TWI648680B - System of smart contract, method for making the contract and computer-readable storage device - Google Patents

Abstract

A smart contract system, a contract formulation method and a computer readable storage device. In a contract development method implemented by a computer system, a software program executed on a user device provides a user interface for formulating a smart contract, wherein multiple The quick option, the contract server receives the selection signal from the user to generate a contract option through the user interface, so the corresponding contract formulation procedure is initiated, and the user enters the contract input parameter in a conditional input interface, and confirms the payment of a digit. After the currency, the contract content is compiled into a contract digital file. After the package is generated, the transaction code is generated and published on a blockchain. After waiting for the mining result, a contract address is obtained.

Description

Smart contract system, contract development method and computer readable storage device

A smart contract system and method of development, in particular a method based on blockchain technology and providing a user interface to develop smart contracts, as well as related systems and storage media.

Blockchain refers to a decentralized management technique through decentralization (such as servo center) and de-trust (such as third-party authentication). It operates in a distributed topology and participates in it. Each node encrypts the data generated over a period of time by a cryptographic algorithm to generate a hash, records it into a decentralized block of data, and can link the next block of data. Thus, the block chain The data bases are stored in different nodes, and the data is monitored by each other. The data changes need to be agreed by the rest of the nodes. Therefore, this decentralized management mechanism forms a decentralized public ledger (ledger), and the relevant application system can jointly verify the authenticity of the record through all participating nodes, and the content of each data block is covered by the area on the subsequent sub-chain. Block to ensure that its contents cannot be tampered with.

Each block on the blockchain is suitable for a variety of security and fair-demand applications, such as currency, equity, bonds, etc. Transaction information is maintained, updated, and verified by countless independent nodes (computers) to ensure fair accounting results. Fair, open and transparent, without the need for review and maintenance by any central organization.

In a transactional application of blockchain technology, users need a digital wallet to record digital currency, or cryptocurrency, and each digital wallet is encrypted. The key pair (public key and private key) is encrypted and protected. When executing a transaction, the public key is used to encrypt the transaction content. When the transaction object is delivered to the transaction object, only the object with the corresponding private key can decrypt the transaction content; otherwise, the transaction content is encrypted with the private key, and the object with the public key can be paired. The public key is decrypted to obtain the transaction content. Thus, in the application of the blockchain decentralized ledger, someone wants to execute a transaction, such as a transfer, can encrypt the transfer information with his private key, and generate a digital signature with the private key to confirm the transfer. The authenticity of the data transmission source, and then broadcasted to the network, each node that receives the transfer data can use the paired public key to decrypt the transfer information, thus ensuring the identity of the person transmitting the message, and also using the encryption technology for the transfer information. Stored in each node. Therefore, each node maintains a book that records every transaction record on the network using a blockchain technology.

The program running on the blockchain can be called Smart Contract. Ethereum is one of the public blockchain platforms for writing smart contract functions. It is provided by Ethereum's special cryptocurrency Ether. A centralized virtual machine (Ethereum Virtual Machine) to process contracts. Under this Ethereum platform, after the contract is written, the code (such as Solidity code) will be compiled into a standardized binary code to be deployed to the Ethereum blockchain and deployed to the blockchain. There will be a Contract Address in the same format as the Wallet Address.

Once the smart contract is deployed successfully, it becomes part of the unchangeable blockchain and is stored decentralized on nodes at Ethereum around the world. Common smart contracts are various cryptocurrency contracts, such as providing some kind of crypto token running on Ethereum, which can be used to directly receive encrypted tokens in Ethereum's digital wallet.

The disclosure proposes a smart contract system and contract formulation method, which provides users with a soft interface to quickly set up smart contracts, and connects with a system server to transmit smart contract formulation requests to the system server and set up contracts through the user interface. Content, the system server issues the contract to the blockchain, and the miners of the blockchain get the address of the smart contract and complete the contract.

According to an embodiment, the smart contract system provides a contract server, and a software program executed on each user device, the user device connects to the contract server, and initiates execution of a user interface for formulating a smart contract, including providing A quick contract development interface with multiple shortcut options.

The contract server obtains the user's choice of smart contract through the user interface of the user to execute a corresponding smart contract formulation process, including starting the condition input interface of the corresponding contract item, and the user can input the contract to formulate parameters. The contract server completes the contract content, and when the contract server confirms the payment of a digital currency, such as Ethereum, the contract content to be completed is compiled into a contract digital file, and the transaction code is generated after parsing, and is published on a blockchain. For example, in the Ethereum blockchain, after waiting for a mining result, a contract address is obtained.

