Privacy-preserving task offloading method and system in vehicle platooning

Abstract

The present invention discloses a privacy-protected task offloading method and system in a vehicle formation, comprising: a pilot vehicle divides a task into multiple subtasks, signs a task request and broadcasts it to all following vehicles; the following vehicles calculate the time required to execute the subtasks, generate task parameters and encrypt and return them to the pilot vehicle; the pilot vehicle summarizes the task parameters of all following vehicles and forwards them to a first cloud server CSA ; First Cloud Server CSA and the second cloud server CSB The task execution time is encrypted and compared to determine the most suitable vehicle to execute each subtask; the pilot vehicle distributes the specific task content to each designated follower vehicle; each designated follower vehicle signs and encrypts the specific task result and sends it to the pilot vehicle, which verifies the signature and decrypts the result. The technical solution of the present invention improves the efficiency and security of task offloading while ensuring the privacy of the vehicle and the task content.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle networking security technology, and in particular relates to a task offloading method and system for privacy protection in a vehicle formation. Background Art

[0002] Vehicle platooning technology adopts a leader-follower structure. The members of the vehicle platoon can be divided into a pilot vehicle and a follower vehicle. These vehicles communicate through the Internet of Vehicles to achieve data exchange and coordination within the vehicle platoon. The pilot vehicle needs to be responsible for dynamically monitoring road conditions, collecting and processing this information, and issuing driving instructions to the follower vehicles, while the latter only needs to follow these instructions, which brings a heavy computational burden to the pilot vehicle. To address this problem, existing research usually uses task offloading schemes to enable multiple vehicles to cooperate in processing tasks. For example, Xiao et al. (T. Xiao, C. Chen, Q. Pei, and HH Song, Consortium blockchain-based computation offloading using mobile edgeplatoon cloud in internet of vehicles, IEEE Transactions on IntelligentTransportation Systems, vol. 23, no. 10, pp. 17 769–17 783, 2022.) proposed a resource allocation strategy within a mobile edge vehicle platoon cloud, using the Stackelberg game model to optimize resource utilization in vehicle edge computing with a pilot-led vehicle platoon and a follower vehicle platoon. However, this scheme only considers the efficiency of task offloading of vehicle formations, and does not solve the problem of privacy protection in the process. For vehicle formations, the privacy of the task offloading process is crucial because it directly affects the safety of the vehicle formation and the privacy of related vehicles. In task offloading, attackers can obtain the trajectory of the vehicle through link attacks. At the same time, the computing power of the following vehicle, as an important basis for task scheduling, usually needs to be passed to the leading vehicle. However, the leakage of computing power may also lead to the leakage of vehicle privacy, because even if the identity information of the vehicle is protected by a pseudonym, the attacker can still track the movement trajectory of the vehicle through the constant computing power of the vehicle. In addition, the task content and task results also involve data transmission security issues. When offloading a task to a specific following vehicle, it is necessary to ensure that only authorized vehicles can receive and process the task content. At the same time, after the task is completed, the return of the task result also needs to consider confidentiality to prevent the data from being stolen during transmission. Some existing authentication schemes use signcryption technology to achieve the integrity, non-repudiation and confidentiality of task data in one operation, which is considered to be an ideal method for secure transmission of task data.Zhao et al. (Y. Zhao, Y. Wang, Y. Liang, H. Yu, and Y. Ren, Identity-based broadcast signcryption scheme for vehicular platoon communication, IEEE Transactions on Industrial Informatics, vol. 19, no. 6, pp. 7814–7824, 2022.) proposed an identity-based broadcast signature encryption scheme for vehicular platoon communication. In this scheme, the lead vehicle only needs to sign once to generate a fixed-length publicly verifiable ciphertext for the following vehicle, and then use the broadcast function to send the ciphertext to multiple following vehicles at the same time. However, this signcryption communication scheme cannot support the lead vehicle to specify the following vehicle to receive the task content when unloading the task, so it is difficult to meet the needs of vehicle platoon task unloading. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a task unloading method and system with privacy protection in a vehicle formation, thereby ensuring effective matching between tasks and vehicles and selecting suitable vehicles for tasks; and also protecting the privacy of user vehicles through encryption algorithms, thereby ensuring that no malicious attackers can obtain task and vehicle privacy information through eavesdropping in an open communication environment.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] A privacy-preserving task offloading method in a vehicle formation comprises:

