WO2021018312A1

WO2021018312A1 - Blockchain-based over-the-counter transaction method and system, storage medium, and electronic apparatus

Info

Publication number: WO2021018312A1
Application number: PCT/CN2020/110236
Authority: WO
Inventors: 邱炜伟; 李伟; 张帅; 蔡亮; 张珂杰
Original assignee: 杭州趣链科技有限公司
Priority date: 2019-07-30
Filing date: 2020-08-20
Publication date: 2021-02-04

Abstract

A blockchain-based over-the-counter transaction method and system, a storage medium, and an electronic apparatus. The blockchain-based over-the-counter transaction system comprises: a permissions management module, used for controlling data viewing permissions of ordinary users and system administrators; an account module, used for user registration, identity authentication, login and basic information modification, and for implementing blockchain-based distributed CA authentication; a market condition module, used for displaying market-wide bond quotations, responding to click completion requests of users, controlling automatic transaction executions according to conditions, and recording transaction processes on a blockchain; a contract management module, used for generating, signing and managing bond transaction contracts, and recording contract signature processes on the blockchain; a transaction management module, used for users to initiate new transaction intentions, and for settling funds and bond positions of users according to data recorded on the blockchain. The present invention can thus increase quotation and completion efficiency, transaction security and bond market liquidity for over-the-counter bond transactions.

Description

Block chain-based over-the-counter transaction method, system, storage medium and electronic device

Related application

This application requires applications on July 30, 2019, the application number is 201910694153.3, the title of the invention is "a blockchain-based over-the-counter bond trading system" and the application on August 21, 2019, the application number is 201910772367.8, the priority of a Chinese patent application entitled "A Formal Verification Method for Over-the-Counter Smart Contracts", the entire content of which is incorporated into this application by reference.

Technical field

This application relates to the application field of blockchain, and in particular to a blockchain-based OTC transaction method, system, storage medium and electronic device.

Background technique

Currently, inter-bank bond transactions are mainly achieved through bilateral negotiations or brokerage company inquiry, and can also be achieved through the trading platform of the Foreign Exchange Trading Center. In general, the over-the-counter bond market has problems such as low transaction efficiency, difficult to trace transaction information, and inability to grasp market information in a timely manner by supervision.

Summary of the invention

According to various embodiments of the present application, a blockchain-based over-the-counter transaction system is provided. The system includes a rights management module, an account module, a market quotation module, a contract management module, and transaction management running on a blockchain Module, where:

The authority management module is used to control the data viewing and operation authority of the administrator account and ordinary users through smart contracts, so that the administrator account can view contracts and transactions in the entire market and modify contract templates , Said ordinary users can only view contracts and transactions related to them;

The account module is used to manage changes or authentication related to the user's account. The account module includes a user registration unit, a CA authentication unit, an account management unit, a user login unit, and a user information modification unit, wherein:

The user registration unit is used to receive the identity authentication information filled in by the user and submit the registration request, and bind the blockchain address for the user;

The CA authentication unit is used to simultaneously send the identity authentication information filled in by the user to multiple authoritative nodes through the blockchain for data comparison, and receive the comparison result returned by the authoritative node to authenticate the user's identity information Whether it is true or not; if all nodes return the comparison correctly, the user’s identity authentication is passed, and the system adds the user’s blockchain address to the authorized list to authorize the user; if any node returns a comparison error, it will not pass User authentication;

The account management unit is used to collect and record user identity information, allocate blockchain accounts for users, and escrow public and private keys;

The user login unit is used for users to log in to the blockchain system with the registered account password;

The user information modification unit is used to improve the user's basic information other than the identity authentication information, and to modify the basic information that the user has filled in;

The market quotation module includes a large transaction screen unit, a quotation detail unit, and a click transaction unit, wherein: the large transaction screen unit is used to display bond quotation information issued by all users in the entire market; the quotation details unit is used to display The detailed information of a certain bond quotation; the click transaction unit is used to receive the transaction process initiated by the user on a certain quotation in the transaction screen, or receive the transaction process initiated by a batch of quotations in the transaction screen, and determine Detailed information of both parties to the transaction and the subject of the transaction;

The contract management module includes a template management unit, a contract signing unit, a contract to be signed unit, and a historical contract unit, among which:

The template management unit includes template making and template display, the template making function is only open to administrators, and the template display is used to display contract templates made by the administrator to ordinary users;

The contract signing unit includes contract generation and contract signing. The contract generation is used to generate contract elements according to the detailed information of the transaction parties and the target obtained by clicking the transaction unit, and generate the contract to be signed according to the contract template formulated by the administrator; The contract signing is used to send the contract information to be signed to both parties of the transaction obtained by clicking the transaction unit, and to receive the contract signed by both parties to the transaction, mark the signed contract as an effective contract, and send it to the historical contract unit. Then upload the contract to the blockchain for recording;

The contract to be signed unit is used to display the contract to be signed or the contract to be signed by the bidder generated in the contract signing unit; the contract to be signed is invalidated after the signing time limit is exceeded and enters the historical contract unit;

The historical contract unit is used to display the valid contracts signed and completed by both parties to the transaction generated in the contract signing unit, and used to display contracts to be signed that are invalidated after the signing time limit;

The transaction management module includes a new intention unit and a current position unit, wherein:

The new intention unit is used to receive a new buying or selling intention quotation initiated by the user, and after the user fills in all the elements of the transaction intention, the quotation is sent to the transaction large screen unit for display;

The current position holding unit is used to display the bonds and cash balance currently held by the user.

The above-mentioned blockchain-based over-the-counter trading system has the following advantages: the system provides online quotation and trading platforms for participating institutions in the over-the-counter bond market; provides registration, identity authentication, login, quotation, transaction, contract signing, Complete functional modules for contract management and position management; replace paper contracts with electronic contracts to improve contract signing efficiency and reduce contract management difficulty; add supervisory agencies, ie administrators, to blockchain nodes to improve supervision efficiency. The system also provides customers with online contract signing and online bond trading functions to improve the efficiency of over-the-counter bond transactions and improve the liquidity of the inter-bank bond market. In addition, the system is based on the underlying blockchain, and data cannot be tampered with. By uploading account information and transaction information to the chain, it is convenient to trace the transaction history and improve supervision efficiency.

In one of the embodiments, all the contract records of the contract signing unit are secured through the blockchain, and the secured data includes the blockchain addresses of the signing parties and the time stamp at the time of signing, and the electronic contract documents containing the electronic signatures of both parties.

In one of the embodiments, the identity authentication of the user in the CA authentication unit uses blockchain-based distributed CA authentication.

According to various embodiments of the present application, there is also provided a blockchain-based OTC transaction method, which is implemented based on the blockchain-based OTC transaction system of any of the various embodiments of the present application , The method specifically includes the following steps:

The user browses the large-screen transaction unit and views the quotation details unit, and selects the quotation to be traded;

The user clicks on the click transaction unit, and the system first verifies the user’s cash balance or bond balance to ensure that the purchase amount does not exceed the cash balance, and that the number of bonds sold does not exceed the bond balance; The blockchain address of the bidder and the details of the offer generate the contract to be signed;

The user confirms whether the content of the contract is correct. When the confirmation opinion is no, the user gives up signing the contract, the contract is invalidated, and enters the historical contract unit; when the confirmation opinion is yes, it is judged whether the contract has exceeded the signing time limit; when the judgment result is yes, then The contract is invalidated and enter the historical contract unit; when the judgment result is no, the user can use the electronic signature to sign the contract; then judge whether the bidder has signed the contract, if the judgment result is no, judge whether the contract has exceeded the signing time limit, judge If the result is yes, the contract is invalidated and enter the historical contract unit. If the judgment result is no, then continue to judge whether the bidder has signed the contract; if the judgment result is yes, the contract takes effect;

The system clears the bonds and funds of both parties through the transaction records on the blockchain, and then changes the positions of both parties through the clearing results, that is, settlement.

