CN111445356A

CN111445356A - Commodity housing construction project approval and commodity housing transaction method based on block chain intelligent contracts

Info

Publication number: CN111445356A
Application number: CN201911176105.1A
Authority: CN
Inventors: 徐若晨
Original assignee: Hangzhou Yifangda Technology Co ltd
Current assignee: Hangzhou Yifangda Technology Co ltd
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2020-07-24

Abstract

The invention discloses a commodity house construction project approval and commodity house transaction method based on a block chain intelligent contract, which eliminates the phenomena of price change, price sealing, poor selling and the like. Various problems of varying added price, cheering to sell peacefully and buying in the truest relation will therefore be eliminated. The problem of allocation reduction and crazy compression period is solved: information such as a finishing schedule, a design scheme, a project development progress and the like which is originally not transparent enough in a project development link is linked up and disclosed, and any change of the information is synchronized to a client, so that the quality of building development is ensured by higher transparency and wider public supervision. False advertising is avoided from deceiving the consumer, and developers cannot reuse air special houses that may not exist to mislead the consumer due to the chain and announcement of the pre-sale price.

Description

Commodity housing construction project approval and commodity housing transaction method based on block chain intelligent contracts

Technical Field

The invention relates to a commodity room construction project approval and commodity room transaction method based on a block chain intelligent contract.

Background

The concept of the "lemon market" was proposed by george, akrolov, a famous american economics in the last 70 th century, and it is considered that when the information of the product to be sold is not symmetrical, i.e., the seller has more knowledge of the commodity than the buyer, the market deterioration phenomenon of "bad coin expelling good coin" is easy to cause market failure and even occur. Since the lemon market presupposes that the seller has more knowledge of the goods than the buyer, it is easier to occur in the seller-dominated market. The total stock of commodity houses at the end of 2018 in China is 52414 ten thousand, the removal period is only about 3.7 months according to the selling speed of 171654 ten thousand in 2018 all the year, the removal period is obviously lower than the supply and demand balance interval of 6-12 months, and the commodity houses are typical seller markets; in addition, the commodity house market has serious information asymmetry, so that the commodity house market in China is in a lemon market state unexpectedly.

In a commodity house market dominated by a seller, the problems of phase change and price addition, bad sale, shrinkage of floor configuration, wild construction period of a developer and the like often occur in a transaction link; even in the market dominated by buyers, problems such as false advertisements, contract execution disputes, intermediary disordering, etc. are also emerging. In the development link, due to the fact that excessive project cycles of internal participants of the supervision main body involve tens of units and the fact that all the units are lack of mutual confidence and are taken as information islands, the whole set of approval process is long and inefficient, and 1 year is needed when four certificates are prepared; in addition, the file interaction means is relatively original, and the friction cost of a developer is very high.

Disclosure of Invention

The invention provides a commodity house construction project approval and commodity house transaction method based on a block chain intelligent contract, aiming at solving the problems of the existing commodity house in the sale process.

The method for solving the existing problems comprises the following steps: a commodity house construction project approval and commodity house transaction method based on a block chain intelligent contract is provided with a platform for commodity house development and transaction flow service based on the block chain intelligent contract, and land auction, project loan application, project approval and acceptance, house property transaction and house property delivery are sequentially carried out.

The auction of the land is carried out,

1) the developer enters a 'soil auction entrance' of a commodity house development platform, the field in a certain listing is registered and a soil auction deposit is paid, so as to obtain auction qualification, after the auction is finished, the deposit of the winning bidder is automatically converted into a fixed deposit by the platform, and a 'national land use right giving contract' is received, while the deposit of the non-winning bidder is automatically returned.

2) After a developer signs a contract for giving the national property of land use, the developer enters a project declaration of a development platform of a commodity house, selects a declaration of the national property of land use certificate, pays duties and land release funds in full amount, signs the national property of land use certificate by relevant departments, and uploads the certificate to a block chain for storage.

And (5) applying project loan.

1) The method comprises the following steps that a developer initiates an application for project loan in a loan application of a commodity house development platform, the developer selects corresponding banks in sequence according to prompts and uploads materials to be examined, the corresponding banks will examine and approve the corresponding banks, the developer signs a project loan credit line contract after the examination and approval is passed, and after the contract becomes effective, the corresponding banks call an intelligent contract function in charge of contract uplink and upload the contract to a block chain for storage.

The items are approved and accepted by the system,

1) in the project declaration of the commodity room development platform, developers can successively complete the application of 'construction land planning permit', 'construction engineering planning permit' and 'construction engineering permit', and the materials required for all the things can be prompted on the front-end page, and the developers upload the platforms one by one.

2) And (3) the developer continuously completes the gray line acceptance, pile foundation acceptance, foundation pit acceptance and positive and negative zero acceptance of the intermediate acceptance stage in the project declaration of the commodity house development platform according to the project construction progress. All the matters need to entrust intermediary institutions arranged under related departments to perform on-site acceptance, and the platform can provide basic information and business volume of each institution to help developers to select.

The real estate transaction is carried out,

1) a developer initiates a claim of 'pre-sale license of a commodity house' in 'project declaration' of a commodity house development platform, after uploading of submission materials is completed according to prompts, the 'detailed decoration statement' and credit and right policy are automatically approved by an intelligent contract, other materials are manually approved by related departments, and the 'pre-sale license' of the commodity house is issued and uploaded in a block chain for storage after approval is passed.

