Product supply chain carbon data tracing method based on privacy protection of block chain

Abstract

The invention discloses a privacy protection product supply chain carbon data tracing method based on a block chain, and belongs to the field of block chain application. The method comprises the steps that a product supply chain carbon data traceability information model is constructed according to ISO 14067 product carbon footprint accounting standards and industry practices, and all enterprises collect carbon data according to the content defined by the traceability information model and structurally store the carbon data into private cloud; building a product supply chain model based on a block chain, zero-knowledge proof, a commitment scheme and an RSA accumulator, and realizing on-chain evidence storage and information integration of carbon data digital fingerprints; the traceability authority verification and access control are realized based on an RSA accumulator and an RBAC technology, and the authenticity verification of the traceability information is realized by using the stored digital fingerprint. The method can effectively solve the difficulty of structured management and information integration of the carbon data in a complex product supply chain scene, effectively solves the problems of enterprise privacy protection and traceability information authenticity, and can realize access control of the carbon data according to data privacy requirements.

Description

Technical Field

[0001] The present invention belongs to the field of blockchain technology application, and specifically relates to a product supply chain carbon data traceability method based on blockchain privacy protection. Background Art

[0002] Product supply chain carbon data refers to a collection of information related to carbon emissions generated in all links of the supply chain around a certain product (including raw material acquisition, manufacturing, transportation, etc.). Product supply chain carbon data traceability is the use of technical means to record, track and verify carbon data within the product supply chain life cycle. Realizing product supply chain carbon data traceability can effectively help relevant entities and regulatory authorities in the product supply chain understand the source and composition of the product's carbon footprint from the perspective of the product life cycle, and help to effectively evaluate the scientificity and standardization of the calculation process from the perspective of carbon footprint calculation, and can provide technical support for enterprises to identify high-carbon links and explore emission reduction space.

[0003] Product supply chain carbon data mainly includes carbon footprint, inventory data, carbon emission activities and other aspects. These data involve sensitive information of enterprises and come from multiple independent entities in various links of the supply chain (such as raw material suppliers, manufacturers, logistics providers, etc.). The data format and collection method are different. Therefore, product supply chain carbon data has the characteristics of high privacy, scattered sources and diverse formats. Product supply chain carbon data traceability mainly includes the following aspects: carbon data storage, product supply chain carbon data information integration and carbon data acquisition and verification. Among them, carbon data storage mainly focuses on selecting appropriate storage technology and architecture to manage carbon data generated in various links of the product supply chain, and at the same time, it is necessary to provide a standardized carbon data information model to support structured management of carbon data in various formats; product supply chain carbon data information integration focuses on associating and integrating carbon data from scattered sources according to supply chain relationships, so as to establish the traceability of carbon data in the entire chain of product supply chain; carbon data acquisition and verification focuses on the accurate traceability and authenticity verification of carbon data, and also includes relevant content of access control, which requires verification of the traceability authority of the traceability party, and opens specific data access scopes for different traceability parties according to the privacy level of different types of carbon data. In addition, in order to deepen corporate cooperation and build a highly credible and sustainable traceability system, product supply chain carbon data traceability has put forward higher requirements for privacy protection of corporate information, authenticity assurance of traceability information, and system scalability. Currently, relevant research can be divided into the following two aspects:

[0004] 1. Research on the traceability of carbon data in the product supply chain. At present, blockchain technology has been initially applied in the field of carbon data traceability in the product supply chain. In terms of carbon data storage, there are studies based on the idea of ​​"on-chain verification, off-chain traceability" to achieve on-chain evidence storage, and store the original data off-chain, effectively solving the problems of data privacy and system scalability caused by putting all carbon data on the chain. However, there is no research on the clear definition of the product supply chain carbon data model, and there is a lack of structured management methods for carbon data; in terms of supply chain carbon data integration, there are studies that have realized the construction of product supply chain models based on zero-knowledge proofs and data commitments, and realized the integration of supply chain carbon data under the premise of privacy protection; in terms of carbon data access control, there are studies that have adopted attribute-based access control methods, which require a large number of access attributes to be stored on the chain, and have not made good use of supply chain roles to simplify permission access control.

[0005] 2. Research on supply chain information traceability based on blockchain. Blockchain has been widely used in supply chain information traceability research in other fields, such as textiles, food, and medicine. In terms of supply chain information storage, some studies have combined zero-knowledge range proofs to upload the data range of traceability information to the chain, and verify the correctness of the range before uploading it to the chain, so as to achieve the "available but invisible" traceability information and effectively protect the privacy of data; in terms of supply chain information integration, some studies have also built product supply chain models based on blockchain, and combined with the identity mixer certificate provided by Fabric to realize anonymous verification of supply chain members, effectively realizing the privacy protection of supply chain member identities and supply chain relationships.