In one of the embodiments, the method further includes:

According to the logical judgment in the transaction control process of the smart contract, the logical judgment includes: the user's bond holdings and the bond balance verification when the user sells the transaction; the user's cash balance when the user buys the transaction Inspection; control of signing time limit when electronic contract is signed; on-chain storage of transaction record details, electronic contract hash, and electronic contract files; control of different permissions between administrator accounts and ordinary user accounts; users complete a buy or sell transaction , The system liquidates the bonds and funds held by the user according to the underlying bonds of the transaction and the transaction amount, and changes the balance of the bonds and funds.

In one of the embodiments, before signing the contract, the method further includes:

Defining a smart contract to perform over-the-counter transactions according to the smart contract, and the method of the over-the-counter transaction includes the declaration and realization of the data structure and contract method of the smart contract;

Define formal verification specifications to regulate the function, loop body, return value and attribute value changes of internal state variables of each smart contract related contract method in the smart contract;

Use the formal verification specification to perform formal verification on the smart contract to check whether the implementation of the over-the-counter transaction method complies with the description of the formal verification specification; if it complies, it means the smart contract is safe; if it does not comply, modify The smart contract until the formal verification description conforms to the relevant implementation in the over-the-counter transaction function.

In one of the embodiments, the definition of the smart contract includes uploading file information on-chain, recipient information on-chain, and feedbacker information on-chain; the data structure includes uploaded file information structure, recipient information structure, and feedback Information structure.

In one of the embodiments, the formal verification specification satisfies the following conditions: the uploaded file information structure corresponding to the uploaded file information structure is uploaded according to the file information, the recipient information, and the feedbacker information. , The recipient information structure and the feedback information structure are checked to obtain the return values of the file information on the chain, the recipient information on the chain, and the feedback information on the chain; check the loop The body does not overflow; when the smart contract is defined, the function is called without throwing an exception; after the function is called, the state variables of the data structure in the over-the-counter trading method change, and other state variables remain unchanged.

In one of the embodiments, the method further includes: during formal verification, the incoming parameter parameters are kept within the controllable range of the application layer; the overflow of the loop body array length is ignored, and the loop body is ignored. Temporary variable value overflow; judge whether the internal state variable exists, if the internal state variable already exists, then the formal verification returns a failure code on the chain; if the internal state variable does not exist, the formal verification returns a success flag code on the chain, Get the built formal verification model.

According to various embodiments of the present application, there is also provided a blockchain-based over-the-counter transaction method, which includes the following steps:

Defining an over-the-counter smart contract to conduct over-the-counter transactions. The method of the over-the-counter transaction includes the declaration and realization of the data structure and contract method of the over-the-counter smart contract;

Define formal verification specifications to describe the functions implemented by the over-the-counter transaction method, and standardize the functions, loop body, return value and internal state variable properties of each contract method related to the over-the-counter transaction contract in the smart contract Value change

Use the formal verification specification to perform formal verification on the over-the-counter smart contract, and according to the formal verification model, check whether the implementation of the over-the-counter transaction complies with the description of the formal verification specification; The over-the-counter smart contract is safe; if not, the over-the-counter smart contract is modified until the formal verification description complies with the relevant implementation of the over-the-counter function.

According to various embodiments of the present application, there is also provided an over-the-counter transaction system based on a blockchain. The system includes a rights management module, an account module, a market quotation module, a contract management module, Transaction management module; wherein: the authority management module is used to control the data viewing authority and operation authority of the administrator account and ordinary users according to the smart contract; wherein the data viewing authority of the administrator account includes viewing contracts and transaction records of the entire market The operation authority of the administrator account includes the authority to modify the contract template, the data viewing authority of the ordinary user includes the authority to view the contract and transaction related to the user; the account module is used to manage changes related to the user account Or authentication; the market quotation module is used to display bond quotation information issued by all users in the entire market; the contract management module is used to generate a contract to be signed according to the contract template and the acquired transaction information, and to The contract is sent to both parties to the transaction for signing; the transaction management module is used to send the received quotation information to the market quotation module and display the user's asset information.

In one of the embodiments, the account module includes a user registration unit, a CA authentication unit, an account management unit, a user login unit, and a user information modification unit, wherein: the user registration unit is used to receive user identity authentication information and Submit a registration request to bind the user to the corresponding blockchain address; the CA authentication unit is used to send the user's identity authentication information to multiple authoritative nodes through the blockchain, and receive each of the authoritative nodes The returned comparison result is used to verify the authenticity of the user’s identity information; if the comparison results of all the authoritative nodes are correct, the user’s corresponding blockchain address is added to the authorized list to pass the user’s registration Request; if the comparison result of the authoritative node shows an error, the user’s registration request is rejected; the account management unit: used to collect and record the user’s identity information, assign the user a blockchain account and escrow public keys and private The user login unit: used to log in to the blockchain system according to the registered account password entered by the user; the user information modification unit is used to manage and modify other basic information of the user.

In one of the embodiments, the CA authentication unit is also used to authenticate the user identity according to the distributed CA authentication rules based on the blockchain.

In one of the embodiments, the market quotation module includes a large transaction screen unit, a quotation detail unit, and a click transaction unit, wherein: the large transaction screen unit is used to display bond quotation information issued by all users in the entire market; The quotation detail unit is used to display the detailed information of a single bond quotation; the click transaction unit is used to receive a single transaction process initiated by the user for a certain quotation in the transaction screen or batches initiated for a certain batch of quotations Transaction process, and determine the details of both parties to the transaction and the subject of the transaction.

In one of the embodiments, the contract management module includes a template management unit, a contract signing unit, a contract to be signed, and a historical contract unit, wherein: the template management unit is used for the administrator to make templates and show management to ordinary users The contract template made by the administrator; the contract signing unit is used to generate contract elements based on the detailed information of the transaction parties and the transaction target obtained by the click transaction unit, and generate the contract to be signed based on the contract elements and the contract template made by the administrator , Send the contract information to be signed to both parties to the transaction, and receive the signed contract signed by both parties, mark the signed contract as an effective contract, send the effective contract to the historical contract unit, The contract to be signed is uploaded and recorded; the contract to be signed unit is used to display the contract to be signed generated in the contract signing unit or the contract to be signed by the bidding party, and the contract to be signed that exceeds the signing time limit is invalidated, And the invalidated contract to be signed is sent to the historical contract unit; the historical contract unit is used to display the effective contract and the invalidated contract to be signed.

In one of the embodiments, the contract signing record in the contract signing unit is stored by the blockchain, and the contract signing record includes the blockchain addresses of the signing parties and the signing timestamp, and the electronic contract file containing the electronic signatures of both parties .

