection and data transformation mechanism with time factor M (minute value) as a dynamic variable is introduced, and combined with random number challenge and response, so that the key and parameters of each authentication session are dynamically changed and valid only once, avoiding the vulnerability of traditional fixed encryption strategy, and realizing the essential improvement of the anti-attack ability of the communication link, thereby providing high-strength active security protection for agricultural machinery under the condition of limited hardware cost.

[0062] Specifically, in actual application, the anti-disassembly method of the agricultural machinery T-Box constructs a safety control system with time factor as the dynamic core. The method is automatically executed in the device startup phase, and the T-Box is time-synchronized to the ECU to ensure the uniformity of the time reference, and the ECU initiates a challenge request containing a random number. The T-Box end dynamically selects a private key from the preset key pool according to the current minute value, and synchronously transforms the challenge value, and then uses the selected private key to complete the encryption. The ECU end uses the pre-stored public key of the T-Box for verification, and decides whether the device is allowed to run according to the verification result. This method combines the static preset key with the dynamic time parameter and random number adjustment, ensuring the uniqueness and one-time validity of each authentication session, thereby realizing effective resistance to replay attacks, key theft and illegal disassembly of the device at the communication link level.

[0063] Correspondingly, before the device is shipped, a special device is used to inject multiple sets of ECC key pairs into the T-Box and the ECU respectively, which together constitute an initial key pool as the root of trust for device identity authentication and secure communication. The design of the key pool allows multiple keys to coexist, and the use of which key at a certain moment is dynamically determined by the real-time clock minute value obtained during system operation, which significantly increases the unpredictability of the key.

[0064] In terms of key management strategy, the present scheme combines static presetting and dynamic updating, and has both security and flexibility. On the one hand, the pre-shipped key pool can be used as a static credential to ensure the basic security of the device throughout its life cycle; on the other hand, the system supports periodic rotation, replacement or expansion of the key pool through secure wired or wireless (OTA) communication channels. This dual strategy not only meets the needs of cost-sensitive applications for simplified deployment, but also effectively deals with the risk of key leakage during long-term use through online updating, realizing the sustainable evolution of security protection capability.

[0065] More specifically, in step R2, within 5 seconds to 1 minute after the device starts up, the ECU internally generates an 8-byte random number "Challenge" and sends it to the T-Box to initiate a handshake verification request. This delay design ensures that the critical modules of the system have completed initialization and also reserves the necessary response time for the subsequent security authentication process, thereby guaranteeing the reliability and stability of the verification process.

[0066] In a preferred embodiment of the present invention, the vehicle-mounted IoT terminal T-Box communicates with the vehicle engine controller ECU via a CAN bus.

[0067] Specifically, in this embodiment of the invention, the CAN bus, with its high reliability, real-time performance, and anti-interference capabilities, provides a solid physical foundation for secure communication between the T-Box and the ECU. Under this bus architecture, key data such as time synchronization commands, random number adjustments, and encryption processing are all transmitted through standardized data frames, ensuring the timeliness and integrity of command delivery.

[0068] Furthermore, the inherent broadcast characteristics and message ID filtering mechanism of the CAN bus not only meet the needs of multi-node collaborative work within the system, but also set independent communication priorities for critical security messages, effectively avoiding interference from non-secure gateway communication on the authentication process. This creates a stable, efficient, and protected data interaction channel in the complex vehicle electrical environment, laying a solid foundation for the reliable execution of upper-layer encryption authentication algorithms.

[0069] In a preferred embodiment of the present invention, in step S1, the vehicle-mounted IoT terminal T-Box obtains the current time information through its internally integrated Beidou positioning module or RTC clock circuit.

[0070] Specifically, since agricultural machinery operations are often located in remote areas with weak mobile network signal coverage, relying solely on network time synchronization poses reliability risks. This invention innovatively employs a dual time synchronization scheme, with the BeiDou positioning module and the RTC clock circuit serving as backups for each other. The BeiDou positioning module can directly obtain high-precision standard time from satellite signals, ensuring the authority and tamper resistance of the time source; while in situations where the signal is temporarily blocked, the built-in high-precision RTC clock circuit provides a continuous and stable local time reference. This dual protection mechanism effectively avoids interruptions or misjudgments in the security authentication process due to time source failure or asynchrony, ensuring the accuracy and consistency of the time factor M relied upon in the dynamic key generation and verification process, fundamentally improving the environmental adaptability and robustness of the entire anti-disassembly system.