2) After obtaining the "house pre-sale license", the item will be disclosed as "soon to be released from the building" for the corresponding number of days, e.g. three days, at the house transaction platform, and then will be automatically released and transferred to "being sold. In the meantime, developers and house buyers can check the detailed information of the project on the commodity house transaction platform; the house buyer can also directly carry out online consultation with the corridor sales consultant on the platform and can add attention to the house source with the purchase intention, so that the house buyer can receive notification prompts 24 hours and 2 hours before opening the stock.

3) After opening the disk, the house buyer initiates a house buying application to a house source, pays a shaking number guarantee deposit after house buying qualification verification, and after a one-minute waiting period, the house buyer who proposes the house buying application to the house source shakes the number together with other house buyers, wherein the number shaking process is executed by an intelligent contract, and the number shaking is decentralized and cannot be tampered.

4) The middle signer will automatically return to the deposit and start to execute the house-buying process, and interact with the developer, the bank and the like under the prompt of the platform, and complete the signing of texts such as 'commercial house purchase contract' and 'commercial loan contract' and the payment of the house-buying initial payment in sequence; the people who have not signed the house can choose to reserve the deposit, continue to choose the house, or give up choosing the house temporarily, return the deposit.

The delivery of the real estate is carried out,

1) after the developer continues to sequentially complete the rest 'structure acceptance' and 'completion acceptance' in the middle acceptance stage and the items of multinomial acceptance, real house surveying and mapping, property maintenance fund payment, completion acceptance filing and the like in the comprehensive acceptance stage in the 'project declaration' of the commodity room development platform, the developer can communicate with all purchased house owners to complete the handing over of floors in the 'sold house source' of the commodity room transaction platform and sign 'early-stage admission service agreement' with a property company.

2) The house buyer can check the house on site after receiving the house handing notification, and can initiate a house handing application after checking and accepting are correct, and a house handing process is started. The house buyer interacts with a developer, a tax department and a property company according to platform prompts, finishes the processes of multi-refund and less-mend house money, paying of tax and property maintenance fund, paying of property charge and signing of 'early-stage property service agreement', and finally uploads invoices for paying of tax charge and 'early-stage property service agreement' to a functional department responsible for issuing 'immotile property certificate' for filing together, thereby finishing the whole house handing process.

3) After the developer continues to complete the remaining items of land parcel mapping and construction project land rechecking acceptance in the project declaration of the commodity house development platform in the comprehensive acceptance stage, the intelligent contract automatically issues the immortal property certificate to the owner who has completed the house delivery process, and the whole life cycle of the commodity house project is basically finished.

As a further improvement, in the land auction, the effective quotation of the developer is transferred to a land auction interface of a Java external interface from a background, and an intelligent contract function responsible for the land auction is transmitted through the contract interface, and the intelligent contract function returns the highest quotation of the round, and is displayed on a front-end page after being processed by the land auction interface.

As a further improvement, the platform realizes the covert interaction of the submission materials and the business contracts based on the KMS key management service.

As a further improvement, the platform applies the TEE property of the ant blockchain BaaS platform to a specific intelligent contract.

As a further improvement, the developer initiates an application for project loan in a loan application of a commodity house development platform, and a background calls an intelligent contract function which is responsible for loan qualification verification through a Java external interface to check whether the developer has project loan qualification.

As a further improvement, in the house property transaction, if a house buyer needs to make a loan, the background calls an intelligent contract function responsible for checking the loan qualification through a Java external interface, based on the marital, house property, credit investigation and credit division conditions of the house buyer, whether the house buyer has the loan qualification is checked, if the check is not passed, the loan request is rejected, and the house buyer can only select one-time payment to continue the transaction; if the check is passed, the intelligent contract returns to a first payment proportion interval for the house buyer to select.

As a further improvement, in the project approval and acceptance check, a government department checks and approves each item application through a general interface and checks received materials, and if a service report reported by an intermediary organization is received, whether the signature of the intermediary organization in the file is real and effective needs to be verified; if the verification is passed, the government department calls a related intelligent contract function through a Java interface, calculates the intermediary service fee to be paid by the developer and informs the developer, then the developer pays through a Java interface payForAgency, and the intermediary organization confirms collection through a Java interface receivableConfirm, so that the issuing link of the approved certificate is entered.

As a further improvement, after uploading the certificate and completing the signature through a universal interface, a government department calls a related intelligent contract function through a Java interface pass the object document to link the certificate and the Hash Code reported by the agency service, and meanwhile, the file body is clouded, and then a developer can download the file from the cloud.

As a further improvement, after the house buyer, the bank branch and the public accumulation fund center sign the three-party seal, the bank branch and the public accumulation fund center respectively transfer the intelligent contract function responsible for the contract chain through the updatebanklonContract of the Java external interface and the updateGjlonContract of the Java external interface, and respectively upload the housing commercial loan contract and the public accumulation fund borrowing contract to the block chain for storage.

As a further improvement, in the house property delivery, a house buyer uploads filing materials required by 'permanent property certificate' through Java external interfaces, such as 'tax completion evidence', 'property maintenance fund receipt', 'early-stage property service agreement', 'house money full invoice', and the like, to a rule office, the rule office receives the files and then carries out auditing, after the auditing, an intelligent contract function produceThenotMoving is called through Java external interface distribution, and the materials are stored in a block chain.