In one of the embodiments, the transaction management module includes a new intention unit and a current position holding unit, wherein: the new intention unit is used to receive a new buying intention quotation or a selling intention quotation initiated by the user, and placing The buying intention quotation and the selling intention quotation are sent to the large transaction screen unit; the current position holding unit is used to display the bonds and cash balance currently held by the user.

According to various embodiments of the present application, there is also provided a blockchain-based OTC transaction method, which is implemented based on the blockchain-based OTC transaction system of any of the various embodiments of the present application The method specifically includes the following steps: obtaining a transaction quotation selected by the user, the transaction quotation being selected by the user based on the bond quotation information in the transaction large screen unit and the detailed information of a single bond quotation in the quotation detail unit Check the user’s asset information to ensure that the transaction offer is within the user’s asset control range; obtain the blockchain addresses of both parties to the transaction, and based on the detailed information of the transaction offer and the transaction The blockchain addresses of both parties generate the contract to be signed; the transaction parties include the user and the bidder; send the contract to be signed to the transaction parties and obtain the contract signing result; according to the contract signing result and the transaction Record the clearing of the assets of the two parties to the transaction, and change the positions of the two parties to the transaction according to the clearing result.

In one of the embodiments, the sending the contract to be signed to the two parties to the transaction and obtaining the result of contract signing includes: sending the contract to be signed to the two parties to the transaction and obtaining confirmation from the two parties to the transaction Opinion; if the confirmation opinions of both parties to the transaction are both yes, and both parties to the transaction complete the signing of the contract to be signed within the signing time limit, then the contract signed by both parties to the transaction is marked as an effective contract.

In one of the embodiments, the method further includes: if the confirmation opinion of either of the two parties to the transaction is no, or, either of the two parties to the transaction fails to complete the contract to be signed within the signing time limit. Signed, the contract to be signed is invalidated, and the invalid contract to be signed is sent to the historical contract unit.

In one of the embodiments, the method further includes: controlling the logical judgment in the transaction flow according to the smart contract, the logical judgment including the verification of the user asset information, the judgment of the signing time limit, the storage of transaction information, The use of account permissions and the liquidation and change of assets during the transaction.

In one of the embodiments, the method further includes: defining a smart contract; defining a formal verification specification to regulate the functions, loop body, return value, and internal state variables of each contract method related to the smart contract in the smart contract The property value of the change; determine whether the smart contract meets the description in the formal verification specification, if the smart contract meets the description in the formal verification specification, send the smart contract to the transaction parties for signing ; If the smart contract does not meet the description in the formal verification specification, the smart contract is modified until the smart contract meets the description in the formal verification specification.

In one of the embodiments, the method further includes: performing an over-the-counter transaction according to the smart contract to declare and implement the data structure and contract method of the smart contract.

In one of the embodiments, the defined formal verification specification includes: uploading according to the file information, uploading the recipient information, and uploading the feedback information corresponding to the uploaded file information structure, The recipient information structure and the feedback information structure are checked to obtain the return values of the file information on the chain, the recipient information on the chain, and the feedback information on the chain; verify the loop body No overflow; when the smart contract is defined, the function is called without throwing an exception; after the function is called, the state variables of the data structure in the over-the-counter trading method change, and other state variables remain unchanged.

In one of the embodiments, the method further includes: keeping the incoming parameter parameters within the preset parameter range of the application layer; ignoring the overflow of the length of the loop body array; ignoring the temporary variable value in the loop body The overflow; judge whether the internal state variable exists, if the internal state variable already exists, the formal verification returns a failure code on the chain; if the internal state variable does not exist, the formal verification returns a successful sign code on the chain, and the construction is completed According to the formal verification model, the smart contract is formally verified.

According to various embodiments of the present application, there is also provided an electronic device, including a memory and a processor, characterized in that a computer program is stored in the memory, and the processor is configured to run the computer program to execute the computer program. The blockchain-based over-the-counter transaction method described in any of the various embodiments of the application.

According to various embodiments of the present application, there is also provided a storage medium in which a computer program is stored, wherein the computer program is configured to execute any one of the various embodiments of the present application when running. The described OTC transaction method based on blockchain.

Description of the drawings

In order to better describe and illustrate the embodiments and/or examples of the inventions disclosed herein, one or more drawings may be referred to. The additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the currently described embodiments and/or examples, and the best mode of these inventions currently understood.

Fig. 1 is a basic structure diagram of a blockchain-based over-the-counter transaction system according to an embodiment of the application.

Fig. 2 is a structural block diagram of a blockchain-based over-the-counter transaction system according to a specific embodiment of the application.

Figure 3 is a flowchart of formal verification of smart contracts in an embodiment of the application.

Figure 4 is a schematic diagram of a formal verification model of a smart contract in an embodiment of the application.

Fig. 5 is a flowchart of a blockchain-based OTC transaction method according to an embodiment of the application.

Fig. 6 is a flowchart of a blockchain-based OTC transaction method according to a specific embodiment of the application.

Fig. 7 is a flowchart of formal verification of a smart contract according to a specific embodiment of the application.

Detailed ways

In order to facilitate the understanding of this application and to make the above-mentioned objectives, features and advantages of this application more obvious and understandable, the specific implementations of this application will be described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth in order to fully understand the application, and the preferred embodiments of the application are given in the accompanying drawings. However, this application can be implemented in many different forms and is not limited to the implementation described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of this application more thorough and comprehensive. This application can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of this application, so this application is not limited by the specific embodiments disclosed below.

In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "a plurality of" means at least two, such as two, three, etc., unless specifically defined otherwise. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise specifically defined.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of this application. The terminology used herein is only for the purpose of describing specific embodiments, and is not intended to limit the application. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

The following will further explain the blockchain-based OTC transaction methods, systems, storage media, and electronic devices provided in this application:

Figure 1 is a basic architecture diagram of a blockchain-based over-the-counter transaction system according to an embodiment of the application. As shown in Figure 1, the system includes a rights management module, an account module, a market quotation module, and Contract management module and transaction management module, including:

The authority management module is used to control the data viewing and operation authority of the administrator account and ordinary users through smart contracts, so that the administrator account can view contracts and transactions in the entire market and modify contract templates , Said ordinary users can only view contracts and transactions related to them.

The user information modification unit is used to complete the user's basic information except for the identity authentication information, and to modify the basic information that the user has filled in.

The market quotation module includes a large trading screen unit, a quotation detail unit and a click transaction unit, among which:

The large trading screen unit is used to display bond quotation information issued by all users in the entire market;

The quotation details unit is used to display detailed information of a bond quotation;

The click transaction unit is used to receive the transaction process initiated by the user on a certain quotation in the large transaction screen, or receive the transaction process initiated by a batch of quotations in the large transaction screen, and determine the detailed information of the transaction parties and the transaction target.

The historical contract unit is used to display the valid contracts signed and completed by both parties to the transaction generated in the contract signing unit, and used to display the contracts to be signed that are invalidated after the signing time limit.

The new intention unit is used to receive a new buying or selling intention quotation initiated by the user, and after the user fills in all the elements of the transaction intention, the quotation is sent to the transaction large screen unit for display; the current position holding unit , Used to display the bond and cash balance currently held by the user.