[0071] In a preferred embodiment of the present invention, the vehicle-mounted IoT terminal T-Box also integrates a 5G communication module for wireless data interaction with a remote monitoring platform.

[0072] Specifically, in this embodiment of the invention, the 5G communication module, with its high bandwidth, low latency, and massive connectivity, provides the system with remote management capabilities that surpass traditional communication methods. This module not only efficiently uploads key information such as the device's real-time location, operating status, and security authentication logs to the monitoring platform, enabling panoramic and visual management of the device; more importantly, it constructs a reliable remote command downlink channel. The monitoring platform can use this channel to send security commands to the T-Box when necessary (such as in case of risk warnings, device disconnection, or changes in legitimate permissions), for example, triggering key updates, initiating remote vehicle locking, or executing unlocking authorization. This extends security policies beyond local execution on the vehicle network, creating a layered defense system integrating local protection and cloud-based control, significantly enhancing enterprises' asset security management capabilities and emergency response efficiency.

[0073] As a preferred embodiment of the present invention, refer to Figure 2 Step S3 includes:

[0074] Step S31: Calculate the private key index using the private key selection function F_{key}(M);

[0075] Step S32: Select the corresponding private key from the key pool as the current private key K1 according to the private key index.

[0076] Specifically, in this embodiment of the invention, by introducing a mathematical function based on a time factor M to dynamically calculate the key index, the automation and regularity of private key selection are achieved. The private key selection function is as follows:

[0077] Where K is a preset positive integer time interval constant, and M is the current time in minutes. This indicates the floor function.

[0078] The following is an illustration using a specific example:

[0079] Example 1:

[0080] If the time interval constant K = 6, then the private key index... This function implements a mechanism that automatically switches the private key every 6 minutes. For example, when the minute value M is 0-5, index = 0, and the system selects the 0th private key in the key pool; when M is 6-11, index = 1, and the system switches to the 1st private key, and so on. This periodic key rotation strategy significantly increases the difficulty for attackers to crack the keys, effectively improving the security of the communication process, while ensuring that the system only needs to pre-set a limited number of keys.

[0081] As a preferred embodiment of the present invention, refer to Figure 3 Step S4 includes:

[0082] Step S41: Determine the number of shifts, shift_times, based on the time factor M;

[0083] Step S42: Perform a cyclic left shift operation on the random number Challenge.

[0084] Step S43: Extract the first i bytes of the data after the circular left shift as the temporary public key K2.

[0085] Specifically, in this embodiment of the invention, by dynamically transforming the random number Challenge based on a time factor, the randomness and unpredictability of each authentication session are further enhanced. The public key processing function can be expressed as:

[0086] shift_times = F_{shift}(M)

[0087] Msg=Truncate(RotateLeft(Challenge,shift_times),i)

[0088] in:

[0089] F_{shift}(M) is the function for calculating the number of shifts, which can be dynamically determined based on the time factor M;

[0090] Challenge is a random number sent by the ECU;

[0091] RotateLeft() represents a circular left shift operation;

[0092] Truncate() is a truncation function that truncates a length of i bytes.

[0093] The following is an illustration using a specific example:

[0094] Example 2:

[0095] The function for calculating the number of shifts is set as follows: The truncation length i = 4. This function changes the shift rule every 6 minutes. For example, when M = 8, The system will perform a single circular left shift on the 8-byte Challenge and take the first 4 bytes of the result as K2; when M=15, Then, a left shift is performed twice, followed by truncation. This dynamic transformation mechanism ensures that even the same random number Challenge will generate completely different temporary public keys K2 at different times, effectively resisting replay attacks and increasing the randomness of the encryption result.

[0096] In a preferred embodiment of the present invention, the encryption algorithm in step S5 is an elliptic curve digital signature algorithm.

[0097] Specifically, in this embodiment of the invention, the elliptic curve digital signature algorithm adopts either the national cryptographic SM2 algorithm or the ECDSA algorithm. This algorithm includes two processes: signature generation and signature verification. During signature generation, the T-Box uses the selected private key K1 and temporary public key K2, and processes them through elliptic curve dot product and hash functions to generate a digital signature containing two large integers (r, s). During signature verification, the ECU performs a reverse operation on the received signature, and determines the validity of the signature by verifying whether the mathematical relationship holds. This security mechanism based on mathematical problems ensures that even if an attacker obtains multiple communication data, they cannot deduce the device's private key information, providing the system with strong resistance to cryptanalysis.

