CN107038578A - Multi-signature exchange information processing method in data trade platform based on block chain - Google Patents

Abstract

The invention discloses a multi-signature transaction information processing method in a blockchain-based data transaction platform. Each of the buyer and seller generates a transaction key pair on their own client, and the data transaction platform generates and distributes a single transaction key pair for each transaction process; the seller publishes the data to be traded on the blockchain through the data transaction platform; the buyer After the seller submits the transaction application, an intermediate address is generated according to the three-party public key. After payment, the funds are transferred to the intermediate address. After receiving the funds and writing them into the blockchain, the seller encrypts the data and sends it to the buyer; Both parties sign, and the funds are transferred to the seller's address; if there is any objection, it will be judged by the data trading platform, and the funds will be transferred to the buyer or seller according to the judgment result. The invention processes the data and transaction information of both parties through a special area chain method, and at the same time prevents the data transaction platform from misappropriating transaction funds, further ensuring the security of digital assets during transactions.

Description

Multi-signature transaction information processing method in blockchain-based data transaction platform

technical field

The invention relates to a multi-signature method, in particular to a method for processing multi-signature transaction information in a blockchain-based data transaction platform in the technical field of blockchain.

Background technique

With the rapid development of cloud computing and the Internet of Things, more and more data has been recorded and saved, and it has now entered the era of big data. Data trading is an inevitable demand of the market and reality. In order to maximize the value of data, data trading centers have been established in various places. However, due to the particularity of data, such as easy copying and no clear ownership constraints, it is difficult to guarantee data security and rights, so companies and individuals do not want to Take the data out and share the transaction.

In order to better ensure data security and the rights and interests of enterprises and individuals, existing people have proposed to apply blockchain technology and cryptography to data transactions to establish a data transaction platform based on blockchain. The data transaction platform only performs link functions and cannot View and save transaction data to protect the rights and interests of individuals and businesses while ensuring data security. Blockchain technology originated from "Bitcoin: A Peer-to-Peer Electronic Cash System" published by Satoshi Nakamoto in 2008. In this paper, a peer-to-peer (P2P)-based electronic cash system is proposed, which is based on the principle of cryptography. The two parties in the transaction directly pay when they reach an agreement, creating a mode that breaks away from the traditional payment through a third-party intermediary to ensure transaction security.

The blockchain is the underlying technical support of Bitcoin. The key innovation of blockchain technology is to solve the double payment and Byzantine general problem through the hash chain with time stamp and the proof-of-work mechanism, that is, to ensure that the same bitcoin will not appear in the same time Two addresses, and on the basis of reliable channels, all nodes can allow other nodes to accept their own real transactions, technically ensuring the security and trustworthiness of transactions.

The traditional blockchain-based Bitcoin transaction process is generally as follows: the buyer user directly transfers money to the merchant's address, the payment is one-way irreversible, and does not support "deduction claim". The so-called "deduction claim" refers to when the buyer user Chargeback claims occur when their credit card company is asked to reverse an already approved transaction. When a dispute arises at this time, the quality of both parties needs to be tested.

In order to better guarantee the rights and interests of both parties to the transaction, multi-signature transactions came into being. The address of a multi-signature transaction can have three associated private keys, and the trader needs two of them to complete a transfer. In fact, you can also set it to 1/3, 5/5, 6/11, but the most common combination is 2/3.

The benefits that multi-signature technology can bring: (1) Protect the rights and interests of consumers. After the traditional bitcoin transaction occurs, the merchant can immediately obtain the money. After adding the multi-signature technology, the merchant needs the explicit consent of the buyer to actually obtain the bitcoin. (2) Security. Because of the guarantee of Multisig technology, buyers and sellers can transparently see the safe storage of transaction funds, and data transaction platform providers cannot embezzle transaction funds. (3) Easy to operate. Through technical encapsulation, users do not feel the complexity of Multisig.

However, existing multi-signature transactions do not necessarily guarantee security. In most cases, multi-signature wallets appear as a client-side Javascript web application. If attackers control the server of the trading platform, they have the ability to send wrong web applications to users. Such client-browser multi-signature wallets can be considered a complete threat to the security of the crypto economy. Providers of browser Javascript multi-signature wallets originally hoped to establish a protocol that is not affected by a single point of failure, but they played the roles of client and server in the protocol. Multisig provided in this way does not provide the security guarantees that some would imagine it would.

Contents of the invention

In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a method for processing multi-signature transaction information in a blockchain-based data transaction platform, aiming at providing a transaction method that is not affected by a single party, ensuring the rights and interests of buyers and sellers while enabling Data trading platforms are also unable to misappropriate transaction funds, and try to avoid external threats to economic security.

The technical scheme adopted in the present invention comprises:

The method of the present invention is aimed at the information processing of the data transaction platform, the buyer user and the seller user in the transaction process with data as the object, including the following aspects:

A. Generate a key:

Each user of the buyer user and the seller user generates a user transaction key pair (pk ^C , sk ^C ) on its own client, where pk ^C represents the user transaction public key, sk ^C represents the user transaction private key, and the user sends the key pair The public key pk ^C in is sent to the data trading platform, and pk ^C ＝sk ^C · ^P , ^P represents the generator of cyclically added groups; The transaction key pair of the home user is expressed as The transaction key pair of the seller user is expressed as

During each transaction between any seller user and buyer user, the data transaction platform generates a single transaction key pair (pk ^T , sk ^T ) for each transaction process, where pk ^T represents a single transaction public key, sk ^T represents the private key of a single transaction, and makes the public key of a single transaction public; the single transaction key pair (pk ^T , sk ^T ) does not distinguish between sellers and buyers, and is only generated by the data transaction platform for each transaction , which can also be expressed as

In the present invention, in the superscripts represented by letters, U represents the login key, C represents the transaction key, and T represents the single transaction key. In the letter representation of the present invention, a in the subscript indicates a buyer user, b indicates the ordinal number of a seller user, and c indicates a data transaction platform.

The client for users to generate and store transaction public and private keys is provided by the partner of the data trading platform, not the data trading platform. The data trading platform cannot obtain the user's private key to ensure the security of user information.

