CN114726535A - Privacy protection anti-counterfeiting automobile supply chain method based on block chain - Google Patents

Abstract

The invention relates to a privacy protection anti-counterfeiting automobile supply chain method based on a block chain, and belongs to the technical field of block chain privacy protection and intelligent car networking. The method utilizes the Hash chain and the group signature technology to protect the identity privacy problem of merchants participating in the supply chain, simultaneously uses the block chain technology to effectively deal with the unreliability of the traditional central server, realizes the public and verifiable product information, and achieves the aim of product anti-counterfeiting. Compared with the traditional anti-counterfeiting supply chain, the anti-counterfeiting supply chain for the automobile parts can store automobile part information and transaction information such as ownership certification and ownership transfer process by using the block chain technology, and can realize the anti-counterfeiting supply chain for the automobile parts without centralization and tampering. Compared with the traditional anti-counterfeiting supply chain based on the block chain, the anti-counterfeiting supply chain based on the block chain utilizes the cryptography technologies such as the hash chain and the group signature, protects the privacy information such as the business relationship among suppliers in the automobile supply chain, and the group signature technology can ensure that the anti-counterfeiting supply chain is traced by a trusted authority when any dispute occurs.

Description

A privacy protection and anti-counterfeiting automotive supply chain method based on blockchain

technical field

The invention relates to a privacy protection and anti-counterfeiting automobile supply chain method, in particular to a privacy protection and anti-counterfeiting automobile supply chain method based on blockchain, and belongs to the technical fields of blockchain privacy protection and intelligent vehicle networking.

Background technique

In the context of current globalization, more and more multinational companies have established supply chains for auto parts to achieve efficient auto parts supply. However, the problem of counterfeit auto parts is growing. Counterfeit auto parts can easily lead to traffic accidents and seriously threaten the safety of life and property of vehicle drivers and pedestrians.

In recent years, radio frequency identification technology (RFID, Radio Frequency Identification) has been mostly used in anti-counterfeiting technology. Product Identifier. In this type of scheme, the user scans the unique identifier of the product, and then compares it with the unique identifier of the product stored in the database. If the product is consistent, the product is considered to be true, otherwise it is false. However, this type of scheme has certain security risks. First, the product's identifier may be copy-forged. Second, traditional centralized servers are vulnerable to adversary attacks, and stored data may be corrupted or tampered with.

Blockchain technology has the characteristics of decentralization, non-tampering, open and transparent data, etc. No one or organization can control the entire blockchain network by controlling one or several nodes, and once the data is stored on the blockchain, it is Cannot be modified or deleted. Therefore, the application of blockchain technology in the automotive supply chain can effectively solve the above problems. In the existing anti-counterfeiting automobile supply chain implementation scheme, auto parts information (such as auto parts manufacturer, production date, PID, etc.) and auto parts transaction information (such as logistics information, ownership transfer information, etc.) are stored in the block. chain. If there is an inconsistency between the received information and the information stored on the blockchain, the buyer can treat the auto part as a counterfeit product.

However, the existing solutions have the problem of leakage of private information. Due to the transparency of the blockchain, every user can obtain the data on the blockchain, which leads to the leakage of sensitive information. The sales volume, profit, buyer, seller, etc. of a certain product are all trade secrets that need to be kept secret. The disclosure of these trade secrets will also cause economic losses to businesses in the automotive supply chain.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the technical problems that the traditional anti-counterfeiting automobile supply chain method based on block chain cannot satisfy the technical problem of data disclosure, verifiability and privacy protection at the same time, and creatively proposes a block chain-based A privacy-preserving anti-counterfeiting automotive supply chain approach to blockchain. This method uses hash chain and group signature technology to protect the identity and privacy issues of merchants participating in the supply chain, and at the same time uses blockchain technology to effectively deal with the unreliability of traditional central servers, and realizes the public and verifiable product information to achieve product anti-counterfeiting. the goal of.

First, the relevant content involved in the present invention is described as follows:

Trusted Authority: Its tasks are identity registration and product tracking. Any entity (including auto parts manufacturers, auto parts dealers, and auto parts retailers) needs to register with a trusted agency with real identification information. In general, the trusted agency is offline, and when there is a problem with the auto parts, the trusted agency can trace its logistics information.