[0006] In Chinese patent document CN118246927A, a product carbon footprint evidence storage and traceability method is proposed. This method realizes accurate traceability of product carbon footprint based on blockchain technology. However, when integrating carbon data information of product supply chain, this method directly stores the plain text information of both parties on the chain to realize supply chain relationship verification, which fails to effectively protect the privacy of supply chain relationship. In addition, this method does not realize the authority verification and access control of the traceability party, and does not open the corresponding carbon data to different traceability parties in accordance with the requirements of carbon data privacy.

[0007] In summary, in the current research on product supply chain carbon data traceability methods, there is an urgent need for a method that can achieve structured management, information integration and efficient access control of product supply chain carbon data, and can effectively protect the privacy of carbon data and supply chain relationships. Summary of the invention

[0008] The product supply chain carbon data traceability method proposed in the present invention proposes a product supply chain carbon data traceability information model, supports structured management of carbon data, and can effectively establish the traceability of carbon data within the boundary from "cradle" to "gate", and provides access control and traceability methods for product supply chain carbon data, and supports verification of the authenticity of traceability information. The present invention adopts blockchain technology, zero-knowledge proof technology, commitment technology, RSA accumulator and role-based access control technology to effectively solve the problems of difficulty in ensuring the privacy of the relationship between carbon data and the supply chain, difficulty in structured management and effective integration of product supply chain carbon data with dispersed sources and multi-source heterogeneity, difficulty in ensuring the authenticity of traceability information, and lack of efficient carbon data access control means.

[0009] The technical solution adopted by the present invention is as follows:

[0010] Step 1: Based on the ISO 14067 product carbon footprint accounting standard and industry practices, a product supply chain carbon data traceability information model is constructed. Each enterprise collects carbon data and stores it in a structured manner in a private cloud according to the content defined in the traceability information model;

[0011] Step 2: Build a product supply chain model based on blockchain, zero-knowledge proof, commitment scheme and RSA accumulator to achieve on-chain storage and information integration of carbon data digital fingerprints;

[0012] Step 3: Implement traceability permission verification and access control based on RSA accumulator and RBAC technology, and use the stored digital fingerprint to verify the authenticity of the traceability information.

[0013] Furthermore, the specific method in step 1 includes:

[0014] Step 1.1: Based on the ISO 14067 product carbon footprint accounting standard and industry practices, a product supply chain carbon data traceability information model is constructed in accordance with the hierarchical division method of "supply chain information-product structure-carbon emission activities-inventory data-carbon footprint". This information model clearly defines all the information involved in the product supply chain carbon data traceability, and provides standards and basis for the carbon data collection and structured storage of each enterprise in the supply chain;

[0015] Step 1.2: Each supply chain enterprise first collects carbon data generated by each carbon emission activity it conducts. The collection method is usually automatic collection by IoT devices or manual collection. Carbon data may also come from the LCI database, other enterprise information systems (such as ERP, SCM, etc.) and the carbon footprint value PCF of upstream suppliers obtained through network requests. up ,After completing carbon data collection, the enterprise completes carbon footprint accounting on the local server;

[0016] Step 1.3: According to the content and hierarchy defined by the product supply chain carbon data traceability information model, the enterprise generates a corresponding carbon data storage unit for each carbon emission activity it conducts, and uses the snowflake algorithm to generate a globally unique ID for each carbon data storage unit;

[0017] Step 1.4: Securely store the carbon data storage unit in a private cloud server trusted by the enterprise.

[0018] Furthermore, the specific method in step 2 includes:

[0019] Step 2.1: Each supply chain enterprise uses Pedersen commitment and SHA256 to calculate the digital fingerprint of the product supply chain information commitment and carbon data storage unit locally, and then generates the product supply chain relationship proof locally, using the product supply chain information data as private data input, and uses the supply chain information commitment data publicly disclosed on the supply chain upstream enterprise chain to generate witness and publicWitness, and finally uses r1cs,pk,witness to generate the relationship proof;

[0020] Step 2.2: The enterprise initiates a blockchain transaction. The transaction request parameters mainly include the ID and off-chain access address of the carbon data storage unit to be stored, the ID of the referenced upstream carbon data storage unit, and the supply chain information commitment, carbon data storage unit digital fingerprint and supply chain relationship proof generated in step 2.1. Then the blockchain calls the storage contract and uses the verification key vk to verify the supply chain relationship proof;

[0021] Step 2.3: After verification, the evidence storage contract will be responsible for adding the current product supply chain members to the RSA accumulator and calculating the latest accumulator state value A mem ;

[0022] Step 2.4: Update the blockchain status database and complete the on-chain storage information of the carbon data storage unit. The storage information includes the current carbon data storage unit ID, the referenced upstream storage unit ID list, the storage unit's corresponding carbon emission activity type, digital fingerprint, supply chain information commitment, the current RSA accumulator value, and the carbon data storage unit access address. By recording the reference relationship between storage units on the chain, different carbon data storage units within the same product supply chain and distributedly stored in each enterprise's private cloud can be effectively associated and integrated.