[0006] The pilot vehicle divides the task into multiple subtasks, issues a task request by broadcasting the queryable information of the subtasks, signs the task request and broadcasts it to all following vehicles;

[0007] Each follower vehicle receives the task request and calculates the execution time of its assigned subtask, generates task parameters, and returns the task parameters together with the signature to the lead vehicle; the task parameters include: execution time and task load capacity;

[0008] The pilot vehicle forwards the mission parameters and signature to the first cloud server CS A ,First Cloud Server CS A and the second cloud server CS B Collaborative privacy-preserving encryption execution time comparison, making the first cloud server CS AOffload each subtask to the most appropriate following vehicle;

[0009] The lead vehicle distributes the specific mission content to each designated follower vehicle;

[0010] Each designated follower vehicle signs and encrypts the specific task results and sends them to the pilot vehicle, which verifies the signature and decrypts the results.

[0011] The present invention also provides a task unloading system for privacy protection in a vehicle formation, comprising:

[0012] The first processing module is used to enable the pilot vehicle to divide the task into multiple subtasks, issue a task request by broadcasting the queryable information of the subtasks, and then broadcast the task request to all following vehicles after signing;

[0013] The second processing module is used to enable each following vehicle to receive the task request and calculate the execution time of its assigned subtask, generate task parameters, and return the task parameters together with the signature to the leading vehicle; wherein the task parameters include: execution time and task load capacity;

[0014] The third processing module is used to enable the pilot vehicle to forward the mission parameters together with the signature to the first cloud server CS A ,First Cloud Server CS A and the second cloud server CS B Collaborative privacy-preserving encryption execution time comparison, making the first cloud server CS A Offload each subtask to the most appropriate following vehicle;

[0015] A fourth processing module is used to enable the pilot vehicle to distribute specific task content to each designated following vehicle;

[0016] The fifth processing module is used to enable each designated following vehicle to sign and encrypt the specific task result and send it to the pilot vehicle, and the pilot vehicle verifies the signature and decrypts the result.

[0017] Compared with the prior art, it has the following advantages and effects:

[0018] 1. Based on ECC and the modified Paillier cryptographic system, the present invention realizes the unloading of designated tasks under the premise of protecting privacy. This solution effectively solves the problem of heavy task load on the pilot vehicle, can select the appropriate vehicle for the task, ensures efficient processing of tasks, and significantly protects the privacy information of vehicles and tasks, thereby improving overall efficiency.

[0019] 2. The present invention has the ability to resist various common attacks in vehicle formations, enhancing the security and reliability of the system. This design ensures that the system can effectively maintain the privacy and data security of users when facing potential threats.

[0020] 3. The present invention adopts lightweight cryptographic technology (i.e., ECC) to avoid time-consuming bilinear pairing, while supporting batch verification of signatures and message signcryption of multiple messages and multiple recipients. This ensures security while improving system efficiency, significantly reduces computing and communication overhead, and improves the overall performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the physical structure of a task offloading method for privacy protection in a vehicle formation according to an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of task unloading in a vehicle formation according to an embodiment of the present invention;

[0024] Figure 3 A flowchart of a task offloading method for privacy protection in a vehicle formation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Embodiment 1:

[0028] The embodiment of the present invention provides a method for offloading tasks of privacy protection in a vehicle formation, such as Figure 1As shown, the entities involved in this embodiment include: a trusted authority (TA), a cloud server (CS), a roadside unit and a vehicle. The trusted authority is used to generate system parameters and maintain vehicle information. The cloud server includes: a first cloud server and the second cloud server , they have sufficient computing and storage capabilities, and they cooperate to achieve privacy-preserving task offloading. The Road-Side Unit (RSU) only serves as a communication interface between the vehicle and the upper-layer entity (i.e., TA and CS). The vehicle has two roles in the vehicle formation, namely, the leading vehicle and the following vehicle. Figure 2 As shown in the figure, the pilot vehicle fully controls the entire vehicle formation and sends the task content to the following vehicles in the same fleet according to the task offloading strategy. The following vehicles are responsible for completing the task and returning the results to the pilot vehicle. Among them, TA is completely trustworthy, while RSU, pilot vehicle, following vehicles, and two cloud services are honest but curious, which means that they will strictly follow the protocol of the scheme and may be curious about some private information.