B. Publishing of data to be traded: seller users release the data information of data to be traded on the blockchain through the data trading platform for buyers to purchase;

C. During each transaction, the transaction information is processed in the following ways:

1) After the buyer user sends an application to purchase a certain data to the data trading platform, the data trading platform generates a single transaction key (pk ^T , sk ^T ) for the transaction process, and at the same time according to the respective user IDs of the buyer user and the seller user The transaction public key and the single transaction public key of the data transaction platform generate an intermediate address A, and the data transaction platform, buyer users and seller users use the intermediate address A to perform subsequent multi-signatures;

2) The buyer user performs the payment operation and transfers the transaction funds of its own address to the intermediate address A through blockchain technology, and the seller user inquires on the blockchain that the transaction funds of the buyer user have been transferred to the intermediate address A. After information, obtain the user transaction public key of the buyer user from the data transaction platform Treat transaction data Encrypted and sent to the buyer user,

3) The buyer user receives the encrypted data to be traded Finally, verify the correctness through data decryption, hash and hash value comparison, and perform steps 4.1), 4.2) or 4.3);

4.1) If the buyer user verifies that the data is correct, confirms the transaction and sends the confirmation transaction information to the data trading platform, then the buyer user and the seller user use their respective user transaction private keys to pair the successful transaction information After signing, the data transaction platform verifies the signature and broadcasts it to the blockchain network. After the blockchain node verifies the signature, the transaction funds in the intermediate address A are transferred to the address of the seller user;

4.2) If the buyer user does not confirm the transaction within the specified time, the data transaction platform will use its own private key for a single transaction and the user transaction private key of the seller user to pair the transaction information of the successful transaction After signing, the data transaction platform verifies the signature and broadcasts it to the blockchain network. After the blockchain node verifies the signature, the transaction funds in the intermediate address A are transferred to the address of the seller user;

4.3) If the buyer raises an objection to the transaction, it will be decided to transfer the funds in the intermediate address A to the address of the buyer or seller according to the seller's handling or the judgment result of the data trading platform, specifically divided into:

4.3.1) If the buyer user applies for a refund operation, the buyer user generates the refund information that the transaction funds of the intermediate address A are returned to the buyer user address And signed and sent to the seller user, if the seller user agrees to refund, the refund information After signing, the data trading platform verifies the signature and broadcasts it to the blockchain network. After the blockchain node verifies the signature, the funds in the intermediate address A will be returned to the buyer's user address;

4.3.2) If the buyer user applies for a refund operation, the buyer user generates the refund information that the transaction funds of the intermediate address A are returned to the buyer user address After the signature is sent to the seller user, if the seller user does not agree to the refund, the data transaction platform will judge the result, and decide to transfer the funds in the intermediate address A to the buyer user or seller user according to the judgment result.

The transaction funds mentioned above refer to digital currency, such as Bitcoin.

The data trading platform of the present invention operates through the server and its processor when generating keys and processing transaction information in the block chain.

In the step B, the seller user publishes the data to be traded on the block chain through the data trading platform, specifically: the seller user selects the data to be traded The hash value of the seller user's identification number ID, the description information of the data to be traded, the hash value of the data to be traded, the price of the data to be traded, the public key of the user's transaction of the seller user Packaged to form a data package, and then use the seller's user's user transaction private key Sign the data package and send it to the data trading platform. After receiving the data package sent by the seller user, the data trading platform first verifies that the seller user is a valid identity of the data trading platform, and then uses the seller user's user transaction public key after the verification is correct. Verify the signature of the data packet and confirm that the data packet is sent by the seller user, then add the data information in the data packet to the block to form a chain.

The intermediate address A in the step 1) is based on the user transaction public key of the buyer user by the data transaction platform The user transaction public key of the seller user And the single transaction public key pk ^T of the data trading platform is generated using the secure hash function H:

Among them, H is a secure hash function.

In the step 3), the buyer user receives the encrypted data to be traded After that, verify the correctness by decrypting, hashing, and comparing hash values, including:

After the buyer user receives the encrypted data to be traded Finally, first use your own user transaction private key Decrypt, and then decrypt the data to be traded Calculate its hash value, and then compare the calculated hash value with the hash value of the transaction data in the data information on the blockchain to confirm whether they are consistent and obtain the correctness result.

The step 4.1) specifically includes:

4.1.1) If the buyer user verifies that the data is correct, the buyer user generates the transaction information that the transaction funds of the intermediate address A are transferred to the seller user address And evaluate this transaction to generate the evaluation information of buyers and users as The buyer user uses its own user transaction private key information on transactions and review information Sign separately to generate transaction information buyer's signature Sign with buyer evaluation information will then contain The data package is sent to the seller user and the data trading platform;

Among them, "·||·" indicates the concatenation of data, is the verification public key of the buyer user, Indicates the transaction information The hash value obtained by hashing, H ₁ () represents a secure hash function, Indicates the transaction information and buyer evaluation information The hash value obtained by hashing after concatenation;

4.1.2) The seller user receives the After extracting the data packet, verify the authenticity of the signature first by extracting the information. The verification method is:

Calculate transaction information the hash value of Trading Information and buyer evaluation information The hash value obtained by hashing after concatenation

Confirm whether the following equations are all true, and if all the equations are true, it means that the signature is authentic;

Among them, P represents the generator of the cyclic plus group between the public key and the private key, and e is a bilinear map, which satisfies bilinearity, non-degeneration and computability;

4.1.3) After confirming that the signature of the buyer user is authentic, the seller user evaluates the transaction to generate the evaluation information of the seller user And use its own user transaction private key information on transactions and review information Signature, generate transaction information seller's signature Sign with the seller's evaluation information will then contain The data package is sent to the data trading platform;

Among them, P represents the generator of the cyclic plus group between the public key and the private key, Indicates the transaction information and seller evaluation information The hash value obtained by hashing after concatenation, It is the verification public key of the seller user;

4.1.4) After receiving the data packets sent by buyers and sellers, the data trading platform uses the following methods to verify the authenticity of the signatures extracted from them:

Calculate transaction information the hash value of Trading Information and buyer evaluation information The hash value obtained by hashing after concatenation Trading Information and seller evaluation information The hash value obtained by hashing after concatenation

Verify the buyer's user signature. If the following equations are all true, it means that the buyer's signature is true:

Verify the seller's user signature. If the following equations are all true, it means that the seller's signature is true:

After the signatures of both parties are verified to be true, the evaluation information of buyers and sellers will be with Displayed in the transaction results, the following algorithm is used to calculate the signatures of both parties in the transaction information and the verification public key N _c of this transaction, and then will contain The data packets broadcast to each node of the blockchain;

Among them, N _c is the verification public key of this transaction;

4.1.5) The node with write permission on the blockchain uses the following equation to verify the authenticity of the signature on the data packet sent by the data trading platform, and writes the transaction information into the blockchain after verifying the authenticity, so that the intermediate address A Funds transferred to seller user address:

Among them, e is a bilinear map.