Compared with the prior art, the invention has the advantages of solving the following pain points in the market of the commodity house:

firstly, the discordance of price changing and adding, keeping cover and selling the house for the best, and the like is eliminated, because the house source is pre-sold for one house and one price is stored in the chain, as long as the house buyer is willing to match the pre-sold price of the house source and has the qualification of buying the house, the intelligent contract is activated and automatically executes the whole house buying process. Various problems of varying added price, cheering to sell peacefully and buying in the truest relation will therefore be eliminated.

Secondly, the problems of allocation reduction and crazy compression period are solved: information such as a finishing schedule, a design scheme, a project development progress and the like which is originally not transparent enough in a project development link is linked up and disclosed, and any change of the information is synchronized to a client, so that the quality of building development is ensured by higher transparency and wider public supervision. The method relates to how to solve the problem of excessive and deficient reporting price in the fine decoration detail list.

Thirdly, avoiding the false advertisement from deceiving the consumer: because the pre-sale price is linked and posted, developers cannot reuse air special houses, which may not exist, to mislead consumers. The information matched with the building is automatically added by the platform according to the information issued by the authoritative node and the position of the building, so that the problem of air matching is solved.

Fourthly, eliminating intermediate disorder: the platform shows comprehensive and real floor information to users, breaks through information asymmetry, allows consumers to directly communicate with floor sales personnel, breaks through the traditional profit mode that some real estate agents monopolize the source of the customers by illegal means, eliminates the disorder of the agents from the source and forces the agents to change to the service role.

Fifthly, a secret data interaction channel is provided: the platform realizes the secret interaction of partial submission materials and business contracts based on the KMS key management service, and adapts to the complex business requirements of government and bank users.

Sixthly, the problem of personal privacy disclosure is solved: the TEE characteristic of the ant blockchain BaaS platform is applied to a specific intelligent contract by the platform, so that any node irrelevant to transaction cannot randomly view sensitive information including personal privacy in the contract.

Seventhly, dispute is reduced in contract execution: by utilizing the characteristics of irreversibility and irreversibility of the intelligent contract, the execution of the contract is fair and transparent, and disputes generated by executing the contract by both trading parties are reduced.

Eighthly, the operation cost of the supervision main body is reduced: compared with the traditional internet approach, the scheme of the invention can effectively reduce the cost of opening an information island by a supervision department and enhance the credibility and safety of data by utilizing the multicenter characteristic of the alliance chain.

In addition, the scheme of the invention can also effectively improve the user experience of the development and transaction links of the commodity house, such as: the commodity room development platform and the transaction platform respectively display the items of the project development link, including the approval progress of project loan application, the transaction flow of the house resource transaction link and the progress of the house delivery flow, and are available for platform users such as developers, house purchasers and government departments to check at any time.

For another example, if the subsequent processes need to be submitted again, the files stored on the platform can be directly and automatically collected and acquired by the background, and manual uploading by a user is not needed, so that the user experience is improved, and particularly the experience of a developer in the project approval process is improved.

For another example, the platform integrates the Token-free block chain with the evidence passing concept, and provides a credit division mechanism and a rights and interests mechanism, so that a transaction main body is stimulated to perform forward behaviors on the premise of legal compliance.

By adopting the method, on one hand, the problem that information islands exist among government departments and subordinate intermediary institutions is solved, so that the development link is changed from serial examination and approval to parallel examination and approval, the examination and approval efficiency is greatly improved, the project period is greatly shortened, developers can run once at most, and a large amount of friction cost is saved; on the other hand, the house buyer acquires more informed rights in the development link, and the asymmetry of market information is broken, so that the house buyer can carry out effective public supervision.

The method of the invention can also greatly improve the process efficiency of acquiring the immotile property right from house selection to house delivery of house purchasers, and greatly reduce the intermediary cost of the house purchasers and developers through mediation.

The data intercommunication between the development platform and the transaction platform can really break the serious information asymmetry of the market of the commercial house, thereby properly solving various pain points in the market.

Drawings

Fig. 1 is a schematic flow chart of a land auction phase in an embodiment of the present invention.

Fig. 2 is a flow chart illustrating a project loan application phase according to an embodiment of the invention.

FIG. 3 is a schematic flow chart of the project approval and acceptance phase according to the embodiment of the present invention.

FIG. 4 is a flow chart illustrating a real estate transaction stage according to an embodiment of the present invention.

FIG. 5 is a flow chart of the house property delivery stage according to the embodiment of the present invention.

Detailed Description

Referring to fig. 1-5, fig. 1 is a schematic flow chart of a first embodiment of a land auction phase of the present invention, as shown in fig. 1, the phase includes:

step 101: the developer initiates a shooting application for a certain land, and the background calls a target object application table interface of the Java external interface to accept the shooting application.

Step 102: the developer then pays a guarantee fund for the soil swatter, the amount of money is generally 20% -50% of the initial price of the land, and the amount of money is specifically determined by a land governing department. The background will call the guarantee payment interface of the Java external interface to process the payment operation of the developer.

Step 103: if the guarantee money is paid in full amount, the land administration department will confirm the collection, the background will call the government of Java external interface to confirm the collection interface to complete the operation, and return to the developer "Bin Bing Notification book" as the qualification certificate of taking a auction.