[0029] like Figure 3 As shown, an embodiment of the present invention provides a task offloading method for privacy protection in a vehicle formation, comprising:

[0030] Step S1, system initialization:

[0031] TA initializes multiple parameters, publishes public parameters, and securely transmits private parameters to and .

[0032] Step S2: Entity registration:

[0033] Each vehicle registers with TA using its real ID. TA generates a pseudonym and a pair of public and private keys for each registered vehicle. TA and Stores vehicle formation information, including the lead vehicle and follower vehicles.

[0034] Step S3: Task request:

[0035] The pilot vehicle will be tasked Divided into multiple subtasks. For each subtask, the pilot vehicle extracts the queryable information and forms a task request, which the pilot vehicle signs and broadcasts.

[0036] Step S4: Information return:

[0037] Each follower vehicle receives a task request and calculates the execution time of its assigned subtask. It generates its own set of task parameters, including the execution time and task load capacity, and returns this information along with a signature to the lead vehicle.

[0038] Step S5: Task Unloading

[0039] Based on the mission parameters received from the following vehicles, the leading vehicle summarizes the information and forwards it to CS A , CS A and CS B Comparison of execution time of collaborative privacy-preserving encryption, CS A Ability to offload each subtask to the most appropriate following vehicle without leaking sensitive information.

[0040] Step S6: Task scheduling:

[0041] The lead vehicle securely distributes specific mission content to each designated follower vehicle, ensuring the confidentiality and integrity of the mission content.

[0042] Step S7: Content retrieval:

[0043] Each designated follower vehicle retrieves the encrypted mission content and corresponding timestamp from the broadcast data. They decrypt the signcryption to obtain the mission content.

[0044] Step S8: Submit the result:

[0045] After completing the task, each designated follower vehicle signs and encrypts the task result and sends it to the pilot vehicle, which verifies the signature and decrypts the result.

[0046] As an implementation of the embodiment of the present invention, step S1 includes:

[0047] Given a security parameter λ, TA initializes the ECC algorithm: given a prime number Finite field defined , generate elliptic curve ,in, and , all points on the elliptic curve and the point at infinity form a prime order q The additive cyclic group of , the generator is TA randomly selects a private key ,in, are all prime numbers q The set of relatively prime integers, , and set its public key to . Then, TA randomly selects CS A Private key , and calculate CS A The public key .

[0048] TA selects four secure one-way hash functions: , , , In addition, TA also defines a one-way index function , which is used to generate a mapping from multiple messages to multiple receivers. middle, express The number of inputs, represents the recipient's vehicle identifier, The output is .in other words, Each user Uniform mapping to the set Then, given a safety factor , TA runs the key generation algorithm in the modified Paillier cryptosystem to obtain the public key in the modified Paillier cryptosystem and private key The modified Paillier cryptosystem is a homomorphic encryption method. First, two large prime numbers are selected. and ,calculate ,definition ,in, , then, choose two random numbers , ,make , and finally, the public key , private key , assuming there is news Need to be encrypted, where It is a model n The set of integers from 1 to -1, then select a random number first , then use the public key Encrypted to get ciphertext ,in, , , when decryption is needed, first use Will Convert to partially decrypted ciphertext ,in , ,for , you can further use To decrypt the plaintext ,in, , . This method satisfies additive homomorphism Homomorphic to multiplication :Given two ciphertexts and , we can get ,in , ,remember ; Given a ciphertext and a plaintext , we can get ,in , ,remember .