Described step 4.3.2) is specifically divided into:

4.3.2.1) If the data transaction platform determines that the refund is successful according to the transaction situation, the data transaction platform and the buyer user will verify the refund information After signing, the funds in the intermediate address A will be returned to the buyer's user address;

4.3.2.2) If the data trading platform judges that the refund is unsuccessful according to the transaction situation, it is equivalent to considering that the transaction is successful, and the data trading platform and the seller user will verify the transaction information After signing, the funds in the intermediate address Α will be transferred to the seller's user address.

The step 4.2) specifically includes:

4.2.1) After the buyer user fails to confirm the transaction within the specified time, the data trading platform evaluates the transaction and generates evaluation information as follows: Use the private key sk ^T of this transaction key to pair the transaction information and review information Make a signature and generate a transaction information platform signature Sign with platform evaluation information will then contain The data package is sent to the seller user;

in, Indicates the verification public key of the data trading platform, Indicates the transaction information The hash value obtained by hashing, H ₁ () represents a secure hash function, Indicates the transaction information and platform evaluation information The hash value obtained by hashing after concatenation;

4.2.2) The seller user receives the After extracting the data packet, verify the authenticity of the signature first by extracting the information. The verification method is:

Calculate transaction information the hash value of Trading Information and platform evaluation information The hash value obtained by hashing after concatenation

Confirm whether the following equations are all true, and if all the equations are true, the signature is authentic;

4.2.3) After confirming that the signature of the data transaction platform is authentic, the seller user uses his own user transaction private key information on transactions Trade reviews with sellers Signature, generate transaction information seller's signature and the evaluation information seller's signature will then contain The data package is sent to the data trading platform;

in, Indicates the transaction information Trade reviews with sellers The hash value obtained by hashing after concatenation, It is the verification public key of the seller user;

4.2.4) After receiving the data package sent by the seller user, the data trading platform uses the following equation to verify the authenticity of the signature extracted from the information:

Calculate transaction information Trade reviews with sellers The hash value obtained by hashing after concatenation

Verify the seller's user signature. If the following equations are all true, the signature is authentic:

After the seller's signature is verified to be true, the evaluation information of the data trading platform and the seller will be with It is displayed on the transaction result page, and the following formula is used to calculate the signatures of both parties of the transaction information and the verification public key N _c of this transaction, and then will contain The data packets broadcast to each node of the blockchain;

Among them, N _c is the verification public key of this transaction;

4.2.5) The node with write permission on the blockchain uses the following equation to verify the authenticity of the signature on the data packet sent by the data transaction platform, and writes the transaction information into the blockchain after verifying the authenticity, so that the intermediate address A Funds transferred to seller user address:

Among them, e is a bilinear map.

In the described step 4.3.1), specifically include:

4.3.1.1) After the buyer user performs the refund operation, evaluate the transaction to generate the evaluation information of the buyer user as The buyer user uses its own user transaction private key information on refunds and review information Signature, generate transaction information buyer signature signature And the evaluation information buyer's signature will then contain The data package is sent to the seller user and the data trading platform;

Among them, "·||·" indicates the concatenation of data, is the verification public key of the buyer user, express refund information The hash value obtained by hashing, H ₁ () represents a secure hash function, express refund information and buyer evaluation information The hash value obtained by hashing after concatenation;

4.3.1.2) The seller user receives the After extracting the data packet, verify the authenticity of the signature first by extracting the information. The verification method is:

Calculate Refund Information Hash value obtained by hashing refund information and buyer evaluation information The hash value obtained by hashing after concatenation

Confirm whether the following equations are all true, and if all the equations are true, it means that the signature is authentic;

Among them, P represents the generator of the cyclic plus group between the public key and the private key, and e is a bilinear map, which satisfies bilinearity, non-degeneration and computability;

4.3.1.3) After confirming that the signature of the buyer user is authentic, the seller user evaluates the transaction to generate the evaluation information of the seller user The seller user uses its own user transaction private key information on refunds and review information Signature, generate transaction information seller's signature and the evaluation information seller's signature will then contain The data package is sent to the data trading platform;

Among them, P represents the generator of the cyclic plus group between the public key and the private key, express refund information and seller evaluation information The hash value obtained by hashing after concatenation, It is the verification public key of the seller user;

4.3.1.4) After receiving the data packets sent by buyers and sellers, the data trading platform uses the following equation to verify the authenticity of signatures extracted from the information:

Calculate Refund Information Hash value obtained by hashing refund information and buyer evaluation information The hash value obtained by hashing after concatenation refund information and seller evaluation information The hash value obtained by hashing after concatenation

Verify the buyer's user signature. If the following equations are all true, it means that the buyer's signature is true:

Verify the seller's user signature. If the following equations are all true, it means that the seller's signature is true:

After the signatures of both parties are verified to be true, the evaluation information of buyers and sellers will be with Displayed in the transaction results, the following algorithm is used to calculate the signatures of both parties in the transaction information and the verification public key N _c of this transaction, and then will contain The data packets broadcast to each node of the blockchain;

Among them, N _c is the verification public key of this transaction;

4.3.1.5) The node with write permission on the blockchain uses the following equation to verify the authenticity of the signature on the information sent by the data trading platform, and writes the transaction information into the blockchain after verifying the authenticity, so that the funds in the intermediate address A Transfer to seller user address:

Among them, e is a bilinear map.

In the step 4.3.2), if the funds in the final intermediate address A are transferred to the buyer user, the details are:

4.3.2.a.1) The data trading platform judges that the refund is successful according to the transaction status, and the data trading platform evaluates the transaction and generates evaluation information as Use the single transaction private key sk ^T of this transaction to pair the refund information and review information Make a signature and generate a transaction information platform signature Sign with the evaluation information platform will then contain The data package is sent to the buyer user;

in, Indicates the verification public key of the data trading platform, express refund information The hash value obtained by hashing, H ₁ () represents a secure hash function, express refund information and platform evaluation information The hash value obtained by hashing after concatenation;

4.3.2.a.2) The buyer user receives the After extracting the data packet, verify the authenticity of the signature first by extracting the information. The verification method is:

Calculate Refund Information Hash value obtained by hashing Refund information and platform evaluation information The hash value obtained by hashing after concatenation

Confirm whether the following equations are all true, and if all the equations are true, the signature is correct;

4.3.2.a.3) After confirming that the signature of the data transaction platform is authentic, the buyer user uses his own user transaction private key information on refunds and transaction evaluation Signature, generate transaction information buyer's signature And the evaluation information buyer's signature will then contain The data package is sent to the data trading platform;

in, express refund information and buyer evaluation information The hash value obtained by hashing after concatenation;

