A vehicle fault remote diagnosis method and system based on information security technology

Abstract

This application relates to a remote vehicle fault diagnosis method and system based on information security technology, applied to a vehicle fault diagnosis system, including the following steps: acquiring vehicle fault information and matching it with a target security policy; generating a dynamic session key and encrypting the encrypted target object; acquiring the public key of the target cloud platform and encrypting the dynamic session key; encapsulating the corresponding dataset according to the target security policy to generate a secure data packet; sending the secure data packet to the target cloud platform, so that the target cloud platform, after receiving the secure data packet, performs data authentication and fault diagnosis based on the decrypted encrypted target object. In summary, this application achieves differentiated security processing by matching the fault code with the target security policy and dynamically generating a session key, which can dynamically adjust the security policy according to the urgency of the fault, improve the response speed of emergency faults, and enhance the security of non-emergency faults.

Description

Technical Field

[0001] This application relates to the technical field of vehicle fault diagnosis, and in particular to a method and system for remote vehicle fault diagnosis based on information security technology. Background Technology

[0002] With the rapid development of intelligent connected vehicles, remote vehicle diagnostics technology has become an indispensable and important component of modern automotive maintenance systems. Currently, mainstream remote vehicle diagnostic systems typically employ static secure communication protocols to handle data transmission between the vehicle and the cloud platform. However, this fixed-mode security mechanism is increasingly showing significant limitations in practical applications. In emergency fault scenarios, such as those involving critical faults in the powertrain or braking system, existing technologies struggle to provide a rapid-response secure communication mechanism, leading to delays in fault information transmission that could jeopardize driving safety. Conversely, in non-emergency fault scenarios, existing technologies lack targeted security enhancements, making the diagnostic process vulnerable to security threats such as man-in-the-middle attacks and data tampering.

[0003] Specifically, for emergency failures, complex encryption and verification processes can significantly increase information transmission delays; for non-emergency failures, simple encryption mechanisms are insufficient to provide adequate security; and existing technologies cannot dynamically adjust encryption strategies and security verification strengths based on failure characteristics, lacking differentiated data encapsulation mechanisms for different failure types. Summary of the Invention

[0004] To address the aforementioned shortcomings, this application provides a method and system for remote vehicle fault diagnosis based on information security technology.

[0005] The above-mentioned objective of this application is achieved through the following technical solution:

[0006] A remote vehicle fault diagnosis method based on information security technology, the method being applied to a vehicle fault diagnosis system, the vehicle fault diagnosis system including a vehicle terminal and a target cloud platform, the method comprising the following steps:

[0007] Obtain vehicle fault information and identify fault codes, and match target safety strategies based on fault codes. The target safety strategies include a first safety strategy for emergency faults and a second safety strategy for non-emergency faults.

[0008] A dynamic session key is generated based on the target security policy, and the target object is encrypted using the dynamic session key to obtain the target encrypted data.

[0009] Obtain the public key of the target cloud platform, and encrypt the dynamic session key using the public key to obtain the encrypted session key;

[0010] According to the target security policy, the corresponding dataset is encapsulated to generate a security data packet. The dataset corresponding to the first security policy includes the encrypted session key and the target encrypted data, and the dataset corresponding to the second security policy includes vehicle fault information, the encrypted session key and the target encrypted data.

[0011] The security data packet is sent to the target cloud platform so that the target cloud platform can perform data authentication and fault diagnosis based on the decrypted encrypted target object after receiving the security data packet.

[0012] The encrypted target object is defined by the target security policy. The encrypted target object corresponding to the first security policy includes vehicle fault information, and the encrypted target object corresponding to the second security policy includes a verification mapping table generated based on the fault code.

[0013] The second objective of this invention is achieved through the following technical solution:

[0014] A remote vehicle fault diagnosis system based on information security technology includes:

[0015] The strategy matching module is used to acquire vehicle fault information and identify fault codes, and match target safety strategies according to the fault codes. The target safety strategies include a first safety strategy for emergency faults and a second safety strategy for non-emergency faults.

[0016] The first encryption module is used to generate a dynamic session key based on the target security policy, and to encrypt the target object using the dynamic session key to obtain the target encrypted data.

[0017] The second encryption module is used to obtain the public key of the target cloud platform and encrypt the dynamic session key using the public key to obtain the encrypted session key;

[0018] The data encapsulation module is used to encapsulate vehicle fault information, encrypted session keys, and target encrypted data according to the target security policy, and generate a secure data packet.

[0019] The data sending module is used to send secure data packets to the target cloud platform, so that the target cloud platform can perform data authentication and fault diagnosis based on the decrypted encrypted target object after receiving the secure data packets;

[0020] The encrypted target object is defined by the target security policy. The encrypted target object corresponding to the first security policy includes vehicle fault information, and the encrypted target object corresponding to the second security policy includes a verification mapping table generated based on the fault code.

[0021] This application also relates to a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method for remote diagnosis of vehicle faults based on information security technology.

[0022] In summary, the vehicle fault remote diagnosis method and system provided in this application, based on information security technology, achieves differentiated security processing by matching the target security policy according to the fault code and dynamically generating a session key. It can dynamically adjust the security policy according to the urgency of the fault, improve the response speed of emergency faults, and enhance the security of non-emergency faults. Attached Figure Description

[0023] Figure 1 This is a flowchart of an embodiment of a remote vehicle fault diagnosis method based on information security technology according to this application;

[0024] Figure 2 This is a flowchart of step S10 in an embodiment of a vehicle fault remote diagnosis method based on information security technology according to this application;

[0025] Figure 3 This is a flowchart of step S20 in an embodiment of a vehicle fault remote diagnosis method based on information security technology according to this application. Detailed Implementation

[0026] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.

[0027] In one embodiment, such as Figure 1 As shown, this application discloses a remote vehicle fault diagnosis method based on information security technology, applied to a vehicle fault diagnosis system. The vehicle fault diagnosis system includes a vehicle terminal and a target cloud platform, and specifically includes the following steps:

[0028] S10: Obtain vehicle fault information and identify fault codes, and match target safety strategies according to fault codes. The target safety strategies include a first safety strategy for emergency faults and a second safety strategy for non-emergency faults.

[0029] In this embodiment, the vehicle fault diagnosis system refers to an integrated platform whose main function is to detect, analyze, and diagnose abnormal conditions that occur during vehicle operation. This system consists of two parts: a vehicle terminal and a target cloud platform, which work together to achieve remote fault diagnosis. The vehicle terminal refers to a collection of hardware and software modules installed inside the vehicle, responsible for real-time monitoring of various vehicle operating parameters, identifying fault information, and performing tasks such as data encryption, encapsulation, and communication with the target cloud platform. The target cloud platform is a remote data processing center with powerful computing and storage capabilities. It receives secure data packets from the vehicle terminal, performs data decryption, authentication, and fault diagnosis, and can send instructions or provide further services to the vehicle terminal. Vehicle fault information refers to the collection of all relevant data describing the fault state, collected and generated by modules such as the electronic control unit when a fault occurs. Furthermore, vehicle fault information includes fault codes, status parameters, and context information. Status parameters refer to the real-time operating data of the vehicle at the time of the fault, such as vehicle speed. The information includes engine speed, battery voltage, temperature, and pressure; contextual information refers to precise timestamps, vehicle identifiers, and the number of fault occurrences (counts); fault codes, or diagnostic fault codes, are standardized codes used by vehicle electronic systems to identify specific fault types, following industry standards (such as OBD-II standards), for example, P0300 indicates "random / multi-cylinder misfire"; the target security policy refers to a set of pre-defined security processing rules based on the urgency or type of vehicle faults. The target security policy defines specific requirements for data encryption, key generation, data encapsulation, and authentication processes to adapt to different security levels; the first security policy is used to handle emergency faults, aiming to ensure that emergency fault information is transmitted to the target cloud platform with the highest priority and lowest latency, typically optimizing encryption and encapsulation processes to reduce processing time; the second security policy is used to handle non-emergency faults, allowing for more stringent and complex security authentication and data integrity checks to combat potential cyberattacks and ensure the security and reliability of data transmission.

[0030] S20: Generate a dynamic session key based on the target security policy, and encrypt the target object using the dynamic session key to obtain the target encrypted data;

[0031] In this embodiment, the dynamic session key refers to the encryption key that is temporarily generated and used in each communication session. Its dynamism enhances the security of communication, and even if a session key is leaked, it will not affect the security of other sessions. The encrypted target object refers to the core data that needs to be encrypted and protected by the dynamic session key under the target security policy. The content of the encrypted target object varies depending on the target security policy matched. For example, in an emergency, it may be the vehicle fault information itself, while in a non-emergency situation, it may be a verification mapping table used for authentication. The target encrypted data refers to the data generated after the encrypted target object has been encrypted by the dynamic session key. The target encrypted data exists in ciphertext form, and only the receiver with the corresponding dynamic session key can decrypt it.

[0032] S30: Obtain the public key of the target cloud platform, and encrypt the dynamic session key using the public key to obtain the encrypted session key;

[0033] In this embodiment, the public key refers to a key that can be publicly distributed to any communicating party in an asymmetric encryption system. The public key is used to encrypt data but cannot be used to decrypt data; decryption requires the use of the corresponding private key. The encrypted session key refers to the data generated after the dynamic session key is encrypted by the public key of the target cloud platform. The encryption process ensures the confidentiality of the dynamic session key during transmission. Only the target cloud platform can decrypt and obtain the original dynamic session key using its private key.

[0034] S40: Encapsulate the corresponding dataset according to the target security policy to generate a security data packet. The dataset corresponding to the first security policy includes the encrypted session key and the target encrypted data. The dataset corresponding to the second security policy includes vehicle fault information, the encrypted session key and the target encrypted data.

[0035] In this embodiment, a secure data packet refers to a data structure formed by encapsulating the encrypted session key, target encrypted data, and other necessary information according to the target security policy. The secure data packet is the carrier sent by the vehicle to the target cloud platform for remote diagnosis and authentication. Data encapsulation refers to the process of assembling the processed data components (such as encrypted data, keys, metadata, etc.) into a secure data packet according to a predetermined format and order.