Blockchain network: A decentralized network with the characteristics of openness, transparency, and immutability. Data on a blockchain network consists of a large number of blockchain transactions. In the present invention, the product information of the produced auto parts is stored on the blockchain as a non-tamperable evidence, and all auto parts manufacturers, auto parts dealers and auto parts retailers can register on the blockchain Publish transaction information, including auto parts information, ownership transfer information, and ownership certification information. At the same time, since the data on the blockchain is open and transparent, everyone can call the smart contract to view the relevant information.

Auto parts manufacturer: produces tires, batteries, engines and other auto parts, and each product has a unique product identifier PID, any entity can call the RFID reader to obtain the identifier PID of auto parts. At the same time, auto parts manufacturers need to publish auto parts information on the blockchain after producing auto parts. Products can be sold to auto parts dealers and auto parts retailers. After the auto parts are sold, the ownership transfer information needs to be published on the blockchain.

Auto parts dealers: Auto parts manufacturers sell the generated auto parts to auto parts dealers, who in turn sell them to auto parts retailers. After the auto parts agent receives the auto parts sold by the auto parts manufacturer, it needs to find the ownership transfer information of the auto parts from the blockchain, and verify whether the ownership certificate of the auto parts is correct. , then accept the auto part and generate new ownership transfer information and ownership certificate, otherwise refuse to accept.

Auto parts retailers: You can buy auto parts from auto parts dealers, or you can sell auto parts to users who need to buy. When purchasing auto parts, it is necessary to detect the ownership information of auto parts to prevent counterfeit auto parts. When selling auto parts, a retailer's proof of product ownership is required.

User: The user purchases auto parts through auto parts retailers. When purchasing, it is necessary to verify whether the auto part is a counterfeit product. If the product has no problem, the user will pay for the purchase of auto parts. Ownership status will be updated to Purchased.

The present invention is realized by the following technical solutions.

A blockchain-based privacy protection and anti-counterfeiting automotive supply chain method, comprising the following steps:

Step 1: System initialization.

A trusted authority registers each entity and generates public parameters, which are finally sent to each entity through a secure channel. The trusted organization deploys the smart contract part required by the entire solution to the blockchain through standard blockchain deployment tools. After the system is initialized, the trusted authority will remain offline unless a dispute arises.

Specifically, step 1 includes the following steps:

Step 1.1: Provide the trusted authority with a set of entity information for registration, including the entity's real-world real identity and the entity type of the entity in auto parts manufacturers, auto parts dealers, and auto parts retailers. The trusted authority initializes a registration information set for storing the generated registration information.

Step 1.2: The trusted authority first generates a master key, and then uses the key generation algorithm in the group signature scheme to generate the group public key, the master private key and the private key corresponding to each entity in the set required for the group signature.

Step 1.3: For each entity information in the user information set, the trusted authority generates corresponding registration information.

Specifically, a corresponding entity ID is first generated with the help of the master key and entity information, and then a new key K is generated. Finally, the registration information of the entity is composed of the generated entity ID, the new key K, the identity information of the entity and the private key corresponding to the entity in the group signature. The registration information generated by all entities in the entity information set is stored in the registration information set.

Step 1.4: The trusted institution publishes the group public key generated in step 1.2 as a public parameter on the blockchain, and the set of registration information generated in step 1.3 and the master private key generated in step 1.2 are kept by the trusted institution itself, For product traceability. At the same time, auto parts manufacturers, auto parts agents, and auto parts retailers all need to generate corresponding blockchain addresses and send them to trusted institutions.

Step 2: Product Registration.

After the auto parts manufacturer produces a batch of auto parts with unique identifiers, it calls the smart contract to register the auto parts, and publishes the information collection of the auto parts on the blockchain.

Specifically, step 2 includes the following steps:

Step 2.1: Store the identifiers of the produced batch of auto parts in the auto parts information set, and initialize the ownership certificate set and the product information set.

Step 2.2: For each auto part identifier in the auto parts information set, use the key K and the entity ID generated when the auto parts manufacturer registered in step 1 to generate a proof of ownership and calculate its hash value .

Step 2.3: For the hash value of the proof of ownership calculated in step 2.2, use the group public key generated in step 1 and the private key of the auto parts manufacturer to sign it using the signature algorithm in the group signature scheme. as shown in picture 2.