4.3.2.a.4) After receiving the data package sent by the buyer user, the data trading platform uses the following equation to verify the authenticity of the signature extracted from the information:

Calculate Refund Information and buyer evaluation information The hash value obtained by hashing after concatenation

Verify the buyer's user signature. If the following equations are all true, it means that the buyer's signature is true:

After the buyer's signature is verified to be true, the data trading platform and the buyer's evaluation information will be with It is displayed on the transaction result page, and the following formula is used to calculate the signatures of both parties of the transaction information and the verification public key N _c of this transaction, and then will contain The data packets broadcast to each node of the blockchain;

Among them, N _c is the verification public key of this transaction;

4.3.2.a.5) Nodes with write permission on the block chain use the following equation to verify the authenticity of the signature on the data packet sent by the data transaction platform, and write the transaction information into the block chain after verifying the authenticity, so that The funds in the intermediate address A are transferred to the buyer's user address:

Among them, e is a bilinear map.

In the step 4.3.2), if the funds in the final intermediate address A are transferred to the seller user, the details are:

4.3.2.b.1) The data trading platform determines that the refund is unsuccessful according to the transaction situation, and the data trading platform evaluates the transaction and generates evaluation information as Use the single transaction private key sk ^T of this transaction to pair the transaction information and review information Make a signature and generate a transaction information platform signature Sign with the evaluation information platform will then contain The data package is sent to the seller user;

in, Indicates the verification public key of the data trading platform, Indicates the transaction information The hash value obtained by hashing, H ₁ () represents a secure hash function, Indicates the transaction information and platform evaluation information The hash value obtained by hashing after concatenation;

4.3.2.b.2) The seller user receives the After extracting the data packet, verify the authenticity of the signature first by extracting the information. The verification method is:

Calculate transaction information Hash value obtained by hashing Trading Information and platform evaluation information The hash value obtained by hashing after concatenation

Confirm whether the following equations are all true, and if all the equations are true, the signature is correct;

4.3.2.b.3) After confirming that the signature of the data transaction platform is authentic, the seller user uses his own user transaction private key information on transactions and review information Signature, generate transaction information seller's signature and the evaluation information seller's signature will then contain The data package is sent to the data trading platform;

in, Indicates the transaction information and seller evaluation information The hash value obtained by hashing after concatenation;

4.3.2.b.4) After receiving the data package sent by the seller user, the data trading platform uses the following equation to extract the information to verify the authenticity of the signature:

Calculate pair transaction information and seller evaluation information The hash value obtained by hashing after concatenation

Verify the seller's user signature. If the following equations are all true, it means that the seller's signature is true:

After the seller's signature is verified to be true, the data trading platform and the seller's evaluation information will be with It is displayed on the transaction result page, and the following formula is used to calculate the signatures of both parties of the transaction information and the verification public key N _c of this transaction, and then will contain The data packets broadcast to each node of the blockchain;

Among them, N _c is the verification public key of this transaction;

4.3.2.b.5) The node with write permission on the blockchain uses the following equation to verify the authenticity of the signature on the data packet sent by the data transaction platform, and writes the transaction information into the blockchain after verifying the authenticity, so that The funds in the intermediate address A are transferred to the seller's user address:

Among them, e is a bilinear map.

The above-mentioned part of the technical terms involved in the present invention are explained as follows:

Signature: All signatures in this invention refer to digital signatures. Digital signatures are similar to physical signatures written on paper. They are only implemented using the technology in the field of public key encryption, and are the application of asymmetric encryption technology and digital abstract technology. In the usual sense, digital signature includes two operations of signature and verification. Only the signer of the information can generate a digital string that cannot be forged by others. Therefore, digital signature includes the functions of authentication, integrity verification and non-repudiation proof.

Cyclic group: G is a cyclic plus group, and there is an element g in G, so that any element f in G can be expressed as f=g n, n is an integer, then G is said to be a cyclic plus group generated by g, g is called a generator of group G, denote G=<g>.

Bilinear map: G and V are cyclic groups of order prime q, G is a cyclic addition group, and V is a cyclic multiplication group. A bilinear pairing refers to a map e:G×G→V with the following properties:

(1) Bilinear: for all P, Q∈G and

e(wP, vQ) = e(wvP, Q) = e(P, wvQ) = e(P, Q) ^wv

Among them, w and v represent any number in Represents the set of remainders that do not contain 0 when any integer is divided by a prime number q, and P and Q represent any elements in the group G.

(2) Non-degenerate: There exists a P∈G that satisfies e(P,P)≠1.

(3) Computable: For P, Q∈G, there is an effective algorithm to calculate e(P, Q).

Address: The address mentioned in this invention refers to the address in the block chain, which is used to mark the sender and receiver of a transaction. The address in the block chain is obtained through a series of hash and encoding algorithms for the public key .

Compared with prior art, the beneficial effect of the present invention is:

1) Both buyer users and seller users can guarantee the safe storage of transaction funds, and data transaction platform providers cannot misappropriate transaction funds. At the same time, seller users need the explicit consent of buyer users to actually obtain the funds;

2) The data trading platform cannot obtain the user's private key generation method, nor can it know the user's private key, so as to ensure that the transaction is not affected by one party, and the outside world cannot endanger economic security by attacking the server.

To sum up, the present invention can provide a transaction method that is not affected by one party, guarantees the rights and interests of buyers and sellers, makes the data transaction platform unable to embezzle transaction funds, and avoids external threats to economic security as much as possible.

Description of drawings

Fig. 1 is a schematic flow chart of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, an embodiment of the present invention and its specific implementation process are as follows:

A. Generate a key:

Each user of the buyer user and the seller user generates a user transaction key pair (pk ^C , sk ^C ) on its own client, where pk ^C represents the user transaction public key, sk ^C represents the user transaction private key, and the user sends the key pair The public key pk ^C in is sent to the data trading platform, and pk ^C ＝sk ^C · ^P , ^P represents the generator of cyclically added groups; The transaction key pair of the home user is expressed as The transaction key pair of the seller user is expressed as

During each transaction between any seller user and buyer user, the data transaction platform generates and distributes a single transaction key pair (pk ^T , sk ^T ) for each transaction process, where pk ^T represents a single transaction public key , sk ^T represents the private key of a single transaction, and makes the public key of a single transaction public; the key pair of a single transaction (pk ^T , sk ^T ) does not distinguish between sellers and buyers, and is only provided by the data transaction platform for each transaction generated, which can also be expressed as

In the present invention, in the superscripts represented by letters, C represents a transaction key, and T represents a single transaction key. In the letter representation of the present invention, a in the subscript indicates a buyer user, b indicates the ordinal number of a seller user, and c indicates a data transaction platform.