[0036] S50: Sends a security data packet to the target cloud platform so that the target cloud platform can perform data authentication and fault diagnosis based on the decrypted encrypted target object after receiving the security data packet;

[0037] The encrypted target object is defined by the target security policy. The encrypted target object corresponding to the first security policy includes vehicle fault information, and the encrypted target object corresponding to the second security policy includes a verification mapping table generated based on the fault code.

[0038] In this embodiment, data authentication refers to the process by which the target cloud platform verifies the data source, data integrity, and identities of both communicating parties after receiving a secure data packet, aiming to ensure that the received data is authentic, complete, and untampered. Fault diagnosis refers to the process by which the target cloud platform analyzes vehicle fault information after completing data authentication, determines the fault type and cause, and provides solutions. The verification mapping table is a data structure generated from fault codes under the second security strategy, used for interactive verification with the vehicle during authentication on the target cloud platform. The verification mapping table can contain the correspondence between fault codes and specific response commands to enhance the security of authentication.

[0039] This embodiment provides a remote vehicle fault diagnosis method based on information security technology. The method is applied to a vehicle fault diagnosis system, which includes a vehicle terminal and a target cloud platform. The method dynamically adjusts security strategies to adapt to vehicle faults of different urgency levels, thereby achieving an intelligent dynamic trade-off and adaptation between ensuring real-time communication and pursuing the highest level of security.

[0040] Specifically, the process begins by acquiring vehicle fault information and identifying fault codes. The vehicle can be equipped with an on-board diagnostic interface scanner, which can read fault codes stored in the vehicle's internal electronic control units. For example, when the vehicle's engine control unit detects an abnormality, it generates a specific fault code, which is then retrieved by the on-board diagnostic interface scanner. Alternatively, the vehicle can also collect various operating data in real time through an on-board sensor network, and the on-board diagnostic software can analyze this data to infer potential fault information and generate corresponding fault codes. For instance, when a tire pressure sensor continuously reports a pressure value below a threshold, the on-board diagnostic software can generate a fault code indicating abnormal tire pressure.

[0041] Subsequently, the identified fault codes are matched against the target safety policy. In one implementation, the vehicle can pre-set a static mapping table between fault codes and safety policies. For example, all fault codes related to the braking system are directly mapped to the first safety policy as emergency faults, while fault codes related to the entertainment system are mapped to the second safety policy as non-emergency faults. This static mapping table can be stored in the vehicle's non-volatile memory. In another implementation, the matching process can make a preliminary judgment based on the type or severity of the fault codes. For example, fault codes can be classified into Class A (emergency), Class B (medium), and Class C (non-emergency), and then the corresponding safety policy is directly matched according to the classification.

[0042] Next, a dynamic session key is generated based on the target security policy, and the target object is encrypted using the dynamic session key to obtain the target encrypted data. In one implementation, the dynamic session key can be generated by a random number generator inside the vehicle combined with the current timestamp. For example, the vehicle can obtain a high-precision system timestamp and XOR it with the output of a pseudo-random number generator to generate a temporary session key. This temporary session key is then used to perform symmetric encryption on the target object. For example, if the target security policy is the first security policy, the vehicle fault information is considered the target object and is encrypted using AES with the dynamic session key to generate the target encrypted data. If the target security policy is the second security policy, the verification mapping table generated based on the fault code is considered the target object and is encrypted using the dynamic session key.

[0043] Then, the public key of the target cloud platform is obtained, and the dynamic session key is encrypted using the public key to obtain the encrypted session key. In one implementation, the public key of the target cloud platform can be pre-programmed into the security chip on the vehicle. When it is necessary to encrypt the dynamic session key, the vehicle directly reads the public key from the security chip and uses a standard asymmetric encryption algorithm (such as RSA) to encrypt the entire dynamic session key, thereby generating the encrypted session key. This encrypted session key ensures that only an entity with the private key of the target cloud platform can decrypt and obtain the dynamic session key.

[0044] Furthermore, the corresponding dataset is encapsulated according to the target security policy to generate a secure data packet. The dataset corresponding to the first security policy includes an encrypted session key and target encrypted data, while the dataset corresponding to the second security policy includes vehicle fault information, an encrypted session key, and target encrypted data. In one implementation, data encapsulation can be simply accomplished by sequentially concatenating the various data elements in the dataset. For example, when the first security policy is matched, the byte stream of the encrypted session key is directly appended to the byte stream of the target encrypted data to form a continuous data block as a secure data packet. When the second security policy is matched, the original byte stream of the vehicle fault information, the byte stream of the encrypted session key, and the byte stream of the target encrypted data are sequentially concatenated to form the secure data packet.

[0045] Finally, the security data packet is sent to the target cloud platform so that the target cloud platform can perform data authentication and fault diagnosis based on the decrypted encrypted target object after receiving the security data packet. In one implementation, the vehicle can send the generated security data packet to the target cloud platform via a wireless network through the vehicle communication module. After receiving the security data packet, the target cloud platform first attempts to use its private key to decrypt the encrypted session key to obtain the dynamic session key. Subsequently, the target cloud platform uses the dynamic session key to decrypt the target encrypted data to obtain the original encrypted target object. If the target security policy is the first security policy, the decrypted encrypted target object is vehicle fault information. The target cloud platform can perform integrity verification or format verification on the fault information to complete data authentication and then perform fault diagnosis. If the target security policy is the second security policy, the decrypted encrypted target object is a verification mapping table. The target cloud platform can use this verification mapping table to perform further interactive authentication with the vehicle. After successful authentication, it then performs fault diagnosis based on the vehicle fault information contained in the security data packet.

[0046] For example, as a specific implementation, suppose a smart connected vehicle detects two faults simultaneously while driving: one is an emergency fault of "engine overheating" and the other is a non-emergency fault of "windshield wiper motor malfunction".

[0047] First, the vehicle acquires and identifies these two fault codes. For the "engine overheating" fault code, the vehicle matches it to the first safety strategy according to the preset mapping rules, because engine overheating is an emergency fault that requires immediate response; for the "wiper motor malfunction" fault code, the vehicle matches it to the second safety strategy, because this fault does not directly affect driving safety and allows for more stringent safety verification.

[0048] Specifically, for the "engine overheating" fault (first safety strategy): The vehicle generates a dynamic session key based on the first safety strategy; for example, this dynamic session key can be generated from the vehicle identification number (VIN) and the hash value of the current timestamp; subsequently, the vehicle uses the detailed fault information of "engine overheating" (such as temperature value, sensor ID, etc.) as the encryption target object, and performs symmetric encryption using the dynamic session key to obtain the target encrypted data; simultaneously, the vehicle obtains the public key of the target cloud platform and uses this public key to encrypt the dynamic session key to obtain the encrypted session key; then, the vehicle encapsulates the encrypted session key and the target encrypted data (i.e., the encrypted engine overheating information) into a secure data packet. This data packet is designed to be compact and have a high transmission priority.

[0049] For the "wiper motor malfunction" fault (second security strategy): The vehicle generates another independent dynamic session key based on the second security strategy. The generation method of this dynamic session key can be similar to the first security strategy, but may include additional random factors. Subsequently, the vehicle generates a verification mapping table based on the "wiper motor malfunction" fault code. This mapping table may contain the correspondence between fault codes and specific diagnostic instructions, and this verification mapping table is regarded as the encrypted target object. The vehicle uses the dynamic session key to encrypt the verification mapping table to obtain the target encrypted data. At the same time, the vehicle obtains the public key of the target cloud platform and uses the public key to encrypt the dynamic session key to obtain the encrypted session key. Then, the vehicle encapsulates the original "wiper motor malfunction" fault information, the encrypted session key, and the target encrypted data (i.e., the encrypted verification mapping table) into another secure data packet. This secure data packet may contain more metadata to support subsequent complex authentication processes.

[0050] Subsequently, the vehicle sends these two independent security data packets to the target cloud platform. After receiving these two data packets, the target cloud platform will identify them as corresponding to the first security policy and the second security policy, respectively, based on the policy identifiers hidden in the data packets.

[0051] For the data packets of the first security policy: the target cloud platform uses its private key to decrypt the encrypted session key and obtain the dynamic session key; then, it uses the dynamic session key to decrypt the target encrypted data and obtain the original "engine overheating" fault information; the target cloud platform performs a quick verification of the fault information (e.g., checks the data format and integrity), and after confirming that it is correct, it immediately initiates the emergency fault diagnosis process and issues an alert to the relevant operation and maintenance personnel.

[0052] For the data packet of the second security strategy: the target cloud platform uses its private key to decrypt the encrypted session key and obtain the dynamic session key; then, it uses the dynamic session key to decrypt the target encrypted data and obtain the original verification mapping table; the target cloud platform extracts the original "wiper motor abnormality" fault information from the security data packet and, in conjunction with the verification mapping table, sends an authentication challenge to the vehicle, for example, requiring the vehicle to perform a specific operation and return a result. After the vehicle successfully responds to the challenge, the authentication process is completed; subsequently, the target cloud platform performs fault diagnosis in conjunction with the original fault information and may prompt the vehicle to perform a software update or schedule a repair.

[0053] As can be seen from the above examples, the method of this embodiment can dynamically adjust the security strategy according to the urgency of the fault: for urgent faults, priority is given to ensuring the rapid transmission and diagnosis of fault information, simplifying the authentication process to ensure timely response; for non-urgent faults, a more complex authentication mechanism is introduced, thereby significantly improving the security and reliability of communication without sacrificing real-time performance; this dynamic adaptation mechanism effectively solves the technical problem that fixed security protocols in the prior art cannot take into account both real-time performance and high security.

[0054] Compared to the fixed secure communication protocols commonly used in existing technologies, the technical solution in this embodiment has significant advantages. Existing technologies often employ a uniform security processing procedure for all types of fault information. This can lead to unnecessary delays due to excessive security checks in emergency fault scenarios, thereby delaying critical response time. In non-emergency fault scenarios, it fails to fully utilize the time window to deploy higher-level security protection. This embodiment introduces a target security strategy and dynamically matches either the first or second security strategy based on the fault code, achieving intelligent adaptation of the security processing flow. For example, in an emergency scenario of "engine overheating," this embodiment directly uses vehicle fault information as the encrypted target object and employs a relatively simplified data encapsulation method to ensure rapid reporting and diagnosis of fault information, avoiding delays caused by complex authentication processes. In a non-emergency scenario of "wiper motor malfunction," this embodiment uses a verification mapping table generated based on the fault code as the encrypted target object and allows for more complex interactive authentication on the target cloud platform, thereby providing a higher level of security and effectively resisting potential network attacks. Thus, the method of this embodiment achieves a dynamic balance between ensuring real-time communication and pursuing the highest level of security, improving the overall performance and security of the vehicle fault remote diagnosis system.