The beneficial effects of this application are as follows: The blockchain-based over-the-counter trading system provided by this application provides online quotation and trading platforms for participating institutions in the over-the-counter bond market, as well as providing registration, identity authentication, login, quotation, and transaction , Complete functional modules for contract signing, contract management, and position management; replace paper contracts with electronic contracts, improve contract signing efficiency, and reduce contract management difficulties; add regulatory agencies, namely administrators, to blockchain nodes to improve supervision efficiency. The system also provides customers with online contract signing and online bond trading functions to improve the efficiency of over-the-counter bond transactions and improve the liquidity of the inter-bank bond market. In addition, the system is based on the underlying blockchain, and data cannot be tampered with. By uploading account information and transaction information to the chain, it is convenient to trace the transaction history and improve supervision efficiency.

Blockchain technology is a new application mode of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. Blockchain is a new type of decentralized protocol that can safely store digital currency transactions or other data. The information cannot be forged or tampered with. The confirmation of transactions on the blockchain is completed by all nodes on the blockchain, and the consensus algorithm To ensure its consistency, it has the characteristics of decentralization, openness, independence, security and anonymity.

In the following, the blockchain-based over-the-counter trading system will be further explained through the following specific embodiments. Figure 2 is a structural block diagram of the blockchain-based over-the-counter trading system according to a specific embodiment of the application, as shown in Figure 2. As shown, the blockchain-based over-the-counter trading system includes a rights management module 210, an account module 220, a market quotation module 230, a contract management module 240, and a transaction management module 250 running on the underlying blockchain; among them:

The authority management module 210 is used to control the data viewing authority and operation authority of the administrator account and ordinary users according to the smart contract; wherein the data viewing authority of the administrator account includes the authority to view contracts and transaction records of the entire market. The operating authority of the account includes the authority to modify the contract template, and the data viewing authority of the ordinary user includes the authority to view contracts and transactions related to the user;

The account module 220 is used to manage changes or authentication related to user accounts; the market quotation module 230 is used to display bond quotation information issued by all users in the entire market.

The contract management module 240 is configured to generate a contract to be signed according to the contract template and the acquired transaction information, and send the contract to be signed to both parties to the transaction for signing;

The transaction management module 250 is configured to send the received quotation information to the market quotation module 230 and display the user's asset information.

In one of the embodiments, the account module 220 includes a user registration unit, a CA authentication unit, an account management unit, a user login unit, and a user information modification unit, wherein:

The user registration unit is used to receive the user's identity authentication information and submit a registration request to bind the user to the corresponding blockchain address;

The CA authentication unit is used to send the user's identity authentication information to multiple authoritative nodes through the blockchain, and receive the comparison result returned by each of the authoritative nodes to verify whether the user's identity information is authentic; If the comparison result of the authoritative node is correct, the blockchain address corresponding to the user is added to the authorized list to pass the user’s registration request; if the comparison result of the authoritative node shows an error, the user’s request will be rejected Registration request;

The account management unit: used to collect and record the user's identity information, allocate blockchain accounts and escrow public and private keys for users;

The user login unit: used to log in to the blockchain system according to the registered account password entered by the user;

The user information modification unit is used to manage and modify other basic information of the user.

In one of the embodiments, the market quotation module 230 includes a large trading screen unit, a quotation detail unit, and a click transaction unit, wherein:

The large transaction screen unit is used to display bond quotation information issued by all users in the entire market; the quotation detail unit is used to display detailed information of a single bond quotation; the click transaction unit is used to receive user-specific A single transaction process initiated by a certain quotation on the large screen or a batch transaction process initiated for a certain batch of quotations, and the detailed information of the transaction parties and the transaction target is determined.

In one of the embodiments, the contract management module 240 includes a template management unit, a contract signing unit, a contract to be signed unit, and a historical contract unit, wherein:

The template management unit is used for the administrator to make templates and to show ordinary users the contract templates made by the administrator;

The contract signing unit is used to generate contract elements according to the detailed information of the transaction parties and the transaction target obtained by the click transaction unit, and generate the contract to be signed according to the contract elements and the contract template prepared by the administrator, and send the pending contract to both parties Sign the contract information, receive the signed contract signed by both parties to the transaction, mark the signed contract as an effective contract, send the effective contract to the historical contract unit, and upload the effective contract And records;

The contract to be signed unit is used to display the contract to be signed or the contract to be signed by the bidder generated in the contract signing unit, to invalidate the contract to be signed that exceeds the signing time limit, and to send the invalid contract to be signed to The historical contract unit;

The historical contract unit is used to display valid contracts and invalid contracts to be signed.

In one of the embodiments, the contract signing record in the contract signing unit is stored via a blockchain, and the contract signing record includes the blockchain addresses of the signing parties, the signing timestamp, and the electronic contract file containing the electronic signatures of both parties .

In one of the embodiments, the transaction management module 250 includes a new intention unit and a current position unit, wherein: the new intention unit is used to receive a new buying intention quotation or selling intention quotation initiated by the user, and The buying intention quotation and the selling intention quotation are sent to the large transaction screen unit. The current position holding unit is used to display the bonds and cash balance currently held by the user.

This application also provides an over-the-counter transaction method for blockchain, which includes the following steps:

(1) Defining an over-the-counter smart contract to conduct over-the-counter transactions. The method of the over-the-counter transaction includes the declaration and realization of the data structure and contract method of the over-the-counter smart contract. (2) Define formal verification specifications to describe the functions implemented by the over-the-counter transaction method, and standardize the function, loop body, return value and internal state of the contract method related to each over-the-counter transaction contract in the smart contract The attribute value of the variable changes. (3) Use the formal verification specification to perform formal verification on the over-the-counter smart contract, and check whether the implementation of the over-the-counter transaction method meets the description of the formal verification specification according to the formal verification model; It means that the over-the-counter smart contract is safe; if not, the over-the-counter smart contract is modified until the formal verification description complies with the relevant implementation of the over-the-counter transaction function.

Smart contract (Smart contract) is a computer protocol designed to spread, verify or execute contracts in an information-based way. Smart contracts allow trusted transactions without a third party, which are traceable and irreversible. Executing contracts written in code and storing information in an immutable blockchain causes certain risks and problems, so the security of the contract is particularly important.

The beneficial effects of the above-mentioned blockchain OTC trading method are as follows: This application provides a set of common OTC transaction process related smart contract formal verification models, and provides a set of secure formal verification for OTC smart contract related businesses Standards. This method is designed based on software formal verification methods, and improves the security of smart contracts for over-the-counter transactions in contract design. The formal verification method provided by this method has universality. This method can be used for development and security auditing of smart contracts related to over-the-counter transactions, and it can be very suitable for business systems such as over-the-counter transactions.

Specifically, the definition of an over-the-counter smart contract has the following properties: (a) The data structure contains uploaded file information, the recipient information structure contains recipient information, and the feedback information structure contains feedback information. The uploaded file information structure contains at least two fields: the project file primary key and the file hash. The recipient information structure contains at least one field of the project file process progress primary key. The feedback information structure contains at least the project file primary key, file hash, and Is there a dispute about these three fields. (b) The state variable contains the main key of the record project file to the uploaded file information, the mapping of the feedbacker information, and the mapping of the main key of the project file process progress to the recipient information. (c) File information on-chain, recipient information on-chain, and feedbacker information on-chain, the three contract methods respectively loop the incoming parameters in the loop, and put each input parameter into the corresponding data structure In the variables.