After that, the user who made the contract formulation request can obtain the contract address from the contract server. After completing some preliminary procedures, if a certain amount of tokens are transmitted to the contract address, the contract address is transmitted through the social media.

Interested consumers can participate in this smart contract, including sending digital currency to the contract address, so that the smart contract automatically assigns the token to a digital wallet account of the consumer participating in the smart contract.

The contract formulation method further includes stopping the money distribution process when the contract is satisfied or terminated, and allowing the user to start withdrawing the received digital currency.

When the user wants to cancel the contract, the contract formulation method further provides a contract cancellation procedure. The contract server prompts a contract cancellation function through the user interface running on the user device, and thereby initiates the contract cancellation function through the contract. The server receives the contract cancellation instruction transmitted by the user device, and is published by the server on the blockchain. After obtaining the mining result of the miner, the contract server confirms the cancellation contract with the user.

The disclosure further discloses a computer readable storage device in the contract server, wherein the program stored in the contract server executes the smart contract formulation method described above, and the program is executed by one or more processors of the contract server, Acquiring the user device to generate a smart contract request, contract option selection, condition input through the user interface to complete a contract content, and after confirming payment of a digital currency, the contract content can be compiled into a contract digital file, and the transaction code is released. On the blockchain, the contract address is obtained after mining.

In order to further understand the technology, method and effect of the present invention in order to achieve the intended purpose, reference should be made to the detailed description and drawings of the present invention. The drawings are to be considered in all respects as illustrative and not restrictive

10‧‧‧Network

101‧‧‧ contract server

103,105‧‧‧User device

107‧‧‧Network node

20‧‧‧Quick contract development interface

21‧‧‧Quick options

22‧‧‧Contract development interface

41‧‧‧Users

42‧‧‧Server

43‧‧‧ Blockchain

Step S301~S321‧‧‧ Smart Contract Development Process

Step S401~S408‧‧‧ Smart Contract Development Process

Step S501~S509‧‧‧Smart Contract Usage Process

Step S601~S607‧‧‧ settlement process

Step S701~S711‧‧‧ contract cancellation process

1 shows a schematic diagram of a network architecture of a smart contract system; FIG. 2 shows a user interface diagram of a smart contract system provided by a smart contract system; FIG. 3 shows one of the flowcharts of an embodiment of a smart contract formulation method disclosed in the disclosure; 4 shows a second flowchart of an embodiment of a smart contract formulation method proposed by the disclosure; FIG. 5 shows an embodiment of a smart contract use flow proposed by the disclosure; FIG. 6 shows a flowchart of a termination smart contract and a settlement embodiment proposed by the disclosure; Figure 7 shows a flow chart of an embodiment of the disclosure of a smart contract proposed by the disclosure.

The disclosure discloses a smart contract system and a contract formulation method. The smart contract writes the contract text in a code, and uses a blockchain technology to broadcast the contract to the blockchain, such as Ethereum ( Ethereum), a node on the blockchain responsible for encryption and recording, producing decentralized records, and finally a digital contract executed by the computer. The benefit of developing a smart contract on the blockchain is that it is not arbitrarily modified by intervention, and has the advantages of both openness and security.

The application of smart contracts, such as insurance, trading, leases, etc., will automatically perform follow-up actions, such as insurance claims, sale and purchase transactions, lease transactions and expiration, etc., and the respective computer devices participating in the smart contract run an etheric In the virtual machine, the computer device becomes a node on the Ethereum under this operating system.

A smart contract is a computer program stored on the Ethereum blockchain that can be activated or run using Ethereum. For example, when the two parties want to make a sale in Ethereum, first create an Ethereum account and upload it to the Ethereum blockchain. After that, the buyer agrees to pay Ether to buy an item for the seller, using the computer program. To develop a smart contract, the practical thing is to write an Ethereum virtual machine program, or an Ethereum virtual machine program compiled by a specific computer language.

The program includes obtaining the buyer's digital wallet at the address of the Ethereum from the buyer, recording the amount of the Ethereum payment run on the Ethereum, allowing the buyer to control the amount. After both parties agree to the transaction, activate the contract, and then wait Mining results to complete this smart contract and complete the Ethereum transfer process. Smart contracts are code that is stored, verified, and executed on the Ethereum blockchain.