[0055] In some implementations, a scheme has been proposed to acquire vehicle fault information and identify fault codes, and then match target safety policies based on the fault codes. However, in practical applications, relying solely on fault codes to match safety policies may not fully reflect the real-time urgency of vehicle faults. For example, the potential risks and handling priorities of the same fault code may differ significantly when the vehicle is in different operating states. If the urgency of the fault is not dynamically assessed, the matching of safety policies may not be accurate enough, thereby affecting the timeliness and effectiveness of fault diagnosis.

[0056] In this regard, this application further proposes that, in one embodiment, as Figure 2 As shown, step S10 includes:

[0057] S11: Query the pre-set fault urgency mapping table and determine the corresponding basic urgency level based on the identified fault code;

[0058] In this embodiment, the pre-set fault urgency mapping table refers to a lookup table pre-stored on the vehicle. This mapping table establishes a fixed correspondence between standard fault codes and basic urgency levels. Typically, this mapping table is developed based on the vehicle manufacturer's safety specifications, historical fault data, and expert experience. The basic urgency level refers to the initial level obtained directly by querying the fault urgency mapping table, which only reflects the inherent danger level of the fault code itself. It is usually discrete, for example, it can be divided into three levels: "high", "medium", and "low", or represented by the numbers 1, 2, and 3.

[0059] S12: Obtain vehicle status information and determine dynamic adjustment factors based on the vehicle status information;

[0060] In this embodiment, vehicle status information refers to the overall operation and environmental context information of the vehicle at the time of the fault, rather than the parameters of the fault itself, which reflects the real-time status of the vehicle; dynamic adjustment factor refers to the adjustment coefficient or adjustment instruction calculated based on vehicle status information through predefined rules, which is used to fine-tune the basic urgency level. For example, rule 1: if the network signal strength is less than 2 bars, the adjustment factor is the adjustment coefficient or adjustment instruction that tends to use a more reliable fast strategy; rule 2: if the vehicle speed is greater than 100 km / h, the adjustment factor is the adjustment coefficient or adjustment instruction that tends to use a safer strategy.

[0061] Furthermore, vehicle status information includes:

[0062] Dynamic operating status: such as current vehicle speed, engine load, and gear information;

[0063] Environmental conditions: such as vehicle location (whether on a highway or in a tunnel) and time (day / night);

[0064] System resource status: such as current network signal strength and CPU load.

[0065] S13: Adjust the basic urgency level by dynamically adjusting the factor to generate an optimized urgency level, and map the optimized urgency level to the corresponding target security policy.

[0066] In this embodiment, the optimized urgency level refers to the urgency determination result obtained after applying the dynamic adjustment factor to the basic urgency level. The optimized urgency level more comprehensively and accurately reflects the actual risk of the current fault in a specific environment.

[0067] Specifically, the steps of querying a pre-set fault urgency mapping table and determining the corresponding basic urgency level based on the identified fault code aim to provide a pre-set, standardized urgency assessment benchmark for each identified fault code. This basic urgency level is an inherent attribute of the fault code itself, regardless of the vehicle's real-time operating status. In one implementation, the vehicle can have a built-in storage module containing a pre-stored fault urgency mapping table. This mapping table can be a hash table, lookup table, or database, associating each fault code with a predefined basic urgency level. When a fault code is identified, the mapping table is directly queried to obtain the corresponding basic urgency level. Alternatively, the fault urgency mapping table can also be stored in the vehicle's erasable and rewritable memory and periodically updated from the cloud platform via an OTA update mechanism to ensure the accuracy and timeliness of the urgency assessment.

[0068] The steps of acquiring vehicle status information and determining dynamic adjustment factors based on this information aim to introduce the vehicle's real-time operating context to dynamically adjust the basic urgency level. Vehicle status information reflects the specific environment and conditions at the time of the fault, while the dynamic adjustment factor is a parameter used to quantify and adjust the urgency level based on this information. Vehicle status information may include, but is not limited to, vehicle speed, engine speed, vehicle load, mileage, ambient temperature, battery charge, driving mode, and vehicle location. This data is collected in real-time by the vehicle via onboard sensors, ECU, or GPS module. The dynamic adjustment factor can be calculated based on preset rules or machine learning models. Additionally, in one implementation, vehicle status information may include historical vehicle health data, such as the wear level of a component or the last maintenance date. The dynamic adjustment factor can be a function that takes vehicle status information as input and outputs a positive or negative value or a multiplier to increase or decrease the basic urgency level.

[0069] The core decision-making process of this embodiment is to adjust the basic urgency level by dynamically adjusting the factor to generate an optimized urgency level, and then map the optimized urgency level to the corresponding target safety strategy. This process combines the static urgency level of the fault code with the dynamic vehicle operating status to generate a more accurate and timely optimized urgency level, and ultimately selects the most suitable safety strategy based on this. The adjustment process can be a simple addition, subtraction, or multiplication operation, for example, optimized urgency level = basic urgency level + dynamic adjustment factor. Then, the vehicle-side system can store a mapping table between optimized urgency levels and safety strategies, for example, optimized levels 1-2 correspond to the second safety strategy, and optimized levels 3-5 correspond to the first safety strategy. Alternatively, the adjustment process can use more complex algorithms, such as fuzzy logic or decision tree models, taking the basic urgency level and dynamic adjustment factor as input, outputting a continuous optimized urgency value, and then discretizing this value into several preset levels. When mapping to the target safety strategy, a threshold can be set, for example, if the optimized urgency level is higher than a certain threshold, the first safety strategy is selected; otherwise, the second safety strategy is selected.

[0070] For example, as a specific implementation, suppose the vehicle identifies a fault code "P0301", which means cylinder 1 misfire. First, the vehicle queries its internally stored fault urgency mapping table, which pre-sets the basic urgency level corresponding to "P0301" to be "medium urgency", for example, a value of 3. Simultaneously, the vehicle obtains real-time vehicle status information, for example, the current speed is 120 km / h, the engine speed is 3000 RPM, and the vehicle is traveling on a highway. According to preset rules, if the speed exceeds 100 km / h and the engine speed is higher than 2500 RPM... RPM, then the dynamic adjustment factor is "high risk", for example, a value of +2; then, the basic urgency level 3 is adjusted with the dynamic adjustment factor +2 to obtain an optimized urgency level of 5; finally, based on the optimized urgency level 5, it is mapped to the corresponding target safety strategy. For example, if the preset rule is to select the first safety strategy when the optimized urgency level is greater than or equal to 4, then the first safety strategy is selected at this time; that is to say, the "cylinder 1 misfire" fault will be regarded as an emergency fault in the current high-speed driving emergency state, thereby triggering the data encapsulation and transmission mechanism defined by the first safety strategy.

[0071] Through the above technical solution, this application overcomes the limitations of traditional fault diagnosis methods that rely solely on fault codes for safety policy matching. By introducing vehicle status information and dynamically adjusting the urgency level of the fault, this solution can more accurately assess the real-time risk of the fault, avoiding resource waste or safety hazards caused by static assessment. For example, the same fault code may be judged as a non-urgent fault when the vehicle is stationary or traveling at low speed, but can be promptly identified as an urgent fault under high-speed driving or critical operating conditions, thereby triggering a higher level of safety policy. This dynamic and intelligent policy matching mechanism enables fault information to be encrypted, encapsulated, and transmitted in a manner most appropriate to its urgency level, significantly improving the timeliness, accuracy, and security of remote fault diagnosis. Especially in emergency situations, it ensures that critical fault information is prioritized for processing and transmission, providing a reliable guarantee for the target cloud platform to respond and make decisions quickly, thereby effectively reducing the risks that vehicle faults may bring.

[0072] In other implementations, if the generation process of the dynamic session key lacks sufficient randomness, correlation, and security, the key may be easily predicted or cracked, thereby jeopardizing the confidentiality and integrity of the encrypted data. Furthermore, how to flexibly define the encrypted object according to different security strategies and ensure its encryption strength is also a problem that needs to be addressed.

[0073] In this regard, this application further proposes that, in one embodiment, as Figure 3 As shown, step S20 includes:

[0074] S21: Obtain the basic factors used to generate the dynamic session key, the basic factors including the vehicle information identifier and the current timestamp;

[0075] In this embodiment, the basic factor refers to the initial input information used to generate the dynamic session key. The basic factor is the starting point of the key generation process, and its diversity and unpredictability directly affect the strength of the final key. The basic factor includes the vehicle information identifier and the current timestamp. The vehicle information identifier is a unique sequence of numbers or characters that identifies a vehicle, such as a vehicle identification number (VIN), license plate number, or a unique device ID inside the vehicle. Its function is to provide an identity marker for each vehicle, ensuring that the key generation is bound to a specific vehicle and improving the exclusivity of the key. The vehicle information identifier can be read from the vehicle's electronic control unit or pre-configured when the vehicle leaves the factory. The current timestamp is a numerical value representing a specific point in time, usually the number of seconds or milliseconds since a fixed point in time. Its function is to introduce randomness and freshness in the time dimension, ensuring that each key generation is related to the current moment and preventing replay attacks. The timestamp can be provided by the vehicle's internal clock module or obtained by synchronizing with an external time server.

[0076] S22: Obtain the corresponding specific factors according to the target security policy, and combine the specific factors with the basic factors to generate combined factors;

[0077] In this embodiment, the specific factor is additional input information dynamically selected based on the target security policy matched by the current diagnostic task. Its function is to introduce contextual information related to specific business data into the key generation process according to the urgency of the fault and security requirements, thereby enhancing the relevance and security of the key. The combined factor is a comprehensive input data formed by fusing the basic factor and the specific factor in some way. Its function is to gather multi-dimensional information such as vehicle identity, time freshness, and business context, providing richer and more complex inputs for subsequent key derivation functions, thereby improving the randomness and anti-attack capability of the dynamic session key. The combination methods include simple concatenation, XOR operation, hash operation, etc.