Step 2.4: Combine the auto part identifier, the hash value of the proof of ownership, the entity ID of the auto part manufacturer, the flag indicating whether the auto part is sold, and the signature generated using the group signature technology, and Stored in the product information collection. Ultimately, the manufacturer stores a collection of product information on the blockchain. Store the auto part identifier, proof of ownership in the proof of ownership collection, and return the proof of ownership collection to the auto parts manufacturer.

Step 3: Ownership transfer.

When the seller (auto parts manufacturer or auto parts dealer) is ready to sell a batch of auto parts to the buyer (another auto parts dealer or auto parts retailer), the smart contract is invoked for the auto parts transfer of ownership to the corresponding retailer or agent. In this process, a hash chain is used for identity authentication between two entities, and the ownership information of auto parts must be encrypted and stored to achieve safe, reliable and privacy-protected ownership transfer.

Specifically, step 3 includes the following steps:

Step 3.1: Before transferring ownership between buyer and seller, both parties negotiate a hash chain and a shared state. Among them, a hash chain is a collection of multiple hashes, which are linked through a hash function. Specifically, the previous hash value in the hash chain comes from the hash of the next hash value, and the initial hash value comes from the off-chain negotiation. The shared state contains a counter c and the hash value β _c on the hash chain corresponding to the counter position.

Step 3.2: The seller first needs to find the c+1th hash value from the pre-generated hash chain in step 3.1, denoted as β _c+1 , and then the hash value and the auto parts generated in step 2. The ownership certificate information is encrypted, and the encrypted information is stored on the blockchain in the form of a blockchain transaction, and the corresponding transaction identifier is T _id .

Step 3.3: The seller entity continues to evaluate the hash value β _c in the shared state negotiated between the two entities, the transaction identifier T _id of the encrypted information stored in step 3.2, and the c+1th hash value on the hash chain β _c+1 encrypts the three to obtain a transaction retrieval token and sends the token to the buyer.

Step 3.4: The seller will update the shared state, incrementing the counter shared with the buyer in step 3.1. At this time, the state information of the seller becomes the counter c+1 and β _c+1 .

Step 4: Ownership Verification.

When auto parts retailers, auto parts agents or users buy auto parts, check whether the corresponding auto parts are the auto parts they really want to buy, and verify their ownership information, whether they are sold, etc. When all inspections pass, the auto parts will be accepted, otherwise the product will be rejected as a fake.

Among them, for the auto parts dealers and auto parts retailers as buyers, use the token transmitted by the seller in step 3.3 to verify whether the ownership information of the auto parts is correct, whether it is transferred by the corresponding seller, and the identification of the auto parts If the information such as sign and signature is correct, if the check is successful, the ownership information of the auto parts will be updated and the updated information will be saved on the blockchain.

As a buyer, the user only needs to verify whether the ownership information and vehicle identifier of the vehicle product are correct. If the verification is successful, it means that the auto part is genuine. When the user successfully purchases the auto parts, the sales status of the auto parts will be updated, and the updated information will be saved on the blockchain.

Specifically, step 4 includes the following steps:

For auto parts dealers and auto parts retailers, the following methods are used:

Step 4.1: The buyer uses the state information shared with the seller in Step 3.1 to obtain the transaction retrieval token from the seller who sells the auto parts, decrypt the token to obtain the transaction identifier T _id in cipher text, and use it as a token for the transaction. The hash value β _c+1 of the next bit of the counter on the hash chain of the one-time session key.

Step 4.2: Hash the hash value of the one-time session key, and compare the hash content with the hash content of the shared state. If the comparison is successful, the identity authentication of both parties is successful. Otherwise, the authentication fails and the execution is rejected. operation.

Step 4.3: After the verification in step 4.2 is successful, obtain the transaction identifier T _id stored on the blockchain, and decrypt the ciphertext information stored on the corresponding transaction to obtain a collection of ownership information containing auto parts, and pass Call the smart contract to find the corresponding product information from the blockchain. For each auto part information, compare whether the hash value of the ownership certificate in the received ownership information set is the same as the hash value in the corresponding product information stored on the blockchain, and whether the status of the auto part is Not sold status, finally check whether the signature content is correct. When all the information is successfully checked, it means that the auto parts are genuine and go to step 4.4, otherwise the product will be regarded as a counterfeit product and the buyer will refuse to accept the product.