The client for users to generate and store transaction public and private keys is provided by the partner of the data trading platform, not the data trading platform, and the data trading platform cannot obtain the user's private key. If the attacker controls the data trading platform, the attacker still cannot obtain the private key of any user to ensure the security of user information.

In the specific implementation, when buyers and sellers register on the data trading platform, the users set the login account and corresponding password, and the data trading platform will encrypt and store the user's login password to ensure the valid identity of the user and the user's login. Passwords are not disclosed. The specific implementation can also generate and assign a user login key pair (pk ^U , sk ^U ) for each user of the buyer user and the seller user, where pk ^U represents the user login public key, sk ^U represents the user login private key, and the user Its own private key is sent to the user. Both the seller user and the buyer user have a user login key pair (pk ^U , sk ^U ), and the buyer user’s login key pair is expressed as The login key pair of the seller user is expressed as

B. Publishing of data to be traded: seller users release the data information of data to be traded on the blockchain through the data trading platform for buyers to purchase;

The seller user selects the data to be traded The hash value of the seller user's identification number ID, the description information of the data to be traded, the hash value of the data to be traded, the price of the data to be traded, the public key of the user's transaction of the seller user Packaged to form a data package, and then use the seller's user's user transaction private key Sign the data packet and send it to the data transaction platform. The data transaction platform will first verify the valid identity of the seller user as the data transaction platform for the data packet sent by the seller user, and then use the seller user's user transaction public key after the verification is correct. Verify the signature of the data packet and confirm that the data packet is sent by the seller user, then add the data information in the data packet to the block to form a chain.

According to the data package provided by the seller user, verifying the effective identity of the seller user as the data trading platform is specifically: verifying the identity of the buyer through the user login account and login password of the seller user.

C. After the buyer sees the data to be traded on the page of the data trading platform, he sends an application for purchasing certain data to be traded and then starts the transaction process, which is processed according to the method of the present invention:

1) After the buyer user sends an application to purchase a certain data to the data trading platform, the data trading platform generates a single transaction key (pk ^T , sk ^T ) for the transaction process, and at the same time according to the respective user IDs of the buyer user and the seller user The transaction public key and the single transaction key of the data trading platform use the secure hash function H to generate an intermediate address A, and the data trading platform, buyer users and seller users use the intermediate address A to perform subsequent multi-signatures;

2) The buyer user performs the payment operation, uses the digital currency as the transaction fund, and transfers the transaction fund of its own address to the intermediate address A through the blockchain technology, and the seller user queries the transaction fund of the buyer user on the blockchain. After transferring the transaction information to the intermediate address A, obtain the transaction public key of the buyer user from the data transaction platform Treat transaction data Encrypted and sent to the buyer user,

3) The buyer user receives the encrypted data to be traded After that, its correctness is verified by data decryption, hash and hash value comparison: the buyer user receives the encrypted data to be traded Finally, first use your own user transaction private key Decrypt, and then decrypt the data to be traded Calculate its hash value, and then compare the calculated hash value with the hash value of the data to be traded in the data information published on the blockchain to confirm whether they are consistent and obtain the correctness result.

4) Carry out steps 4.1), 4.2) or 4.3);

4.1) If the buyer user verifies that the data is correct, generate the transaction information that the transaction funds in the intermediate address A are transferred to the seller user address and for transaction information After signing and confirming, the seller user will also send the transaction information Make a signature confirmation The funds in the intermediate address A will be transferred to the seller user address.

4.2) After the buyer user receives the data, if the buyer user does not confirm the transaction within the specified time, the data transaction platform will generate transaction information that the funds in the intermediate address A are transferred to the seller user address Data transaction platform and seller user transaction information Make a signature confirmation The funds in A will be transferred to the seller's user address.

4.3) If the buyer raises an objection to the transaction, it will be decided to transfer the funds in the intermediate address A to the address of the buyer or seller according to the seller's handling or the judgment result of the data trading platform, specifically divided into:

4.3.1) If the buyer user applies for a refund operation, the buyer user generates the refund information that the transaction funds of the intermediate address A are returned to the buyer user address And signed and sent to the seller user, if the seller user agrees to refund, the refund information to sign The funds in the intermediate address A will be returned to the buyer's user address;

4.3.2) If the seller user does not agree to refund, there are two situations as follows:

4.3.2.a) If the buyer user applies for a refund operation, the buyer user generates the refund information that the transaction funds of the intermediate address A are returned to the buyer user address And sign it and send it to the seller user. If the seller user does not agree to the refund, the data trading platform will judge the result. According to the judgment result, the refund is successful, and the funds in the intermediate address A will be transferred to the buyer user.

4.3.2.b) If the buyer user applies for a refund operation, the buyer user generates the refund information that the transaction funds of the intermediate address A are returned to the buyer user address And sign it and send it to the seller user. If the seller user disagrees with the refund, the data trading platform will judge the result. According to the judgment result, if the refund is unsuccessful, the funds in the intermediate address A will be transferred to the seller user.

Blockchain-based transactions are all one-way irreversible. In the prior art, blockchain-based transaction methods often appear: if the buyer transfers funds to the seller’s user address, the transaction is irreversible, and the buyer’s When the product is not satisfied, the funds cannot be obtained again, and if the buyer user temporarily stores the funds on the transaction data trading platform, and then transfers the funds to the seller user from the data trading platform, the funds are not safe. Therefore, someone proposed a multi-signature transaction, and in the existing multi-signature transaction, the trading platform plays the roles of client and server. If the attacker controls the server of the trading platform, they can use the client to obtain user information. Therefore, existing multi-signature transactions are not necessarily safe, and do not provide imaginable security.

Therefore, it can be seen from the above-mentioned embodiments that in the method of the present invention, each user of the user generates a user transaction key pair on its own client, and performs multi-signature processing on the data encryption and transaction information during the transaction between the two parties through a special area chain method, Recording in the block makes it impossible for any party to misappropriate transaction funds. This method is used in data transactions to ensure the security of data information processed every time during the transaction process and make transactions reliable.

The above specific embodiments are used to explain the present invention, rather than to limit the present invention. Within the spirit of the present invention and the protection scope of the claims, any modification and change made to the present invention will fall into the protection scope of the present invention.

