A traceable privacy protection method and system for crowd sensing

Abstract

The application discloses a kind of traceable privacy protection methods and systems for crowd-sensing. The method comprises the following steps: step 1: system initialization;Step 2: data demander registration;Step 3: task group building;Step 4: data collection submission;Step 5: user traceability.The application solves the problem of user privacy leakage in the traditional blockchain traceability process by combining blockchain technology and group signature technology.Group signature allows users to participate anonymously in transactions while ensuring the non-forgery and traceability of the signature.In protecting user privacy, it can effectively trace malicious behavior.When there is a dispute or the need for audit, the auditor can trace the signature without revealing the privacy of other users, ensuring the accuracy and fairness of the traceability.

Description

Technical Field

[0001] The present invention relates to the technical field of blockchain, and in particular to a traceable privacy protection method and system for crowd-sensing. Background Art

[0002] Crowd sensing leverages sensor networks and data fusion technologies, combined with crowdsourcing, to collect and process massive amounts of sensory data in real time, improving both comprehensiveness and accuracy. The integration of blockchain can effectively mitigate the shortcomings of traditional crowd sensing, such as centralization, low transparency, and incomplete trustworthiness. Crowdsourcing requires a large number of participants, who upload sensitive information such as identity and location. Blockchain can provide limited privacy protection for users. Introducing zero-knowledge proofs, differential privacy, and homomorphic encryption can enhance on-chain privacy, but this also increases the difficulty of data traceability.

[0003] Blockchain's inherent traceability has significant practical implications for improving the security and reliability of various types of information in modern society. By recording and tracking the progress of specific projects or information, blockchain ensures the legitimacy and authenticity of every transaction throughout its lifecycle. However, this traceability process carries the risk of privacy breaches, necessitating the simultaneous maintenance of both the privacy and traceability of on-chain data. Furthermore, blockchain's traceability provides technical support for blockchain audits. However, due to the low transparency of the audit process, current audit effectiveness is low, necessitating increased public participation in the audit process.

[0004] In order to coordinate the traceability and privacy of blockchain under crowdsourcing and improve the transparency of on-chain audits, this application is based on blockchain technology and is applied to the scenario of crowd intelligence perception. It integrates group signature and secret sharing technology. Without destroying the privacy of data, it can realize the retroactive audit of malicious behavior, improve the transparency of the on-chain audit process, protect user rights and interests and promote industry development. Summary of the Invention

[0005] The purpose of the present invention is to propose a traceable privacy protection method and system for crowd-sensing, which integrates blockchain, group signature, and secret sharing technologies, and has the characteristics of decentralization, data credibility, data privacy, traceability, and audit transparency, thereby constructing a traceable privacy protection method for crowd-sensing to improve the blockchain and crowd-sensing environment.

[0006] To achieve the purpose of the present invention, the technical solutions provided by the present invention are as follows:

[0007] First aspect

[0008] This application provides a traceable privacy protection method for crowd intelligence perception, including the following steps:

[0009] Step 1: System initialization: deploy the underlying blockchain network, and deploy the key generation function, the auditor completes authentication and initializes the behavior record list about the user and the data demander;

[0010] Step 2: Data demander registration: the data demander needs to interact with the auditor, register and authenticate; generate an on-chain identifier, further set specific task requirements and package, send to the auditor, the auditor verifies the credibility of the task, and publishes it on the chain;

[0011] Step 3: Task group building: on-chain users with wisdom perception task execution intention register, users use their own key pairs, interact with auditors through algorithms, complete sensitive data protection and data desensitization operations, and update records, and the contract and the auditor jointly give the group permission and auxiliary supervision permission to the on-chain user;

[0012] Step 4: Collecting data submission: participants who complete task data collection group sign the collected data without revealing personal information, send it to the data demander while backing it up on the blockchain; the data demander uses the group public key to verify the validity of the data, and all roles cannot be associated with the data collector and the associated data submission;

[0013] Step 5: User traceability: when the data collector or data collector raises a request to the auditor, the identity information is attached for identity confirmation; through signature verification, whether the identity information is consistent with the information at the initialization time is verified, after verification, the on-chain contract sends an audit request to all users in the group, adopts the idea of secret sharing, when the number exceeds the threshold, the opener's key can be restored, and then the group administrator's key is used to open the record list containing complete information, complete the traceability of the activity data and the user identity.