Step 4.4: The buyer performs the same operations as in step 2.2, ie, uses the buyer's own ID and key K to generate a new proof of ownership and a hash of the proof of ownership. Then perform the same operation as in step 2.3, that is, generate the signature message using the group public key and the private key owned by the buyer.

Step 4.5: For each received auto part, update the product information stored on its blockchain, including the hash value of the auto parts ownership certificate and the auto part signature information.

For users, use the following methods:

Step 4-1: The auto parts retailer gives the product ownership information set of the corresponding auto parts, checks the product information of the corresponding auto parts according to the product identifier contained in it, and calculates whether the hash value of the ownership certificate is the same as the area. The information saved on the blockchain is consistent, and check whether the status of the auto parts has been sold. If the information is consistent and the auto parts are still unsold, go to step 4-2, otherwise the product will be regarded as a counterfeit product , the buyer will refuse to accept the product.

Step 4-2: Use the public key of the group to check whether the signature information is correct, if it is correct, proceed to the next step, otherwise the product will be regarded as a counterfeit product, and the buyer will refuse to accept the product.

Step 4-3: When the inspections of steps 4-1 and 4-2 are passed, it means that the auto parts are genuine. After the user purchases the product, the user will call the smart contract to change the sales status of the auto parts, and the status of the auto parts will change to sold.

beneficial effect

The present invention, compared with the prior art, has the following advantages:

1. The present invention realizes decentralization. Compared with the traditional anti-counterfeiting supply chain, the use of blockchain technology to store auto parts information and transaction information such as ownership certificate and ownership transfer process can realize a decentralized and tamper-resistant auto parts anti-counterfeiting supply chain.

2. The present invention realizes privacy protection. Compared with the traditional anti-counterfeiting supply chain based on block chain, the present invention uses cryptographic technologies such as hash chain and group signature to protect the private information such as business relationship between suppliers in the automotive supply chain, and the group signature technology can Make sure that in the event of any disputes, it is traced and traced by a trusted agency.

Description of drawings

Figure 1 is a schematic diagram of the method of the present invention.

Figure 2 is a schematic diagram of auto parts information stored on the blockchain.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. For example, in the embodiment of the present invention, it is possible that the auto parts dealer will hand over to the next-level auto parts dealer, and then to the auto parts retailer.

Example

In this case, the auto parts manufacturer produces a batch of auto parts with a unique identifier, and then passes the ownership of the auto parts to the auto parts dealer, who in turn transfers the auto parts dealer to the auto parts retailer dealers, and finally auto parts retailers to sell to users.

As shown in Figure 1, a blockchain-based privacy protection and anti-counterfeiting automotive supply chain method includes the following steps:

Step 1: System initialization.

Step 1.1: Provide an entity information set U={u ₁ , . . . , _um } and security parameter λ (λ=256) to be registered to the trusted authority TA, wherein the entity information set contains m entities that need to be registered .

For any entity _ui in the entity information set U, the information used for registration includes the identity id _i of the entity i in the real world and the entity type type _i , and the entity type is represented as type _i = {manufacturer, agent, retailer}, where , manufacturer on behalf of auto parts manufacturers, agent on behalf of auto parts dealers, retailer on behalf of auto parts retailers. The trusted authority initializes a set R for storing the registration information generated later.

Step 1.2: The trusted authority first generates the master key K _M , and then executes the key generation algorithm GS.KeyGen in the group signature scheme GS to generate the group public key gpk, master private key gsk required for the group signature, and for each registered entity Generated m private keys {sk ₁ ,...,sk _m } for group signature.

Step 1.3: For each entity information in the entity information set U, the trusted authority generates corresponding registration information. For the i-th entity, first calculate the entity ID _i = F(K _M , _ui ), where F is a secure pseudo-random function, input a string with a length of 256 bits and a string with a length of any bits, The output is a string of length 256 bits. Here, K _M is the master key generated in step 1.2, and _ui is the entity information of the entity information set in step 1.1. Then, the trusted authority generates the key K i corresponding to the entity _i . Finally, the trusted authority TA generates registration information ri =(ID _i , _ui ,ski ,K _{i )} for entity _i , where _ski is the m private keys for group signature generated by the trusted authority in step 1.2 The private key corresponding to entity i.