Figure 3 is a flow chart of formal verification of smart contracts in an embodiment of the application. As shown in Figure 3, the formal verification specification satisfies the following conditions: uploading according to the file information, uploading the recipient information and all The feedback information on the chain corresponds to the incoming file information structure, the recipient information structure, and the feedback information structure to verify that the file information is on the chain and the recipient information is uploaded. Chain and the return value of the feedbacker’s information on the chain; verify that the loop body does not overflow; when the smart contract is defined, the function is called without throwing an exception; after the function is called, the over-the-counter transaction The state variables of the data structure in the method change, and other state variables remain unchanged.

Specifically, the formal verification specification satisfies the following conditions: (a) The formal verification specification is executed according to the function method, and the function method is required to be executed correctly, the purpose is to verify whether the smart contract is in accordance with the formal verification model Go design. (b) According to the uploaded file information structure, the recipient information structure and the feedback information corresponding to the upload of the file information, the recipient information, and the feedback information The structure is checked and different return values are obtained. When the relevant information is on the chain, if the information already exists on the chain, an error message will be returned; if it does not exist, the subsequent on-chain business process will be performed, and the successful on-chain will be returned. information. (c) Verify that the loop body does not have the risk of overflow; since control has been done at the application layer, it is agreed that the loop variable will not overflow, and the number of loops will not be changed. (d) When defining the OTC smart contract, call the function to ensure that no exception will be thrown; after the function is called, the state variable of the data structure in the OTC trading method changes, and other state variables remain constant. After uploading the file information on the chain, the recipient information on the chain, and the feedbacker information on the chain is initiated, the transaction is verified on the chain to not exist, and the OTC transaction information is assigned to the corresponding field according to the corresponding logic, the candidate object and the OTC trader The corresponding field of the information state variable is equal to the expected value, and other fields and state variables are equal to the original value.

Fig. 4 is a schematic diagram of a formal verification model of a smart contract in an embodiment of the application. As shown in Fig. 4, constructing a formal verification model of a smart contract specifically includes the following steps:

During the formal verification, the incoming parameter parameters are kept within the controllable range of the application layer; the overflow of the loop body array length is ignored, and the overflow of the temporary variable value in the loop body is ignored; the internal state variable is judged whether it exists, If the internal state variable already exists, the formal verification returns an on-chain failure code; if the internal state variable does not exist, the formal verification returns an on-chain success flag code, and a built formal verification model is obtained.

Specifically, during the formal verification, the incoming parameter parameters are kept within the controllable range of the application layer, and will not cause the incoming parameter group to overflow, and the parameter overflow will cause the formal verification to fail, and the correct form cannot be obtained. Calibration results. The overflow of the length of the loop body array is ignored, and the overflow of the temporary variable value in the loop body is ignored. Since control has been done at the application layer, there is no risk of overflow of the array length and the risk of overflow of the temporary variable value in the loop. Ignore these two items without formal verification, and get more accurate verification results. Judge whether the internal state variable exists, if it already exists, the formal verification returns the chaining failure code, and the chaining failure flag code is returned, which means that the internal state variable is duplicate data and the method cannot be called again; if the internal The state variable does not exist, and the formal verification returns a successful logo code. The return of the successful sign code on the chain means that the entire method function can operate correctly and the safety verification has passed.

Figure 5 is a flowchart of a blockchain-based OTC transaction method according to an embodiment of the application. As shown in Figure 5, the method is based on any of the various embodiments of the application. System implementation, the method specifically includes the following steps:

(1) The user browses the large-screen transaction unit and views the quotation details unit, and selects the quotation to be transacted; (2) the user clicks the click transaction unit, and the system first verifies the user’s cash balance or Bond balance, ensure that the purchase amount does not exceed the cash balance, and that the number of bonds sold does not exceed the bond balance; then generate a contract to be signed based on the blockchain address of the user and the bidder and the details of the quotation; (3) the user confirms the contract Whether the content is correct, when the confirmation opinion is no, the user gives up signing the contract, the contract is invalidated, and enters the historical contract unit; when the confirmation opinion is yes, it is judged whether the contract has exceeded the signing time limit; when the judgment result is yes, the contract is invalidated. Enter the historical contract unit; when the judgment result is no, the user can use the electronic signature to sign the contract; then judge whether the bidder has signed the contract, if the judgment result is no, judge whether the contract has exceeded the signing time limit, and the judgment result is yes , The contract is invalidated, enter the historical contract unit, the judgment result is no, then continue to judge whether the bidder has signed the contract; the judgment result is yes, then the contract takes effect; (4) The system uses the transaction records on the blockchain to conduct transactions on both parties Bonds and funds are cleared, and then the positions of both parties to the transaction are changed through the clearing results, that is, settlement.

In one of the embodiments, according to the logical judgment in the transaction control process of the smart contract: wherein, the logical judgment includes: the user's bond holdings and the bond balance verification when the user sells the transaction; The verification of the user’s cash balance; the control of the signing time limit when signing the electronic contract; the on-chain storage of transaction record details, electronic contract hashes, and electronic contract documents; control of different permissions between the administrator account and the ordinary user account; the user completes a For a buy or sell transaction, the system liquidates the bonds and funds held by the user according to the target bond of the transaction and the transaction amount, and changes the balance of the bonds and funds.

In one of the embodiments, before signing the contract, the smart contract needs to be verified, which specifically includes the following steps:

(1) Define a smart contract to conduct over-the-counter transactions according to the smart contract. The method of the over-the-counter transaction includes the declaration and implementation of the data structure and contract method of the smart contract; (2) Define formal verification specifications, To standardize the function, loop body, return value, and property value changes of the internal state variables of each contract method related to the smart contract in the smart contract; (3) Use the formal verification specification to perform formal verification on the smart contract , To check whether the over-the-counter transaction method meets the description of the formal verification specification; if it does, it means the smart contract is safe; if it does not, modify the smart contract until the formal verification description complies with the over-the-counter transaction function In the relevant implementation.

In one of the embodiments, during the formal verification, the incoming parameter parameters are kept within the controllable range of the application layer; the overflow of the length of the loop body array is ignored, and the overflow of the temporary variable value in the loop body is ignored; Judge whether the internal state variable exists, if the internal state variable already exists, the formal verification returns a failure code on the chain; if the internal state variable does not exist, the formal verification returns a successful sign code on the chain, and the constructed formal verification is obtained model.

Hereinafter, the blockchain-based over-the-counter transaction method will be further described through the following specific embodiments. FIG. 6 is a flowchart of the blockchain-based over-the-counter transaction method according to a specific embodiment of the application, as shown in FIG. As shown, the method includes step S610 to step S650:

Step S610: Obtain a transaction quotation selected by the user, the transaction quotation selected by the user according to the bond quotation information in the large transaction screen unit and the detailed information of a single bond quotation in the quotation detail unit;

Step S620: verify the user's asset information to ensure that the transaction quotation is within the user's asset control range;

Step S630: Obtain the blockchain addresses of the transaction parties, and generate a contract to be signed according to the detailed information of the transaction quotation and the blockchain addresses of the transaction parties; the transaction parties include the user and the offerer;

Step S640: Send the contract to be signed to both parties to the transaction, and obtain the contract signing result;

Step S650: liquidate the assets of both parties to the transaction according to the result of the contract signing and the transaction records, and change the positions of the two parties to the transaction according to the result of the settlement.