[0098] More specifically, in this embodiment of the invention, the process of generating a signature using the elliptic curve digital signature algorithm is as follows: The T-Box uses its currently selected private key K1 to digitally sign the temporary public key K2. This algorithm, based on elliptic curve cryptography, can achieve security strength comparable to traditional asymmetric cryptographic algorithms with longer keys using a shorter key length (e.g., 256 bits), making it particularly suitable for in-vehicle embedded terminal environments where computing power, storage space, and communication bandwidth are limited. During the signing process, the T-Box uses its currently selected private key K1 to digitally sign the temporary public key K2, generating unique signature data as the encryption result. This process not only ensures the confidentiality of the data but, more importantly, provides identity authentication and integrity verification functions, ensuring that the response is indeed generated by a legitimate T-Box holding the correct private key and has not been tampered with during transmission. The application of the elliptic curve digital signature algorithm, while meeting high security requirements, significantly reduces the computational and communication overhead of the system and optimizes overall performance.

[0099] In a preferred embodiment of the present invention, the vehicle engine controller ECU uses a pre-stored T-Box public key K3 to verify the encryption result. If the verification is successful, the device operates normally. If the verification fails, a handshake verification request is initiated again after a period of time. If multiple verifications fail consecutively, a device lock operation is performed to prevent the device from starting, including:

[0100] The vehicle engine controller (ECU) determines the current T-Box public key K3 based on the time factor M, using the same private key selection rule as the vehicle-mounted IoT terminal (T-Box).

[0101] The received encryption result is decrypted using the current T-Box public key K3 to obtain the decryption public key K2”;

[0102] The vehicle engine controller (ECU) processes the locally stored random number Challenge based on the time factor M using the same public key processing rules as the in-vehicle IoT terminal (T-Box), and generates a local reference public key K2'.

[0103] The local reference public key K2' is compared with the decryption public key K2". If they match, the verification is successful; otherwise, the verification fails. The vehicle engine controller ECU waits for a period of time and then initiates a handshake verification request again. If the verification fails multiple times in a row, the ECU is locked to prevent the device from starting.

[0104] Specifically, in this embodiment of the invention, the verification process on the ECU side strictly corresponds to the signature process on the T-Box side, ensuring the rigor of the verification logic. Since the ECU and T-Box have achieved time synchronization through step R1, both parties independently execute the same key selection and data transformation rules based on the same time factor M. The specific verification process is as follows:

[0105] First, the ECU determines the T-Box public key K3 to be used based on the time factor M using the same private key selection rule F_key(M) function.

[0106] Subsequently, the ECU uses the public key K3 to decrypt the received digital signature, obtaining the decryption result K2.

[0107] At the same time, the ECU uses the same dynamic transformation rules as the T-Box (the same F_shift(M) function and truncation length i) to process the locally stored raw random number Challenge and generate the local reference public key K2'.

[0108] Finally, the decrypted K2” is compared with the locally calculated K2’. If they match, it proves that the T-Box holds the correct private key and the communication process is complete, and the verification is successful. If they do not match, it indicates that the authentication has failed. At this time, the ECU waits for 10 seconds and then initiates a handshake verification request again. If the verification fails three times in a row, the device is locked and the device is prevented from starting.

[0109] This verification process ensures that only legitimate T-Boxes with the correct private key and the ability to perform dynamic transformations correctly can pass the verification, effectively preventing unauthorized access.

[0110] In summary, this invention provides a method for preventing the dismantling of agricultural machinery T-Boxes based on encryption algorithms. By introducing a dynamic key selection and data transformation mechanism centered on a time factor, combined with an elliptic curve digital signature algorithm, a highly efficient and reliable security authentication system is constructed. This method utilizes time synchronization, random number challenge-response, and dynamic cryptographic parameters to ensure the uniqueness of each authentication session and resistance to replay attacks. Simultaneously, through a dual-key management strategy and optional online update functionality, it balances system deployment flexibility with long-term security. This invention effectively solves industry pain points such as the vulnerability of static keys to cracking and the susceptibility of communication links to attacks. It provides a high-strength, low-cost, and easily integrated proactive security protection solution for high-value agricultural machinery with limited hardware resources, demonstrating significant practical value and promising prospects for widespread adoption.