[0014] Second aspect

[0015] Corresponding to the above method, the application also provides a traceable privacy protection system for group wisdom perception, comprising the following units: initialization unit, demander registration unit and task group building unit, data submission unit, traceability unit;

[0016] The initialization unit is used for system initialization: deploying the underlying blockchain network, and deploying the key generation function, the auditor completes authentication and initializes the behavior record list about the user and the data demander;

[0017] The demander registration unit is used for data demander registration: the data demander needs to interact with the auditor, register and authenticate; generate an on-chain identifier, further set specific task requirements and package, send to the auditor, the auditor verifies the credibility of the task, and publishes it on the chain;

[0018] The task group building unit is used for task group building: on-chain users with wisdom perception task execution intention register, and the users interact with the audit party through an algorithm using their own key pairs, wherein sensitive data protection and data desensitization operations are completed, and records are updated, and the group permissions and auxiliary supervision permissions of the on-chain users are jointly given by the contract and the audit party;

[0019] The data submission unit is used for data collection submission: participants who complete task data collection perform group signature on collected data without leaking personal information, and send the data to a data demand party while backing up the data on a blockchain; the data demand party verifies the validity of the data using a group public key, and all roles cannot be associated with data collectors and data submission;

[0020] The tracing unit is used for user tracing: when a data collector or a data collector raises a request to the audit party during an activity, the identity information of the data collector or the data collector is attached for identity confirmation; identity information is verified through signature to check whether the identity information is consistent with the information at the initialization, after the verification, the on-chain contract sends an audit request to all users of the group, and the idea of secret sharing is adopted, when the number of people exceeds a threshold, the key of the opener can be restored, and then the group administrator key is used to open the record list containing complete information, and the tracing of the activity data and the user identity is completed.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. The present application solves the problem of user privacy leakage in the traditional blockchain traceability process by combining blockchain technology and group signature technology. Group signature allows users to participate in transactions anonymously while ensuring the non-forgery and traceability of the signature. While protecting user privacy, it can effectively trace malicious behavior. When a dispute or audit is needed, the audit party can track the signature without leaking the privacy of other users, ensuring the accuracy and fairness of the traceability.

[0023] 2. The present application combines secret sharing technology to make the on-chain audit process more transparent. By storing data fragments and reconstructing them when needed, the audit process is verifiable and the data is complete. In the context of wisdom perception, the present application can effectively prevent data tampering and forgery, and improve the reliability of the audit result. By improving the transparency of on-chain audit, it helps regulatory authorities effectively regulate blockchain applications, reduces industry risk, and creates a safe and reliable network environment for users. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The method flowchart provided by the embodiment of the present application is shown in the figure;

[0025] Figure 2This is a schematic diagram of the system initialization process in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the data requester registration process in an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the participant group formation process in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the data collection and submission process in an embodiment of the present invention;

[0029] Figure 6 Schematic diagram of the user tracing process in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Example 1

[0032] like Figure 1 As shown, this embodiment provides a traceable privacy protection method for crowd intelligence perception, including the following steps:

[0033] Step 1: System Initialization: Deploy the underlying blockchain network to meet the needs of user privacy protection and traceability auditing, and deploy the key generation function. The auditor completes the authentication and initializes the behavior record list of users and data requesters to facilitate the thorough investigation of violations.

[0034] like Figure 2 As shown, the step 1 specifically includes the following:

[0035] Step 1.1: Deploy the blockchain network BC. Each time a crowd-sensing task is completed, it needs to be packaged into a block;

[0036] Step 1.2: Preset the task record structure, including the task serial number TID and the participant's identity tag Uaddr i , data submission time TT, task hash THash and random number R generation structure TR are task records, where:

[0037] TR={TID:value,Uaddr i :value,TT:value,THash:value,R:value};

[0038] Step 1.3: The task record TR will be attached to the block body generated during the reward distribution process, packaged into a block, and attached to the end of the blockchain;

[0039] Step 1.4: The auditor AT randomly selects a key parameter u to generate the auditor key pair AK = (APK, ask), where APK is the auditor's public key and ask is the auditor's private key.

[0040] Step 1.5: Package the auditor authentication information ACT and the auditor public key APK to generate the auditor authentication certificate SCT, where SCT = (APK, ACT). The auditor authentication certificate SCT is used in the identity authentication process when the auditor serves as the group manager GM. After authentication, the auditor AT becomes the task group manager GM.

[0041] Step 1.6: The auditor generates the auditor's address Saddr = AddrGene (SPK) based on the auditor's public key SPK.

[0042] Step 1.7: Initialize the data requester list Lr[j] = {Caddr j :value,Tr j :value,c j :value}, and publish the auditor's address Saddr and the data demander list Lr[j] on the chain.

[0043] Step 2: Data demander registration: Data demanders need to interact with the auditor to register and authenticate, including verification of demander qualifications, primarily to protect data security and meet the reliability requirements of the published tasks. Generate an on-chain identifier, further set specific task requirements, package them, and send them to the auditor. The auditor verifies the credibility of the task and publishes it on-chain.

[0044] like Figure 3 As shown, the step 2 specifically includes the following:

[0045] Step 2.1: The data collection task is set by the data demander DR. Before the collection task is released, the data demander DR needs to interact with the auditor AT and register;

[0046] Step 2.2: The data demander DR randomly selects the key generation parameter τ to generate the data demander key pair RK j =(RPK j ,rsk j ), RPK is the public key of the data demander, rsk j The private key of the data demander;

[0047] Step 2.3: Generate the on-chain identity Caddr based on the public key RPK j , where Caddr j =AddrGene(RPK j );

[0048] Step 2.4: Set TX according to your needs j ,DX j ,LX j And other task requirements, and use the private key rsk j Sign and package the task requirements to generate Tr j , where Tr j ←sign(TX j ,DX j ,LX j ), and {c j ,Caddr j ,RPK j ,Tr j} to AT, where c j It is a reliability certificate for data demanders;

[0049] Step 2.5: The auditor receives {c j ,Caddr j ,RPK j ,Tr j}, using the data demander's public key RPK j Test Tr j If the correctness of the signature is verified, the entry is added to Lr[j], assigned the task number TID, and signed, where (TID|sign({Caddr j ,RPK i ,Tr j},ask)) and publish it on the blockchain.