Step 104: after the auction begins, the background calls a submission and quotation interface of the Java external interface to make qualification limitation, and developers who do not register to participate in the auction or pay the guarantee money in insufficient amount cannot participate in the quotation; the developers taking the bids, the background calls the external Java interface to inquire the bid, if the bid is not in accordance with the requirement, the bid is rejected if the bid is less than the minimum bid.

Step 105: the effective quotation can call a land auction interface of a Java external interface from a background, an intelligent contract function responsible for land auction is transmitted through the contract interface, the function returns the highest quotation of the round, and the highest quotation is displayed on a front page after being processed by the land auction interface. The last non-bidding round of developers will then lose the eligibility to continue bidding, and the remaining developers will immediately begin the next round of auctions.

In practical implementation, the bidding time of each round is limited to 4 minutes, each developer has one and only one bidding opportunity in each round, and the bidding amplitude of each round cannot be less than three thousandth of the starting amount of the plot. The bidding of the round is ended early after all developers submit their respective bids, otherwise it will continue to wait until the 4 minute countdown is over.

Step 106: after the auction is finished, the background calls an auction processing interface of the Java external interface to process, and the auction result is returned to all participating enterprises.

Step 107: the winning bid developer calls a Java external interface from the background to automatically convert the deposit into the fixed deposit and receives a contract for signing the national land use right release; the developers who have not bid for the bid automatically refund the guarantee fee by the Java external interface.

After electronic signature is made by the winning bid developer and the land governing department on the 'national land use right issue contract', the contract takes effect and is linked up and stored by the land governing department. The contract will specify the price and payment method for the land to be paid.

Fig. 2 is a schematic flow chart of a project loan application phase according to a second embodiment of the invention, as shown in fig. 2, the phase includes:

step 201: the developer enters a loan application module of the development platform to initiate the application of project loan. The background calls an intelligent contract function which is responsible for loan qualification verification through a Java external interface to check whether the developer has project loan qualification. Developers with reputation scores below 200 will not be able to apply for project loans.

Step 202: then, the developer selects multiple choices among the major commercial bank brands, and then selects a single choice in a branch line at a place set under the selected bank brand. The background can call corresponding Java interfaces to complete the operation.

Step 203: the developer uploads the materials required for approval of the project loan, wherein the project loan feasibility research report and the stockholder background are encrypted. The background calls the Java external interface to finish uploading the materials and sends the materials to the bank branch.

Step 204: the bank branch decrypts the file and then carries out initial examination, and after the initial examination passes, the 'comprehensive credit report' is uploaded through the sendTeCompressehensiveCreditreport of the Java external interface and is encrypted, and then the encrypted comprehensive credit report and the audit-sending materials of the developer are reported to the upper branch of the branch.

If the initial review fails, the branch may give a return reason and the developer may re-prepare the material and initiate a loan application again.

Step 205: and after the secondary inspection is passed, the sub-bank needs to fill in a project loan crediting scheme, wherein the contents comprise the qualification, credit line, loan interest rate, credit equity policy, loan term and the like of a developer.

The calculation of the credit line is completed by calling an intelligent contract function businessFormwork which is responsible for calculating the credit line through a Java external interface. The specific calculation logic is as follows: the total investment of the project, the land yielding of the fund, the own fund of the enterprise, and the proportion of the own fund is at least 30 percent of the total investment of the project; and if the credit score of the developer is between 200 and 399 sub-sections, the lowest proportion of the own fund in the total investment of the project is increased to 50 percent.

If the branch line II is not passed, the reason for quitting the work is given to the developer, and the developer can prepare the materials again and apply for the materials again.

And step 206, after the completion of the filling of the authorization scheme, calling a Java external interface seeTheproject L oanCreditScheme by branches, and sending the scheme to a developer.

In step 207, since there may be multiple project loan authorization schemes from multiple banks, the developer is required to select the optimal scheme list, and the background will complete the operation through the Java interface choice of project L oancredittScheme.

And step 208, the selected bank branch of the credit granting scheme encrypts and sends the uploaded project loan credit granting amount contract to the developer, and the background finishes the operation through a Java external interface sendTheproject L oanQuotaContract.

Step 209: the developer and the bank branch sign the contract in sequence, and the contract takes effect. Then the bank branch can call the intelligent contract function responsible for contract uplink through the Java external interface seal the comprehensive CreditContractByBank, and store the contract uplink.

Fig. 3 is a schematic flow chart of a project approval and acceptance stage according to a third embodiment of the present invention, which includes the acceptance approval of the license application such as "project for construction land planning license", "project for construction license", "house pre-sale license", and the like, and the intermediate acceptance, comprehensive acceptance, and the like, as shown in fig. 3. Since the business logic is substantially the same and there are a large number of common interfaces, the following description is made collectively:

step 301: the developer first initiates an application for a certain file, and the background processes the request through a Java interface product. The interface is a general interface, and developers can initiate application of various files through the interface.

Step 302: then, the developer uploads the audit-sending material to the platform for encryption as required, wherein the uploading operation is completed through the Java external interface oneosspasswordpumload. This is a common interface through which all file upload operations pass.

The encryption operation is carried out by using KMS service by a background, developers only need to input a string of numbers randomly as EncryptionContext which can be understood as a password, the background combines the block chain address Identity of a file receiver on the platform with the password to carry out hash once to generate a plaintext key, and then the file is symmetrically encrypted by using an AES256 encryption algorithm; and calling an encryption API of the KMS service, and performing one-layer encryption on the plaintext key by using the password to generate a ciphertext key. And finally, the background sends the cipher text key, the password and the encrypted file to a file receiver.