[0078] S23: Input the combination factor into the preset key derivation function to generate a dynamic session key;

[0079] In this embodiment, the key derivation function is a cryptographic function that derives one or more keys from a secret value (such as a combination factor). Key derivation functions typically possess properties such as one-wayness, collision resistance, and avalanche effect, enabling them to convert inputs of arbitrary length into fixed-length, high-quality keys. Utilizing the complexity of the combination factor, the key derivation function securely generates dynamic session keys with sufficient entropy and randomness through cryptographic transformations. Common key derivation functions include PBKDF2 and HKDF. The dynamic session key is a symmetric key dynamically generated by the key derivation function based on the base factor and specific factors, used only in the current session. Its function is to serve as the key for symmetric encryption algorithms, encrypting sensitive data and ensuring data confidentiality during transmission. Because it is dynamically generated and bound to a specific session, even if leaked, it only affects the current session, reducing long-term risks.

[0080] S24: Using a dynamic session key, perform encryption operations on the encrypted target object corresponding to the target security policy to generate target encrypted data;

[0081] Wherein, if the target security policy is the first security policy, the specific factor includes the integrity verification value of the vehicle fault information; if the target security policy is the second security policy, the specific factor includes the integrity verification value of the verification mapping table.

[0082] In this embodiment, the encrypted target object is the data that needs to be encrypted and protected according to the target security policy definition. Its function is to clarify the core information that needs to be protected and ensure that only authorized parties can decrypt and obtain it. Encryption operation refers to the process of converting the encrypted target object into data using a dynamic session key and a symmetric encryption algorithm. Its function is to achieve data confidentiality protection, converting the original data into unreadable ciphertext to prevent unauthorized access. When the target security policy is the first security policy, corresponding to an emergency fault scenario, the real-time and integrity requirements for data transmission are high. The integrity check value of the vehicle fault information is the hash value or... calculated from the vehicle fault information (such as fault codes, sensor data, etc.). The message authentication code serves as a specific factor, linking the specific content of the fault information to the key generation process. This ensures that the key generation is closely related to the authenticity of the current fault data. If the fault information is tampered with, the verification value will not match, thus affecting key generation or subsequent authentication. When the target security policy is the second security policy, corresponding to non-emergency fault scenarios, a stronger authentication mechanism may be required. The integrity verification value of the verification mapping table is a hash value or message authentication code calculated based on the verification mapping table generated from the fault code. Its function is to serve as a specific factor, linking the core data of the authentication mechanism to the key generation process, strengthening the binding between the key and the authentication logic, and improving the security of the non-emergency fault diagnosis process.

[0083] Specifically, the process involves obtaining fundamental factors for generating dynamic session keys. These factors include vehicle information identifiers and the current timestamp, which provide the vehicle's unique identity and time freshness, laying the foundation for key generation. Subsequently, specific factors are obtained based on the currently matched target security policy. When handling emergency faults, these specific factors serve as integrity verification values ​​for vehicle fault information, closely linking key generation to the authenticity of the fault data. When handling non-emergency faults, these specific factors serve as integrity verification values ​​for the verification mapping table, tightly binding key generation to subsequent authentication logic. By combining these specific factors with the fundamental factors, a combined factor containing multi-dimensional security context information is generated. This combined factor is then input into a pre-set key derivation function, undergoing a series of cryptographic transformations to generate a key with high security context. A dynamic session key with randomness and strength, unique to the current diagnostic session, effectively avoids the security risks associated with key reuse. Finally, the dynamic session key is used to perform encryption operations on the encrypted target object defined by the target security policy, thereby generating the target encrypted data. For example, in an emergency fault scenario, the encrypted target object is the vehicle fault information itself; while in a non-emergency fault scenario, the encrypted target object is a verification mapping table generated based on the fault code. This method of dynamically adjusting the encrypted object according to the security policy and using a dynamic key for encryption not only ensures the confidentiality of critical data but also significantly improves the security and flexibility of the entire diagnostic communication process by integrating business context information into the key generation process, effectively solving the security vulnerabilities that may arise from traditional fixed-key or simple key generation methods.

[0084] For example, as a specific implementation, after the vehicle acquires vehicle fault information and identifies the fault code, it matches the corresponding target security policy based on the fault code. Assuming the current matched security policy is the first one, indicating an emergency fault, the vehicle first reads the vehicle identification number (VIN) from the vehicle's ECU as the vehicle information identifier and obtains the current UTC timestamp from the vehicle's internal real-time clock module. Simultaneously, it calculates the SHA-256 hash value of the current vehicle fault information as the integrity verification value. Then, it concatenates the VIN, timestamp, and SHA-256 hash value to form a combination factor; for example, the binary representations of the VIN, timestamp, and hash value can be sequentially linked. Next, the vehicle... The terminal inputs this combination factor into a preset key derivation function, such as HKDF based on HMAC. The HKDF function uses the combination factor as input key material and combines it with preset salt value and context information to generate a 256-bit dynamic session key through iterative calculation. This dynamic session key is only used for the current session. Since the current security policy is the first security policy, the encrypted target is vehicle fault information. The vehicle terminal uses this dynamic session key to encrypt the original vehicle fault information in GCM mode using the AES-256 symmetric encryption algorithm to obtain the target encrypted data. This method ensures that critical fault information can be securely encrypted and transmitted in emergency fault scenarios, and the key generation is closely related to the vehicle, time, and fault data itself, thus improving security.

[0085] Through the above technical solution, this application achieves the generation of dynamic session keys and secure processing of encrypted target objects during remote vehicle fault diagnosis. By introducing vehicle information identifiers and current timestamps as basic factors, the uniqueness and timeliness of key generation are ensured. Furthermore, according to different target security strategies, the integrity verification value of vehicle fault information or the integrity verification value of the verification mapping table is dynamically introduced as a specific factor, making the generated dynamic session key closely related to specific business scenarios and data content. This combination of basic and specific factors provides richer and more complex inputs to the key derivation function, significantly enhancing the randomness, anti-predictability, and anti-replay attack capabilities of the dynamic session key. In addition, this embodiment flexibly defines encrypted target objects according to target security strategies and encrypts them using dynamic session keys, thereby ensuring the confidentiality of critical data. For example, in emergency fault scenarios, vehicle fault information is directly encrypted to ensure rapid and secure transmission of fault information; in non-emergency fault scenarios, the verification mapping table is encrypted, providing stronger security for subsequent authentication processes. The mechanism described above effectively solves the problems that traditional key generation methods may have, such as fixed keys, easy prediction, or disconnect from business scenarios, and significantly improves the overall security, flexibility, and reliability of data transmission during remote vehicle fault diagnosis.

[0086] In some embodiments described above in this application, a scheme is proposed to generate a dynamic session key based on a target security policy, and to encrypt the target object using the dynamic session key to obtain the target encrypted data. This scheme involves combining basic factors with specific factors to generate a combined factor. However, if the combination of basic factors and specific factors is too simple or fixed, such as direct concatenation, the generated combined factor may lack sufficient randomness and complexity. This makes the subsequently generated dynamic session key susceptible to prediction or reverse analysis, reducing the overall security of information transmission.

[0087] In this regard, this application further proposes that, in one embodiment, step S22 includes:

[0088] S221: Match predefined bit obfuscation rules according to the target security policy and obtain dynamic communication parameters, including the current wireless signal strength value and the low-order bits of the data packet sequence number;

[0089] In this embodiment, matching predefined bit obfuscation rules according to the target security policy refers to selecting a pre-set bit obfuscation algorithm or rule pattern based on the current target security policy. The bit obfuscation rule can be a set of different bit operation sequences, permutation tables, or logical operation combinations used to scramble the original order of the data bit sequence, aiming to perform complex and irreversible bit-level rearrangement and transformation on the input data. The matching process can search in a preset rule base based on the policy identifier to ensure that the selected rule is adapted to the current security requirements. Obtaining dynamic communication parameters refers to the real-time collection of parameters that change with time or environment by the vehicle end or extraction from the communication module. These dynamic communication parameters have a certain degree of randomness and unpredictability, which can introduce additional entropy into the key generation process. The dynamic communication parameters may include, but are not limited to, the current wireless signal strength value, such as the received signal strength indication value of cellular network or Wi-Fi signals obtained through the vehicle communication module; and the low-order bits of the data packet sequence number, such as the least significant bit of the sequence number extracted from the header of the data packet currently being sent or received.

[0090] For example, bit confusion rules include: bit interleaving rules: specifying how to interleave the bits of two bit sequences like shuffling cards (e.g., bits a1, a2... of sequence A and bits b1, b2... of sequence B are interleaved to a1, b1, a2, b2...).

[0091] Bit block permutation rules: These rules specify how to rearrange the order of bits after dividing a bit sequence into multiple blocks.

[0092] Bitwise XOR rules: Define how to perform an XOR operation between a bit sequence and a mask sequence.

[0093] S222: Generate the obfuscation operation parameters corresponding to the bit obfuscation rules based on the bit obfuscation rules and dynamic communication parameters;

[0094] In this embodiment, the obfuscation operation parameter refers to the specific value calculated based on the bit obfuscation rule and dynamic communication parameters, used to precisely control a single obfuscation operation. Generating the obfuscation operation parameter corresponding to the bit obfuscation rule based on the bit obfuscation rule and dynamic communication parameters means using the dynamic communication parameters to parameterize or adjust the matched bit obfuscation rule to generate specific control parameters for performing the obfuscation operation. For example, the dynamic communication parameters can be used as a seed input into a pseudo-random number generator, which outputs a specific permutation table or permutation sequence according to the type of bit obfuscation rule. Alternatively, the dynamic communication parameters can determine the step size of bit interleaving, the mask of XOR operation, etc.

[0095] S223: Based on the matched bit confusion rules and confusion operation parameters, perform corresponding confusion operations on the data bits of the basic factor and the data bits of the specific factor. The confusion operations include bit interleaving, bit block permutation, and bitwise XOR.