[0050] Step 3: Task group formation: This step mainly involves the registration of on-chain users who intend to perform the task through crowd intelligence perception. Users use their own key pairs to interact with the auditor through algorithms, completing sensitive data protection and data desensitization operations, and updating records. The contract and the auditor jointly grant the on-chain user group permissions and auxiliary supervision permissions;

[0051] like Figure 4 As shown, the step 3 specifically includes the following:

[0052] Step 3.1: After the task is released, the auditor AT creates a task group for the task numbered TID, and the auditor AT becomes the group manager GM;

[0053] Step 3.2: Generate a group registration key pair CK = (CPK, csk), where CPK is the group registration public key, used by participants to join the group, and csk is the group registration private key, visible only to the administrator GM;

[0054] Step 3.3, initialize the member list Lu[i]:

[0055] Lu[i]={Uaddr:value,UPK:value,usg i :value,HashData i :value,u i :value}, which contains information that can be traced back to the user's real identity and is invisible to all roles before the key is restored;

[0056] Step 3.4: Set the opener's traceability key pair OK = (OPK, osk), and the task group manager GM selects two keys that meet For large prime numbers p and q, select a generator g of order q in GF(p);

[0057] Step 3.5: Set up the traceability key This key is the opener key, which can be used by any The secrets recovered by members are used to assist group managers in tracing and improve group member participation; generate a group key pair (OPK, osk), publish the opener public key OPK and keep osk invisible;

[0058] Step 3.6: For any group of m members to be able to compute the secret, compute as well as Optional stk i and calculate according to Calculate UT i , (SPK i ,UT i ) is sent to the traceability group; at the same time, the selection of parameters should satisfy m and more members cannot pass f i (0)(modq), group public key GK, user public key UPK i and (SPK i ,UT i ) Conspire to obtain secret parameters of the system;

[0059] Step 3.7: ID i with x i For every future participant u i The system selects the key and identity authentication of m members and constructs the Lagrange interpolation theorem Also check f i (0)! = 0, if true, reselect the identity ID i With key x i ; If not established, then take the one that does not satisfy the current The t+1th pair of different numbers, where ID t+1 ∈Z q ,xt+1 ∈Z q And construct m polynomials f with the first m-1 numbers i (x)(i=1,2,……,t+1), all opener key fragments are non-zero and not equal to each other, and any secret F sum mod q is not zero; construct polynomials in So we can see that the group tracing secret is The key to trace is The group traceability public key is OPK=g f(0) mod p(i=1,2,…,n);

[0060] Step 3.8: For each on-chain user u i ∈U, users who want to participate in the crowd intelligence perception task need to first register to become data collectors DC; specifically, users generate personal key pairs UK i :(UPK i ,usk i );

[0061] Step 3.9: Data collector DC uses the public key UPK i Generate on-chain identity Uaddr i , where Uaddr i =AddrGene(UPK i );

[0062] Step 3.10: User public key UPK i , User ID Uaddr i And user sensitive information u i Combine to generate the UrAsk structure i , called a registration request, where UrAsk i ={UPK i ,Uaddri,u i};

[0063] Step 3.11: Send a registration request UrAsk through a secure channel i , and append usk i Interact with the group registration public key CPK and group administrator GM;

[0064] Step 3.12: After verification, grant the user group authority and distribute the group key gsk i and opener part key osk i , to give users the power to sign and assist in supervision, and update the list Lu[i].

[0065] Step 4: Collected data submission: Participants who have completed task data collection will group-sign the collected data without disclosing personal information, send it to the data requester, and back it up on the blockchain. The data requester uses the group public key to verify the validity of the data. No role can be associated with the data collector or the submitted data.

[0066] like Figure 5 As shown, the step 4 specifically includes the following:

[0067] Step 4.1: The data submission phase after participant screening involves many participants;

[0068] Step 4.2: Participants collect the data required for the task and enter the collection time in UTX i 、Collection location UDX i And collect data ULX i Various types of data are encapsulated into structure UTr i , called submitting collected data, where UTr i ={UTX i ,UDX i ,ULX i};

[0069] Step 4.3: The submitter attaches the task number TID and generates a new structure Ua i , called submitted data: Ua i ={TID,UTr i};

[0070] Step 4.4: Participants use the group private key gsk i Signature get sign(Ua i ,gsk i ) and sent to the data demander DR;

[0071] Step 4.5: Data demander DR verifies whether Uaddr i ∈Lu[i];

[0072] Step 4.6: Calculation Let R = R i , and generate a signature (R, a, r) ​​to verify the validity of the signature and authenticate the sender's identity. i )} is sent to the chain for verification.