Figure 1 shows a schematic diagram of the network architecture of a smart contract system.

The smart contract system proposes a contract server 101, which runs on the network 10 and is built on a blockchain service, such as the Ethereum blockchain. Ethereum is a blockchain platform that allows users to Ethereum's platform for writing and publishing programs, such as smart contracts, provides a wide range of applications. On this platform, smart contracts are passed through a decentralized Ethereum Virtual Machine. Handling contracts.

The contract server 101 is used to deploy code in the blockchain to create a new contract, to provide contract development through software programs executed on the user devices 103, 105, or agents on the application (APP) on the mobile device. Service. According to an embodiment, the software program on the user devices 103, 105 initiates the graphical user interface, as shown in the schematic diagram of FIG. 2, providing a plurality of contract options, allowing the user to quickly develop a contract through the interactive function and through the contract server. 101 is broadcast to the blockchain, and the miners on the blockchain, such as the mining program on network node 107, mine the result as a blockchain address that stores the smart contract. The Ethereum virtual machine runs on the network node 107, and also acts as a blockchain data saver, as a node for collecting, transmitting, confirming, and executing transactions on the Ethereum blockchain. The network node 107 can also obtain remuneration from the transaction fees generated by the contract.

Figure 2 shows a schematic diagram of the user interface of the smart contract system provided by the smart contract system.

The smart contract system includes a user interface that provides the user with the option to select a quick contract option. In an embodiment, the user interface is a web interface, and the smart contract system is provided with a web server (such as an HTTP server), and the web browser of the user device provides a user interface of the quick contract option, such as the shortcut shown in the figure. The contract development interface 20 includes a plurality of shortcut options 21, such as ticket contracts (such as restaurant meal contracts), electronic lock contracts, lease contracts, sale and purchase contracts, music copyright processing, and the like. In actual implementation, the graphical user interface is not limited to the mode shown in the example, and the appropriate display interface can be provided according to the user's hardware and software and the user's needs.

Each shortcut option 21 is associated with a computer program corresponding to a contract item, when the user selects one of the contract items, and starts a computer program corresponding to the contract development program of the contract item, including the start as shown in the figure. Contract development interface 22, which shows the conditions for the corresponding smart contract. This example shows several contract formulation parameters, such as contract function, threshold, issue time, reference URL, token address and contract developer. random combination. When the user completes the system request user setting After several contracts are formulated, the release can be performed, and the contract file is compiled into a two-digit code and transmitted to the server of the smart contract system, as shown in the contract server 101.

According to another embodiment, the smart contract system provides a user device to install an application APP on a mobile device. When the user device launches the application, a graphical user interface is started, which is an application interface, and can also be displayed. The quick contract development interface 20 includes a plurality of shortcut options 21, and the user selects one of the contract options, the application program, and the computer program for executing the corresponding contract through the operation of the touch display of the mobile device or other forms of display. The user enters the contract formulation parameters of the corresponding contract, and after delivery, transmits the parameters to the contract server.

When the user completes the contract setting through the user interface executed on the computer device, the executed computer program is shown in FIG. 3 as one of the flowcharts of the embodiment of the smart contract formulation method proposed in the book.

At the beginning of the process, as in step S301, the smart contract system is used to execute the smart contract formulation method, and each user device connects the contract server through the running software program, and provides a smart contract to formulate a user interface, wherein the display includes multiple shortcuts. The shortcut contract development interface (20) of the option (21) allows the user to select one of the contract options according to the shortcut contract development interface. In step S303, the software program running in the user device is received through the user interface. The generated selection signal, the selection signal is linked to a corresponding contract computer program. In step S305, the processor in the user device executes the corresponding contract formulation process, such as step S307, including starting a user interface corresponding to the selected contract item, such as a condition input interface, and the system requests the user input through the user interface. The contract formulates the parameters and receives the contract formulation parameters generated by the interface. In step S309, a contract formulation content is formed.