Step 1.4: Finally, the trusted authority uses the group public key gpk as a public parameter and publicly publishes it on the blockchain network. The set R={r ₁ , . . . , r _m } with m entity registration information and the master private key gsk are stored by a trusted organization for product traceability. At the same time, auto parts manufacturers, auto parts dealers and auto parts retailers all need to generate corresponding blockchain addresses and send them to trusted institutions.

Step 2: Auto Parts Manufacturer Registers Auto Parts.

Step 2.1: After entity registration, let the auto parts manufacturer produce n auto parts, where each auto part i corresponds to a unique identifier PID _i , and the corresponding set of product identifiers is P = {PID ₁ , ...,PID _n }.

Step 2.2: The auto parts manufacturer calls the smart contract to initialize two empty collections PI and PO.

For each auto part PID _i in the product identifier set P generated in step 2.1, first calculate the ownership certificate p _i =F(K,ID||PID _i ), where F is the pseudo-random function defined in step 1.3 , || is the string splicing operation, K is the key of the auto parts manufacturer in step 1.3, ID is the entity ID of the auto parts manufacturer in step 1.3, and the hash value of the proof of ownership h _i = H( _pi ), where H stands for the SHA256 hash function.

Then, the manufacturer uses the group signature technology to sign the hash value of the vehicle product ownership certificate σ _i =GS.Sign(gpk,sk, _hi ), where GS is a secure group signature scheme and GS.Sign is a group signature Function, the input is the group public key, the user's private key for signing and the signature content, and the output is the corresponding digital signature.

Finally, the manufacturer adds the corresponding product information (PID _i , _hi ,ID,false,σ _i ) to the set PI and (PID _i , _pi ) to the set PO, where ID is the auto part Manufacturer's identity information, false means that the auto parts have not been sold to any user. In step 6, if the auto part is sold to the user, the corresponding false state will be changed to true.

Step 2.3: The manufacturer calls the smart contract to store the collection PI in the blockchain, and returns the collection PO to the auto parts supplier.

Step 3: The auto parts manufacturer makes a transfer of ownership.

和一个共享状态S_c＝(c,β_c)。其中哈希链

的生成规则如下：h_p为一个长度为256 比特的字符串，由ID_a和ID_b通过事先协商得到，当i＝1,2,…,p-1时，h_i＝ H(h_i+1)，其中H为SHA256哈希函数。共享状态S_c中的c为计数器，而β_c＝h_c为对应的哈希链

上的第c个哈希值。Step 3.1: The auto parts manufacturer ID _a transfers the ownership of the registered auto parts to the auto parts dealer ID _b . First, the two parties need to negotiate a hash chain in advance

and a shared state S _c =(c, β _c ). where the hash chain

The generation rules of , are as follows: h _p is a character string with a length of 256 bits, obtained by ID _a and ID _b through prior negotiation, when i=1,2,...,p-1, h _i = H(h _{i+ 1} ), where H is the SHA256 hash function. c in the shared state S _c is a counter, and β _c =h _c is the corresponding hash chain

The c-th hash value on .

获得第c+1个哈希h_c+1，并设置β_c+1＝h_c+1，对β_c+1以及由步骤2.2中生成这批汽车零部件的注册集合PO进行加密处理，将使用密钥β_c+1加密后的密文信息AES.Enc(β_c+1,PO)以交易的形式存储到区块链上，对应的交易标识符为T_id。其中AES为一种安全的对称加密算法，AES.Enc为加密操作。Step 3.2: Auto Parts Manufacturer ID _a from the hash chain

Obtain the c+1th hash h _c+1 , set β _c+1 =h _c+1 , encrypt β _c+1 and the registration set PO of the batch of auto parts generated in step 2.2, and set the The ciphertext information AES.Enc(β _c+1 , PO) encrypted with the key β _c+1 is stored on the blockchain in the form of a transaction, and the corresponding transaction identifier is T _id . AES is a secure symmetric encryption algorithm, and AES.Enc is an encryption operation.

其中AES.Enc为步骤3.2定义的对称加密函数，||为字符串拼接操作。之后，将生成的令牌

发送给车辆代理商ID_b。Step 3.3: The auto parts manufacturer ID _a uses the key β _c+1 to encrypt the transaction identifier T _id obtained in step 3.2 and the key to be used in the next product ownership transfer with ID _b to generate a query order Card

AES.Enc is the symmetric encryption function defined in step 3.2, and || is the string concatenation operation. After that, the generated token will be

Sent to vehicle dealer ID _b .