[0096] In this embodiment, based on the matched bit obfuscation rules and obfuscation operation parameters, corresponding obfuscation operations are performed on the data bits of the basic factor and the data bits of the specific factor. This means taking the binary data bits of the basic factor and the specific factor as input and performing bit-level operations according to the matched bit obfuscation rules and the generated obfuscation operation parameters. Among them, the obfuscation operations include bit interleaving, bit block permutation, and bitwise XOR. Bit interleaving refers to alternating the bits of two or more input data streams according to a specific pattern to form a new data stream. For example, odd bits are taken from the basic factor and even bits are taken from the specific factor. Bit block permutation refers to dividing the data stream into several fixed-size bit blocks and then rearranging the positions of these bit blocks according to a preset permutation table or a dynamically generated permutation sequence. Bitwise XOR refers to performing a logical XOR operation on the corresponding bits of two input data streams to generate new bits. The above obfuscation operations can be used individually or in combination to scramble the bit order and value of the original data to the greatest extent and increase the complexity of the combined factors.

[0097] Specifically, the solution in this embodiment significantly enhances the security of the combination process of basic factors and specific factors by introducing a dynamic bit obfuscation mechanism. Specifically, firstly, based on the current target security strategy, predefined bit obfuscation rules are intelligently matched, enabling the combination method to adaptively adjust according to emergency or non-emergency fault scenarios, thereby meeting the requirements of different security levels. Subsequently, dynamic communication parameters such as the current wireless signal strength value and the low-order bits of the data packet sequence number are acquired in real time. These parameters have high randomness and unpredictability, introducing an additional entropy source into the combination process. Based on the dynamic communication parameters and the matched bit obfuscation rules, dynamic obfuscation operation parameters are further generated, meaning that the specific execution method of bit obfuscation is no longer fixed but changes with the real-time environment and communication state. Finally, using the dynamically generated obfuscation operation parameters, obfuscation operations, including bit interleaving, bit block permutation, and bitwise XOR, are performed on the data bits of the basic and specific factors. Through this multi-level, dynamic bit-level processing, the basic and specific factors, after combination, form a highly complex and unpredictable combination factor. Compared to simple splicing or fixed combination methods, this scheme increases the difficulty for attackers to infer the original factors or predict the dynamic session key by analyzing the combination factors, thereby effectively improving the generation strength of the dynamic session key and the overall security of communication.

[0098] For example, as a specific implementation, assume the current target security policy is a first security policy, i.e., for emergency faults; the vehicle first obtains basic factors, such as the binary representation of the vehicle information identifier and the binary representation of the current timestamp; simultaneously, it obtains specific factors, i.e., the binary representation of the integrity check value of the vehicle fault information; to generate combined factors, it matches the predefined high-strength bit obfuscation rules according to the first security policy, then obtains dynamic communication parameters, such as the current wireless signal strength value of -80dBm, converts it into a value, such as 120, and the low-order bits of the current data packet sequence number are 0110; these dynamic communication parameters are then... The parameters are input into a hash function, and combined with the identifier of the matched bit-obfuscation rule, a seed value is generated. This seed value is used to initialize a pseudo-random number generator, which in turn generates specific obfuscation operation parameters, such as a permutation table for bit block permutation and a mask for bitwise XOR. Then, the data bits of the base factor and the specific factor are bit-interleaved; for example, the odd bits of the base factor are alternated with the even bits of the specific factor. Next, the interleaved data stream is divided into several bit blocks, and these bit blocks are rearranged according to the generated permutation table. Finally, the bit-block permuted data stream is bitwise XORed with the generated XOR mask. After these dynamic and complex bit-obfuscation operations, a highly randomized and security-enhanced combination factor is obtained. This combination factor is then used in the key derivation function to generate a dynamic session key.

[0099] The above technical solution endows the combination process of basic factors and specific factors with high dynamism and complexity, effectively avoiding the predictability problem caused by simple combination of factors; at the same time, this dynamic bit obfuscation mechanism, combined with real-time changing dynamic communication parameters, makes each generated combination factor have unique randomness, thereby significantly improving the generation strength and anti-attack capability of dynamic session keys, and improving the confidentiality and integrity of information transmission during remote vehicle fault diagnosis.

[0100] In other implementations, if the number of iterations in the key derivation function is fixed during the generation of the dynamic session key, it may not adequately meet the varying security and computational efficiency requirements of the vehicle under different operating conditions. For example, in some scenarios, higher security may be needed to protect sensitive data, and a fixed number of iterations may result in insufficient key strength; in other scenarios, faster response times may be required, and an excessively high number of fixed iterations may cause unnecessary computational overhead and latency.

[0101] In this regard, this application further proposes that, in one embodiment, step S23 includes:

[0102] S231: Obtain vehicle status information and dynamically set the number of iterations for the key derivation function based on the target security policy and vehicle status information;

[0103] S232: Execute the key derivation function to generate a dynamic session key by setting the number of iterations.

[0104] In this embodiment, acquiring vehicle status information aims to collect current vehicle operation or environmental data. Vehicle status information may include, but is not limited to, vehicle speed, engine speed, fuel level, battery charge, geographical location, ambient temperature, network connection quality, and vehicle load. This reflects the vehicle's real-time operating condition and environment. This can be achieved by reading data from internal vehicle sensors through the on-board diagnostic system interface or by acquiring external environmental data through the on-board communication module. Furthermore, vehicle status information may include vehicle health indicators, such as the wear and tear of key components, fault indicator status, and historical fault records. This information provides a more comprehensive reflection of the vehicle's overall operating status, thus providing deeper input for the dynamic adjustment of security strategies. The number of iterations in the key derivation function refers to the number of rounds in which the core hash function is repeatedly executed during the execution of the key derivation function. The number of iterations is a key parameter for measuring the computational strength and resistance to brute-force attacks of the key derivation function. A higher number of iterations means a longer time is required to derive the key from the seed, resulting in a stronger key, but also a greater computational overhead.

[0105] The number of iterations for the key derivation function is dynamically set based on the target security policy and vehicle status information. The purpose is to flexibly adjust the computational intensity of the key derivation function according to the current security requirements and the actual vehicle conditions. The target security policy defines the basic security level requirements, while the vehicle status information provides the real-time context. Dynamically setting the number of iterations means that the computational load of the key derivation function can be adaptively adjusted under different security scenarios and different vehicle operating conditions. For example, a mapping table or algorithm can be preset to map different combinations of target security policies and vehicle status information to different iteration ranges.

[0106] By executing the key derivation function with a dynamically set number of iterations, the generated dynamic session key is ensured to meet security requirements while also taking into account computational efficiency and resource consumption. For example, the key derivation function can use standard algorithms such as PBKDF2 or Argon2. These algorithms support adjusting their computational strength through the number of iterations. During execution, the previously generated combination factors are used as input, and the calculation is performed according to the dynamically set number of iterations, ultimately outputting a dynamic session key with the required length and strength.

[0107] Specifically, when generating dynamic session keys, a dynamic adjustment mechanism for the number of iterations in the key derivation function is introduced. This makes the key generation process no longer static and fixed, but flexible and adaptable to actual conditions. Specifically, the vehicle acquires real-time vehicle status information, reflecting the vehicle's current operating environment and security requirements. A balance between the required key strength and computational efficiency is assessed based on a pre-determined target security strategy. For example, when the vehicle is in an emergency fault state and needs to transmit highly sensitive fault information, a higher number of iterations may be set based on the first security strategy and vehicle status information (such as good network signal and sufficient computing resources) to ensure the generated dynamic session key has extremely high security and prevent potential eavesdropping or tampering. Conversely, if it is a non-emergency fault and the vehicle status information indicates limited computing resources or high network latency, a relatively lower number of iterations may be set based on the second security strategy, but still meeting the security baseline, to accelerate key generation and reduce communication latency. Through this dynamic adjustment, the combination factor is input into the key derivation function and calculated according to the set number of iterations, ultimately generating a dynamic session key that adapts to the current security requirements and vehicle operating conditions. The aforementioned mechanism allows the key generation process to adapt flexibly to the actual situation, thereby optimizing the utilization efficiency of system resources while ensuring information security, and effectively solving the problem of insufficient security or waste of resources that may be caused by a fixed number of iterations.

[0108] For example, as a specific implementation, assuming that after the vehicle detects a fault, it first identifies the fault code and matches it to a target security policy. For instance, if the identified fault is an emergency fault of engine overheating, the first security policy is matched. At this time, the vehicle obtains the vehicle information identifier and the current timestamp as basic factors. Simultaneously, according to the first security policy, it obtains the integrity verification value of the vehicle fault information as a specific factor. The basic factor and the specific factor are combined to form a combined factor. In order to generate a dynamic session key, the vehicle status information is further obtained, for example, the current vehicle speed is 0 km / h (parked state), the network signal strength is good, and based on the first security policy... By taking into account the vehicle status information, the number of iterations for the key derivation function is dynamically set. For example, a preset rule can be used: when the first security strategy is in effect and the vehicle is parked with a good network signal, the number of iterations is set to 1000; while when the vehicle is in motion or the network signal is poor, the number of iterations may be set to 500. In this example, since the vehicle is parked and the signal is good, the number of iterations is set to 1000. Then, the combination factor is input into the preset key derivation function, and 1000 iterations are performed to finally generate a high-strength dynamic session key. This dynamic session key is then used to encrypt vehicle fault information to ensure its confidentiality during transmission.

[0109] Through the above technical solution, this application can dynamically adjust the number of iterations of the key derivation function based on the vehicle's real-time status information and the current security policy. This allows the strength of the generated dynamic session key to adaptively match actual security requirements, avoiding the problems of insufficient key strength or wasted computational resources that may result from a fixed number of iterations. In scenarios requiring high security, the number of iterations can be increased to enhance the key's resistance to attacks; in scenarios with high real-time requirements or limited resources, the number of iterations can be appropriately reduced to optimize computational efficiency. This flexibility significantly improves the security and performance balance of the vehicle remote diagnostic system under different operating conditions, ensures the secure transmission of sensitive fault information, and optimizes system response speed and resource consumption.

[0110] In some of the embodiments described above in this application, the public key of the target cloud platform is obtained, and the dynamic session key is encrypted using the public key to obtain an encrypted session key. However, in practical applications, if the encrypted session key is maliciously intercepted during transmission, or if the public key encryption mechanism of the target cloud platform has potential vulnerabilities, the dynamic session key may be leaked, thereby endangering the security of the entire communication process. This single encryption and transmission method may not be secure and robust enough in the face of advanced persistent threats.