At this time, under the smart contract formulation rules of blockchains such as Ethereum, the user will be required to pay the fee in a specific digital currency (such as Ethereum) after the completion of the contract, and the fee will be provided to the miners on the blockchain such as Ethereum. Incentives for mining. And the system can still ask for the payment of digital currency before the contract begins to be developed. Essential technical features are not limited. Then, in step S311, the user agrees to pay the digital currency and then transmits it to the contract server to confirm the digital token payment. At the same time, or within a certain period of time, the software program in the user's computer will operate, or be operated by the contract server. In step S313, the contract content is compiled into a contract file, as in step S315, The contract package is broadcasted on the blockchain. In step S317, the contract server posts the package to the blockchain to wait for the mining result of each miner on the blockchain, as in step S319.

Within a certain period of time, the contract server will receive the mining result, which is actually a contract address. If it is received by the server in step S321, it is transmitted to the user device to inform the contract address. The smart contract development method flow runs between the user device, the contract server, and the nodes on the blockchain. For an embodiment, reference may also be made to the flowchart of the embodiment of the smart contract formulation method shown in FIG. 4, which is shown as using 41, the smart contract formulation process of steps S401 to S408 between the server 42 and the blockchain 43.

In this context, the user 41 operates a user device, such as a personal computer, a mobile device, etc., to run a software program on the user device. The embodiment is to initiate a user interface, and the user selects a required contract. The option, once the server 42 is connected, the contract option will be accompanied by personal authentication information, encrypted data, etc., to the server 42 to transmit a request to contract the service (step S401).

The server 42 then initiates a user interface, such as a mobile device's APP or web interface, by requesting input of contract content (step S402), such as the number of tokens, usage, and digital currency information (wallet address). , Ethereum account, etc.). After the user 41 completes the input, the contract content and related authentication and security information (such as user identification information) are transmitted to the server 42, and the release contract is confirmed (step S403).

At this time, the server 42 may request payment of a token, and the user 2 is required to provide a digital currency account address, such as a digital currency running on the Ethereum blockchain (step S404). In the case of Ethereum, which is the fuel that activates the smart contract on the Ethereum blockchain, two types of accounts can be used. One is an external account, which is encrypted by the private key. And the contract account, such as an operation to obtain the address message, controlled by the contract code. When paying for the Ethereum, the user sends a payment message via a digital signature. When the contract account receives the message, the internal code of the contract is activated, allowing reading and writing to create a smart contract.

In this example, once the user 41 sends a message confirming the payment to the server 42 (step S405), the server 42 compiles the contract content to form a smart contract digital file, and generates a transaction code, which is a digital signature. Data packet (hash value), the transaction code contains contract content, user identification information and payment information (token), etc., and issues a contract to the blockchain 43 (step S406), and waits for the mining result on the blockchain. That is, waiting for a contract address (step S407). When the server 42 receives the mining results on the blockchain 43, in this case a new block is created (the miners get an Ethereum reward for each successful block) and the position of the contract is obtained. The address, that is, the contract address is notified to the user 41 who made the contract (step S408). Once the unlocked account and digital currency payment are guaranteed on the blockchain, the deployment is complete and a contract is created on the blockchain.

After that, the user 41 announces the contract address on the Internet (such as social media), and interested parties can participate in the contract. After the contract is deployed, the process flow diagram shown in Figure 5 can be referred to. The flow process steps S501~S509 describe the smart contract usage flow.

As shown in FIG. 5, initially, in step S501, the user successfully generates and obtains a contract address through the user interface on the user device through the smart contract system, and in step S503, the user sets a certain number of tokens. Transferred to the contract address, these tokens can be used for tickets, admission tickets, and permission certificates for the use of specific items. After the announcement of the contract address, as in step S505, the contract is executed, and a currency program is started. .

The consumer participating in the contract, in step S507, can follow the contract conditions published by the user on the online community to send the digital currency to the contract address. Once the payment is confirmed, the smart contract will automatically dispatch the token as in step S509. For consumers, including consumer The fee is in the digital wallet account.

For example, when a user formulates a contract, which includes a meal coupon, a wallet address, and time information (contract termination term) for transmitting a certain amount of tokens, the consumer can learn the contract address from the contract developer and is interested. The person can transfer the digital currency according to the wallet address, and once the payment is confirmed, the meal coupon will be dispatched to the consumer's device, which can be a digital wallet account assigned to the consumer.

Next, the smart contract system provides a solution for terminating (or withdrawing money) smart contracts, as shown in Figure 6, terminating the smart contract and the settlement embodiment flow chart.