[0111] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preventing the disassembly of agricultural machinery T-Boxes based on encryption algorithms, characterized in that, include: Step S1: The vehicle-mounted IoT terminal T-Box obtains the current time information and sends the current time information to the vehicle engine controller ECU; Step S2: The in-vehicle IoT terminal T-Box receives a random number Challenge from the vehicle engine controller ECU. Step S3: The vehicle-mounted IoT terminal T-Box selects a current private key K1 from the key pool based on the time factor M in the current time information and according to the preset private key selection rules. Step S4: The vehicle-mounted IoT terminal T-Box processes the random number Challenge based on the time factor M in the current time information and uses a preset public key processing rule to generate a temporary public key K2. Step S5: The vehicle-mounted IoT terminal T-Box, based on the current private key K1, encrypts the temporary public key K2 using an encryption algorithm to generate an encryption result; Step S6: The encryption result is sent to the vehicle engine controller ECU for verification by the vehicle engine controller ECU.

2. The method for preventing disassembly of agricultural machinery T-Box based on encryption algorithm according to claim 1, characterized in that, Also includes: The vehicle engine controller (ECU) receives current time information from the in-vehicle IoT terminal T-Box and calibrates the local time based on the current time information; After the device is started, the vehicle engine controller ECU generates a random number Challenge and sends the random number Challenge to the vehicle IoT terminal T-Box to initiate a handshake verification request. The vehicle engine controller (ECU) receives the encrypted result from the in-vehicle IoT terminal T-Box; The vehicle engine controller (ECU) uses the pre-stored T-Box public key K3 to verify the encryption result. If the verification is successful, the device will work normally. If the verification fails, it will wait for a period of time and then initiate a handshake verification request again. If the verification fails multiple times in a row, the device will be locked to prevent it from starting.

3. The method for preventing disassembly of agricultural machinery T-Box based on encryption algorithm according to claim 2, characterized in that, The time factor M is the minute value of the current time.

4. The method for preventing disassembly of agricultural machinery T-Box based on encryption algorithm according to claim 3, characterized in that, Step S3 includes: Step S31: Calculate the private key index using the private key selection function F_{key}(M); Step S32: Select the corresponding private key from the key pool as the current private key K1 according to the private key index.

5. The method for preventing disassembly of agricultural machinery T-Box based on encryption algorithm according to claim 4, characterized in that, The private key selection function in step S31 is: Where K is a preset positive integer time interval constant.

6. The method for preventing disassembly of an agricultural machinery T-Box based on an encryption algorithm according to claim 3, characterized in that, Step S4 includes: Step S41: Determine the number of shifts, shift_times, based on the time factor M; Step S42: Perform a cyclic left shift operation on the random number Challenge. Step S43: Extract the first i bytes of the data after the circular left shift as the temporary public key K2.

7. The method for preventing disassembly of agricultural machinery T-Box based on encryption algorithm according to claim 1, characterized in that, The encryption algorithm in step S5 is the elliptic curve digital signature algorithm.

8. A method for preventing disassembly of agricultural machinery T-Box based on encryption algorithm according to claim 3, characterized in that, The vehicle engine controller (ECU) uses the pre-stored T-Box public key K3 to verify the encryption result. If the verification is successful, the device operates normally. If the verification fails, it waits for a period of time and then initiates a handshake verification request again. If multiple verifications fail consecutively, a device lock operation is performed to prevent the device from starting, including: The vehicle engine controller (ECU) determines the current T-Box public key K3 based on the time factor M, using the same private key selection rule as the vehicle-mounted IoT terminal (T-Box). The received encryption result is decrypted using the current T-Box public key K3 to obtain the decryption public key K2”; The vehicle engine controller (ECU) processes the locally stored random number Challenge based on the time factor M using the same public key processing rules as the in-vehicle IoT terminal (T-Box), and generates a local reference public key K2'. The local reference public key K2' is compared with the decryption public key K2". If they match, the verification is successful; otherwise, the verification fails. The vehicle engine controller ECU waits for a period of time and then initiates a handshake verification request again. If the verification fails multiple times in a row, the ECU is locked to prevent the device from starting.

9. A method for preventing disassembly of agricultural machinery T-Box based on encryption algorithm according to claim 1, characterized in that, In step S1, the vehicle-mounted IoT terminal T-Box obtains the current time information through its internally integrated Beidou positioning module or RTC clock circuit.

10. A method for preventing disassembly of agricultural machinery T-Box based on an encryption algorithm according to claim 1, characterized in that, The in-vehicle IoT terminal T-Box communicates with the vehicle engine controller ECU via a CAN bus.

Images