[0023] Step 2.5: Repeat the above process until all members of the product supply chain have completed the on-chain storage and information integration of carbon data information, and finally realize the construction of the product supply chain model on the chain, and establish the traceability of product supply chain carbon data within the boundary from "cradle" to "gate".

[0024] Furthermore, the specific method in step 3 includes:

[0025] Step 3.1: The traceability party provides the product number and initiates a traceability request;

[0026] Step 3.2: Verify whether the current traceability party has the traceability authority for the product. If the current traceability party is a regulatory department, the verification is skipped directly. If it is a supply chain enterprise or consumer user, the access control contract queries the blockchain according to the product number, obtains the latest RSA accumulator value of the product, and determines whether the current traceability party exists in the product supply chain member maintained by the RSA accumulator. If so, the current traceability party has the traceability authority for the product.

[0027] Step 3.3: After verification, the access control contract obtains the role of the current traceability party and determines the traceability data scope of the traceability party based on the data open permissions pre-set for the role of the current traceability party;

[0028] Step 3.4: Call the traceability contract to trace the evidence information according to the product supply chain model established on the chain, read the carbon data storage unit access address in the evidence information for routing addressing, and obtain and integrate the traceability information;

[0029] Step 3.5: The traceability contract uses the SHA256 hash algorithm to generate a hash for each carbon data storage unit obtained from the private cloud. cloud , hash cloud The digital fingerprint hash of the carbon data storage unit stored on the chain blockchain The comparisons are performed one by one. If they are consistent, it means that the carbon data storage unit has not been tampered with during the storage process, thus realizing the authenticity verification of the traceability information, and finally returning the traceability results to the traceability party.

[0030] Compared with the existing technical solutions, the beneficial effects of the present invention are:

[0031] 1. The present invention constructs a product supply chain carbon data traceability information model to refine the relevant carbon data involved in the carbon emission calculation process of the product in the raw material acquisition, transportation, parts production and product production links, provides a standardized layered architecture, and clearly defines the carbon data of the product supply chain with dispersed sources and multi-source heterogeneity, and supports the structured management of massive data in complex supply chain scenarios.

[0032] 2. Based on zero-knowledge proof technology and commitment technology, the present invention realizes the integration of product supply chain carbon data information under the premise of protecting the privacy of supply chain relationships, and realizes the traceability of carbon data within the boundaries of products from "cradle" to "gate".

[0033] 3. The present invention combines the idea of ​​"on-chain verification and off-chain traceability" to securely store the original carbon data in a private cloud, and store the digital fingerprint of the carbon data on the chain, effectively protecting the privacy of the carbon data and improving the scalability of the system to a certain extent. At the same time, the tamper-proof characteristics of the blockchain are used to help verify the authenticity of the traceability information based on the stored digital fingerprint during traceability.

[0034] 4. The present invention utilizes RSA accumulators to maintain product supply chain member information, realizes efficient traceability authority verification, and simplifies access control based on RBAC, and can selectively disclose carbon data for different traceability roles to meet the carbon data traceability needs of different users. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure is a flow chart of the method of the present invention.

[0036] Figure 2 This is a method model diagram of the present invention.

[0037] Figure 3 This is a general architecture diagram of the product supply chain carbon data traceability method based on blockchain privacy protection of the present invention.

[0038] Figure 4 This is a diagram of the product supply chain carbon data traceability information model of the present invention.

[0039] Figure 5 This is an example diagram of a carbon data storage unit of the present invention.

[0040] Figure 6 This is a diagram of the content of the on-chain evidence information of the carbon data storage unit of the present invention.

[0041] Figure 7 This is a timing diagram of the evidence storage and information integration process on the product supply chain carbon data chain of the present invention.

[0042] Figure 8 This is a design diagram of carbon data access rights opened to different traceability party roles based on RBAC in the present invention.

[0043] Fig. 9 This is a timing diagram of the product supply chain carbon data traceability and verification process of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is clearly and completely described below in combination with the embodiments and the drawings of the specification. Obviously, the described embodiments are 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.