[0073] Step 5: User tracing: When data collectors or data collectors have doubts during an activity, they initiate a request to the auditor and attach their own identification information for identity confirmation. The signature is used to verify whether the identity information is consistent with the information at the time of initialization. After the verification is passed, the on-chain contract sends an audit request to all users in the group. Using the idea of ​​secret sharing, when the number of people exceeds the threshold, the opener key can be recovered, and then combined with the group administrator's key to unlock the record list containing complete information, completing the tracing of activity data and user identity.

[0074] like Figure 6 As shown, the step 5 specifically includes the following:

[0075] Step 5.1: Users with traceability requirements include data collectors (DCs) and data demanders (DRs);

[0076] Step 5.2: If the DC disagrees with the subsequent bonus or score and needs to obtain relevant proof, it can search the chain through the task ID TID to find the GM of the task group;

[0077] Step 5.3: The group manager GM receives the user's identity information u i 、Tag Uaddr i And the user's signature information and verify the correctness of the user's identity information. At the same time, initiate an opener key recovery request to the group users to recover the opener key osk;

[0078] Step 5.4: If the verification is successful, the member's relevant proof i Send to DC;

[0079] Step 5.5: If the application is initiated by the data demander DR, verify c i Correctness of identity;

[0080] Step 5.6: If verification is successful, request to recover the opener key osk and group signature δ i , the group member list Lu generates the signature δ i The user entry Lu[i] is also based on c j The request made sends the associated proof ρ.

[0081] Example 2

[0082] Corresponding to the above method, this embodiment provides a traceable privacy protection system for crowd intelligence perception, including the following units: an initialization unit, a demander registration unit, a task group formation unit, a data submission unit, and a tracing unit;

[0083] The initialization unit is used to initialize the system: deploy the underlying blockchain network and the key generation function, complete the audit party's authentication and initialize the behavior record list of users and data demanders;

[0084] The demander registration unit is used for data demander registration: the data demander needs to interact with the auditor to register and authenticate; generate an on-chain identifier, further set specific task requirements and package them, and send them to the auditor. The auditor verifies the credibility of the task and publishes it on the chain;

[0085] The task group formation unit is used to form a task group: on-chain users who intend to execute the group intelligence perception task register, and the user uses their own key pair to interact with the auditor through the algorithm, completing sensitive data protection and data desensitization operations, and updating records. The contract and the auditor jointly grant the on-chain user group permissions and auxiliary supervision permissions;

[0086] The data submission unit is used to collect and submit data: participants who have completed task data collection will group-sign the collected data without disclosing personal information, and send it to the data requester while backing it up on the blockchain; the data requester uses the group public key to verify the validity of the data, and no role can be associated with the data collector or the submitted data;

[0087] The tracing unit is used for user tracing: when a data collector or data collector has doubts during an activity, they initiate a request to the auditor and attach their own identification information for identity confirmation; the identity information is verified by signature to see if it is consistent with the information at the time of initialization. After the verification is passed, the on-chain contract sends an audit request to all users in the group. Using the idea of ​​secret sharing, when the number of people exceeds the threshold, the opener key can be recovered, and then combined with the group administrator's key to unlock the record list containing complete information, completing the tracing of activity data and user identity.

[0088] Preferably, the initialization unit is specifically configured to perform the following steps:

[0089] Step 1.1: Deploy the blockchain network BC. Each time a crowd-sensing task is completed, it needs to be packaged into a block;

[0090] Step 1.2: Preset the task record structure, including the task serial number TID and the participant's identity tag Uaddr i , data submission time TT, task hash THash and random number R generation structure TR are task records, where:

[0091] TR={TID:value,Uaddr i :value,TT:value,THash:value,R:value};

[0092] Step 1.3: The task record TR will be attached to the block body generated during the reward distribution process, packaged into a block, and attached to the end of the blockchain;

[0093] Step 1.4: The auditor AT randomly selects a key parameter u to generate the auditor key pair AK = (APK, ask), where APK is the auditor's public key and ask is the auditor's private key.

[0094] Step 1.5: Package the auditor authentication information ACT and the auditor public key APK to generate the auditor authentication certificate SCT, where SCT = (APK, ACT). The auditor authentication certificate SCT is used in the identity authentication process when the auditor serves as the group manager GM. After authentication, the auditor AT becomes the task group manager GM.

[0095] Step 1.6: The auditor generates the auditor's address Saddr = AddrGene (SPK) based on the auditor's public key SPK.

[0096] Step 1.7: Initialize the data requester list Lr[j] = {Caddr j :value,Tr j :value,c j :value}, and publish the auditor's address Saddr and the data demander list Lr[j] on the chain.