Step 3.4: The auto parts agency ID _a updates the shared state S _c+1 =(c+1, β _c+1 ).

Step 4: Auto parts dealer conducts ownership verification.

Step 4.1: Let the state information shared between the auto parts agent ID _b and the auto parts manufacturer ID _a be S _c =(c, β _c ). After receiving the token T=AES.Enc(β _c ,T _id ||β _c+1 ) sent by ID _a , the agent first uses its own key to decrypt T _dec =AES.Dec(β _c ,T ) to obtain the transaction identifier T _id and the one-time key β _c+1 . AES.Dec is the symmetric decryption function of the AES encryption scheme.

Step 4.2: First judge whether H(β _c+1 ) and β _c are equal, if not, the authentication fails. If successful, find the transaction with the identifier T _id stored in the blockchain, extract the data data stored in the transaction, and decrypt it to obtain PO=AES.Dec(β _c+1 ,data), where PO represents each A collection of product ownership information for auto parts, each entry in the collection contains the product identifier PID _i of an auto part and the corresponding product ownership certification information _pi , according to the PO's auto parts product identifier, it can be obtained from Find the corresponding auto parts information in the blockchain, which constitutes the product information set PI.

Step 4.3: After obtaining the auto parts ownership information set PO and the product information set PI, for any product ownership information PO _i = (PID _i , _pi ) in PO, the corresponding product information in PI is PI _i = ( PID _i , _hi ,ID,false,σ _i ), where PID _i is the product identifier, _hi is the hash value of the product ownership certificate, ID is the ID of the product manufacturer, and false means that the product has not been sold to any user. The agent first calculates h′=H(pi ), and compares it with the hash _{hi in PI i , if} it is the same and the sale status is also false, execute the group signature verification algorithm GS.Verify(gpk,σ ,h), continue to verify that the signature is correct. If the output of the GS.Verify algorithm is true, it means that the verification is successful, and the product is regarded as genuine. Step 4.4 is executed. If the output is false, the verification fails, and the product is regarded as a counterfeit product.

Step 4.4: Generate a new proof of ownership p′ _i = F(K _b ,ID _b ||PID _i ) for the car parts deemed authentic, where F is the pseudo-random function defined in step 1.3, and || is a character String concatenation operation. Then calculate the hash value h'=H(p' _i ) and the signature σ _i =GS.Sign(gpk,sk, _hi ), where GS.Sign is the signature function of step 2.2. After that, the agent adds the newly generated (PID _i , p′ _i ) to the set PO′, and calls the smart contract to update the auto parts information with the identifier PID, where the hash of the product ownership certificate is updated to h′ _i , The signature is updated to σ _i .

Step 4.5: The auto parts agency ID _b updates the shared state S _c+1 =(c+1, β _c+1 ).

Step 5: The auto parts dealer delivers the vehicle parts to the auto parts retailer.

At this stage, the auto parts dealer performs step 3 to transfer the ownership of the auto parts, while the auto parts retailer performs step 4 for ownership verification.

Step 6: The auto parts retailer sells the auto parts to users.

Step 6.1: The auto parts retailer sells auto parts to users, and sends the auto parts information set PO _i = (PID _i , p _i ) that needs to be sold to users to the user, where PID _i is the unique identifier of the product , _pi is the ownership certificate information of the product.

Step 6.2: The user invokes the smart contract according to PID _i to find the corresponding product information PI _i = (PID _i , _hi ,ID,false,σ _i ).

First, calculate h'=H(pi) according to the ownership certificate of the auto parts in PI, and compare it with _{hi in PI i ,} if h' _{= hi} and the corresponding sales status is also false, That is, if the product has not been sold to other users, continue to verify whether the signature is correct. If all the above verifications are passed, the auto parts are considered genuine.

Step 6.3: After the user purchases the auto parts, the user invokes the smart contract to update the status of the product PID _i and update the sales status to true, that is, the product has been sold.

In order to illustrate the content and implementation method of the present invention, the above-mentioned specific embodiments are provided in this specification. However, those skilled in the art should understand that the present invention is not limited to the above-mentioned best embodiment, and anyone can draw other various forms of products under the inspiration of the present invention, but no matter what changes are made in its shape or structure , any technical solutions that are identical or similar to those of the present application fall within the protection scope of the present invention.