[0049] Get the public key in the modified Paillier cryptosystem and private key After that, TA publishes public parameters:

[0050]

[0051] And through the safe channel and private key Transmit to CS A ,Will Transmit to CS B 。

[0052] As an implementation of the embodiment of the present invention, step S2 includes:

[0053] 1) Vehicle pseudonym generation and key generation

[0054] In this step, each vehicle applies to TA for registration. Vehicles applying for registration , TA randomly selects And calculate Then, TA calculates ,in, , is the timestamp, represents XOR, Indicates concatenation of two strings. The pseudonym is TA will use the vehicle's real identity and pseudonym Stored in its database. Then, TA is the vehicle Generate a pair of public and private keys, TA first randomly selects , then calculate and Next, TA calculates , then, TA will vehicle The private key is set to , the vehicle The public key is set to Finally, TA passes the Send to vehicle .

[0055] 2) Vehicle formation settings

[0056] Since the formation of vehicle formation and the selection of leading and following vehicles have been solved in previous studies, they are not the focus of this invention. This invention only considers a pre-formed single-vehicle vehicle scenario. N A vehicle formation consisting of vehicles, of which Represents the pilot vehicle, represents each following vehicle. Therefore, the vehicle formation contains TA stores the vehicle formation information in the database ,in is the unique identifier of the vehicle formation, is the formation time of the vehicle formation. CS A Vehicle formation information Sync to its database.

[0057] As an implementation of the embodiment of the present invention, step S3 includes:

[0058] In the task offloading of vehicle formation, the following vehicles in the vehicle formation act as task participants, represented as ,in, Following vehicle The computing power of Following vehicle Add the start time of the task. When the help of the following vehicle is needed, the leading vehicle issues a task request by broadcasting the queryable information of the subtask.

[0059] First, the pilot vehicle The task Processed as subtasks, among which, Indicates the task A unique identifier for Indicates the task content that requires privacy protection. Indicates processing task The computing resources required, Indicates the task The start time of Indicates the task The time required, Indicates the task The maximum number of participants. Each subtask is represented by ,in . Then, the pilot vehicle From each subtask Extract queryable information , and then the task The complete queryable information is assembled into .

[0060] Next, the pilot vehicle Use the signature algorithm, as shown in Algorithm 1 (Sign()), to generate a signature for the queryable information of the task. By executing Generate signature ,in Indicates the timestamp, is a random number.

[0061] Finally, the pilot vehicle Will Broadcast to all following vehicles and transmit it to all roadside units RSU CS A Perform subsequent task offloading.

[0062]

[0063] As an implementation of the embodiment of the present invention, step S4 includes:

[0064] exist and CSA Received Then, they verify the signature by checking formula (1) ,in, ,

[0065]

[0066] Next, Compute subtasks Execution time ,in ,Then, Using Public Key Subtask execution time and Join the task start time Encryption is performed, and the encryption result is and .also, It is also necessary to calculate it in the task The maximum task load that can be processed within the time limit ,Then, By executing To generate a signature, Indicates the timestamp, is a random number. Finally, Will Send to ,in, Representative for Participate in the task The set of task parameters to use.

[0067] exist Received from all of Finally, it can use batch verification technology to verify multiple signatures at once. The signature is verified by checking formula (2):

[0068]

[0069] As an implementation of the embodiment of the present invention, step S5 includes:

[0070] By combining all Task parameter set , create a task The task parameter set of all participants in is expressed as ,Then, Sign the task parameter set by executing the signature algorithm To generate a signature ,in, Indicates the timestamp, represents a random number. Next, Through RSU Send to CS A , CS A The validity of the signature is verified by checking Formula 3.

[0071]

[0072]

[0073] Next, CSA Execute Algorithm 2 to offload tasks. In lines 8-9 of Algorithm 2, CS A Comparing encrypted task completion times using a privacy-preserving comparison algorithm and , they represent the assignments to the same subtask The encrypted form of the task completion time for different vehicles.

[0074] To better understand the privacy protection comparison process, the operations in lines 8-9 of Algorithm 2 are described as CS A Processing two key-value pairs and To simplify the description, the time required for different vehicles to complete the task is expressed as and ,Right now and ,in .

[0075] CS A need t 1 and t 2 Compare their sizes in the encrypted state, specifically, CS A and CS B Hold , which are the private keys of the modified Paillier cryptosystem part of, therefore, CS A Can be used CS B To help them obtain and ,if ,but , ;otherwise , .at last, CS A Output reordered key-value pairs As the comparison result, the detailed steps are given in Algorithm 3.