In one of the embodiments, the process of signing a contract by both parties to the transaction is specifically: sending the contract to be signed to the parties to the transaction, and obtaining the confirmation opinions of the parties to the transaction; if the confirmation opinions of both parties to the transaction are both yes , And both parties to the transaction complete the signing of the contract to be signed within the signing time limit, then the contract signed by both parties to the transaction is marked as an effective contract.

In one of the embodiments, if the confirmation opinion of either of the two parties to the transaction is no, or any one of the two parties to the transaction does not complete the signing of the contract to be signed within the signing time limit, the The contract to be signed is voided, and the voided contract to be signed is sent to the historical contract unit.

In one of the embodiments, the logical judgment in the transaction process is controlled according to the smart contract, the logical judgment including the verification of the user asset information, the judgment of the signing time limit, the storage of transaction information, the use of account permissions, and the transaction Asset liquidation and changes in the process.

FIG. 7 is a flowchart of formal verification of a smart contract according to a specific embodiment of the application. As shown in FIG. 7, the method includes steps S710 to S740:

Step S710: Define a smart contract;

Step S720: Define formal verification specifications to regulate the function, loop body, return value, and attribute value changes of internal state variables of each contract method related to the smart contract in the smart contract;

Step S730: Determine whether the smart contract meets the description in the formal verification specification, and if the smart contract meets the description in the formal verification specification, send the smart contract to the transaction parties for signing;

Step S740: If the smart contract does not meet the description in the formal verification specification, modify the smart contract until the smart contract meets the description in the formal verification specification.

In one of the embodiments, over-the-counter transactions are performed according to the smart contract to declare and implement the data structure and contract method of the smart contract.

In one of the embodiments, the formal verification of the smart contract according to the formal verification model includes: keeping the incoming parameter parameters within a preset parameter range of the application layer; ignoring the length of the loop body array Overflow; Ignore the overflow of the temporary variable value in the loop body; judge whether the internal state variable exists, if the internal state variable already exists, the formal verification returns the chain failure code; if the internal state variable does not exist, the formal The verification returns a successful logo code on the chain, and a built formal verification model is obtained, and the smart contract is formally verified according to the formal verification model.

This embodiment also provides an electronic device, including a memory and a processor, the memory stores a computer program, and the processor is configured to run the computer program to execute the steps in any of the foregoing method embodiments.

Optionally, the aforementioned electronic device may further include a transmission device and an input-output device, wherein the transmission device is connected to the aforementioned processor, and the input-output device is connected to the aforementioned processor.

Optionally, in this embodiment, the foregoing processor may be configured to execute the following steps through a computer program:

S1. Obtain a transaction quotation selected by a user, the transaction quotation selected by the user based on bond quotation information in the large transaction screen unit and detailed information of a single bond quotation in the quotation detail unit;

S2, verifying the user's asset information to ensure that the transaction quotation is within the user's asset control range;

S3: Obtain the blockchain addresses of both parties to the transaction, and generate a contract to be signed according to the detailed information of the transaction quotation and the blockchain addresses of both parties to the transaction; the parties to the transaction include the user and the bidder;

S4, sending the contract to be signed to the two parties to the transaction, and obtaining the contract signing result;

S5, liquidating the assets of the two parties to the transaction according to the result of the contract signing and the transaction records, and changing the positions of the two parties to the transaction according to the result of the settlement.

It should be noted that, for specific examples in this embodiment, reference may be made to the examples described in the above-mentioned embodiments and alternative implementations, and this embodiment will not be repeated here.

In addition, in combination with the blockchain-based over-the-counter transaction method in the foregoing embodiment, the embodiment of the present application may provide a storage medium for implementation. The storage medium stores a computer program; when the computer program is executed by the processor, any one of the blockchain-based over-the-counter transaction methods in the foregoing embodiments is implemented.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express a few implementation modes of the present application, and their description is relatively specific and detailed, but they should not be understood as a limitation on the scope of the patent application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can be made, and these all fall within the protection scope of this application. Therefore, the scope of protection of the patent of this application shall be subject to the appended claims.

Claims

A blockchain-based over-the-counter transaction system, characterized in that the system includes a rights management module, an account module, a market quotation module, a contract management module and a transaction management module running on the blockchain, wherein:

The authority management module is used to control the data viewing and operation authority of the administrator account and ordinary users through smart contracts, so that the administrator account can view contracts and transactions in the entire market and modify contract templates , Said ordinary users can only view contracts and transactions related to them;

The account module is used to manage changes or authentication related to the user's account. The account module includes a user registration unit, a CA authentication unit, an account management unit, a user login unit, and a user information modification unit, wherein:

The user registration unit is used to receive the identity authentication information filled in by the user and submit the registration request, and bind the blockchain address for the user;

The CA authentication unit is used to simultaneously send the identity authentication information filled in by the user to multiple authoritative nodes through the blockchain for data comparison, and receive the comparison result returned by the authoritative node to authenticate the user's identity information Whether it is true or not; if all nodes return the comparison correctly, the user’s identity authentication is passed, and the system adds the user’s blockchain address to the authorized list to authorize the user; if any node returns a comparison error, it will not pass User authentication;

The account management unit is used to collect and record user identity information, allocate blockchain accounts for users, and escrow public and private keys;

The user login unit is used for users to log in to the blockchain system with the registered account password;

The user information modification unit is used to improve the user's basic information other than the identity authentication information, and to modify the basic information that the user has filled in;

The market quotation module includes a large trading screen unit, a quotation detail unit and a click transaction unit, among which:

The large trading screen unit is used to display bond quotation information issued by all users in the entire market;

The quotation details unit is used to display detailed information of a bond quotation;

The click transaction unit is used to receive the transaction process initiated by the user on a certain quotation in the transaction screen, or receive the transaction process initiated by a batch of quotations in the transaction screen, and determine the detailed information of the transaction parties and the transaction target;

The contract management module includes a template management unit, a contract signing unit, a contract to be signed unit, and a historical contract unit, among which:

The template management unit includes template making and template display, the template making function is only open to administrators, and the template display is used to display contract templates made by the administrator to ordinary users;

The contract signing unit includes contract generation and contract signing. The contract generation is used to generate contract elements according to the detailed information of the transaction parties and the target obtained by clicking the transaction unit, and generate the contract to be signed according to the contract template formulated by the administrator; The contract signing is used to send the contract information to be signed to both parties of the transaction obtained by clicking the transaction unit, and to receive the contract signed by both parties to the transaction, mark the signed contract as an effective contract, and send it to the historical contract unit. Then upload the contract to the blockchain for recording;

The contract to be signed unit is used to display the contract to be signed or the contract to be signed by the bidder generated in the contract signing unit; the contract to be signed is invalidated after the signing time limit is exceeded and enters the historical contract unit;

The historical contract unit is used to display the valid contracts signed and completed by both parties to the transaction generated in the contract signing unit, and used to display contracts to be signed that are invalidated after the signing time limit;

The transaction management module includes a new intention unit and a current position unit, wherein:

The new intention unit is used to receive a new buying or selling intention quotation initiated by the user, and after the user fills in all the elements of the transaction intention, the quotation is sent to the transaction large screen unit for display;

