CN107103473A - A kind of intelligent contract implementation method based on block chain - Google Patents

Abstract

The invention discloses a block chain-based smart contract realization method, which belongs to the smart contract field and mainly includes three parts: smart contract formulation, smart contract storage into the block chain, and smart contract automatic execution. The formulation of the smart contract is jointly participated by multiple users, and the participants digitally sign it and transmit it to the blockchain network. When data sharing occurs between the participants, the smart contract will regularly check the status of the automaton. Once a transaction When the smart contract trigger condition is met, the verification node will authenticate the transaction, and the verified transaction will be successfully executed by the system.

Description

A blockchain-based smart contract implementation method

technical field

The invention relates to the technical field of block chains, in particular to a block chain-based smart contract implementation method.

Background technique

A contract refers to a provision that two or more parties enter into to determine their respective rights and obligations when handling something.

Traditional contracts are written on paper, and will only take effect after signing and stamping. The execution process of the contract is composed of many control agreements. The control agreements include the preservation of records such as forms and bills, and the review and negotiation of records. The participation of a third party, and the performance of the contract can only be guaranteed by law and force.

With the development of information technology, it has gradually become a new development trend to reduce the cost of contract designation, control and execution through technologies such as computer, Internet and cryptography. In 1997, Nick Szabo introduced the concept of "smart contracts": smart contracts embed contract terms into software and hardware, and promote the execution of contracts through protocols and user interfaces. It is the key to forming a secure and digital relationship on the Internet. In other words, in the computer world, contracts are implemented in the form of code. Digital contracts have the risk of being valid, easily denied, tampered with, and hacked. Therefore, digital contracts are not always credible.

Contents of the invention

In view of the above-mentioned prior art, the purpose of the present invention is to provide a blockchain-based smart contract implementation method.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A blockchain-based smart contract execution method, comprising the following steps:

Step 1. For two or more users who have data sharing needs, formulate a contract according to each user's own needs. The contract is used to clarify the rights and obligations of each party, and obtain an electronic contract through a programming language. Each user of the contract formulation digitally signs the electronic contract to obtain a valid contract, and the signature is used to ensure the validity of the contract and realize the formulation of the smart contract;

Step 2. The valid contract spreads in the blockchain through P2P. Each node in the blockchain that participates in the formulation of the valid contract receives a valid contract and saves it in the corresponding block. In the corresponding block, except In addition to ontology information, it also includes valid contract records and timestamps corresponding to valid contract records, enabling smart contracts to be stored in the blockchain network;

Step 3. Set the valid contract to periodically check the state of the automaton, traverse the state machine, transaction and trigger conditions contained in the valid contract one by one, when the transaction meets the trigger condition, use the verification node to first verify the signature of the transaction, where the signature is used to ensure the transaction Validity, when the verification node executes the transaction after signature verification, the automatic execution of the smart contract is realized.

In the above method, the step 3 includes the following steps:

Step 3.1. After the user initiates a data sharing request, a corresponding transaction is generated, and the user's operation is recorded in the corresponding block;

Step 3.2. Check the execution status of the valid contract state machine, traverse the valid contract to find the trigger condition corresponding to the transaction;

Step 3.3. When the transaction satisfies the trigger condition, the transaction is signed and authenticated by the verification node;

Step 3.3.1. After the transaction passes the signature verification, initiate a corresponding request to the database and return the data required by the user, that is, the transaction is successfully executed by the system and the user is notified;

Step 3.3.2. If the transaction cannot pass the verification of the verification node, the data sharing request initiated by the user fails, that is, the execution of the transaction fails, and the system returns the corresponding status and notifies the user;

Step 3.4. During the execution process, the effective contract monitors the transaction in real time to see if there is any operation that violates the contract. If there is an operation that violates the contract, the execution of the transaction will be suspended and the status will be returned to the user.

In the above method, the step 1 also includes that before formulating the contract, the user who needs data sharing registers an account in the blockchain, and after registration, the corresponding account receives a pair of public key and private key assigned by the blockchain. key.

In the above method, in step 1, each user participating in the formulation of the contract signs the electronic contract with the private key of their own account to ensure the validity of the contract.

In the above method, in step 2, when the valid contract spreads to the blockchain through P2P, the valid contract is verified by the verification nodes in the blockchain, and when more than half of the verification nodes pass the verification and reach a consensus Valid contracts are stored in corresponding blocks.

A blockchain-based smart contract system, including

The smart contract designated module receives the electronic contract converted from the user contract;

The smart contract is stored in the module, and the effective contract transmitted by the smart contract designated module is received;

The smart contract automatic execution module traverses and checks the state machine, transaction and trigger condition contained in the valid contract stored in the block by the smart contract storage module, and selectively executes the transaction according to the inspection result.