Step 303: the developer can then query the intermediary organization list set under the government department through the Java interface checkTheSuborderline and complete the selection through the Java interface select TheSuborderline; and uploading the audit material body to a cloud end, and sending the returned Hash Code to the selected intermediary mechanism through a Java interface applyThecertificate. The intermediary organization can check the applications initiated by each developer through the Java interface project and can start to primarily examine a certain application through the Java interface project interface; after entering the approval page, the intermediary mechanism can check the file through the Java interface showTheapplyData, the background can use the Hash Code of the file to obtain the submission material body from the cloud, and if the file is an encrypted file, the file can be checked only by decrypting the file by the intermediary mechanism. The interfaces are all universal interfaces, and then developers inquire, select the intermediary organization and submit the submission materials, and the intermediary organization or the government department checks, approves and applies for each item, checks the submission materials and the like, and all the operations are completed through the interfaces.

Step 303 may be skipped if the approval is directly from the government department without requiring the initial review by the intermediary.

Decryption is also done through the KMS service. After the file receiver obtains the encrypted file, the password and the ciphertext key, the background can automatically call the decryption API by clicking a password obtaining button, and the premise that the file receiver uses the password obtained by the file receiver to decrypt the ciphertext key is that the file receiver is granted the authority by an alliance owner through the RAM resource access control service in advance to generate a plaintext key; and then, based on an AES256 algorithm, decrypting the file by using the plaintext key to obtain the decrypted file.

Step 304: after the audit materials pass through by the agency or the government department, arranging the time of on-site acceptance and calling the Java interface notice to inform a developer; after the acceptance is finished, the intermediary organization or the government department judges whether the acceptance passes through the Java interface SiteAcceptance. The interfaces are all universal interfaces, and then the operations of informing the field acceptance time and arbitrating the acceptance conclusion by the intermediary organization or the government department are also completed through the interfaces.

If an event does not require field acceptance, but only document approval, step 304 may be skipped.

Step 305: the intermediary organization signs various service reports through the Java interface seal the object and then calls the general interface to report the service reports to the superior government department. The Java interface seal the object is also a generic interface that all intermediary agencies will use to issue service reports.

Step 305 may be skipped if an event is directly approved by a governmental agency without requiring prior review by an intermediary.

Step 306: the government department reviews and approves each item application through the universal interface and reviews the received materials. If the received service report is reported by the intermediary mechanism, whether the signature of the intermediary mechanism in the file is real and effective needs to be verified; if the verification is passed, the government department calls a related intelligent contract function through a Java interface, calculates the intermediary service fee to be paid by the developer and informs the developer, then the developer pays through a Java interface payForAgency, and the intermediary organization confirms collection through a Java interface receivableConfirm, so that the issuing link of the approved certificate is entered.

If the government department receives the transmitted materials which are directly uploaded by the developer, the materials are directly examined and approved without checking labels, and the process enters the issuing link of the certificate after the examination and approval is passed.

Step 307: after uploading the certificate and completing the signature through the universal interface, the government department calls a relevant intelligent contract function through the Java interface pass the object document to link the certificate and the HashCode of the service report of the intermediary institution, and meanwhile, the file body is clouded, and then developers can download the certificate and the HashCode from the cloud. The Java interface is also a generic interface through which government agencies will issue various types of certified certificates.

If the file body is tampered at the cloud end, the Hash Code of the file body can come in and go out of the Hash Code which is stored on the chain and cannot be tampered; when the user views the tampered file, the background returns a prompt that the file is tampered.

When the developer uploads various review materials in step 303, if the materials are already kept on the blockchain, the materials will be automatically collected by the background without manual uploading. The specific method comprises the following steps: the background operates a 'QueryBlock' command and a 'QueryTransaction' command based on the unified social credit Code of the enterprise to automatically search and collect Hash codes of materials stored on the chain, and the Hash codes are sent to an approval department; and acquiring a file body from the cloud based on the Hash Code, and downloading and checking the file body by an approval department.

The initial review by the agency of step 303, the adjudication acceptance conclusion of step 304, and the verification of the signature by the government department of step 306 all have the possibility of "refusal". If a "refund" operation occurs, the intermediary agency or government agency will refund the application over the Java interface and give a return reason. This is a common interface through which all refund operations are performed.

Fig. 4 is a flow chart of a real estate transaction stage according to a fourth embodiment of the present invention, as shown in fig. 4, the stage includes:

step 401: after the number shaking is finished, a certain house buyer receives the mid-signed result returned by the background, and can select a payment mode of the buyer, such as one-time payment, pure commercial loan or combined loan of commercial loan and mixed accumulation loan.

Step 402: if the house buyer needs to make a loan, the background calls an intelligent contract function which is responsible for checking the loan qualification through a Java external interface loranBuyHouse, and checks whether the house buyer has the loan qualification or not based on the marital, house property, credit investigation and credit division conditions of the house buyer, if the check is not passed, the loan request is rejected, and the house buyer can only select one-time payment to continue the transaction; if the check is passed, the intelligent contract returns to a first payment proportion interval for the house buyer to select.