[0045] Example

[0046] The following is a detailed description of the product supply chain carbon data traceability method based on blockchain privacy protection. The method flow is as follows: Figure 1 As shown, the method model is as Figure 2 As shown, the method architecture is as follows Figure 3 shown.

[0047] Step 1: Based on the ISO 14067 product carbon footprint accounting standard and industry practices, a product supply chain carbon data traceability information model is constructed. Each enterprise collects carbon data according to the content defined by the traceability information model and stores it in a structured manner in a private cloud. In this process, it is first necessary to refine the relevant carbon data involved in the carbon emission calculation process of the product in the raw material acquisition, transportation, parts production and product production links, and construct a product supply chain carbon data traceability information model according to the hierarchical division method of "supply chain information-product structure-carbon emission activities-inventory data-carbon footprint". Then, each enterprise generates a carbon data storage unit in JSON format based on this model for each carbon emission activity it conducts, and uses the snowflake algorithm to generate a distributed ID for the carbon data storage unit to ensure the global uniqueness of the carbon data storage unit ID. The product supply chain carbon data traceability information model is as follows: Figure 4 An example of a carbon data storage unit is shown in Figure 5 shown.

[0048] Further, in step 1, the description of the product supply chain carbon data traceability information model and the process of generating a distributed ID for a carbon data storage unit using the snowflake algorithm are as follows:

[0049] 1. The product supply chain carbon data traceability information model is described as follows:

[0050] The traceability information of the supply chain information layer and the product structure layer can effectively correlate and integrate the carbon data scattered among various enterprises to form complete product supply chain carbon data, helping the traceability party to understand the composition, source and emission subject of the product carbon footprint from the perspective of the product life cycle; the carbon emission activity layer and the inventory data layer record the carbon footprint accounting process and related carbon data from the perspective of carbon footprint accounting, making the scientificity and standardization of the accounting process transparent and traceable; the carbon footprint layer, as the accounting result, quantifies the impact of the product on the environment.

[0051] 2. The process of generating a distributed ID for a Carbon Data storage unit using the Snowflake algorithm is as follows:

[0052] 1) Design stage: The structure of the snowflake algorithm usually includes three parts: timestamp, machine ID, and serial number. The standard snowflake algorithm is 64 bits in binary, and the usual allocation method is: 1 sign bit, 41 timestamp, 10 machine ID, 12 serial number, which means that this allocation method guarantees that at most 2 10 (i.e. 1024) carbon data storage unit IDs generated by different supply chain enterprise servers will not be repeated, but for some large and complex products, their product supply chains may have higher requirements for the number of accessible enterprises. Therefore, the present invention appropriately transforms the allocation method of the snowflake algorithm, expands the machine ID to 14 bits, and expands the number of supply chain members that the distributed system can accommodate to 2 14 (i.e. 16384), and the serial number is shortened to 8 digits, supporting the same supply chain enterprise to generate at most 2 8 (That is, 256) non-repetitive carbon data storage unit IDs can still meet the requirements of distributed ID generation speed within the enterprise.

[0053] 2) Generation phase: GenSUID(curTimeStamp,machineID,seq)→SUID. After completing the design and configuration of the snowflake algorithm, the algorithm is used to generate the carbon data storage unit ID. The algorithm can effectively ensure that the carbon data storage unit ID generated locally by each enterprise in the distributed system is unique, and can support the number of connected supply chain members and the ID generation speed to meet actual production requirements. The input parameters are the current millisecond timestamp curTimeStamp, the unique machine ID machineID assigned to the current supply chain enterprise server, and the serial number seq of the current millisecond carbon data storage unit. The output parameter SUID represents the carbon data storage unit ID converted to decimal.

[0054] Step 2: Based on blockchain, zero-knowledge proof, commitment scheme and RSA accumulator, the product supply chain model is constructed to complete the on-chain notarization and information integration of the digital fingerprint of the carbon data storage unit. In this process, each enterprise generates supply chain relationship proof, supply chain information commitment and carbon data storage unit digital fingerprint on the local server based on zero-knowledge proof, Pedersen commitment scheme and SHA256 hash summary algorithm, and then initiates a blockchain transaction request. The smart contract is responsible for verifying the supply chain relationship proof and managing the product supply chain members based on the RSA accumulator after the verification is passed. It is used to verify the traceability authority of the traceability party during subsequent traceability. Finally, the blockchain status database is updated to complete the on-chain notarization of the carbon data storage unit. By recording the reference relationship between carbon data storage units in the notarization information, the integration of product supply chain carbon data is realized. In this process, the on-chain notarization information corresponding to the carbon data storage unit is as follows: Figure 6The timing diagram of this process is shown in Figure 7 shown.