[0097] Preferably, the demander registration unit is specifically configured to perform the following steps:

[0098] Step 2.1: The data collection task is set by the data demander DR. Before the collection task is released, the data demander DR needs to interact with the auditor AT and register;

[0099] Step 2.2: The data demander DR randomly selects the key generation parameter τ to generate the data demander key pair RK j =(RPK j ,rsk j ), RPK is the public key of the data demander, rsk j The private key of the data demander;

[0100] Step 2.3: Generate the on-chain identity Caddr based on the public key RPK j , where Caddr j =AddrGene(RPK j );

[0101] Step 2.4: Set TX according to your needs j ,DX j ,LX jMultiple task requirements, and use the private key rsk j Sign and package the task requirements to generate Tr j , where Tr j ←sign(TX j ,DX j ,LX j ), and {c j ,Caddr j ,RPK j ,Tr j} to AT, where c j It is a reliability certificate for data demanders;

[0102] Step 2.5: The auditor receives {c j ,Caddr j ,RPK j ,Tr j}, using the data demander's public key RPK j Test Tr j If the correctness of the signature is verified, the entry is added to Lr[j], assigned the task number TID, and signed, where (TID|sign({Caddr j ,RPK i ,Tr j},ask)) and publish it on the blockchain.

[0103] Preferably, the task group forming unit is specifically configured to perform the following steps:

[0104] Step 3.1: After the task is released, the auditor AT creates a task group for the task numbered TID, and the auditor AT becomes the group manager GM;

[0105] Step 3.2: Generate a group registration key pair CK = (CPK, csk), where CPK is the group registration public key, used by participants to join the group, and csk is the group registration private key, visible only to the administrator GM;

[0106] Step 3.3, initialize the member list Lu[i]:

[0107] Lu[i]={Uaddr:value,UPK:value,usg i :value,HashData i :value,u i :value}, which contains information that can be traced back to the user's real identity and is invisible to all roles before the key is restored;

[0108] Step 3.4: Set the opener's traceability key pair OK = (OPK, osk), and the task group manager GM selects two keys that meet For large prime numbers p and q, select a generator g of order q in GF(p);

[0109] Step 3.5: Set up the traceability key This key is the opener key, which can be used by any The secrets recovered by members are used to assist group managers in tracing and improve group member participation; generate a group key pair (OPK, osk), publish the opener public key OPK and keep osk invisible;

[0110] Step 3.6: For any group of m members to be able to compute the secret, compute as well as Optional stk i and calculate according to Calculate UT i , (SPK i ,UT i ) is sent to the traceability group; at the same time, the selection of parameters should satisfy m and more members cannot pass f i (0)(modq), group public key GK, user public key UPK i and (SPK i ,UT i ) Conspire to obtain secret parameters of the system;

[0111] Step 3.7: ID i with x i For every future participant u i The system selects the key and identity authentication of m members and constructs the Lagrange interpolation theorem Also check f i (0)! = 0, if true, reselect the identity ID i With key x i ; If not established, then take the one that does not satisfy the current The t+1th pair of different numbers, where ID t+1 ∈Z q ,x t+1 ∈Z q And construct m polynomials f with the first m-1 numbers i (x)(i=1,2,……,t+1), all opener key fragments are non-zero and not equal to each other, and any secret F sum mod q is not zero; construct polynomials in So we can see that the group tracing secret is The key to trace is The group traceability public key is OPK=g f(0) mod p(i=1,2,…,n);

[0112] Step 3.8: For each on-chain user u i ∈U, users who want to participate in the crowd intelligence perception task need to first register to become data collectors DC; specifically, users generate personal key pairs UK i :(UPK i ,usk i );

[0113] Step 3.9: Data collector DC uses the public key UPK i Generate on-chain identity Uaddr i , where Uaddr i =AddrGene(UPK i );

[0114] Step 3.10: User public key UPK i , User ID Uaddr i And user sensitive information u i Combine to generate the UrAsk structure i , called a registration request, where UrAsk i ={UPK i ,Uaddri,u i};

[0115] Step 3.11: Send a registration request UrAsk through a secure channel i , and append usk i Interact with the group registration public key CPK and group administrator GM;

[0116] Step 3.12: After verification, grant the user group authority and distribute the group key gsk i and opener part key osk i , to give users the power to sign and assist in supervision, and update the list Lu[i].

[0117] The above describes in detail the optional implementation methods of the embodiments of the present invention in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation methods. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the scope of protection of the embodiments of the present invention.

Claims

1. A traceable privacy protection method for crowd intelligence perception, characterized by: The steps include: Step 1: System initialization: Deploy the underlying blockchain network and the key generation function. The auditor completes the authentication and initializes the behavior record list of users and data requesters. Step 2: Data demander registration: The data demander needs to interact with the auditor to register and authenticate; Generate an on-chain identifier, further set specific task requirements, package them, and send them to the auditor. The auditor verifies the credibility of the task and publishes it on the chain; Step 3: Task group formation: On-chain users who intend to perform group intelligence perception tasks register. Users use their own key pairs to interact with the auditor through algorithms, completing sensitive data protection and data desensitization operations, and updating records. The contract and the auditor jointly grant the on-chain user group permissions and auxiliary supervision permissions; Step 4: Collected data submission: Participants who have completed task data collection will group-sign the collected data without disclosing personal information, send it to the data requester, and back it up on the blockchain; The data demander uses the group public key to verify the validity of the data. No role can be associated with the data collector or the submitted data; Step 5: User tracing: When data collectors or data collectors have doubts during an activity, they initiate a request to the auditor and attach their own identification information for identity confirmation. The signature is used to verify whether the identity information is consistent with the information at the time of initialization. After the verification is passed, the on-chain contract sends an audit request to all users in the group. Using the idea of ​​secret sharing, when the number of people exceeds the threshold, the opener key can be recovered, and then combined with the group administrator's key to unlock the record list containing complete information, completing the tracing of activity data and user identity.