In actual implementation, the automatic checking logic of the intelligent contract for the loan qualification of the house buyer is formulated based on the current policy, and when the customer has more than 20 bad credit investigation records or the credit score is lower than 200 minutes, the customer refuses the loan application; if the buyer is judged to be qualified for loan, then when the buyer is a house-free buyer, the buyer needs a first payment proportion of at least three components; when both couples have a set of houses, at least the first payment ratio of six is needed. And if the reputation of the house buyer is divided into 200-399 points, the first payment proportion is required to be improved by 20 percent.

Step 403: after the house buyer selects the first payment proportion, the intelligent dating point judges whether the house buyer can enjoy the house price preference according to the credit score of the house buyer. The room price after preferential treatment is filled into a trade contract sample of the commodity room together with information such as payment mode, initial payment proportion and the like to form a formal trade contract of the commodity room.

Step 404: after confirming that the content of the contract for buying and selling in the commodity house is correct, the house buyer signs and encrypts the contract and transfers the contract to the developer; meanwhile, the house buyer pays the first payment to the developer, and the background calls the Java interface to finish the operation. After the developer confirms that the full-amount initial payment is received, the developer also signs the trade contract of the commodity house, and the trade contract of the commodity house takes effect.

Step 405: a developer records a commodity room buying and selling contract to a room management office, the room management office calls an intelligent contract function responsible for contract chaining through a Java external interface updateHomeContract, and a contract text is chained in a cloud mode and a Hash of the contract. At the same time, the status of the house source changes from "in trade" to "sold".

Step 406: the buyer then submits the materials required for loan approval to the bank, and the back office calls the Java external interface to complete the operation. The bank branch bank starts to perform initial examination after receiving the materials.

Step 407: if the bank branch passes the preliminary examination, the bank branch signs and signs 'the preliminary examination report' and encrypts the report, and the report is continuously reported to the upper level together with other materials to be examined, and the pure commercial loan of the public accumulation fund center is not needed, and the background calls a Java external interface to complete the operation. If the initial trial fails, the Java interface can be rejected by the branch line, and the background can call the Java interface to complete the operation; after the loan application is rejected, the buyer can only change to one-time payment and re-sign the contract for buying and selling in the commercial housing, and then re-register and link up.

Step 408: if the buyer applies for the combined loan, the accumulation fund center carries out the audit before the bank branch. The state of the approval result of the accumulation fund center is written into the database through a Java interface, the state in the default approval is 0, the state in which the approval is passed is 1, and the state in which the approval is not passed is 2; after the bank branches inquire the result, the bank branches can start the self-audit.

And 409, if the audit of the bank branch is passed, on one hand, calling an intelligent contract function in charge of chaining the preliminary examination report through a FenhangPassThe L oan of a Java external interface to perform chaining storage of the preliminary examination report, and on the other hand, sending the loan scheme including the lowest first payment proportion, the loan interest rate, the credit allocation equity policy, the advance repayment policy and the like to the buyer through the Java external interface.

Step 410: the buyer may receive the loan schemes sent by multiple banks, so that the buyer needs to select the optimal scheme; the selected result will be returned to each bank by the Java external interface.

Step 411: the bank branch selected by the buyer will call Java external interface to send 'housing business loan contract' to the developer; if the loan is a combined loan, the public accumulation fund center also calls a corresponding interface to send out a public accumulation fund borrowing contract to the developer.

Step 412: and the two contracts are subjected to pipeline signature according to the sequence of developers, house buyers and bank branch/public accumulation fund centers, and the signature operation is completed by calling a Java interface.

The house buyer clicks the encryption after signing the signature, the background combines the Identity of the bank branch/public accumulation fund center to use the KMS service to complete the encryption, so that the contract can not be freely viewed by any people including developers except the lending bank and the house buyer.

Step 413: after the three-party signature is completed, the bank branch and the public accumulation fund center respectively call an intelligent contract function responsible for contract chaining through the updatebanklonContract of the Java external interface and the updateGjlonContract of the Java external interface, and respectively link and store the housing commercial loan contract and the public accumulation fund borrowing contract.

Fig. 5 is a schematic flow chart of a real estate delivery phase according to a fifth embodiment of the invention, as shown in fig. 5, the phase includes:

step 501: after the developer meets the condition of delivering the building, the developer sends files such as ' notice of delivery ' of house ', ' instruction for use of house ', ' certificate of quality guarantee of residence ' to all owners, and the background calls a Java external interface to complete the operation. After receiving the file, the owner can come to the building site for field inspection.

Step 502: if the house is checked to be correct, the house buyer can initiate a house handing-over application and can enter a house handing-over process after the developer confirms the application; the background can complete the above operations through a Java interface. If the house check is in a problem, the house buyer can put forward 'negotiation compensation/refund' to the developer; if the negotiation is not successful, arbitration can be requested from the administration office.

Step 503: entering into the house-handing process, the background will read the information in the database first, and generate a house-handing information table for the house buyer to confirm, including the name of the developer, the name of the owner, the house number, the unit price of the deal, the predicted area, the actually measured area, etc.

Step 504: after the house buyer confirms, the house buyer can make more, less and more house money according to the real mapping area. Firstly, the background calls an intelligent contract function which is responsible for multi-return-and-little-supplement calculation through the reflonds and libraries of the Java external interface, and the intelligent contract function returns a calculation result to a user, namely, whether a developer returns a difference price or a house buyer supplements the difference price.