Claims (5)

1. A privacy protection anti-counterfeiting automobile supply chain method based on a block chain is characterized by comprising the following steps:

step 1: initializing a system;

the trusted authority registers each entity and generates public parameters, and finally, the public parameters are sent to each entity through a secure channel; the trusted authority deploys the intelligent contract part required by the whole scheme to the block chain through a standard block chain deployment tool; after the system is initialized, the trusted authority keeps an offline state unless disputes occur;

step 2: product registration;

after an automobile part manufacturer produces a batch of automobile parts containing unique identifiers, calling an intelligent contract to register the automobile parts, and publishing information sets of the automobile parts on a block chain;

and step 3: transfer of ownership;

when a seller prepares to sell a batch of automobile parts to a buyer, calling an intelligent contract to transfer ownership of the automobile parts to a corresponding retailer or agent; in the process, identity authentication between two entities is carried out by using a hash chain, and ownership information of the automobile parts must be encrypted and stored to realize safe and reliable ownership transfer with privacy protection;

and 4, step 4: verifying ownership;

when an automobile part retailer, an automobile part agent or a user purchases an automobile part, whether the corresponding automobile part is really the automobile part which wants to be purchased is checked, ownership information, whether the automobile part is sold and the like are verified, when all the checks are passed, the automobile part is accepted, otherwise, the automobile part is rejected as fake goods;

for the automobile part agent and the automobile part retailer which are taken as buyers, verifying whether the ownership information of the automobile part is correct and is transferred by the corresponding seller and the information such as the identifier, the signature and the like of the automobile part is correct by using the token transmitted by the seller in the step 3.3, updating the ownership information of the automobile part if the checking is successful, and storing the updated information on the block chain;

for a user serving as a buyer, only the ownership information, the vehicle identifier and other information of the vehicle product need to be verified to be correct, and if the verification is successful, the automobile part is a genuine product; when the user successfully purchases the automobile part, the sales state of the automobile part is updated, and the updated information is stored in the blockchain.

2. The block chain based privacy protection anti-counterfeiting automobile supply chain method according to claim 1, wherein the step 1 comprises the following steps:

step 1.1: providing a set of entity information to the trusted authority for registration, wherein the set of entity information includes a real-world identity of the entity and a type of entity belonging to the automobile parts manufacturer, the automobile parts agent, and the automobile parts retailer; the trusted authority initializes a registration information set for storing the generated registration information;

step 1.2: the trusted authority firstly generates a master key, and then generates a group public key and a master private key required by group signature and a private key corresponding to each entity in a set by using a key generation algorithm in a group signature scheme;

step 1.3: for each entity information in the user information set, the trusted authority generates corresponding registration information;

specifically, a corresponding entity ID is generated by means of a master key and entity information, and then a new key K is generated; finally, the generated entity ID, the new key K, the identity information of the entity and the private key corresponding to the entity in the group signature form registration information of the entity; storing the registration information generated by all entities in the entity information set in a registration information set;

step 1.4: the trusted authority issues the group public key generated in the step 1.2 as a public parameter to a block chain, and the registration information set generated in the step 1.3 and the main private key generated in the step 1.2 are stored by the trusted authority for product tracing; meanwhile, automobile part manufacturers, automobile part dealers and automobile part retailers all need to generate corresponding blockchain addresses and send the addresses to trusted authorities.

3. The block chain based privacy protection anti-counterfeiting automobile supply chain method according to claim 1, wherein the step 2 comprises the following steps:

step 2.1: storing the identifiers of the produced automobile parts in an automobile part information set, and initializing an ownership certification set and a product information set;

step 2.2: for each automobile part identifier in the automobile part information set, generating an ownership certificate by using the key K and the entity ID generated when the automobile part manufacturer is registered in the step 1, and calculating a hash value of the ownership certificate;

step 2.3: for the ownership certificate hash value calculated in the step 2.2, signing the ownership certificate hash value by using the group public key generated in the step 1 and the private key of the automobile part manufacturer by using a signature algorithm in a group signature scheme;

step 2.4: combining the identifier of the automobile part, the hash value of the ownership certificate, the entity ID of the manufacturer of the automobile part, a flag bit indicating whether the automobile part is sold or not and a signature generated by using a group signature technology, and storing the combined identifier and the hash value in a product information set; finally, the manufacturer stores the product information set on the blockchain; the vehicle component identifier, the proof of ownership are stored in a proof of ownership set, and the proof of ownership set is returned to the vehicle component manufacturer.