[0076]

[0077] In Algorithm 3, for and ,if ,but and The values ​​of will be swapped. When CS B Exchange, when When CS A Exchange. If , their values ​​are not swapped.

[0078] After completing the task offloading described in Algorithm 2, CS A Output task offloading strategy , then, CS A By executing the signature algorithm To generate a signature ,in express CS A identity, Indicates the timestamp, is a random number. Finally, CS A Through RSU Send to .

[0079] As an implementation of the embodiment of the present invention, the above step S6 includes:

[0080] exist receive After that, it verifies the signature by checking formula (6), where .

[0081]

[0082] If the signature is valid, The task will be uninstalled according to the strategy To send the task content, according to , subtask Contents is sent to the corresponding vehicle, where the task content Need to be protected. In the task offloading strategy, some following vehicles may be assigned to multiple subtasks, while other vehicles may not be assigned to any subtask, which requires the leading vehicle to be able to select the following vehicle as the task recipient, and only the designated following vehicle can access the task content.

[0083] The embodiment of the present invention adopts an improved multi-message multi-receiver broadcast signature encryption algorithm to implement batch signature verification in the result submission phase. Assume that the number of following vehicles designated to receive the task content is ,in Each specified FV is expressed as . Responsible for selecting the identities of these designated following vehicles from the vehicle formation, expressed as , It is necessary to ensure that only these designated following vehicles can receive the task content. Need to be sent, where A task contains one or more subtasks, each of which is represented by , depending on the task offloading strategy . right The steps for signature encryption are as follows:

[0084] 1) Random Selection And calculate .

[0085] For each ,in j From 1 to , The execution steps are as follows.

[0086] 2) Calculation ,in .

[0087] 3) Calculation , ,in, is with The associated timestamp.

[0088] 4) Calculation Signature , then, generate the ciphertext .

[0089] 5) As a ciphertext middle , thereby establishing .Will As a timestamp set middle , thereby establishing This ensures According to the index Retrieve the corresponding ciphertext and timestamp .

[0090] at last, Simultaneous broadcasting For all .

[0091] As an implementation of the embodiment of the present invention, step S7 includes:

[0092] Upon receiving back, Decrypt the signature to obtain the task content .first, Calculate the index first ,Then, Use this index to retrieve the ciphertext set and timestamp set Retrieve the ciphertext and timestamp .

[0093] Next, calculate

[0094]

[0095] Then, The validity of the signature is verified by checking formula (10). If it passes the verification, then take over , process the task and obtain the task result, expressed as .

[0096]

[0097] As an implementation of the embodiment of the present invention, step S8 includes:

[0098] Use its private key and The public key Task results Perform signcryption.

[0099] Random Selection And calculate . Then, calculate , and ,in, yes The associated timestamp.

[0100] Then, calculate As Then, Generate ciphertext .at last, Will Send to .

[0101] exist From all Received Afterwards, for each , calculate

[0102]

[0103] To improve verification efficiency and reduce overhead, Batch verification can be performed, as shown in formula (14). If the verification passes, then accept .

[0104]

[0105] Embodiment 2:

[0106] The embodiment of the present invention further provides a task offloading system for privacy protection in a vehicle formation, comprising:

[0107] The first processing module is used to enable the pilot vehicle to divide the task into multiple subtasks, issue a task request by broadcasting the queryable information of the subtasks, and then broadcast the task request to all following vehicles after signing;

[0108] The second processing module is used to enable each following vehicle to receive the task request and calculate the execution time of its assigned subtask, generate task parameters, and return the task parameters together with the signature to the leading vehicle; wherein the task parameters include: execution time and task load capacity;

[0109] The third processing module is used to enable the pilot vehicle to forward the mission parameters together with the signature to the first cloud server CS A ,First Cloud Server CS A and the second cloud server CS B Collaborative privacy-preserving encryption execution time comparison, making the first cloud server CS A Offload each subtask to the most appropriate following vehicle;

[0110] A fourth processing module is used to enable the pilot vehicle to distribute specific task content to each designated following vehicle;

[0111] The fifth processing module is used to enable each designated following vehicle to sign and encrypt the specific task result and send it to the pilot vehicle, and the pilot vehicle verifies the signature and decrypts the result.