Claims (10)

1. A multi-signature transaction information processing method in a data transaction platform based on a block chain is characterized in that the method is used for processing information of the data transaction platform, a buyer user and a seller user in a transaction process taking data as an object, and comprises the following aspects:

A. and (3) generating a secret key:

each of the buyer user and the seller user generates a user transaction key pair (pk) at its own client^C,sk^C) Wherein pk^CRepresenting the user's transaction public key, sk^CIndicating privacy of user transactionsKey, the user shares the public key pk in the key pair^CSent to the data trading platform, and pk^C＝sk^CP, P represents the generator of the cyclic addition; and for the user transaction key pair (pk) of the buyer-seller user^C,sk^C) The transaction key pair of the buyer user is expressed asThe seller user's transaction key pair is represented as

During each transaction occurring between any seller user and buyer user, the data transaction platform generates a single transaction key pair (pk) for each transaction process^T,sk^T) Wherein pk^TRepresenting a single transaction public key, sk^TRepresenting a single-transaction private key and disclosing a single-transaction public key;

B. and (3) releasing data to be traded: a seller user publishes data information of data to be transacted on a block chain through a data transaction platform for a buyer user to purchase;

C. in each transaction process, the transaction information is processed in the following mode:

1) after a buyer user sends an application for purchasing certain data to a data transaction platform, an intermediate address A is generated according to respective user transaction public keys of the buyer user and a seller user and a single transaction public key of the data transaction platform;

2) the buyer user carries out payment operation, the transaction fund of the self address is transferred to the intermediate address A through the blockchain technology, the seller user inquires the transaction information that the transaction fund of the buyer user is transferred to the intermediate address A on the blockchain, and then the user transaction public key of the buyer user is obtained from the data transaction platformData to be transactedEncrypted and then sent to the buyer user,

3) the buyer user receives the encrypted data to be transactedThen, verifying the correctness through data decryption, hash and hash value comparison, and performing the steps 4.1), 4.2) or 4.3);

4.1) if the buyer user verifies that the data is correct, the transaction is confirmed and confirmed transaction information is sent to the data transaction platform, and then the buyer user and the seller user use respective user transaction private keys to the transaction information of successful transactionThe data transaction platform verifies the signature and broadcasts the signature to the blockchain network, and after the blockchain node verifies that the signature passes, the transaction fund in the intermediate address A is transferred to the address of the seller user;

4.2) if the buyer user does not confirm the transaction within the specified time, the data transaction platform uses the private key of the buyer user for the transaction information of successful transaction by using the private key of the buyer user for the single transaction and the private key of the seller user for the transactionThe data transaction platform verifies the signature and broadcasts the signature to the blockchain network, and after the blockchain node verifies that the signature passes, the transaction fund in the intermediate address A is transferred to the address of the seller user;

4.3) if the buyer user disagrees with the transaction, determining to transfer the funds in the intermediate address A to the address of the buyer user or the seller user according to the processing condition of the seller user or the judgment result of the data transaction platform, wherein the steps are specifically as follows:

4.3.1) if the buyer user applies for refund operation, the buyer user generates refund information that the transaction fund of the intermediate address A is returned to the address of the buyer userAnd sending the signature to the seller user, and if the seller user agrees to refund, refund information is sent to the seller userThe data transaction platform verifies the signature and broadcasts the signature to the blockchain network, and funds in the intermediate address A can be returned to the address of the buyer user after the blockchain node verifies that the signature passes;

4.3.2) if the buyer user applies for refund operation, the buyer user generates refund information that the transaction fund of the intermediate address A is returned to the address of the buyer userAnd sending the signature to the seller user, judging a result by the data transaction platform if the seller user does not agree with the refund, and determining to transfer the funds in the intermediate address A to the buyer user or the seller user according to the judgment result.

2. The method for processing the multi-signature transaction information in the data transaction platform based on the blockchain as claimed in claim 1, wherein the method comprises the following steps: the step B of issuing the data to be traded on the blockchain by the seller user through the data trading platform specifically includes: seller user selection of data to be transactedThe hash value of the identification number ID of the seller user, the description information of the data to be transacted, the hash value of the data to be transacted, the price of the data to be transacted and the user transaction public key of the seller userPackaging the data into a data packet, and then using a user transaction private key of a seller userThe data packet is signed and then sent to a data transaction platform, and the data transaction platform receives the number sent by the seller userAfter the data is packaged, the seller user is verified to be the effective identity of the data transaction platform, and the user transaction public key of the seller user is used after the verification is correctAnd verifying the signature of the data packet, and adding the data information in the data packet into the block to form a chain when the data packet is confirmed to be sent by the seller user.

3. The method of claim 1, wherein the method comprises: the intermediate address A in the step 1) is a user transaction public key of the data transaction platform according to the buyer userUser transaction public key for seller userAnd single transaction public key pk of data transaction platform^TGenerating by using a secure hash function H:

wherein H is a secure hash function.

4. The method for processing the multi-signature transaction information in the data transaction platform based on the blockchain as claimed in claim 1, wherein the method comprises the following steps: the buyer user receives the encrypted data to be transacted in the step 3)And then, verifying the correctness through decryption, hashing and hash value comparison, which specifically comprises the following steps:

the buyer user receives the encrypted data to be transactedThen, firstly, the private key of the user transaction is utilizedDecrypting, and decrypting to obtain data to be transactedAnd calculating the hash value of the block chain, comparing the calculated hash value with the hash value of the data to be traded in the data information on the block chain, and determining whether the calculated hash value is consistent with the hash value of the data to be traded so as to obtain a correctness result.

5. The method for processing the multi-signature transaction information in the data transaction platform based on the blockchain as claimed in claim 1, wherein the method comprises the following steps: the step 4.1) specifically comprises the following steps:

4.1.1) if the buyer user verifies that the data is correct, the buyer user generates the transaction information that the transaction fund of the intermediate address A is transferred to the address of the seller userAnd the transaction is evaluated to generate the evaluation information of the buyer user asBuyer user utilizes own user transaction private keyFor transaction informationAnd evaluation informationRespectively signing to generate transaction information buyer signatureAnd buyer rating information signatureThen will containThe data packet is sent to the seller user and the data transaction platform;

wherein "·| ·" represents a concatenation of data,for the verification of the public key of the buyer user,presentation of transaction informationHash value, H, obtained by hashing₁() A secure hash function is represented that represents a secure hash function,presentation of transaction informationAnd buyer evaluation informationHashing the obtained hash value after the concatenation;

4.1.2) seller user receiving packageAfter the data packet is received, extracting information in the data packet, and verifying the authenticity of the signature, wherein the verification method comprises the following steps:

calculating transaction informationHash value ofTransaction informationAnd buyer evaluation informationHash value obtained by hashing after concatenation