4. The block chain based privacy protection anti-counterfeiting automobile supply chain method according to claim 1, wherein the step 3 comprises the following steps:

step 3.1: before ownership transfer is carried out between a buyer and a seller, the buyer and the seller negotiate to obtain a hash chain and a sharing state; the hash chain is a set of a plurality of hashes and is linked through a hash function; specifically, the previous hash value in the hash chain comes from the hash of the next hash value, and the initial hash value comes from the negotiation under the chain; the shared state contains a counter c and a hash value beta on the hash chain corresponding to the counter position_c；

Step 3.2: the seller first needs to find the (c + 1) th hash value, denoted as β, from the pre-generated hash chain in step 3.1_c+1Then encrypting the hash value and the ownership certification information of the automobile part generated in the step 2, and storing the encrypted information on a blockchain in the form of blockchain transaction, wherein the corresponding transaction identifier is T_id；

Step 3.3: seller entity relayTo hash value beta in shared state negotiated between two entities_cStep 3.2 transaction identifier T of the stored encrypted information_idAnd the c +1 th hash value β on the hash chain_c+1The three are encrypted to obtain a transaction retrieval token, and the token is sent to the buyer;

step 3.4: the seller will update the shared status and increment the counter shared with the buyer in step 3.1 by one; at this time, the status information of the seller becomes the counters c +1 and β_c+1。

5. The block chain based privacy protection anti-counterfeiting automobile supply chain method according to claim 1, wherein the step 4 comprises the following steps:

for automobile part dealers and automobile part retailers, the following is used:

step 4.1: the buyer uses the status information shared with the seller in step 3.1 to retrieve a transaction token from the seller selling the automobile component, decrypts the transaction token to obtain the transaction identifier T in the form of ciphertext_idAnd a hash value β of the next bit of the counter on the hash chain used as the one-time session key_c+1；

Step 4.2: performing hash on the hash value of the one-time session key, comparing the hash content with the hash content in the shared state, if the comparison is successful, indicating that the identity authentication of the two parties is successful, otherwise, failing to authenticate, and refusing to execute the subsequent operation;

step 4.3: after successful verification at step 4.2, the transaction identifier T stored on the blockchain is retrieved_idDecrypting the ciphertext information stored in the corresponding transaction to obtain a set containing ownership information of the automobile parts, and searching corresponding product information from the block chain by calling an intelligent contract; for each piece of automobile part information, comparing whether the hash value of the ownership certificate in the received ownership information set is the same as the hash value in the corresponding product information stored on the block chain and whether the state of the automobile part is in an unsold state, and finally checking whether the signature content is correct; when the information is all checkedIf the result is successful, the automobile part is indicated to be a genuine product, step 4.4 is executed, otherwise the product is regarded as a fake product, and the buyer refuses to accept the product;

step 4.4: the buyer performs the same operation as in step 2.2, i.e. generates a new proof of ownership and a hash value of the proof of ownership using the buyer's own identity ID and the secret key K; then the same operation as in step 2.3 is performed, i.e. the signature information is generated using the group public key and the buyer's own private key;

step 4.5: updating product information stored on a block chain of each received automobile part, wherein the product information comprises a hash value of ownership certification information of the automobile part and signature information of the automobile part;

for the user, the following method is adopted:

step 4-1: giving a product ownership information set of the corresponding automobile parts by the automobile part retailer, checking the product information of the corresponding automobile parts according to the product identifiers contained in the product ownership information set, calculating whether the hash value of the ownership certificate is consistent with the information stored in the block chain or not, checking whether the state of the automobile parts is sold or not, if the information is consistent and the automobile parts are not sold, executing the step 4-2, otherwise, considering the product as a counterfeit product, and refusing to accept the product by a buyer;

step 4-2: checking whether the signature information is correct by using the group public key, if so, continuing the next step, otherwise, the product is regarded as a fake product, and the buyer refuses to accept the product;

step 4-3: when the checks in the step 4-1 and the step 4-2 are passed, the automobile part is proved to be a genuine product; after the user purchases the product, the user invokes the intelligent contract to change the sales state of the automobile parts, and the state of the automobile parts is changed into the sold state.

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