In the above solution, the smart contract automatic execution module includes a smart contract execution state machine, a database for storing data, a user-initiated data sharing request, and a verification node; the smart contract execution state machine receives a data sharing request initiated by the user. Request the generated transaction and traverse the valid contract to find the trigger condition corresponding to the transaction;

The verification node receives the satisfaction of the trigger conditions fed back by the smart contract execution state machine and selectively verifies the transaction signature according to the satisfaction of the conditions;

The database receives the verification status of the verification transaction signed by the verification node and selectively returns data to the user who initiates the data sharing request according to the verification status.

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

The blockchain-based smart contract system brings us a decentralized, non-tamperable, and highly reliable system;

It cannot be tampered with, so that users do not have to worry about the content of the contract being changed;

High reliability, so that users do not have to worry that the system will not be executed when the conditions are met;

Decentralization brings full network backup to users, and complete records can fully support post-event auditing;

Fair rules and procedures, users do not need to trust the other party who signed the contract, they only need to believe that the blockchain system can complete the rest.

Description of drawings

Fig. 1 is a schematic diagram of the overall architecture of the present invention;

Fig. 2 is a schematic diagram of an embodiment of the present invention.

detailed description

All features disclosed in this specification, or steps in all methods or processes disclosed, may be combined in any manner, except for mutually exclusive features and/or steps.

The present invention will be further described below in conjunction with accompanying drawing:

A block chain-based smart contract implementation method includes the steps of making smart contracts, storing the smart contracts in the block chain network, and automatically executing the smart contracts.

The smart contract formulation steps include:

Two or more users who have data sharing needs, formulate a contract according to their own needs, clarify the rights and obligations of each party, and digitize it through a programming language, and all parties to the contract will digitally sign it to ensure its validity sex.

The steps of storing the smart contract in the blockchain network include:

The contract spreads in the blockchain network through p2p, and each node participating in the contract formulation will receive a copy and save it in the corresponding block. In addition to its original information, a block should also contain smart contract records and their corresponding timestamps.

The automatic execution steps of the smart contract include:

The smart contract regularly checks the state of the automaton, traversing the state machine, transactions and trigger conditions contained in the contract one by one. Once the transaction meets the trigger conditions, the verification node will first verify the signature of the transaction to ensure the validity of the transaction, and the transaction will be automatically executed after the verification node passes the verification.

In the present invention, all users with data sharing requirements are registered accounts of the blockchain, and the blockchain will return a pair of public key and private key to the corresponding account.

In the present invention, the contract makers sign the electronic contract with their respective private keys to ensure the validity of the contract.

In the present invention, when the smart contract spreads to the blockchain network through p2p, the verification nodes in the blockchain will verify it, and the smart contract will be stored in the corresponding in the block.

In the present invention, the smart contract execution module includes four modules: a smart contract execution state machine, a database for storing data (ie, a block), an event request initiated by a user (ie, a transaction) and a verification node. The specific execution steps are as follows:

(1) User A initiates a data sharing request to the system, a corresponding transaction is generated, and the operation of user A is recorded in the corresponding block;

(2) The system checks the execution status of the smart contract state machine, and traverses the contract to find the trigger condition corresponding to the transaction;

(3) When the transaction meets the trigger conditions, the system will verify the signature of the transaction through the verification node to ensure the validity of the transaction;

(4) After the transaction is verified, the system will initiate a corresponding request to the database and return the data required by user A, that is, the transaction will be successfully executed by the system and notify user A;

(5) If the transaction cannot pass the verification of the verification node, the request initiated by user A fails, that is, the execution of the transaction fails, and the system will return the corresponding status and notify user A;

(6) The transaction will always be supervised by the smart contract during the execution process. Once there is an operation that violates the contract during the execution process, the transaction will suspend the execution and return the status to user A.