Confirming whether the following equations are all true, and if the equations are all true, indicating that the signature is true;

wherein, P represents the generation element of the circulation adding group between the public key and the private key, and e is bilinear mapping;

4.1.3) after confirming that the signature of the buyer user is authentic, the seller user evaluates the transaction to generate evaluation information of the seller userAnd utilizes its own private key for user transactionFor transaction informationAnd evaluation informationSigning to generate seller signature of transaction informationAnd seller ratings information signatureThen will containSending the data packet to a data transaction platform;

wherein P represents a generator of round-robin clustering between the public key and the private key,presentation of transaction informationAnd seller evaluation informationThe hash value obtained by hashing after concatenation,a verification public key for the seller user;

4.1.4) after receiving the data packets sent by the buyer user and the seller user, the data transaction platform adopts the following modes to verify the authenticity of the signature of the extracted information:

calculating transaction informationHash value ofTransaction informationAnd buyer evaluation informationHash value obtained by hashing after concatenationTransaction informationAnd seller evaluation informationHash value obtained by hashing after concatenation

Verifying the signature of the buyer, and if the following equations are all true, indicating that the signature of the buyer is true:

verifying the signature of the seller user, and if the following equations are all true, indicating that the signature of the seller is true:

after the signatures of both parties are verified to be true, the evaluation information of the buyer and seller users is obtainedAnddisplaying the transaction result, and calculating the signatures of both parties of the transaction information by the following algorithmAnd the verification public key N of this transaction_cThen will containThe data packet of (a) is broadcast to the blockchain;

wherein N is_cA verification public key for the transaction;

4.1.5) the nodes with writing authority on the block chain verify the authenticity of the signature for the data packet sent by the data transaction platform by adopting the following equation, and write the transaction information into the block chain after verifying the authenticity, so that the funds in the intermediate address A are transferred to the address of the user of the seller:

where e is a bilinear map.

6. The method for processing the multi-signature transaction information in the data transaction platform based on the blockchain as claimed in claim 1, wherein the method comprises the following steps: the step 4.3.2) is specifically divided into the following steps:

4.3.2.1) if the data transaction platform determines the refund is successful according to the transaction condition, the data transaction platform and the buyer user can use the refund informationSigning, and returning funds in the intermediate address A to the address of the buyer user;

4.3.2.2) if the data transaction platform determines the refund is not successful according to the transaction condition, the data transaction platform and the seller user can check the transaction informationSigning is performed and funds in the intermediate address a are transferred to the seller user address.

7. The method for processing the multi-signature transaction information in the data transaction platform based on the blockchain as claimed in claim 1, wherein the method comprises the following steps: the step 4.2) specifically comprises the following steps:

4.2.1) after the buyer user does not confirm the transaction within the specified time, the data transaction platform evaluates the transaction and generates evaluation informationPrivate key sk using the transaction key^TFor transaction informationAnd evaluation informationSigning and generating transaction information platform signatureAnd platform rating information signaturesThen will containSending the data packet to the seller user;

wherein,a verification public key representing a data transaction platform,presentation of transaction informationHash value, H, obtained by hashing₁() A secure hash function is represented that represents a secure hash function,presentation of transaction informationAnd platform evaluation informationHashing the obtained hash value after the concatenation;

4.2.2) seller user receiving PackageAfter the data packet is received, extracting information in the data packet, and verifying the authenticity of the signature, wherein the verification method comprises the following steps:

calculating transaction informationHash value ofTransaction informationAnd platform evaluation informationHash value obtained by hashing after concatenation

Confirming whether the following equations are all true, and if the equations are all true, the signature is real;

4.2.3) after confirming that the signature of the data transaction platform is real, the seller user utilizes the own user transaction private keyFor transaction informationAnd seller transaction ratingSigning to generate seller signature of transaction informationAnd evaluating information vendor signaturesThen will containSending the data packet to a data transaction platform;

wherein,presentation of transaction informationAnd seller transaction ratingThe hash value obtained by hashing after concatenation,a verification public key for the seller user;

4.2.4) after receiving the data packet sent by the seller user, the data transaction platform adopts the following equation to verify the authenticity of the signature by extracting the information:

calculating transaction informationAnd seller transaction ratingHash value obtained by hashing after concatenation

Verifying the signature of the seller user, and if the following equations are all true, indicating that the signature is true:

after the signature of the seller is verified to be authentic, the evaluation information of the data transaction platform and the seller is obtainedAnddisplaying on the transaction result page, and calculating the signatures of both parties of the transaction information by using the following formulaAnd the verification public key N of this transaction_cThen will containThe data packet of (a) is broadcast to the blockchain;

wherein N is_cA verification public key for the transaction;

4.2.5) the nodes with the write-in authority on the block chain verify the authenticity of the signature for the data packet sent by the data transaction platform by adopting the following equation, and write the transaction information into the block chain after verifying the authenticity, so that the funds in the intermediate address A are transferred to the address of the user of the seller:

where e is a bilinear map.

8. The method for processing the multi-signature transaction information in the data transaction platform based on the blockchain as claimed in claim 1, wherein the method comprises the following steps: the step 4.3.1) specifically comprises the following steps:

4.3.1.1) after the buyer user performs refund operation, the transaction is evaluated to generate the evaluation information of the buyer user asBuyer user utilizes own user transaction private keyFor refund informationAnd evaluation informationSigning to generate transaction information buyer signatureAnd evaluating information buyer signaturesThen will containThe data packet is sent to the seller user and the data transaction platform;

wherein "·| ·" represents a concatenation of data,for the verification of the public key of the buyer user,indicating information on refundsHash value, H, obtained by hashing₁() A secure hash function is represented that represents a secure hash function,indicating information on refundsAnd buyer evaluation informationHashing the obtained hash value after the concatenation;

4.3.1.2) seller user receiving packageAfter the data packet is received, extracting information in the data packet, and verifying the authenticity of the signature, wherein the verification method comprises the following steps:

calculating refund informationHash value obtained by hashingRefund informationAnd buyer evaluation informationHash value obtained by hashing after concatenation

Confirming whether the following equations are all true, and if the equations are all true, indicating that the signature is true;

5

wherein, P represents the generation element of the circulation adding group between the public key and the private key, and e is bilinear mapping;

4.3.1.3) after confirming that the signature of the buyer user is authentic, the seller user evaluates the transaction to generate evaluation information of the seller userSeller users utilize their own private key for user transactionFor refund informationAnd evaluation informationSigning to generate seller signature of transaction informationAnd evaluating information vendor signaturesThen will containSending the data packet to a data transaction platform;

wherein P represents a generator of round-robin clustering between the public key and the private key,indicating information on refundsAnd seller evaluation informationThe hash value obtained by hashing after concatenation,a verification public key for the seller user;