2. The method for traceable privacy protection for crowd intelligence perception according to claim 1 is characterized in that: The step 1 specifically includes the following: Step 1.1: Deploy the blockchain network BC. Each time a crowd-sensing task is completed, it needs to be packaged into a block; Step 1.2: Preset the task record structure, including the task serial number TID and the participant's identity tag Uaddr i , data submission time TT, task hash THash and random number R generation structure TR are task records, where: TR={TID:value,Uaddr i :value,TT:value,THash:value,R:value}; Step 1.3: The task record TR will be attached to the block body generated during the reward distribution process, packaged into a block, and attached to the end of the blockchain; Step 1.4: The auditor AT randomly selects a key parameter u to generate the auditor key pair AK = (APK, ask), where APK is the auditor's public key and ask is the auditor's private key. Step 1.5: Package the auditor authentication information ACT and the auditor public key APK to generate the auditor authentication certificate SCT, where SCT = (APK, ACT). The auditor authentication certificate SCT is used in the identity authentication process when the auditor serves as the group manager GM. After authentication, the auditor AT becomes the task group manager GM. Step 1.6: The auditor generates the auditor's address Saddr=AddrGene(APK) based on the auditor's public key APK; Step 1.7: Initialize the data requester list Lr[j] = {Caddr j :value,Tr j :value,c j :value}, and publish the auditor's address Saddr and the data demander list Lr[j] on the chain.

3. The method for traceable privacy protection for crowd intelligence perception according to claim 2 is characterized in that: The step 2 specifically includes the following: Step 2.1: The data collection task is set by the data demander DR. Before the collection task is released, the data demander DR needs to interact with the auditor AT and register; Step 2.2: The data demander DR randomly selects the key generation parameter τ to generate the data demander key pair RK j =(RPK j ,rsk j ), RPK j The public key of the data demander, rsk j The private key of the data demander; Step 2.3: Based on the public key RPK j Generate on-chain identity Caddr j , where Caddr j =AddrGene(RPK j ); Step 2.4: Set TX according to your needs j ,DX j ,LX j Multiple task requirements, and use the private key rsk j Sign and package the task requirements to generate Tr j , where Tr j ←sign(TX j ,DX j ,LX j ), and {c j ,Caddr j ,RPK j ,Tr j }Send to AT, where c j It is a reliability certificate for data demanders; Step 2.5: The auditor receives {c j ,Caddr j ,RPK j ,Tr j }, using the data demander's public key RPK j Test Tr j If the correctness of the signature is verified, the entry is added to Lr[j], assigned the task number TID, and signed, where (TID|sign({Caddr j ,RPK j ,Tr j },ask)) and publish it on the blockchain.

4. The method for traceable privacy protection for crowd intelligence perception according to claim 3 is characterized in that: The step 3 specifically includes the following: Step 3.1: After the task is released, the auditor AT creates a task group for the task numbered TID, and the auditor AT becomes the group manager GM; Step 3.2: Generate a group registration key pair CK = (CPK, csk), where CPK is the group registration public key, used by participants to join the group, and csk is the group registration private key, visible only to the administrator GM; Step 3.3, initialize the member list Lu[i]: Lu[i]={Uaddr:value,UPK:value,usg i :value,HashData i :value,u i :value}, This list contains information that can be traced back to the user's real identity and is invisible to all roles until the key is restored; Step 3.4: Set the opener's traceability key pair OK = (OPK, osk), and the task group manager GM selects two keys that meet For large prime numbers p and q, select a generator g of order q in GF(p); Step 3.5: Set up the traceability key This key is the opener key, which can be used by any The secrets recovered by members are used to assist group managers in tracing and improve group member participation; generate a group key pair (OPK, osk), publish the opener public key OPK and keep osk invisible; Step 3.6: For any group of m members to be able to compute the secret, compute as well as Optional stk i and calculate according to Calculate UT i , (SPK i ,UT i ) is sent to the traceability group; at the same time, the selection of parameters should satisfy that m and more members cannot pass f i (0)(mod q), group public key GK, user public key UPK i and (SPK i ,UT i ) Conspire to obtain secret parameters of the system; Step 3.7: ID i with x i For every future participant u i The system selects the key and identity authentication of m members and constructs the Lagrange interpolation theorem Also check f i (0)! = 0, if true, reselect the identity ID i With key x i ; If not established, then take the one that does not satisfy the current The t+1th pair of different numbers, where ID t+1 ∈Z q ,x t+1 ∈Z q And construct m polynomials f with the first m-1 numbers i (x)(i=1,2,……,t+1), all opener key fragments are non-zero and not equal to each other, and any secret F sum mod q is not zero; structure polynomials in So we can see that the group tracing secret is The key to trace is The group traceability public key is OPK=g f(0) mod p(i=1,2,…,n); Step 3.8: For each on-chain user u i ∈U, users who want to participate in the crowd intelligence perception task need to first register to become data collectors DC; specifically, users generate personal key pairs UK i :(UPK i ,usk i ); Step 3.9: Data collector DC uses the public key UPK i Generate on-chain identity Uaddr i , where Uaddr i =AddrGene(UPK i ); Step 3.10: User public key UPK i , User ID Uaddr i And user sensitive information u i Combine to generate the UrAsk structure i , called a registration request, where UrAsk i ={UPK i ,Uaddr i ,u i }; Step 3.11: Send a registration request UrAsk through a secure channel i , and append usk i Interact with the group registration public key CPK and group administrator GM; Step 3.12: After verification, grant the user group authority and distribute the group key gsk i and opener part key osk i , to give users the power to sign and assist in supervision, and update the list Lu[i].