When the smart contract is satisfied by the condition or the user terminates, as in step S601, the paying currency program will be stopped. For example, if the above meal coupon expires, or the contract expires, the coin is automatically stopped, and the coin is no longer automatically stopped. Accept the consumer to pay the digital currency to get the meal coupon. At this time, the user who made the contract can log in to the contract server, and in step S603, request to receive the received digital currency, such as the Ethereum. In the process, the user generates a ping message through the software program running on the user device, and transmits the message to the contract address. In step S605, the server executes the contract withdrawal instruction, and the contract will receive the digital currency and the like. The contract currency, that is, the settlement digital currency, is transferred to the user's digital currency account, as by step S607.

Once the smart contract is successfully developed, it already has an address on the blockchain and becomes a permanent record, ie it cannot be deleted. However, in the case of a contract, it is possible to break the contract in a specific case. In the scheme of the smart contract formulation method, a flowchart of an embodiment of the cancellation smart contract proposed in the disclosure shown in FIG. 7 may be employed.

In terms of conditions, since the contract formulation is through the smart contract system disclosed in the disclosure book, as described in step S701, the contract server has provided the user blockchain account, and the digital wallet address, so that the user can use the smart The user account provided by the contract system performs the contract cancellation process.

Then, in step S703, the contract server prompts several functions of the smart contract through the user interface running on the user device, including the contract cancellation function, and once the contract cancellation function is executed, in step S705, the contract server receives the user through the contract. Jie The function selection of the cancellation contract generated by the surface, the software program generates a contract cancellation instruction. In step S707, the contract server obtains the cancellation instruction transmitted by the user, and then, after step S709, after being released on the blockchain, is waiting After the mining result is obtained, after obtaining the mining result of the miner, in step S711, the contract server confirms the cancellation contract with the user.

The disclosure further discloses a computer readable storage device in the contract server, wherein the assembly of the smart contract development method executed in the contract server is executed by one or more processors of the contract server to obtain The user device generates a request for formulating a smart contract through the user interface; receives a selection signal generated through the user interface, initiates a corresponding contract formulation procedure; receives a contract formulation parameter generated through a conditional input interface, and completes a contract content After confirming the payment of a digital currency, the contract content is compiled into a contract digital file, the transaction code is generated after parceling, and posted on the blockchain; and after waiting for the mining result, a contract address is obtained. The computer readable storage device further stores a program of a contract cancellation program, and after being executed by the contract server processor, includes a contract cancellation function prompted by a user interface running on the user device, and receiving the cancellation contract The function selection, that is, the start of the contract cancellation function, generates a contract cancellation instruction, and after the release on the blockchain and the mining result of the miner, the user cancels the cancellation contract.

Therefore, according to the smart contract system, the formulation method and the computer readable storage device described in the above embodiments, the proposed smart contract system provides a plurality of quick contract options and requirements through a user interface executed on the user device. Enter the contract development interface for the contract content so that users can easily execute the program that normally needs to write a program to complete the contract formulation, and a contract server assists in the process of contract management, withdrawal and cancellation on the blockchain.

However, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, equivalent structural changes that are made by using the specification and the contents of the present invention are equally included in the present invention. Within the scope, it is combined with Chen Ming.

Claims (11)