[0055] Furthermore, in step 2, the supply chain enterprise generates a supply chain relationship certificate, a supply chain information commitment, and a carbon data storage unit digital fingerprint on the local server, initiates a blockchain transaction, and the smart contract verifies the product supply chain relationship certificate and manages the product supply chain member information using the RSA accumulator as follows:

[0056] 1. The process of supply chain enterprises generating product supply chain relationship proof, calculating product supply chain information commitment, and calculating carbon data storage unit digital fingerprint specifically includes the following steps:

[0057] Step 1: Initialization of product supply chain relationship proof algorithm and Pedersen commitment algorithm: For the product supply chain relationship proof algorithm, first define the circuit that describes the relationship between supply chain members, define private data and public data descriptions, then compile the circuit into constraint conditions 5r1cs, initialize the algorithm's proof key pk and verification key vk, distribute pk to all members of the product supply chain, and distribute vk to the blockchain;

[0058] Step 2: Generate a witness withess using the supply chain information and the supply chain information commitment stored on the chain of the previous level member (if there is a previous level member);

[0059] Step 3: Proof generation, GenRelationZKP(r1cs,pk,witness)→zkp. This algorithm generates the product supply chain relationship proof zkp. The input parameters include the constraints r1cs, the proof key pk, and the witness wintness of the product supply chain relationship proof algorithm.

[0060] Step 4: Generate a public witness publicWitness using the data commitment of the product recipient as public data;

[0061] Step 5: Calculate the commitment, CommitTo(G,H,r,info)→comm. This algorithm uses the Pedersen commitment scheme to calculate the supply chain information commitment. The input parameters are two points G and H on the elliptic curve, a random blinding factor r, and the supply chain information info. The commitment comm is returned. It should be noted that since the Pedersen commitment only supports calculations on numerical data, non-numerical data must first be converted into a hash value through a hash function before calculation.

[0062] Step 6: Calculate the digital fingerprint of the carbon data storage unit, SHA256(SU) → hash cloud , the input parameter is the carbon data storage unit doc, and the output parameter is the hash value hash of the carbon data storage unitcloud .

[0063] 2. The necessary parameters for supply chain enterprises to initiate blockchain transactions are as follows:

[0064] tx:=(type,inSUs[],outSU,hash,comms[],addr,zkp)

[0065] Among them, type represents the type of carbon emission activity corresponding to the carbon data storage unit, upSUs[] represents the carbon data storage unit ID list of the upper-level supply chain members (if the current supply chain member does not have an upstream supplier, upSUs[] can be an empty list), curSU represents the current stored carbon data storage unit ID, hash represents the digital fingerprint of the carbon data storage unit, comms[] represents the supply chain information commitment, which is used by downstream supply chain members to generate supply chain relationship proofs, specifically including the current sender commitment senderComm, receiver commitment receiverComm, item commitment itemComm and quantity commitment quantityComm, addr represents the off-chain access address of the carbon data storage unit, which is a specific URL address. The carbon data storage unit can be located and retrieved through the URL address and the carbon data storage unit ID, and zkp represents the supply chain relationship proof generated using the supply chain information commitment stored by the upstream enterprise. The specific proof logic depends on the type of carbon emission activity.

[0066] The following is a detailed description of the specific details of the transactions corresponding to different carbon emission activities:

[0067] 1) Raw material acquisition

[0068] Raw material acquisition is the most upstream activity in the product supply chain. entry Indicates that the activity corresponds to a transaction. The specific transaction parameters are as follows:

[0069] tx entry :=(type entry ,upSUs=[],curSU=SU cur .ID,hash,comms,addr,zkp entry )

[0070] Among them, since there is no upper-level member, inSUs is an empty list, SU cur .ID is the ID of the carbon data storage unit to be stored, hash and comms correspond to the digital fingerprint of the carbon data storage unit and the supply chain information commitment of the raw material acquisition activity, addr represents the off-chain access address of the carbon data unit, zkp entryThe supply chain relationship proof generated based on zero-knowledge proof technology for raw material acquisition activities. Since there is no upper-level member, the proof needs to prove to the smart contract that the sender and receiver in the current carbon data storage unit are the same. The proof logic is as follows:

[0071] zk entry ←(SU cur .sender==SU cur .receiver)

[0072] Among them, SU cur .sender and SU cur .receiver represents the sender field and receiver field of the current member carbon data storage unit respectively.