5. The method for traceable privacy protection for crowd intelligence perception according to claim 4 is characterized in that: The step 4 specifically includes the following: Step 4.1: The data submission phase after participant screening involves many participants; Step 4.2: Participants collect the data required for the task and enter the collection time in UTX i 、Collection location UDX i And collect data ULX i Encapsulate various types of data into structure UTr i , called submitting collected data, where UTr i ={UTX i ,UDX i ,ULX i }; Step 4.3: The submitter attaches the task number TID and generates a new structure Ua i , called submitted data: Ua i ={TID,UTr i }; Step 4.4: Participants use the group private key gsk i Signature get sign(Ua i ,gsk i ) and sent to the data demander DR; Step 4.5: Data demander DR verifies whether Uaddr i ∈Lu[i]; Step 4.6: Calculation Let R = R i , and generate a signature (R, a, r) ​​to verify the validity of the signature and authenticate the sender's identity. i )} is sent to the chain for verification.

6. The method for traceable privacy protection for crowd intelligence perception according to claim 5 is characterized in that: The step 5 specifically includes the following: Step 5.1: Users with traceability requirements include data collectors (DCs) and data demanders (DRs); Step 5.2: If the DC disagrees with the subsequent bonus or score and needs to obtain relevant proof, it can search the chain through the task ID TID to find the GM of the task group; Step 5.3: GM receives the user's identity information u i 、Tag Uaddr i And the user's signature information and verify the correctness of the user's identity information. At the same time, initiate an opener key recovery request to the group users to recover the opener key osk; Step 5.4: If the verification is successful, the member's relevant proof i Send to DC; Step 5.5: If the application is initiated by the data demander DR, verify c i Correctness of identity; Step 5.6: After verification, GM requests to recover the opener key osk and group signature δ i And the signature δ generated by the group member list Lu i The user entry Lu[i], and according to c j The request made sends the associated proof ρ.

7. A traceable privacy protection system for crowd intelligence perception, characterized by: It includes the following units: initialization unit, demander registration unit, task group formation unit, data submission unit, and tracing unit; The initialization unit is used to initialize the system: deploy the underlying blockchain network and the key generation function, complete the audit party's authentication and initialize the behavior record list of users and data demanders; The demander registration unit is used for data demander registration: the data demander needs to interact with the auditor to register and authenticate; Generate an on-chain identifier, further set specific task requirements, package them, and send them to the auditor. The auditor verifies the credibility of the task and publishes it on the chain; The task group formation unit is used to form a task group: on-chain users who intend to execute the group intelligence perception task register, and the user uses their own key pair to interact with the auditor through the algorithm, completing sensitive data protection and data desensitization operations, and updating records. The contract and the auditor jointly grant the on-chain user group permissions and auxiliary supervision permissions; The data submission unit is used to collect and submit data: participants who have completed task data collection will group-sign the collected data without disclosing personal information, send it to the data requester, and back it up on the blockchain; The data demander uses the group public key to verify the validity of the data. No role can be associated with the data collector or the submitted data; The tracing unit is used for user tracing: when a data collector or data collector has doubts during an activity, they initiate a request to the auditor and attach their own identification information for identity confirmation; the identity information is verified by signature to see if it is consistent with the information at the time of initialization. After the verification is passed, the on-chain contract sends an audit request to all users in the group. Using the idea of ​​secret sharing, when the number of people exceeds the threshold, the opener key can be recovered, and then combined with the group administrator's key to unlock the record list containing complete information, completing the tracing of activity data and user identity.