4.3.1.4) after receiving the data packets sent by the buyer user and the seller user, the data transaction platform adopts the following equation to verify the authenticity of the signature for the information extracted from the data packets:

calculating refund informationHash value obtained by hashingRefund informationAnd buyer evaluation informationHash value obtained by hashing after concatenationRefund informationAnd sellEvaluation information of homeHash value obtained by hashing after concatenation

Verifying the signature of the buyer, and if the following equations are all true, indicating that the signature of the buyer is true:

verifying the signature of the seller user, and if the following equations are all true, indicating that the signature of the seller is true:

after the signatures of both parties are verified to be true, the evaluation information of the buyer and seller users is obtainedAnddisplaying the transaction result, and calculating the signatures of both parties of the transaction information by the following algorithmAnd the verification public key N of this transaction_cThen will containThe data packet of (a) is broadcast to the blockchain;

wherein N is_cA verification public key for the transaction;

4.3.1.5) verifying the authenticity of the signature for the information sent by the data transaction platform by the node with the writing authority on the block chain by adopting the following equation, writing the transaction information into the block chain after verifying the authenticity, and transferring the funds in the intermediate address A to the address of the seller user:

where e is a bilinear map.

9. The method for processing multiple signature transaction information in a data transaction platform based on block chain according to claim 1 or 6, wherein: in the step 4.3.2), if the funds in the final intermediate address a are transferred to the buyer user, the specific steps are:

4.3.2.a.1) the data transaction platform judges the refund success according to the transaction condition, and the data transaction platform evaluates the transaction to generate evaluation information ofThe private key sk of a single transaction is used^TFor refund informationAnd evaluation informationSigning and generating transaction information platform signatureAnd evaluating information platform signaturesThen will containThe data packet is sent to the buyer user;

wherein,a verification public key representing a data transaction platform,indicating information on refundsHash value, H, obtained by hashing₁() A secure hash function is represented that represents a secure hash function,indicating information on refundsAnd platform evaluation informationHashing the obtained hash value after the concatenation;

4.3.2.a.2) purchaser user receiving packageAfter the data packet is received, extracting information in the data packet, and verifying the authenticity of the signature, wherein the verification method comprises the following steps:

calculating refund informationHash value obtained by hashingRefund information and platform evaluation informationHash value obtained by hashing after concatenation

Confirming whether the following equations are all established, and if the equations are all established, the signature is correct;

4.3.2.a.3) after confirming that the signature of the data transaction platform is authentic, the buyer user utilizes the own user transaction private keyFor refund informationAnd transaction evaluationSigning to generate transaction information buyer signatureAnd evaluating information buyer signaturesThen will containSending the data packet to a data transaction platform;

wherein,indicating information on refundsAnd buyer evaluation informationHashing the obtained hash value after the concatenation;

4.3.2.a.4) after receiving the data packet sent by the buyer user, the data transaction platform adopts the following equation to extract the information therein to verify the authenticity of the signature:

calculating refund informationAnd buyer evaluation informationHash value obtained by hashing after concatenation

Verifying the signature of the buyer, and if the following equations are all true, indicating that the signature of the buyer is true:

after the signature of the buyer is verified to be authentic, the evaluation information of the data transaction platform and the buyer is transmittedAnddisplaying on the transaction result page, and calculating the signatures of both parties of the transaction information by using the following formulaAnd the verification public key N of this transaction_cThen will containThe data packet of (a) is broadcast to the blockchain;

wherein N is_cA verification public key for the transaction;

4.3.2.a.5) the node with write authority on the block chain verifies the authenticity of the signature for the data packet sent by the data transaction platform by adopting the following equation, writes the transaction information into the block chain after verifying the authenticity, and transfers the funds in the intermediate address A to the address of the buyer user:

where e is a bilinear map.

10. The method for processing multiple signature transaction information in a data transaction platform based on block chain as claimed in claim 1 or 6, wherein: the step 4.3.2) is specifically that if the funds in the final intermediate address a are transferred to the seller user:

4.3.2.b.1) the data transaction platform judges that the refund is unsuccessful according to the transaction condition, and the data transaction platform evaluates the transaction to generate evaluation information ofThe private key sk of a single transaction is used^TFor transaction informationAnd evaluation informationSigning and generating transaction information platform signatureAnd evaluating information platform signaturesThen will containSending the data packet to the seller user;

wherein,a verification public key representing a data transaction platform,presentation of transaction informationHash value, H, obtained by hashing₁() A secure hash function is represented that represents a secure hash function,presentation of transaction informationAnd platform evaluation informationHashing the obtained hash value after the concatenation;

4.3.2.b.2) seller user receiving packageAfter the data packet is received, extracting information in the data packet, and verifying the authenticity of the signature, wherein the verification method comprises the following steps:

calculating transaction informationHash value obtained by hashingTransaction informationAnd platform evaluation informationHash value obtained by hashing after concatenation

Confirming whether the following equations are all established, and if the equations are all established, the signature is correct;

4.3.2.b.3) after confirming that the signature of the data transaction platform is real, the seller user utilizes the own user transaction private keyFor transaction informationAnd evaluation informationSigning to generate seller signature of transaction informationAnd evaluating information vendor signaturesThen will containSending the data packet to a data transaction platform;

wherein,presentation of transaction informationAnd seller evaluation informationHashing the obtained hash value after the concatenation;

4.3.2.b.4) after receiving the data packet sent by the seller user, the data transaction platform adopts the following equation to extract the information therein to verify the authenticity of the signature:

calculating transaction informationAnd seller evaluation informationHash value obtained by hashing after concatenation

Verifying the signature of the seller user, and if the following equations are all true, indicating that the signature of the seller is true:

after the signature of the seller is verified to be authentic, the evaluation information of the data transaction platform and the seller is obtainedAnddisplaying on the transaction result page, and calculating the signatures of both parties of the transaction information by using the following formulaAnd the verification public key N of this transaction_cThen will containThe data packet of (a) is broadcast to the blockchain;

wherein N is_cA verification public key for the transaction;

4.3.2.b.5) the nodes with writing authority on the block chain verify the authenticity of the signature for the data packet sent by the data transaction platform by adopting the following equation, and write the transaction information into the block chain after verifying the authenticity, so that the funds in the intermediate address A are transferred to the address of the user of the seller:

where e is a bilinear map.