[0112] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A privacy-preserving task offloading method in a vehicle formation, characterized in that: include: The pilot vehicle divides the task into multiple subtasks, issues a task request by broadcasting the queryable information of the subtasks, signs the task request and broadcasts it to all following vehicles; Each follower vehicle receives the task request and calculates the execution time of its assigned subtask, generates task parameters, and returns the task parameters together with the signature to the lead vehicle; the task parameters include: execution time and task load capacity; The pilot vehicle forwards the mission parameters and signature to the first cloud server CS A ,First Cloud Server CS A and the second cloud server CS B Collaborative privacy-preserving encryption execution time comparison, making the first cloud server CS A Offload each subtask to the most appropriate following vehicle; The lead vehicle distributes the specific mission content to each designated follower vehicle; Each designated follower vehicle signs and encrypts the specific task results and sends them to the pilot vehicle, which verifies the signature and decrypts the results; The method further includes an initialization process: given a security parameter λ, TA initializes the ECC algorithm: given a prime number Finite field defined , generate elliptic curve ,in, and , all points on the elliptic curve and the point at infinity form a prime order q The additive cyclic group of , the generator is 𝑃; TA randomly selects a private key ,in, are all prime numbers q The set of mutually prime integers, , and set its public key to 𝑃;TA randomly selects CS A Private key , and calculate CS A The public key 𝑃; TA selects four secure one-way hash functions: , , , ;TA defines a one-way index function , which is used to generate a mapping from multiple messages to multiple receivers; middle, express The number of inputs, represents the recipient's vehicle identifier, The output is ; Each user Uniform mapping to the set ;Given a safety factor , TA runs the key generation algorithm in the modified Paillier cryptosystem to obtain the public key in the modified Paillier cryptosystem and private key , the modified Paillier cryptosystem is a homomorphic encryption method. First, select two large prime numbers and ,calculate ,definition ,in, , then, choose two random numbers , ,make , and finally, the public key , private key , assuming there is news Need to be encrypted, where It is a model n The set of integers from 1 to -1, then select a random number first , then use the public key Encrypted to get ciphertext ,in, , , when decryption is needed, first use Will Convert to partially decrypted ciphertext ,in , ,for , you can further use To decrypt the plaintext ,in, , ; Get the public key in the modified Paillier cryptosystem and private key After that, TA publishes public parameters: And through the safe channel and private key Transmit to CS A ,Will Transmit to CS B ; Among them, the encryption time of privacy protection is compared: CS A Comparing encrypted task completion times using a privacy-preserving comparison algorithm and , which represents the encrypted form of the task completion time of different vehicles assigned to the same subtask; CS A Processing two key-value pairs and , ; The time for different vehicles to complete the task is expressed as and ,Right now and ,in, ; CS A use CS B To help them obtain and ,if t 1≥ t 2, then , ;otherwise , ; CS A Output reordered key-value pairs As a comparison result.

2. A task offloading system for privacy protection in a vehicle formation that implements the task offloading method for privacy protection in a vehicle formation according to claim 1, characterized in that: include: The first processing module is used to enable the pilot vehicle to divide the task into multiple subtasks, issue a task request by broadcasting the queryable information of the subtasks, and then broadcast the task request to all following vehicles after signing; The second processing module is used to enable each following vehicle to receive the task request and calculate the execution time of its assigned subtask, generate task parameters, and return the task parameters together with the signature to the leading vehicle; wherein the task parameters include: execution time and task load capacity; The third processing module is used to enable the pilot vehicle to forward the mission parameters together with the signature to the first cloud server CS A ,First Cloud Server CS A and the second cloud server CS B Collaborative privacy-preserving encryption execution time comparison, making the first cloud server CS A Offload each subtask to the most appropriate following vehicle; A fourth processing module is used to enable the pilot vehicle to distribute specific task content to each designated following vehicle; The fifth processing module is used to enable each designated following vehicle to sign and encrypt the specific task result and send it to the pilot vehicle, and the pilot vehicle verifies the signature and decrypts the result.

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