The computing logic of the intelligent contract is as follows: if the actually measured drawing area is larger than the predicted drawing area, the house buyer supplements the difference price to the developer; if the actually measured drawing area is smaller than the predicted drawing area, the developer moves back to the house buyer. The spread amount is the "difference in area" bargaining unit price ".

Step 505: the developer/the house buyer completes the payment of the difference price through the Java interface according to the result returned by the intelligent contract, and the other party needs to confirm the operation of collection through the Java interface. And then, the developer issues a full house money invoice, and uploads the invoice through a Java external interface for a house buyer to download.

Step 506: then entering into the link of paying tax, firstly calling the intelligent contract function responsible for calculating the tax amount by the background through the changehouseedtedTex of the Java external interface, and returning the calculation result to the house buyer by the background.

The computing logic of the intelligent contract is as follows: the area was found to be 1% cross unit price. The percentage may be adjusted according to policy changes.

Step 507: the house buyer completes the payment of the fiscal duty through the Java interface according to the result returned by the intelligent contract; the tax department clicks 'confirm collect' through Java interface. Then, the tax department makes tax title and completion certification and uploads the certification through the Java external interface for the house buyer to download.

Step 508: then entering a link of paying the property maintenance fund, firstly calling an intelligent contract function responsible for calculating the property maintenance fund by a background through changehouseRealtyMaintenance Fund of a Java external interface, and returning the intelligent contract function to a house buyer to calculate a result.

The computing logic of the intelligent contract is as follows: area 60 was measured. 60 is the property repair fund to be paid per square meter, which can be adjusted according to policy changes.

Step 509: the house buyer completes the payment of the property maintenance fund through the Java interface according to the result returned by the intelligent contract; the developer clicks "confirm collect" through the Java interface. And then, the developer provides a property maintenance fund receipt, and uploads the receipt through the Java external interface for the house buyer to download.

Step 510: then entering into the link of signing the 'early property service agreement', firstly, the property company sends the contract to the house buyer through the Java external interface, and the latter signs after confirming that the content is correct, and the contract flow returns to the property company.

Step 511: and then, the background calls an intelligent contract function responsible for calculating the property charge through changehousePropertyFee of the Java external interface, calculates the property charge to be paid and returns the property charge to the house buyer.

The computing logic of the intelligent contract is as follows: and the privilege of a property cost unit price per square meter per month, actually measured drawing area per 12 per credit equity profit sharing mechanism. The unit price of the property fee is agreed in the early property service agreement; the preference of the credit and interest allocation mechanism is automatically adjusted by the property company based on the proposed standard given by the invention.

Step 512: after the house buyer pays the property fee through the Java interface, the property company clicks 'confirm collection' through the Java interface; and then the property company signs the contract, the contract takes effect, and both parties can download the contract.

Step 513: the house buyer uploads the tax title certificate, the property maintenance fund receipt, the prior property service agreement, the full invoice of house style and the like to the rule and office through Java external interfaces to handle the record materials required by the immotile property certificate.

Step 514: and after the file is received by the bureau, auditing is carried out, after the auditing is passed, an intelligent contract function product thermal moving is called through the distributed of the Java external interface, and the materials are chain-stored. After the chaining operation is completed, the intelligent dating returns an approved certificate to be issued to the rule bureau; and simultaneously returning a 'delivered' to the house buyer to indicate that the house handing-over process is completed.

Step 515: after the development platform passes the 'construction project land recheck acceptance', the rule bureau calls an intelligent contract function procedure ThenotMoving again through the distribution of the Java external interface, and the intelligent contract automatically issues 'immobility right certificate' to the house buyer who has finished the pre-material filing before.

Claims

1. A commodity room construction project approval and commodity room transaction method based on a block chain intelligent contract is characterized by comprising the following steps: setting a platform of commodity house development and transaction flow service based on a block chain intelligent contract, and sequentially carrying out land auction, wherein 1) developers enter a 'land auction entrance' of the commodity house development platform to register a land in a certain listing and pay a guarantee fund for the land auction so as to obtain auction qualification, after the auction is finished, the guarantee fund of a winning bidder is automatically converted into a fixed fund by the platform and receives a national land use right export contract, and the guarantee fund of a non-winning bidder is automatically returned; 2) After signing a national land use right giving contract, a developer enters a project declaration of a commodity house development platform, selects a national land use certificate declaration, pays duties and land giving funds in full amount, signs a national land use certificate by relevant departments, and uploads the certificate to a block chain for storage; the method comprises the following steps that 1) a developer initiates an application for project loan in a loan application of a commodity house development platform, the developer selects corresponding banks in sequence according to prompts and uploads materials to be checked, the corresponding banks will examine and approve the application, the developer signs a project loan credit line contract after the examination and approval, and after the contract becomes effective, the corresponding banks call an intelligent contract function in charge of contract chaining and upload the contract to a block chain for storage; project approval and acceptance, 1) the developers shall successively complete the applications of construction land planning permit, construction project planning permit and construction project construction permit in the project declaration of the commodity house development platform, the materials required for sending and examining all the matters are prompted on the front-end page, the developers shall upload the platforms one by one, 2) the developers shall successively complete the gray line acceptance, pile foundation acceptance, foundation pit acceptance and positive and negative zero acceptance in the middle acceptance stage according to the project construction progress in the project declaration of the commodity house development platform,