[0111] In this regard, this application further proposes that, in one embodiment, step S30 includes:

[0112] S31: The dynamic session key is split into N key fragments using a preset secret sharing algorithm. Only any K key fragments are needed to recover the original dynamic session key.

[0113] In this embodiment, the secret-sharing algorithm is a cryptographic technique whose core idea is to divide a secret (such as a dynamic session key) into multiple fragments and distribute these fragments to different participants. The characteristic of the secret-sharing algorithm is that the original secret can only be reconstructed when a sufficient number (K) of fragments are collected; a single or a few fragments cannot reveal the complete information of the secret. The secret-sharing algorithm can be implemented in various ways. For example, it can be based on the Shamir secret-sharing scheme, using polynomial interpolation to encode the secret as a constant term of a polynomial, and generating the secret by calculating the value of the polynomial at different points. The key can be divided into fragments; or a secret sharing scheme based on the Chinese Remainder Theorem can be adopted. N key fragments refer to the total number of parts into which the secret sharing algorithm divides the original dynamic session key. The value of N can be flexibly set according to specific security requirements and system architecture, such as 3, 5 or 7. K key fragments refer to the minimum number of key fragments required to recover the original dynamic session key. Its value must satisfy K less than or equal to N. The setting of K is usually determined based on security policies and system fault tolerance requirements. For example, when N is 5, K can be set to 3, which means that at least 3 fragments are needed to successfully recover the key.

[0114] S32: Encrypt M key fragments out of N key fragments using the public key of the target cloud platform to form the main encryption session key packet;

[0115] In this embodiment, the public key of the target cloud platform is a key used for asymmetric encryption. Its function is to encrypt data, and only the private key paired with the public key can decrypt it. This public key is usually generated using an asymmetric encryption algorithm (such as RSA or ECC) and is securely distributed to the vehicle by the target cloud platform before communication is established. M key fragments refer to the number of fragments selected from N key fragments to be encrypted using the public key of the target cloud platform. M is usually less than N, and the value of M can be set according to the security policy and the characteristics of the transmission channel. For example, M can be set to K minus 1, or M can be set to N divided by 2. The main encryption session key packet is a data packet composed of M key fragments encrypted with the public key of the target cloud platform. This data packet is the main component of the encryption session key encapsulated in the secure data packet.

[0116] S33: Send the remaining NM key fragments to the target cloud platform through the auxiliary communication channel, wherein the encrypted session key encapsulated in the security data packet is the main encrypted session key packet.

[0117] In this embodiment, the auxiliary communication channel refers to an independent communication link other than the main communication channel used to send secure data packets. The auxiliary communication channel may have different security features or transmission paths. The implementation of the auxiliary communication channel may include out-of-band communication, such as transmission via SMS, independent virtual private network tunnel, or transmission using different network protocols or ports, to increase the difficulty for attackers to monitor all channels at the same time. Furthermore, the transmission can be staggered in time to make it difficult for attackers to correlate data from different channels.

[0118] Specifically, the solution in this embodiment first splits the dynamic session key into N key fragments using a secret sharing algorithm, ensuring that even if some fragments are leaked, the original key cannot be reconstructed, thereby enhancing the inherent security of the key. Based on this, M of the N key fragments are further encrypted using the public key of the target cloud platform to form a main encrypted session key packet, which is then encapsulated in a secure data packet for transmission. Simultaneously, the remaining NM key fragments are sent through one or more independent auxiliary communication channels. This multi-channel, fragmented encryption transmission strategy requires an attacker to simultaneously compromise both the main and auxiliary communication channels, successfully decrypt the M encrypted fragments, and ultimately collect at least K key fragments to successfully obtain and reconstruct the dynamic session key. This distributed and diversified key transmission mechanism significantly improves the robustness and security of dynamic session key transmission, effectively reducing the security risks that may arise from single encrypted transmission.

[0119] For example, as a specific implementation, the dynamic session key needs to be securely transmitted, and N is set to 5 and K to 3. First, the vehicle uses a preset secret sharing algorithm to split the dynamic session key into 5 independent key fragments, denoted as S1, S2, S3, S4, and S5. To enhance security, the vehicle selects M as 2, that is, it encrypts the two key fragments S1 and S2 using the public key of the target cloud platform, and combines the encrypted S1 and S2 into a master encrypted session key packet. This master encrypted session key packet is then encapsulated in a secure data packet and sent to the target cloud platform through the main communication channel. At the same time, the remaining N... M, which is the remaining 3 key fragments (S3, S4, S5) after 5 minus 2, is sent to the target cloud platform through an independent auxiliary communication channel. For example, it can be transmitted through an independent HTTPS connection or a dedicated VPN tunnel. After receiving the secure data packet, the target cloud platform first uses its private key to decrypt the master encrypted session key packet, thereby obtaining the original S1 and S2. Subsequently, the target cloud platform combines the decrypted S1 and S2 with S3, S4, and S5 received through the auxiliary communication channel. Since K is 3, the target cloud platform only needs any 3 key fragments to successfully reconstruct the original dynamic session key.

[0120] Through the above technical solution, this application effectively solves the security risks that dynamic session keys may face during transmission due to single encryption and transmission, and significantly increases the difficulty for attackers to obtain and reconstruct dynamic session keys. This is because attackers need to break through multiple communication channels at the same time and successfully decrypt some key fragments in order to achieve their goal. This not only enhances the overall security of the key exchange process, but also improves the robustness and reliability of remote diagnostic methods in the face of complex network attacks.

[0121] In other embodiments, when encapsulating the corresponding dataset according to the target security policy to generate a secure data packet, in order to address the problem that simple data splicing may lead to unclear data packet structure and difficulty in efficient parsing, and that partial data loss or tampering during transmission may affect the integrity and availability of the entire data packet, especially in scenarios where data processing requirements differ under different security policies, this application further proposes that, in one embodiment, step S40 includes:

[0122] S41: Transform the data elements in the dataset into independent data units and attach metadata tags to the independent data units, wherein the metadata tags include the logical type identifier of the independent data units;

[0123] In this embodiment, an independent data unit refers to a data block of uniform size and format, which is formed by standardizing each data element in the original dataset; the data elements include vehicle fault information, encrypted session keys, and target encrypted data; the metadata tag is a structured data header attached to the independent data unit, which describes the attribute information of the independent data unit; the logical type identifier is an important data field in the metadata tag. Typically, the logical type identifier is a short code used to uniquely identify the business logic type of the data carried by the data unit.

[0124] S42: Based on independent data units, generate a mixed data bit stream according to the interleaving rules preset according to the target security policy;

[0125] In this embodiment, the interleaving rule refers to a predefined set of instructions that specifies how to break, cut, and re-weave the original bit sequences of multiple independent data units to form a single, mixed bit stream. It defines the transformation method from ordered to disordered. The mixed data bit stream refers to a continuous data bit sequence generated after applying the interleaving rule, which does not contain any inherent structural information. In the mixed data bit stream, bits of data with different logical meanings are completely interleaved together, and it is impossible to distinguish the original composition of the data from the stream itself.

[0126] S43: Set the policy identifier of the target security policy as a global label, and fuse the global label with the mixed data bit stream to generate a security data packet;

[0127] The interleaving rules include: if the target security policy is the first security policy, the bit sequence of the encrypted session key is segmented and interleaved with the bit sequence of the target encrypted data; if the target security policy is the second security policy, the bit sequences of the vehicle fault information, the target encrypted data, and the encrypted session key are interleaved evenly.

[0128] In this embodiment, the global label refers to an identifier that represents the target security policy adopted by the entire security data packet. It is a globally unique identifier that is associated with the data packet as a whole, rather than with a specific data unit.

[0129] Specifically, the original information fragments constituting the dataset, such as encrypted session keys, target encrypted data, and vehicle fault information, are first transformed into independent and identifiable data units. Simultaneously, to clearly indicate the type of data carried by each independent data unit or its logical role within the entire data packet, a metadata tag is attached to each independent data unit. This metadata tag includes a logical type identifier for the independent data unit. For example, a fixed-length field can be added to the header or footer of each data unit as a metadata tag, containing a predefined enumeration value or string to represent the logical type, or TLV encoding can be used, where the "Type" field is the logical type identifier.

[0130] Based on this, using these independent data units as a foundation, a mixed data bit stream is generated by applying preset interleaving rules according to the currently matched target security policy. When a data packet is partially damaged during transmission, interleaving can disperse the error, preventing the error from being concentrated in a single data unit, thereby increasing the possibility of data recovery. For example, multiple interleaving algorithms can be preset, such as block interleaving, convolutional interleaving, etc., and the appropriate algorithm can be selected according to the type of target security policy, or an interleaving mode based on pseudo-random sequences can be defined.

[0131] Furthermore, in order for the receiver to correctly identify and parse the data packet, the policy identifier of the current target security policy is set as a global label, and this global label is merged with the previously generated mixed data bit stream to finally form a complete security data packet; for example, the policy identifier can be placed in the header of the security data packet as the first field of the data packet, or embedded in a predefined structure of the data packet.

[0132] The interleaving rules vary depending on the target security policy: If the target security policy is the first security policy, the bit sequence of the encrypted session key is segmented and interleaved with the bit sequence of the target encrypted data at intervals. This is intended to prioritize the protection or concealment of the session key, or to ensure that critical information can be recovered as much as possible even if some data is lost in an emergency. For example, each bit or every N bits of the encrypted session key can be inserted into a fixed interval position in the bit sequence of the target encrypted data. If the target security policy is the second security policy, the bit sequences of the vehicle fault information, the target encrypted data, and the encrypted session key are interleaved evenly. This is intended to ensure that all data elements receive relatively balanced protection and transmission robustness in non-emergency situations. For example, a cyclic interleaving method can be used, taking one bit or one byte from the three data sources in turn for combination.