[0073] 2) Transportation

[0074] Transportation is the process of transferring supplies from the upstream sender to the downstream receiver in the product supply chain. transport Indicates that the activity corresponds to a transaction. The specific transaction parameters are as follows:

[0075] tx transport :=(type transport ,upSUs=[SU up .ID],curSU

[0076] =SU cur .ID,hash,comms,addr,zkp transport )

[0077] Among them, SU up .ID indicates the carbon data storage unit ID of the upper supply chain member, zkp transport The proof of supply chain relationship representing the transportation activity needs to prove to the smart contract that the sender field of the upstream member carbon data storage unit is consistent with the receiver field of the member carbon data storage unit, and the specific items and quantities involved are also consistent. The proof logic is as follows:

[0078] zk transport ←(SU up .receiver==SU cur .sender)∧(SU up .item==SU cur .item)∧(SU up .quantity==SU cur .quantity)

[0079] Among them, SU up .receiver、SUup .item and SU up .quantity are the recipient field, item name field and item quantity field of the upper-level member carbon data storage unit, SU cur .sender、SU cur .item and SU cur .quantity are the sender field, item name field, and item quantity field of the current member carbon data storage unit.

[0080] 3) Parts production

[0081] Parts production is the process of using upstream raw materials or parts to generate new parts. Unlike raw material acquisition and transportation activities, parts production may involve multiple upstream supply chain members. Assuming there are two upstream supply chain members, use tx partProcess Indicates the transaction corresponding to the parts production activity. The specific transaction parameters are as follows:

[0082] tx partProcess :=(type partProcess ,upSUs=[SU up1 .ID,SU up2 .ID],curSU=

[0083] SU cur .ID,hash,comms,addr,zkp partProcess )

[0084] Among them, SU up1 .ID and SU up2 .ID represents the carbon data storage unit ID of the upper level member, xk ppartProcess To prove the supply chain relationship of parts production activities, it is necessary to prove to the smart contract that the receiver of all upstream members' carbon data storage units is consistent with the sender field in the current carbon data storage unit, and the quantity relationship between items is conserved. The proof logic is as follows:

[0085] zk transport ←(SU up1 .receiver==SU up2 .receiver==SU cur .sender)∧

[0086] (SU up1 .quantity / n 1 ==SU up2 .quantity / n 2 ==SU cur .quantity)

[0087] Among them, SU upi .receiver and SU upi .quantity are the recipient field and item quantity field of the carbon data storage unit of the i-th upper member, SU cur .sender and SU cur .quan are the sender field and item quantity field of the current member carbon data storage unit respectively, and n is the ratio of the number of supplied items to the number of items in the current carbon data unit. For example: 5 units of raw material B are required to produce 1 unit of component A, then n is 5.

[0088] 4)Production

[0089] Product production activities are similar to component production activities, and their transaction parameters also have similar forms. Assume that there are two upper-level supply chain members, using tx productProcess Indicates the transaction corresponding to the product production activity. The specific transaction parameters of the activity are as follows:

[0090] tx productProcess :=(type productProcess ,upSUs=[SU up1 .ID,SU up2 .ID],curSU=

[0091] SU cur .ID,hash,comms,zkp productProcess ,addr,pIDs[])

[0092] Among them, unlike the transaction parameters corresponding to the production of parts, the transaction of product production also contains pIDs, which is used to represent the product ID list obtained through the activity. Its role is to create an additional index for the products in the batch on the chain when the carbon data storage unit of the product production is subsequently stored on the chain, so as to support the traceability of the carbon data of the product supply chain according to the product ID. Supply chain relationship proof of product production activity zkp productProcess With zkp partProcess Same logic.

[0093] 3. The algorithm for smart contract verification of product supply chain relationships is as follows:

[0094] VerRelationZKP(zkp,vk,publicWitness)→Bool

[0095] The algorithm is run by a smart contract to verify the product supply chain relationship proof. The input parameters are the product supply chain relationship proof zkp, the verification key vk, and the public witness publicWitness, and returns the success or failure of the verification.

[0096] 4. The process of adding members to the RSA accumulator includes the following steps:

[0097] Step 1: Generate a prime number mapping of a member: HashToPrime(member)→(memberPrime). This step performs a prime number mapping of a member and always returns the same mapping result for the same input parameter. The input parameter is the member member to be added to the accumulator, and returns the prime number mapping memberPrime of the member.

[0098] Step 2: Accumulator state update: Exp(A mem ,memberPrime,N)→A' mem This step updates the accumulator member state, and the input parameter is the current accumulator state A mem , the prime number map memberPrime of the member, the pre-initialized large integer N, and the updated accumulator state A' mem If the current supply chain enterprise is a product manufacturer, in addition to adding itself to the RSA accumulator, it should also be responsible for adding the consumer of the product as a member of the product supply chain to the RSA accumulator to ensure that the consumer has the carbon data traceability authority for the product.