all the matters need to entrust intermediary mechanisms arranged under relevant departments to perform on-site acceptance, and the platform can provide basic information and business volume of each mechanism to help developers to select; house property transaction, 1) a developer initiates a claim of 'house pre-sale license' in a 'project declaration' of a commodity house development platform, after uploading of materials to be examined is completed according to prompts, the 'fine decoration statement' and credit distribution right policy are automatically approved by an intelligent contract, other materials are manually approved by a relevant department, and the 'house pre-sale license' is issued and stored in an uploading block chain after approval is passed; 2) After obtaining the 'pre-sale license of the commodity house', the item serves as 'the disk to be opened' to show the corresponding days on the commodity house transaction platform, and then the disk is automatically opened and is transferred to 'the disk to be sold'; 3) After opening the disk, a house buyer initiates a house buying application to a house source, pays a number shaking guarantee deposit after house buying qualification verification, and after a waiting period of one minute, the house buyer performs number shaking together with other house buyers who propose house buying applications to the house source, wherein the number shaking process is executed by an intelligent contract; 4) The middle signer will automatically return to the deposit and start to execute the house-buying process, and interact with the developer, the bank and the like under the prompt of the platform, and complete the signing of texts such as 'commercial house purchase contract' and 'commercial loan contract' and the payment of the house-buying initial payment in sequence; the people who have not signed the house can choose to reserve the deposit, continue to choose the house, or give up choosing the house temporarily, return the deposit; delivering house properties, namely 1) continuously completing the rest 'structure acceptance' and 'completion acceptance' in the middle acceptance stage and the items such as multi-item acceptance, real house property mapping, property maintenance fund payment and completion acceptance filing in the comprehensive acceptance stage according to the construction progress by a developer in the 'project declaration' of the commodity house development platform, and then delivering the items to all purchased house owners in the 'sold house resources' of the commodity house transaction platform, signing an 'early-stage admission service agreement' with a property company and completing floor delivery; 2) The house buyer can check the house on site after receiving the house handing notification, and can initiate a house handing application after checking and accepting are correct, and a house handing process is started; 3) After the developer continues to complete the remaining items of land parcel mapping and construction project land rechecking acceptance in the project declaration of the commodity house development platform in the comprehensive acceptance stage, the intelligent contract automatically issues the immortal property certificate to the owner who has completed the house delivery process, and the whole life cycle of the commodity house project is basically finished.

2. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 1, wherein: in the land auction, the effective quotation of a developer can call a land auction interface of a Java external interface from a background, an intelligent contract function responsible for the land auction is transmitted through the contract interface, the intelligent contract function returns the highest quotation of the round, and the highest quotation is displayed on a front-end page after being processed by the land auction interface.

3. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 1, wherein: the platform realizes the covert interaction of the submission materials and the business contracts based on the KMS key management service.

4. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 1, wherein: the platform applies the TEE characteristics of the ant blockchain BaaS platform to a specific intelligent contract.

5. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 1, wherein: the method is characterized in that a developer initiates an application for project loan in loan application of a commodity house development platform, a background calls an intelligent contract function which is responsible for loan qualification verification through a Java external interface, and whether the developer has project loan qualification is checked.

6. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 1, wherein: in the house property transaction, if a house buyer needs to make a loan, a background calls an intelligent contract function responsible for checking loan qualification through a Java external interface, based on the conditions of marriage, house property, credit investigation and credit of the house buyer, whether the house buyer has the loan qualification is checked, if the check is not passed, the loan request is rejected, and the house buyer can only select one-time payment to continue the transaction; if the check is passed, the intelligent contract returns to a first payment proportion interval for the house buyer to select.

7. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 1, wherein: in the process of project approval and acceptance, a government department checks and approves each item application through a general interface and checks received materials, and if a service report reported by an intermediary organization is received, whether the signature of the intermediary organization in a file is real and effective needs to be verified; if the verification is passed, the government department calls a related intelligent contract function through a Java interface, calculates the intermediary service fee to be paid by the developer and informs the developer, then the developer pays through a Java interface payForAgency, and the intermediary organization confirms collection through a Java interface receivableConfirm, so that the issuing link of the approved certificate is entered.

8. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 7, wherein: after uploading the certificate and completing the signature through the universal interface, the government department calls a relevant intelligent contract function through the Java interface pass the object document to link the certificate and the HashCode of the service report of the intermediary institution, and meanwhile, the file body is clouded, and then developers can download the certificate and the HashCode from the cloud.

9. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 6, wherein: after the house buyer, the bank branch and the public accumulation fund center sign, the bank branch and the public accumulation fund center respectively transfer the intelligent contract function responsible for the contract chaining through the updatebanklonContract of the Java external interface and the updateGjLoanoContract of the Java external interface, and respectively upload the housing commercial loan contract and the public accumulation fund borrowing contract to the block chain for storage.

10. The commodity room construction project approval and commodity room transaction method based on the blockchain intelligent contract according to claim 1, wherein: in the house property delivery, house buyers upload records required by 'duty completion certification', 'property maintenance fund receipts', 'early-stage property service agreements', 'house money full invoice' and the like to a rule office through Java external interfaces, the rule office receives files and then verifies the files, after the verification is passed, intelligent contract functions are called through Java external interface distribution, and the materials are stored in a block chain.