The current position holding unit is used to display the bonds and cash balance currently held by the user.
The blockchain-based over-the-counter transaction system according to claim 1, wherein all the contract records of the contract signing unit are preserved through the blockchain, and the preservation data includes the blockchain addresses of the signing parties and the signing time. The timestamp of, the electronic contract file containing the electronic signatures of both parties.
The block chain-based over-the-counter transaction system according to claim 1, wherein the identity authentication of the user in the CA authentication unit uses blockchain-based distributed CA authentication.
A blockchain-based over-the-counter transaction method, characterized in that the method is implemented based on the blockchain-based over-the-counter transaction system of any one of claims 1-3, and the method specifically includes the following steps:

The user browses the large-screen transaction unit and views the quotation details unit, and selects the quotation to be traded;

The user clicks on the click transaction unit, and the system first verifies the user’s cash balance or bond balance to ensure that the purchase amount does not exceed the cash balance, and that the number of bonds sold does not exceed the bond balance; The blockchain address of the bidder and the details of the offer generate the contract to be signed;

The user confirms whether the content of the contract is correct. When the confirmation opinion is no, the user gives up signing the contract, the contract is invalidated, and enters the historical contract unit; when the confirmation opinion is yes, it is judged whether the contract has exceeded the signing time limit; when the judgment result is yes, then The contract is invalidated and enter the historical contract unit; when the judgment result is no, the user can use the electronic signature to sign the contract; then judge whether the bidder has signed the contract, if the judgment result is no, judge whether the contract has exceeded the signing time limit, judge If the result is yes, the contract is invalidated and enter the historical contract unit. If the judgment result is no, then continue to judge whether the bidder has signed the contract; if the judgment result is yes, the contract takes effect;

The system clears the bonds and funds of both parties through the transaction records on the blockchain, and then changes the positions of both parties through the clearing results, that is, settlement.
The OTC transaction method based on blockchain according to claim 4, wherein the method further comprises:

According to the logical judgment in the smart contract transaction control process: wherein, the logical judgment includes:

Verification of the user's holding bonds and bond balance when the user sells;

Verification of the user's cash balance held by the user in the purchase transaction;

Control of the signing time limit when signing electronic contracts;

On-chain storage of transaction record details, electronic contract hash, and electronic contract files;

Different authority control of administrator account and ordinary user account;

The user completes a buy or sell transaction, and the system liquidates the bonds and funds held by the user according to the target bond of the transaction and the transaction amount, and changes the balance of the bonds and funds.
The block chain-based over-the-counter transaction method according to claim 4, characterized in that, before signing the contract, the method further comprises:

Defining a smart contract to perform over-the-counter transactions according to the smart contract, and the method of the over-the-counter transaction includes the declaration and realization of the data structure and contract method of the smart contract;

Define formal verification specifications to regulate the function, loop body, return value and attribute value changes of internal state variables of each smart contract related contract method in the smart contract;

Use the formal verification specification to perform formal verification on the smart contract to check whether the implementation of the over-the-counter transaction method complies with the description of the formal verification specification; if it complies, it means the smart contract is safe; if it does not comply, modify The smart contract until the formal verification description conforms to the relevant implementation in the over-the-counter transaction function.
The block chain-based over-the-counter transaction method according to claim 6, wherein the definition of the smart contract includes uploading file information on the chain, recipient information on the chain, and feedbacker information on the chain; the data structure Including uploaded file information structure, recipient information structure and feedback information structure.
The blockchain-based OTC transaction method according to claim 7, wherein the formal verification specification meets the following conditions:

According to the uploaded file information structure, the recipient information structure, and the feedback information structure corresponding to the file information uploading, the recipient information uploading, and the feedback information uploading Check to obtain the return value of the file information uploading, the recipient information uploading, and the feedbacker information uploading;

Check that the loop body does not overflow;

When the smart contract is defined, the function is called without throwing an exception;

After the function is called, the state variables of the data structure in the over-the-counter trading method change, and other state variables remain unchanged.
The blockchain-based over-the-counter transaction method according to claim 6, wherein the method further comprises:

During formal verification, the incoming parameters are kept within the controllable range of the application layer;

Ignore the overflow of the length of the loop body array, and at the same time ignore the overflow of the temporary variable value in the loop body;

Judge whether the internal state variable exists, if the internal state variable already exists, the formal verification returns a failure code on the chain; if the internal state variable does not exist, the formal verification returns a successful sign code on the chain, and the constructed formal verification is obtained model.
A blockchain-based OTC transaction method, characterized in that the method includes the following steps:

Defining an over-the-counter smart contract to conduct over-the-counter transactions. The method of the over-the-counter transaction includes the declaration and realization of the data structure and contract method of the over-the-counter smart contract;

Define formal verification specifications to describe the functions implemented by the over-the-counter transaction method, and standardize the functions, loop body, return value and internal state variable properties of each contract method related to the over-the-counter transaction contract in the smart contract Value change

Use the formal verification specification to perform formal verification on the over-the-counter smart contract, and according to the formal verification model, check whether the implementation of the over-the-counter transaction complies with the description of the formal verification specification; The over-the-counter smart contract is safe; if not, the over-the-counter smart contract is modified until the formal verification description complies with the relevant implementation of the over-the-counter function.
The blockchain-based over-the-counter transaction method according to claim 10, wherein the definition of the over-the-counter smart contract includes uploading file information on the chain, recipient information on the chain, and feedbacker information on the chain; The data structure includes uploaded file information structure, recipient information structure and feedback information structure.
The blockchain-based OTC transaction method according to claim 11, wherein the formal verification specification satisfies the following conditions:

The formal verification specification is executed according to a function method, and is based on the uploading of the file information, the uploading of the recipient information, and the uploading of the feedbacker information corresponding to the uploaded file information structure and the recipient The information structure body and the feedback information structure body are checked to obtain different return values;

Check that the loop body does not overflow;

When the over-the-counter smart contract is defined, the function is called without throwing an exception;

After the function is called, the state variables of the data structure in the over-the-counter trading method change, and other state variables remain unchanged.
The block chain-based OTC transaction method according to claim 12, characterized in that the method further comprises:

During formal verification, the incoming parameters are kept within the controllable range of the application layer;

Ignore the overflow of the length of the loop body array, and at the same time ignore the overflow of the temporary variable value in the loop body;

It is judged whether the internal state variable exists, and if it already exists, the formal verification returns a link failure code; if the internal state variable does not exist, the formal verification returns a link success flag code.
A blockchain-based over-the-counter transaction system, characterized in that the system includes a rights management module, an account module, a market quotation module, a contract management module, and a transaction management module running on the underlying blockchain; wherein:

The authority management module is used to control the data viewing authority and operation authority of the administrator account and ordinary users according to the smart contract; wherein, the data viewing authority of the administrator account includes the authority to view contracts and transaction records of the entire market, and the administrator account The operation authority of includes the authority to modify the contract template, and the data viewing authority of the ordinary user includes the authority to view contracts and transactions related to the user;

The account module is used to manage changes or authentication related to user accounts; the market quotation module is used to display bond quotation information issued by all users in the entire market;

The contract management module is used to generate a contract to be signed according to the contract template and the acquired transaction information, and send the contract to be signed to both parties to the transaction for signing;

The transaction management module is used to send the received quotation information to the market quotation module and display the user's asset information.
The blockchain-based over-the-counter transaction system according to claim 14, wherein the account module includes a user registration unit, a CA authentication unit, an account management unit, a user login unit and a user information modification unit, wherein:

The user registration unit is used to receive the user's identity authentication information and submit a registration request to bind the user to the corresponding blockchain address;

The CA authentication unit is used to send the user's identity authentication information to multiple authoritative nodes through the blockchain, and receive the comparison result returned by each of the authoritative nodes to verify whether the user's identity information is authentic; If the comparison result of the authoritative node is correct, the blockchain address corresponding to the user is added to the authorized list to pass the user’s registration request; if the comparison result of the authoritative node shows an error, the user’s request will be rejected Registration request;

The account management unit: used to collect and record the user's identity information, allocate blockchain accounts and escrow public and private keys for users;

The user login unit: used to log in to the blockchain system according to the registered account password entered by the user;

The user information modification unit is used to manage and modify other basic information of the user.
The blockchain-based over-the-counter transaction system according to claim 15, wherein the CA authentication unit is further configured to authenticate the user's identity according to the distributed CA authentication rules based on the blockchain.
The block chain-based over-the-counter trading system according to claim 14, wherein the market quotation module includes a large trading screen unit, a quotation detail unit, and a click transaction unit, wherein:

The large transaction screen unit is used to display bond quotation information issued by all users in the entire market;

The quotation detail unit is used to display detailed information of a single bond quotation;

The click transaction unit is used to receive a single transaction process initiated by a user for a certain quotation in the transaction screen or a batch transaction process initiated for a certain batch of quotations, and to determine detailed information of the transaction parties and the transaction target.
The blockchain-based over-the-counter transaction system according to claim 17, wherein the contract management module includes a template management unit, a contract signing unit, a contract to be signed unit, and a historical contract unit, wherein:

The template management unit is used for the administrator to make templates and to show ordinary users the contract templates made by the administrator;

The contract signing unit is used to generate contract elements according to the detailed information of the transaction parties and the transaction target obtained by the click transaction unit, and generate the contract to be signed according to the contract elements and the contract template prepared by the administrator, and send the pending contract to both parties Sign the contract information, receive the signed contract signed by both parties to the transaction, mark the signed contract as an effective contract, send the effective contract to the historical contract unit, and upload the effective contract And records;

The contract to be signed unit is used to display the contract to be signed or the contract to be signed by the bidder generated in the contract signing unit, to invalidate the contract to be signed that exceeds the signing time limit, and to send the invalid contract to be signed to The historical contract unit;

The historical contract unit is used to display valid contracts and invalid contracts to be signed.
The blockchain-based over-the-counter transaction system according to claim 18, wherein the contract signing record in the contract signing unit is stored through a blockchain, and the contract signing record includes the blockchains of both signing parties. Address and signing timestamp and electronic contract document containing both parties' electronic signatures.
The block chain-based over-the-counter transaction system according to claim 14, wherein the transaction management module includes a new intention unit and a current position unit, wherein:

The new intention unit is configured to receive a new buying intention offer or selling intention offer initiated by a user, and send the buying intention offer and the selling intention offer to the large transaction screen unit;

The current position holding unit is used to display the bonds and cash balance currently held by the user.
A blockchain-based over-the-counter transaction method, characterized in that the method is implemented based on the blockchain-based over-the-counter transaction system of any one of claims 14-20, and the method comprises:

Obtaining a transaction quotation selected by the user, the transaction quotation selected by the user according to the bond quotation information in the large transaction screen unit and the detailed information of a single bond quotation in the quotation detail unit;

Verifying the user's asset information to ensure that the transaction quotation is within the user's asset control range;

Obtain the blockchain addresses of both parties to the transaction, and generate a contract to be signed according to the detailed information of the transaction quotation and the blockchain addresses of both parties to the transaction; the parties to the transaction include the user and the bidder;

Send the contract to be signed to the two parties to the transaction, and obtain the result of the contract signing;

The assets of both parties to the transaction are cleared according to the result of the contract signing and the transaction records, and the positions of the two parties to the transaction are changed according to the clearing result.
The block chain-based over-the-counter transaction method of claim 21, wherein the sending the contract to be signed to the two parties to the transaction and obtaining the result of the contract signing comprises:

Send the contract to be signed to the two parties to the transaction, and obtain the confirmation opinions of the two parties;

If the confirmation opinions of both parties to the transaction are both yes, and both parties to the transaction complete the signing of the contract to be signed within the signing time limit, then the contract signed by both parties to the transaction is marked as an effective contract.
The method for over-the-counter transactions based on blockchain according to claim 22, wherein the method further comprises:

If the confirmation opinion of either of the two parties to the transaction is no, or any one of the two parties to the transaction fails to complete the signing of the contract to be signed within the signing time limit, the contract to be signed is invalidated, And send the invalidated contract to be signed to the historical contract unit.
The block chain-based OTC transaction method according to claim 21, characterized in that the method further comprises:

According to the logic judgment in the smart contract control transaction process, the logic judgment includes the verification of the user's asset information, the judgment of the signing time limit, the storage of transaction information, the use of account permissions, and the asset clearing and change during the transaction .
The block chain-based OTC transaction method according to claim 21, characterized in that the method further comprises:

Define smart contracts;

Define formal verification specifications to regulate the function, loop body, return value and attribute value changes of internal state variables of each smart contract related contract method in the smart contract;

Judging whether the smart contract meets the description in the formal verification specification, and if the smart contract meets the description in the formal verification specification, sending the smart contract to both parties to the transaction for signing;

If the smart contract does not meet the description in the formal verification specification, the smart contract is modified until the smart contract meets the description in the formal verification specification.
The block chain-based OTC transaction method according to claim 25, wherein the method further comprises:

Perform over-the-counter transactions according to the smart contract to declare and implement the data structure and contract method of the smart contract.
The block chain-based over-the-counter transaction method according to claim 26, wherein the definition of the smart contract includes uploading file information on the chain, recipient information on the chain, and feedbacker information on the chain; the data structure Including uploaded file information structure, recipient information structure and feedback information structure.
The blockchain-based over-the-counter transaction method of claim 27, wherein the defined formal verification specification comprises:

According to the uploaded file information structure, the recipient information structure, and the feedback information structure corresponding to the file information uploading, the recipient information uploading, and the feedback information uploading Check to obtain the return values of the file information on the chain, the recipient information on the chain, and the feedbacker information on the chain;

Check that the loop body does not overflow;

When the smart contract is defined, the function is called without throwing an exception;

After the function is called, the state variables of the data structure in the over-the-counter trading method change, and other state variables remain unchanged.
The OTC transaction method based on blockchain according to claim 28, wherein the method further comprises:

Keep the incoming parameter parameters within the preset parameter range of the application layer;

Ignore the overflow of the loop body array length;

Ignore the overflow of the temporary variable value in the loop body;

Judge whether the internal state variable exists, if the internal state variable already exists, the formal verification returns a failure code on the chain; if the internal state variable does not exist, the formal verification returns a successful sign code on the chain, and the constructed formal verification is obtained Model, and perform formal verification on the smart contract according to the formal verification model.
An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the computer program described in any one of claims 21 to 29 OTC transaction method based on blockchain.
A storage medium, characterized in that a computer program is stored in the storage medium, wherein the computer program is set to execute the blockchain-based off-site according to any one of claims 21 to 29 when running. Trading method.