A contract development method implemented by a computer system, running on a smart contract system, comprising: connecting a mobile device through a contract server, and providing a user interface for formulating a smart contract through a software program executed on the mobile device, The user interface provides a plurality of shortcut options; the contract server receives a selection signal generated through the user interface, initiates a contract formulation procedure, and the selection signal corresponds to a computer program of a contract item; a conditional input interface of the project, the contract server receives the contract formulation parameters generated by the condition input interface, including the quantity of the token, the usage and the digital currency information, and completes a contract content; after the contract server confirms payment of a digital currency, Compiling the contract content into a contract digital file, generating a transaction code after parceling and publishing it on a blockchain; and after waiting for a mining result, the contract server obtains a contract address and provides the contract position Site to the user who initiated the contract development process to spread via the Internet a contract address; wherein, when the user who initiated the contract development process obtains the contract address, a certain amount of tokens are transferred to the contract address and a currency program is initiated; when the consumer participates in the smart contract When sending a digital currency to the contract address, the smart contract automatically assigns the token to a digital wallet account of the consumer participating in the smart contract; when the smart contract meets or terminates due to conditions, the currency is stopped. Program to start withdrawing the digital currency received. The contract formulation method of claim 1, wherein the contract server obtains the contract address, that is, the user who initiated the contract development process, and the user transmits the contract address via the social media. The contract formulation method of claim 1, further comprising a contract cancellation procedure, comprising: the contract server prompting a contract cancellation function through the user interface running on the mobile device; the contract server receiving the use The functional selection of the cancellation contract generated by the interface, that is, the contract cancellation function is initiated; the contract server receives a contract cancellation instruction and issues it on the blockchain; and after obtaining the mining result of the miner, the contract server and The user confirms the cancellation of the contract. The contract development method of claim 1, wherein the user interface is an application interface executed on a mobile device, the application interface displays a shortcut contract development interface including the plurality of shortcut options, and corresponding The conditional input interface of the selected contract item. The contract formulation method of claim 4, wherein the contract formulation parameters include contract function, threshold, issue time, reference URL, token address, and any combination of contract developers. The contract development method according to claim 1, wherein when the contract digital file is compiled, the transaction code generated is a data packet having a digital signature, the transaction code including contract content, user identification information, and payment. News. The contract development method according to any one of claims 1 to 6, wherein the blockchain is an Ethereum blockchain, and the digit currency is Ethereum. A smart contract system comprising: a contract server; a software program executed on each mobile device for connecting the contract server and initiating a user interface for formulating a smart contract; wherein the contract server Executing a smart contract formulation method, including: connecting one of the mobile devices through the contract server, and executing The software program on the mobile device provides the user interface for formulating a smart contract, the user interface provides a plurality of shortcut options; the contract server receives a selection signal generated through the user interface, initiates a contract formulation a program, the selection signal corresponding to a computer program of a contract item; initiating a conditional input interface corresponding to the contract item, the contract server receiving contract formulation parameters generated by the condition input interface, including the quantity of the token, the use and the digit currency Information, complete a contract content; after the contract server confirms payment of a digital currency, compile the contract content into a contract digital file, generate a transaction code after parcel, and publish it on a blockchain; and wait for a mining After the result, the contract server obtains a contract address and provides the contract address to the user who initiated the contract development process to disseminate the contract address via the Internet; wherein the contract development procedure is initiated When the user gets the contract address, a certain amount of tokens are transferred to the contract address and a currency program; when a consumer participating in the smart contract sends a digital currency to the contract address, the smart contract automatically assigns the token to a digital wallet account of the consumer participating in the smart contract; when the smart contract When the condition is met or terminated, the currency program is stopped to begin withdrawing the received digital currency. The smart contract system of claim 8, wherein the smart contract system performs a contract cancellation procedure through the contract server, comprising: the contract server prompting a contract cancellation function through the user interface running on the mobile device The contract server receives the function selection of the cancellation contract generated through the user interface, that is, the contract cancellation function is initiated; The contract server receives a contract cancellation instruction and publishes it on the blockchain; and upon obtaining the mining result of the miner, the contract server confirms the cancellation contract with the user. A computer readable storage device storing a set of smart contract formulation methods executed in a contract server, the one or more processors of the contract server performing the following steps: obtaining a mobile device through a user The interface generates a request for formulating a smart contract, wherein the user interface provides a plurality of shortcut options; receiving a selection signal generated through the user interface, initiates a contract formulation process, and the selection signal corresponds to a computer program of a contract item Receiving contract formulation parameters generated through a conditional input interface, including the amount of tokens, usage and digital currency information, completing a contract content; confirming the payment of a digital currency, compiling the contract content into a contract digital file, after wrapping Generating a transaction code and posting it on a blockchain; and after waiting for a mining result, the contract server obtains a contract address and provides the contract address to the user who initiated the contract development process to The Internet spreads the contract address; among them, the user who initiated the contract development process The contract address transmits a certain amount of tokens to the contract address and initiates a currency program; when a consumer participating in the smart contract sends a digital currency to the contract address, the smart contract automatically copies the generation The currency is distributed to a digital wallet account of the consumer participating in the smart contract; when the smart contract is met or terminated due to conditions, the currency program is stopped to begin withdrawing the received digital currency. The computer readable storage device of claim 10, further storing a program executed by the contract server to execute a contract cancellation program, and the one or more processors perform the following steps: running on the mobile device The user interface prompts a contract cancellation function; receives a function selection of the cancellation contract generated through the user interface, that is, initiates the contract cancellation function; receives a contract cancellation instruction, and issues it on the blockchain; After obtaining the mining result of the miner, confirm the cancellation contract with the user.