[0099] Step 3: The traceability party provides the product number and initiates a traceability request. The traceability authority verification and access control are implemented based on the RSA accumulator and RBAC technology, and the authenticity of the traceability information is verified using the stored digital fingerprint. In this process, the access control contract uses the product supply chain member information maintained by the RSA accumulator to verify whether the current traceability party has the traceability authority for the product, and based on the RBAC technology, opens different traceability authorities for each role according to the privacy of carbon data at different levels. Then, the carbon data storage unit of each carbon emission activity is obtained in turn along the established product supply chain model on the chain. Finally, the hash value of the carbon data storage unit is compared with the digital fingerprint stored on the chain to ensure that the carbon data storage unit has not been tampered with. The carbon data access rights opened for different roles based on the RBAC technology in this process are designed as follows: Figure 8 As shown in the timing diagram, Fig. 9 shown.

[0100] Furthermore, in step 3, the process of access control and carbon data traceability and verification is as follows:

[0101] 1. The access control process includes the following steps:

[0102] Step 1: Get the role information of the tracing party: GetRole(member)→role. This algorithm queries the role of the current tracing party. The input parameter is the tracing party member.

[0103] Step 2: Determine whether the current traceability party is a regulatory department. If it is a regulatory department, skip the authority verification stage and go directly to step 6 to determine the carbon data open authority for the traceability party. If the current traceability party is a consumer or supply chain enterprise, continue to step 3;

[0104] Step 3: Prime number mapping: HashToPrime(member)→memberPrime. This algorithm generates the prime number mapping memberPrime of the traceability party. The input parameter is the traceability party member.

[0105] Step 4: Get product supply chain member information: GetMemberInfo(pID) → A mem The algorithm obtains the RSA accumulator value A of the product supply chain member according to the product number mem , the input parameter is the product number pID;

[0106] Step 5: Permission verification: VerMem (A mem , memberPrime)→Bool. This algorithm uses the properties of the RSA accumulator to efficiently verify whether the current traceability party is a member of the product supply chain of the product. If the verification fails, it means that the current traceability party does not have the traceability authority for the product, and returns directly. If successful, continue to step 4 and enter the RSA accumulator value A of the product supply chain member of the product. mem Map memberPrime to the prime number of the current traceability party and return the success or failure of the member proof verification;

[0107] Step 6: Determine the carbon data open permissions: GetPermissions(role)→permissions; This algorithm queries the data open permissions permissions pre-set by the smart contract for the role of the current traceability party, and the input parameter is the role of the current traceability party.

[0108] 2. The process of carbon data traceability and verification for product supply chains includes the following steps:

[0109] Step 1: Query the blockchain status database according to the product number to obtain the evidence information corresponding to the carbon data storage unit of the product production activity;

[0110] Step 2: Read the Address field in the evidence information, perform routing addressing according to the access address of the carbon data storage unit, obtain the carbon data storage unit corresponding to the carbon emission activity from the private cloud, and then read the ReferenceIDs field in the evidence information to locate the carbon data storage unit evidence information corresponding to the upstream carbon emission activity;

[0111] Step 3: Repeat step 2, and obtain the carbon data storage units corresponding to each carbon emission activity in the product supply chain in turn according to the access address of the carbon data storage unit recorded on the chain and the reference relationship between the carbon data storage units, until the ReferenceIDs field is empty;

[0112] Step 4: Integrate product supply chain carbon data information and selectively disclose carbon data based on the carbon data disclosure permissions of the current traceability party role;

[0113] Step 5: Use the SHA256 hash algorithm to verify the authenticity of each carbon data storage unit, SHA256(SU)→hash cloud The input parameter is the carbon data storage unit SU obtained from the private cloud, and the output parameter is the hash value hash of the private cloud carbon data storage unit cloud , hash cloud The digital fingerprint hash of the carbon data storage unit stored on the chain blockchain Compare them and if they are consistent, it means the data has not been tampered with.

[0114] The above-described embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A product supply chain carbon data traceability method based on blockchain privacy protection, characterized in that: The following steps are involved: Step 1: Based on the ISO 14067 product carbon footprint accounting standard and industry practices, a product supply chain carbon data traceability information model is constructed. Each enterprise collects carbon data and stores it in a structured manner in a private cloud according to the content defined in the traceability information model; Step 2: Build a product supply chain model based on blockchain, zero-knowledge proof, commitment scheme and RSA accumulator to achieve on-chain storage and information integration of carbon data digital fingerprints; Step 3: Implement traceability permission verification and access control based on RSA accumulator and RBAC technology, and use the stored digital fingerprint to verify the authenticity of the traceability information.