8. The traceable privacy protection system for crowd intelligence perception according to claim 7 is characterized in that: The initialization unit is specifically configured to perform the following steps: Step 1.1: Deploy the blockchain network BC. Each time a crowd-sensing task is completed, it needs to be packaged into a block; Step 1.2: Preset the task record structure, including the task serial number TID and the participant's identity tag Uaddr i , data submission time TT, task hash THash and random number R generation structure TR are task records, where: TR={TID:value,Uaddr i :value,TT:value,THash:value,R:value}; Step 1.3: The task record TR will be attached to the block body generated during the reward distribution process, packaged into a block, and attached to the end of the blockchain; Step 1.4: The auditor AT randomly selects a key parameter u to generate the auditor key pair AK = (APK, ask), where APK is the auditor's public key and ask is the auditor's private key. Step 1.5: Package the auditor authentication information ACT and the auditor public key APK to generate the auditor authentication certificate SCT, where SCT = (APK, ACT). The auditor authentication certificate SCT is used in the identity authentication process when the auditor serves as the group manager GM. After authentication, the auditor AT becomes the task group manager GM. Step 1.6: The auditor generates the auditor's address Saddr=AddrGene(APK) based on the auditor's public key APK; Step 1.7: Initialize the data requester list Lr[j] = {Caddr j :value,Tr j :value,c j :value}, and publish the auditor's address Saddr and the data demander list Lr[j] on the chain.

9. The traceable privacy protection system for crowd intelligence perception according to claim 8 is characterized in that: The demander registration unit is specifically configured to perform the following steps: Step 2.1: The data collection task is set by the data demander DR. Before the collection task is released, the data demander DR needs to interact with the auditor AT and register; Step 2.2: The data demander DR randomly selects the key generation parameter τ to generate the data demander key pair RK j =(RPK j ,rsk j ), RPK j The public key of the data demander, rsk j The private key of the data demander; Step 2.3: Based on the public key RPK j Generate on-chain identity Caddr j , where Caddr j =AddrGene(RPK j ); Step 2.4: Set TX according to your needs j ,DX j ,LX j Multiple task requirements, and use the private key rsk j Sign and package the task requirements to generate Tr j , where Tr j ←sign(TX j ,DX j ,LX j ), and {c j ,Caddr j ,RPK j ,Tr j }Send to AT, where c j It is a reliability certificate for data demanders; Step 2.5: The auditor receives {c j ,Caddr j ,RPK j ,Tr j }, using the data demander's public key RPK j Test Tr j If the correctness of the signature is verified, the entry is added to Lr[j], assigned the task number TID, and signed, where (TID|sign({Caddr j ,RPK j ,Tr j },ask)) and publish it on the blockchain.

10. The traceable privacy protection system for crowd intelligence perception according to claim 9 is characterized in that: The task group forming unit is specifically used to perform the following steps: Step 3.1: After the task is released, the auditor AT creates a task group for the task numbered TID, and the auditor AT becomes the group manager GM; Step 3.2: Generate a group registration key pair CK = (CPK, csk), where CPK is the group registration public key, used by participants to join the group, and csk is the group registration private key, visible only to the administrator GM; Step 3.3, initialize the member list Lu[i]: Lu[i]={Uaddr:value,UPK:value,usg i :value,HashData i :value,u i :value}, which contains information that can be traced back to the user's real identity and is invisible to all roles before the key is restored; Step 3.4: Set the opener's traceability key pair OK = (OPK, osk), and the task group manager GM selects two keys that meet For large prime numbers p and q, select a generator g of order q in GF(p); Step 3.5: Set up the traceability key This key is the opener key, which can be used by any The secrets recovered by members are used to assist group managers in tracing and improve group member participation; generate a group key pair (OPK, osk), publish the opener public key OPK and keep osk invisible; Step 3.6: For any group of m members to be able to compute the secret, compute as well as Optional stk i and calculate according to Calculate UT i , (SPK i ,UT i ) is sent to the traceability group; at the same time, the selection of parameters should satisfy that m and more members cannot pass f i (0)(mod q), group public key GK, user public key UPK i and (SPK i ,UT i ) Conspire to obtain secret parameters of the system; Step 3.7: ID i with x i For every future participant u i The system selects the key and identity authentication of m members and constructs the Lagrange interpolation theorem Also check f i (0)! = 0, if true, reselect the identity ID i With key x i ; If not established, then take the one that does not satisfy the current The t+1th pair of different numbers, where ID t+1 ∈Z q ,x t+1 ∈Z q And construct m polynomials f with the first m-1 numbers i (x)(i=1,2,……,t+1), all opener key fragments are non-zero and not equal to each other, and any secret F sum mod q is not zero; structure polynomials in So we can see that the group tracing secret is The key to trace is The group traceability public key is OPK=g f(0) mod p(i=1,2,…,n); Step 3.8: For each on-chain user u i ∈U, users who want to participate in the crowd intelligence perception task need to first register to become data collectors DC; specifically, users generate personal key pairs UK i :(UPK i ,usk i ); Step 3.9: Data collector DC uses the public key UPK i Generate on-chain identity Uaddr i , where Uaddr i =AddrGene(UPK i ); Step 3.10: User public key UPK i , User ID Uaddr i And user sensitive information u i Combine to generate the UrAsk structure i , called a registration request, where UrAsk i ={UPK i ,Uaddr i ,u i }; Step 3.11: Send a registration request UrAsk through a secure channel i , and append usk i Interact with the group registration public key CPK and group administrator GM; Step 3.12: After verification, grant the user group authority and distribute the group key gsk i and opener part key osk i , to give users the power to sign and assist in supervision, and update the list Lu[i].

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