[0133] For example, as a specific implementation, suppose the vehicle needs to send a security data packet to the target cloud platform, and the current matched security policy is the first security policy. First, the data elements to be encapsulated, namely the encrypted session key and the target encrypted data, are converted into independent data units. For example, the encrypted session key can be encapsulated into an independent data unit and an additional metadata tag is attached, the logical type identifier of which indicates that it is a "session key". Similarly, the target encrypted data is also encapsulated into another independent data unit and an additional logical type identifier is attached to indicate that it is "encrypted data". These metadata tags can be of a fixed length of one byte, for example, "0x01" represents the session key and "0x02" represents the encrypted data. Then... According to the interleaving rules preset by the first security policy, a mixed data bit stream is generated. Specifically, the bit sequence of the encrypted session key is divided into multiple small segments, for example, every 8 bits. These segments are interleaved with the bit sequence of the target encrypted data at intervals. For example, every N bits in the target encrypted data bit sequence, one bit or byte of the encrypted session key is inserted. This interleaving operation can be implemented by a hardware interleaver or a software algorithm, for example, by using a pseudo-random sequence generator to determine the insertion position and interval. Finally, the policy identifier of the first security policy is set as a global label and placed at the beginning of the mixed data bit stream, or as part of the data packet frame header. For example, the structure of the final secure data packet can be: [Policy Identifier] [Mixed Data Bitstream]: After receiving the data packet, the target cloud platform first reads the global tag to identify the first security policy currently being used. Then, according to the deinterleaving rules and decryption process corresponding to this policy, it reverse-processes the mixed data bitstream to accurately recover the encrypted session key and the target encrypted data. If the second security policy is matched, the bit sequence of the vehicle fault information, the target encrypted data, and the encrypted session key will be evenly interleaved. For example, a cyclic interleaving method is used, taking turns extracting one bit or one byte from the bit sequence of the vehicle fault information, the target encrypted data, and the encrypted session key to form a mixed data bitstream. This even interleaving ensures balanced protection of all critical information during transmission.

[0134] Through the above technical solutions, this application can perform fine-grained processing of data elements according to different security strategies during the data encapsulation process, significantly improving the robustness and security of data transmission. It effectively solves the challenges of integrity, parseability and security that data packets may face during transmission, especially in scenarios where data protection requirements vary under different levels of urgency, providing a more flexible and reliable solution.

[0135] In some of the above implementations, a secure data packet is sent to the target cloud platform, so that the target cloud platform, upon receiving the secure data packet, performs data authentication and fault diagnosis based on the decrypted encrypted target object. However, how to ensure that the target cloud platform can efficiently and securely authenticate the received data according to different security policies, and accurately diagnose faults based on this, is a technical problem that needs further resolution.

[0136] In this regard, this application further proposes that, in one embodiment, step S50 includes:

[0137] S51: After receiving the security data packet, the target cloud platform identifies the associated target security policy and executes the corresponding authentication process according to the identified target security policy.

[0138] S52: After the authentication process is completed, the target cloud platform performs fault diagnosis based on the vehicle fault information;

[0139] In this embodiment, the authentication process refers to a series of steps performed by the target cloud platform after receiving a security data packet to verify the authenticity, integrity, and identity of the communication partner. Its fundamental purpose is to confirm whether the data comes from a legitimate vehicle and has not been tampered with.

[0140] When the target security policy is the first security policy, the corresponding authentication process includes:

[0141] S511A: The target cloud platform uses its private key to decrypt the encrypted session key in the security data packet to obtain the dynamic session key;

[0142] S512A: Decrypts the target encrypted data in the secure data packet using a dynamic session key to obtain vehicle fault information;

[0143] S513A: Extract the vehicle identification number and timestamp from vehicle fault information, and calculate the summary value of vehicle fault information;

[0144] S514A: Generate a verification session key based on the vehicle identification code, timestamp, and digest value using the key derivation function;

[0145] S515A: The verification session key is compared with the dynamic session key. If the comparison results are consistent, the authentication process is successful.

[0146] In this embodiment, the digest value refers to a fixed-length and unique hash value obtained by calculating the original data using a cryptographic hash function. The hash function has one-way and collision resistance. The verification session key refers to the session key that the cloud platform independently recalculates in the authentication process of the first security policy, mimicking the behavior of the vehicle end, based on the elements extracted from the decrypted fault information, such as the vehicle identification number, timestamp, and digest value. The comparison refers to the operation of comparing the verification session key with the dynamic session key bit by bit in the first security policy, and the result can only be either consistent or inconsistent.

[0147] When the target security policy is the second security policy, the corresponding authentication process includes:

[0148] S511B: The target cloud platform uses its private key to decrypt the encrypted session key in the security data packet to obtain the dynamic session key;

[0149] S512B: Decrypts the target encrypted data in the secure data packet using a dynamic session key to obtain a verification mapping table;

[0150] S513B: Extract fault codes from vehicle fault information and find the corresponding response instructions for the fault codes by verifying the mapping table;

[0151] S514B: Sends the response command to the vehicle and receives the authentication result from the vehicle. If the authentication result is successful, the authentication process is completed.

[0152] In this embodiment, the verification mapping table refers to the object obtained by the target cloud platform after decrypting the target encrypted data in the second security policy. The verification mapping table is a correspondence table generated by the vehicle end that corresponds to the fault codes and response instructions valid in this session. The response instruction refers to the electrical signal instruction generated by the target cloud platform based on the unique, random instruction string obtained by querying the verification mapping table according to the fault codes in the plaintext fault information in the second security policy. The authentication result fed back by the vehicle end refers to the information that the vehicle end checks against the verification mapping table of this session stored locally after receiving the response instruction issued by the target cloud platform, and returns the check result to the cloud platform.

[0153] Specifically, after receiving a security data packet, the target cloud platform identifies the associated target security policy and executes the corresponding authentication process based on the identified target security policy. This aims to ensure that when processing the received security data packet, the target cloud platform can select and execute the correct authentication logic according to the security policy followed by the data packet. In one implementation, the security data packet may contain an explicit policy identifier, which the target cloud platform parses to identify the associated target security policy. In another implementation, the target cloud platform can infer the associated target security policy based on the structural characteristics of the security data packet or the type of specific data elements therein.

[0154] After the authentication process is successful, the target cloud platform performs fault diagnosis based on the vehicle fault information. When the target security policy is the first security policy, the corresponding authentication process includes: the target cloud platform uses its private key to decrypt the encrypted session key in the security data packet to obtain the dynamic session key; the target encrypted data in the security data packet is decrypted using the dynamic session key to obtain the vehicle fault information; the vehicle identification code and timestamp are extracted from the vehicle fault information, and a digest value of the vehicle fault information is calculated; based on the vehicle identification code, timestamp, and digest value, a verification session key is generated through the key derivation function; the verification session key is compared with the dynamic session key, and if the comparison result is consistent, the authentication process is successful. This authentication process is mainly used in emergency fault scenarios, emphasizing rapid response and data integrity.

[0155] When the target security policy is the second security policy, the corresponding authentication process includes: the target cloud platform uses its private key to decrypt the encrypted session key in the security data packet to obtain a dynamic session key; the target encrypted data in the security data packet is decrypted using the dynamic session key to obtain a verification mapping table; fault codes are extracted from the plaintext vehicle fault information, and the corresponding response instructions are found through the verification mapping table; the response instructions are sent to the vehicle terminal, and the authentication result is received from the vehicle terminal. If the authentication result is successful, the authentication process is completed. This authentication process is mainly used for non-emergency fault scenarios and may require stronger authentication or interactive authentication. The verification mapping table can be a key-value pair structure, where the key is the fault code and the value is the corresponding response instruction. The lookup operation can be a simple hash table query or a database query. The response instruction can be sent to the vehicle terminal through a secure communication protocol. After receiving the response instruction, the vehicle terminal executes the corresponding operation and returns confirmation information. The target cloud platform receives and verifies the confirmation information.

[0156] For example, as a specific implementation, after receiving a security data packet, the target cloud platform can first parse a specific field in the header of the data packet. For example, the field may be a single-byte flag bit. The cloud platform determines the subsequent authentication process based on the value of the flag bit.

[0157] If the target security policy is identified as the first security policy, the target cloud platform uses its pre-configured RSA private key to decrypt the encrypted session key encapsulated in the security data packet, thereby obtaining the original dynamic session key. Then, the target encrypted data in the security data packet is decrypted using the dynamic session key to obtain the vehicle fault information. From the decrypted vehicle fault information, the vehicle identification code and the timestamp of the fault occurrence are extracted, and the SHA-256 digest value of the vehicle fault information is calculated. Using the vehicle identification code, timestamp, and SHA-256 digest value as input, a verification session key is generated through a preset, identical key derivation function. This generated verification session key is precisely compared with the dynamic session key obtained by decryption using the private key. If the two are completely identical, the authentication is considered successful.

[0158] If the target security policy is identified as the second security policy, the target cloud platform also uses its RSA private key to decrypt the encrypted session key to obtain a dynamic session key. Then, it uses this dynamic session key to decrypt the target encrypted data to obtain a verification mapping table. The platform extracts the fault code from the vehicle fault information (plaintext part) contained in the security data packet. For example, if the fault code is "P0420", the platform searches for the response instruction corresponding to "P0420" in the decrypted verification mapping table. This instruction may be a specific diagnostic command, such as "requesting the vehicle to send the current oxygen sensor data". The target cloud platform sends this response instruction to the vehicle through a secure communication channel. After receiving the instruction, the vehicle performs the corresponding operation and sends the execution result or confirmation information back to the target cloud platform. If the target cloud platform receives the confirmation message from the vehicle, the authentication process is successful.

[0159] Once authentication is successful, the target cloud platform will use the decrypted and verified vehicle fault information, combined with its internal expert system or machine learning model, to conduct a detailed analysis of the vehicle fault, such as identifying faulty components, predicting fault trends, or recommending repair solutions.

[0160] By introducing a policy-driven authentication process on the target cloud platform, the above technical solution effectively addresses the challenge of efficiently and securely authenticating received security data packets based on the urgency of the fault during remote diagnostics, and then performing accurate fault diagnosis accordingly. This solution designs different authentication mechanisms for urgent and non-urgent faults: urgent faults employ rapid cryptographic verification to ensure data integrity and source reliability for rapid response; non-urgent faults utilize interactive verification to provide a higher level of identity verification and data protection. This differentiated authentication strategy significantly enhances the overall security of the remote diagnostic system, effectively resisting attacks such as data tampering and injection, and optimizes authentication efficiency, ensuring the reliability of diagnostic data in different scenarios, thereby improving the accuracy and timeliness of fault diagnosis.