Example 1

See Figure 2. When there is a need for data sharing between user A and user B, user A and user B first jointly formulate a smart contract and digitize it through conversion. After signing with their own private keys, both parties will The smart contract is stored in the blocks corresponding to A and B, and the corresponding timestamps are recorded in the corresponding blocks. When user A shares a piece of data with user B, this is a "data sharing behavior" that is passed into the blockchain as a transaction. When the transaction meets the trigger conditions of the smart contract, the verification node will verify the transaction. After the verification is passed, the transaction will be automatically executed, otherwise, the transaction will not be executed because the verification condition is not met. For example: one of the smart contracts formulated by user A and user B is: user A shares data with user B, and user B only has the authority to open, edit, and operate within a specified time range. When the contract is stored in the corresponding blocks of both parties, user B initiates a data sharing request to user A. When the trigger conditions of the smart contract are met, the verification node verifies it. Once the verification is passed, user B can smoothly operate the data shared by user A. The data given to it, but this operation will always be supervised by the smart contract. User B can only open, edit and operate the data shared by user A within the specified time. Once the corresponding time range is exceeded, all operation rights of user B on the data will be withdrawn. If user B performs operations on the data outside of the contract, such as copying, user B will also lose the authority to operate the data due to violation of the smart contract. All operations of user B on the data will be recorded in the corresponding block.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any changes or substitutions that can be easily imagined by those skilled in the art within the technical scope disclosed in the present invention, All should be covered within the protection scope of the present invention.

Claims (7)

1. a kind of intelligent contract based on block chain performs method, it is characterised in that comprise the following steps：

Step 1, the user for having data sharing demand for two and two or more, need to formulate a according to each user itself Contract, and electronic contract is obtained by programming language, each user formulated by participation contract enters line number to electronic contract Word is signed, and obtains effective contract；

Step 2, effective contract are spread by way of P2P in block chain, and each of effective contract formulation is participated in block chain Individual node all receives a effectively contract and is stored in corresponding block, in corresponding block except comprising ontology information it Outside, also recorded comprising effective contract and record corresponding timestamp with effective contract；

Step 3, the effective contract of setting inspect periodically state of automata, and the state machine included in effective contract, affairs are traveled through one by one And trigger condition, when affairs meet trigger condition, using node is verified first to affairs progress signature verification, when checking node leads to Cross after signature verification and perform affairs.

2. a kind of intelligent contract based on block chain as claimed in claim 1 performs method, it is characterised in that described step 3, comprise the following steps：

Step 3.1, data sharing request is initiated by user after produce corresponding affairs, and the operation note of user corresponding In block；

Step 3.2, the execution state for checking effective contract state machine, travel through effective contract and find the corresponding triggering bar of the affairs Part；

Step 3.3, when the affairs meet trigger condition, by verify node to the affairs carry out signature authentication；

Step 3.3.1, after affairs are by signature verification, initiate corresponding requests to database and return to the number required for user According to that is, the affairs are by system successful execution and notify user；

If step 3.3.2, the affairs can not be by verifying the checking of node, Client-initiated data sharing request failure, i.e., The affairs perform failure, and system returns to corresponding state and notifies user；

Step 3.4, in the process of implementation, is operated by whether effective contract occurs running counter to contract to affairs real-time oversight, if occurring Contract operation is run counter to, then stops the execution of affairs and the state is returned into user.

3. a kind of intelligent contract based on block chain as claimed in claim 1 performs method, it is characterised in that described step 1, it is additionally included in before formulation contract, the user for having data sharing demand carries out Account Registration in block chain, by correspondence after registration Account receives a pair of the public keys and private key that block chain is distributed.

4. a kind of intelligent contract based on block chain as claimed in claim 2 performs method, it is characterised in that described step 1, wherein each user for participating in contract formulation is that electronic contract is signed by the private key of respective account.

5. a kind of intelligent contract based on block chain as claimed in claim 1 performs method, it is characterised in that described step 2, wherein when effective contract is diffused into block chain by P2P modes, being entered by the checking node in block chain to effective contract Row checking, effectively contract is stored in corresponding block after more than half checking node is by verifying and reaching common understanding.

6. a kind of intelligent contract system based on block chain, it is characterised in that including

Intelligent contract designated module, receives the electronic contract converted by user's contract；

Intelligent contract is stored in module, receives effective contract that intelligent contract designated module is transmitted；

The intelligent automatic performing module of contract, traversal checks that the effective contract being stored in by intelligent contract deposit module in block is wrapped The state machine, affairs and the trigger condition that contain and affairs are selectively performed by inspection result.

7. a kind of intelligent contract system based on block chain as claimed in claim 6, it is characterised in that described intelligent contract Automatic performing module includes intelligent contract and performs state machine, the database for data storage, user's initiation data sharing request With checking node；Described intelligent contract performs state machine, receive by user initiate data sharing request generation affairs and time Have effect contract all through the ages and find out the corresponding trigger condition of affairs；

Described checking node, the trigger condition that the intelligent contract execution state machine of reception is fed back meets situation and by meeting situation Selectively transaction signature is verified；

Described database, receives the proofing state of checking node institute signature verification affairs and by proofing state selectively to initiating User's returned data of data sharing request.