2. The product supply chain carbon data traceability method based on blockchain privacy protection as claimed in claim 1, characterized in that: The specific method in step 1 is as follows: The first step is to build a product supply chain carbon data traceability information model based on the ISO 14067 product carbon footprint accounting standard and industry practices, in accordance with the hierarchical division of "supply chain information-product structure-carbon emission activities-inventory data-carbon footprint". This information model clearly defines all the information involved in the product supply chain carbon data traceability, and provides standards and basis for the carbon data collection and structured storage of each enterprise in the supply chain; In the second step, each supply chain enterprise first collects carbon data generated by each carbon emission activity it conducts. The collection method is usually automatic collection by IoT devices or manual collection. Carbon data may also come from the LCI database, other ERP, SCM enterprise information systems, and the carbon footprint value PCF of upstream suppliers obtained through network requests. up ,After completing carbon data collection, the enterprise completes carbon footprint accounting on the local server; The third step is to generate corresponding carbon data storage units for each carbon emission activity carried out by the enterprise according to the content and hierarchy defined by the product supply chain carbon data traceability information model, and use the snowflake algorithm to generate a globally unique ID for each carbon data storage unit; The fourth step is to securely store the carbon data storage unit in a private cloud server trusted by the enterprise.

3. The product supply chain carbon data traceability method based on blockchain privacy protection as claimed in claim 1, characterized in that: The specific method in step 2 is as follows: In the first step, each supply chain enterprise uses Pedersen commitment and SHA256 to calculate the digital fingerprint of the product supply chain information commitment and carbon data storage unit locally, and then generates the product supply chain relationship proof locally, using the product supply chain information data as private data input, and uses the public supply chain information commitment data on the upstream enterprise chain to generate witness and publicWitness, and finally uses r1cs,pk,witness to generate the relationship proof; In the second step, the enterprise initiates a blockchain transaction. The transaction request parameters mainly include the ID and off-chain access address of the carbon data storage unit to be stored, the ID of the referenced upstream carbon data storage unit, and the supply chain information commitment, carbon data storage unit digital fingerprint and supply chain relationship proof generated in step 2.

1. Then the blockchain calls the storage contract and uses the verification key vk to verify the supply chain relationship proof. In the third step, after verification, the evidence storage contract will be responsible for adding the current product supply chain members to the RSA accumulator and calculating the latest accumulator state value A mem ; The fourth step is to update the blockchain status database and complete the on-chain storage information of the carbon data storage unit. The on-chain storage information includes the current carbon data storage unit ID, the referenced upstream storage unit ID list, the carbon emission activity type corresponding to the storage unit, the digital fingerprint, the supply chain information commitment, the current RSA accumulator value, and the carbon data storage unit access address. By recording the reference relationship between storage units on the chain, different carbon data storage units in the same product supply chain and distributedly stored in the private clouds of various enterprises can be effectively associated and integrated; The fifth step is to repeat the above process until all members of the product supply chain have completed the on-chain storage and information integration of carbon data information, and finally realize the construction of the product supply chain model on the chain, and establish the traceability of carbon data in the product supply chain within the boundary from "cradle" to "gate".

4. The product supply chain carbon data traceability method based on blockchain privacy protection as claimed in claim 1, characterized in that: The specific method in step 3 is as follows: In the first step, the traceability party provides the product number and initiates a traceability request; The second step is to verify whether the current traceability party has the traceability authority for the product. If the current traceability party is a regulatory department, the verification is skipped directly. If it is a supply chain enterprise or consumer user, the permission access control contract queries the blockchain according to the product number, obtains the latest RSA accumulator value of the product, and determines whether the current traceability party exists in the product supply chain member maintained by the RSA accumulator. If so, the current traceability party has the traceability authority for the product. In the third step, after verification, the access control contract obtains the role of the current traceability party and determines the traceability data scope of the traceability party based on the data open permissions pre-set for the role of the current traceability party; The fourth step is to call the traceability contract to trace the evidence information according to the product supply chain model established on the chain, read the carbon data storage unit access address in the evidence information for routing addressing, and obtain and integrate the traceability information; In the fifth step, the traceability contract uses the SHA256 hash digest algorithm to generate a hash for each carbon data storage unit obtained from the private cloud. cloud , hash cloud The digital fingerprint hash of the carbon data storage unit stored on the chain blockchain The comparisons are performed one by one. If they are consistent, it means that the carbon data storage unit has not been tampered with during the storage process, thus realizing the authenticity verification of the traceability information, and finally returning the traceability results to the traceability party.

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