[0161] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0162] In one embodiment, a vehicle fault remote diagnosis system based on information security technology is provided. This vehicle fault remote diagnosis system based on information security technology corresponds one-to-one with the vehicle fault remote diagnosis method based on information security technology described in the above embodiment. The vehicle fault remote diagnosis system based on information security technology includes:

[0163] The strategy matching module is used to acquire vehicle fault information and identify fault codes, and match target safety strategies according to the fault codes. The target safety strategies include a first safety strategy for emergency faults and a second safety strategy for non-emergency faults.

[0164] The first encryption module is used to generate a dynamic session key based on the target security policy, and to encrypt the target object using the dynamic session key to obtain the target encrypted data.

[0165] The second encryption module is used to obtain the public key of the target cloud platform and encrypt the dynamic session key using the public key to obtain the encrypted session key;

[0166] The data encapsulation module is used to encapsulate vehicle fault information, encrypted session keys, and target encrypted data according to the target security policy, and generate a secure data packet.

[0167] The data sending module is used to send secure data packets to the target cloud platform, so that the target cloud platform can perform data authentication and fault diagnosis based on the decrypted encrypted target object after receiving the secure data packets;

[0168] The encrypted target object is defined by the target security policy. The encrypted target object corresponding to the first security policy includes vehicle fault information, and the encrypted target object corresponding to the second security policy includes a verification mapping table generated based on the fault code.

[0169] For specific limitations regarding a vehicle fault remote diagnosis system based on information security technology, please refer to the limitations of a vehicle fault remote diagnosis method based on information security technology mentioned above, which will not be repeated here. Each module in the aforementioned vehicle fault remote diagnosis system based on information security technology can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0170] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements a remote vehicle fault diagnosis method based on information security technology.

[0171] The above-described 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, and should all be included within the protection scope of this application.

Claims

1. A vehicle fault remote diagnosis method based on information security technology, the method is applied to a vehicle fault diagnosis system, the vehicle fault diagnosis system comprises a vehicle end and a target cloud platform, characterized in that, The method includes the following steps: Obtain vehicle fault information and identify fault codes, and match target safety strategies based on fault codes. The target safety strategies include a first safety strategy for emergency faults and a second safety strategy for non-emergency faults. A dynamic session key is generated based on the target security policy, and the target object is encrypted using the dynamic session key to obtain the target encrypted data. Obtain the public key of the target cloud platform, and encrypt the dynamic session key using the public key to obtain the encrypted session key; According to the target security policy, the corresponding dataset is encapsulated to generate a security data packet. The dataset corresponding to the first security policy includes the encrypted session key and the target encrypted data, and the dataset corresponding to the second security policy includes vehicle fault information, the encrypted session key and the target encrypted data. The security data packet is sent to the target cloud platform so that the target cloud platform can perform data authentication and fault diagnosis based on the decrypted encrypted target object after receiving the security data packet. The encrypted target object is defined by the target security policy. The encrypted target object corresponding to the first security policy includes vehicle fault information. The encrypted target object corresponding to the second security policy includes a verification mapping table generated based on fault codes. The verification mapping table is a data structure generated from fault codes under the second security policy, which is used to perform interactive verification with the vehicle during authentication on the target cloud platform. The verification mapping table includes the correspondence between fault codes and specific response instructions.

2. The method for remote vehicle fault diagnosis based on information security technology according to claim 1, characterized in that: The steps of acquiring vehicle fault information and identifying fault codes, and matching a target safety strategy based on the fault codes, wherein the target safety strategy includes a first safety strategy for emergency faults and a second safety strategy for non-emergency faults, include the following steps: Query the pre-set fault urgency mapping table and determine the corresponding basic urgency level based on the identified fault code; Obtain vehicle status information and determine dynamic adjustment factors based on the vehicle status information; The basic urgency level is adjusted by dynamically adjusting factors to generate an optimized urgency level, and then mapped to the corresponding target security policy based on the optimized urgency level.

3. The method for remote vehicle fault diagnosis based on information security technology according to claim 1, characterized in that: The step of generating a dynamic session key based on the target security policy and encrypting the target object using the dynamic session key to obtain the target encrypted data includes the following steps: Obtain the underlying factors used to generate the dynamic session key, the underlying factors including the vehicle information identifier and the current timestamp; Based on the target security strategy, specific factors are obtained, and these specific factors are combined with basic factors to generate combined factors. Input the combination factor into the preset key derivation function to generate a dynamic session key; Using a dynamic session key, encryption operations are performed on the encrypted target object corresponding to the target security policy to generate target encrypted data; Wherein, if the target security policy is the first security policy, the specific factor includes the integrity verification value of the vehicle fault information; if the target security policy is the second security policy, the specific factor includes the integrity verification value of the verification mapping table.

4. The method for remote vehicle fault diagnosis based on information security technology according to claim 3, characterized in that: The step of obtaining specific factors according to the target security policy and combining the specific factors with the basic factors to generate combined factors includes the following steps: According to the target security policy, a predefined bit obfuscation rule is matched, and dynamic communication parameters are obtained, including the current wireless signal strength value and the low-order bits of the data packet sequence number; Based on bit obfuscation rules and dynamic communication parameters, generate obfuscation operation parameters corresponding to the bit obfuscation rules; Based on the matched bit confusion rules and confusion operation parameters, corresponding confusion operations are performed on the data bits of the basic factor and the data bits of the specific factor. The confusion operations include bit interleaving, bit block permutation, and bitwise XOR.

5. The method for remote vehicle fault diagnosis based on information security technology according to claim 3, characterized in that: The step of inputting the combination factor into a pre-set key derivation function to generate a dynamic session key includes the following steps: Obtain vehicle status information and dynamically set the number of iterations for the key derivation function based on the target security policy and vehicle status information; The key derivation function is executed by setting the number of iterations to generate a dynamic session key.

6. The method for remote vehicle fault diagnosis based on information security technology according to claim 1, characterized in that: The step of obtaining the public key of the target cloud platform and encrypting the dynamic session key with the public key to obtain the encrypted session key includes the following steps: The dynamic session key is split into N key fragments using a preset secret sharing algorithm. Only any K key fragments are needed to recover the original dynamic session key. The public key of the target cloud platform is used to encrypt M key fragments out of N key fragments to form the main encryption session key packet; The remaining NM key fragments are sent to the target cloud platform through an auxiliary communication channel, wherein the encrypted session key encapsulated in the security data packet is the main encrypted session key packet.

7. The method for remote vehicle fault diagnosis based on information security technology according to claim 1, characterized in that: The step of encapsulating the corresponding dataset according to the target security policy to generate a secure data packet, wherein the dataset corresponding to the first security policy includes an encrypted session key and target encrypted data, and the dataset corresponding to the second security policy includes vehicle fault information, an encrypted session key, and target encrypted data, includes the following steps: Transform the data elements in the dataset into independent data units and attach metadata tags to the independent data units, the metadata tags including the logical type identifier of the independent data units; Based on independent data units, a hybrid data bit stream is generated according to the interleaving rules preset according to the target security policy. The policy identifier of the target security policy is set as a global label, and the global label is fused with the mixed data bitstream to generate a security data packet; The interleaving rules include: if the target security policy is the first security policy, the bit sequence of the encrypted session key is segmented and interleaved with the bit sequence of the target encrypted data; if the target security policy is the second security policy, the bit sequences of the vehicle fault information, the target encrypted data, and the encrypted session key are interleaved evenly.

8. The method for remote vehicle fault diagnosis based on information security technology according to claim 3, characterized in that: The step of sending a security data packet to the target cloud platform, so that the target cloud platform can receive the security data packet and perform data authentication and fault diagnosis based on the decrypted encrypted target object, includes the following steps: After receiving the security data packet, the target cloud platform identifies the associated target security policy and executes the corresponding authentication process based on the identified target security policy. After the authentication process is completed, the target cloud platform performs fault diagnosis based on the vehicle fault information. When the target security policy is the first security policy, the corresponding authentication process includes: the target cloud platform using its private key to decrypt the encrypted session key in the security data packet to obtain a dynamic session key; decrypting the target encrypted data in the security data packet using the dynamic session key to obtain vehicle fault information; extracting the vehicle identification code and timestamp from the vehicle fault information and calculating the digest value of the vehicle fault information; generating a verification session key based on the vehicle identification code, timestamp, and digest value using the key derivation function; comparing the verification session key with the dynamic session key, and if the comparison result is consistent, the authentication process is successful. When the target security policy is the second security policy, the corresponding authentication process includes: the target cloud platform uses its private key to decrypt the encrypted session key in the security data packet to obtain the dynamic session key; the target encrypted data in the security data packet is decrypted using the dynamic session key to obtain the verification mapping table; the fault code is extracted from the vehicle fault information, and the corresponding response instruction is found through the verification mapping table; the response instruction is sent to the vehicle terminal, and the authentication result fed back by the vehicle terminal is received. If the authentication result is successful, the authentication process is completed.

9. A vehicle fault remote diagnosis system based on information security technology, characterized in that, include: The strategy matching module is used to acquire vehicle fault information and identify fault codes, and match target safety strategies according to the fault codes. The target safety strategies include a first safety strategy for emergency faults and a second safety strategy for non-emergency faults. The first encryption module is used to generate a dynamic session key based on the target security policy, and to encrypt the target object using the dynamic session key to obtain the target encrypted data. The second encryption module is used to obtain the public key of the target cloud platform and encrypt the dynamic session key using the public key to obtain the encrypted session key; The data encapsulation module is used to encapsulate the corresponding dataset according to the target security policy and generate a secure data packet. The dataset corresponding to the first security policy includes the encrypted session key and the target encrypted data, and the dataset corresponding to the second security policy includes vehicle fault information, the encrypted session key and the target encrypted data. The data sending module is used to send secure data packets to the target cloud platform, so that the target cloud platform can perform data authentication and fault diagnosis based on the decrypted encrypted target object after receiving the secure data packets; The encrypted target object is defined by the target security policy. The encrypted target object corresponding to the first security policy includes vehicle fault information. The encrypted target object corresponding to the second security policy includes a verification mapping table generated based on fault codes. The verification mapping table is a data structure generated from fault codes under the second security policy, which is used to perform interactive verification with the vehicle during authentication on the target cloud platform. The verification mapping table includes the correspondence between fault codes and specific response instructions.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the remote vehicle fault diagnosis method based on information security technology as described in any one of claims 1-8.

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