Writing and querying credit line contract by blockchain

1. Smart contract can be simply understood as a piece of code written on the blockchain, which is event driven, has dynamic state, obtains multi-party recognition, and can automatically process the information on the chain according to the preset conditions. Once an event triggers the terms in the contract, the code will be executed automatically. The biggest advantage of smart contract is to use program algorithm to replace human arbitration and contract execution
smart contract is a contract that uses computer language instead of legal language to record terms. Once it is written, it can be trusted by users. The terms of the contract cannot be changed, so the contract cannot be changed. If the procere meets the conditions, it will be carried out, and there is no human interference to ensure absolute fairness
three technical features of smart contract
● data transparency
all data on the blockchain are open and transparent, so the data processing of smart contract is also open and transparent, and any party can view its code and data at runtime
● can't tamper
all data of the blockchain itself can't be tampered, so the code of the smart contract deployed on the blockchain and the data generated by the operation can't be tampered, and the node running the smart contract doesn't have to worry about malicious modification of the code and data by other nodes
● permanent operation
the number of nodes supporting the blockchain network often reaches hundreds or even thousands. The failure of some nodes will not lead to the stop of the smart contract, and its reliability is close to permanent operation in theory, which ensures that the smart contract can be as effective as the paper contract at all times.

2. With the breakthrough of blockchain technology, the smart contract has a chance of rebirth. The smart contract based on blockchain technology can not only give play to the advantages of smart contract in cost efficiency, but also avoid the interference of malicious behavior on the normal execution of the contract. The smart contract is written into the blockchain in digital form, and the characteristics of blockchain technology ensure that the whole process of storage, reading and execution is transparent, traceable and unchangeable; At the same time, the strong security consensus mechanism does not need the intervention of three parties: a set of state machine system is constructed by the consensus algorithm of the blockchain, so that the intelligent contract can run efficiently.

3. Chongqing jinwowo analyzes the role of smart contract in blockchain technology as follows:
three characteristics of smart contract in blockchain can be summed up:
1) decentralization. It doesn't rely on the centralized server and runs automatically through the network nodes
2) good trust mechanism. The crisis of trust is greatly reced, and it is not necessary to consider whether the participation is trustworthy
3) high degree of autonomy. Once the condition is triggered, the contract will be executed automatically without interference

4.

Ten instry application scenarios of blockchain are listed on Oracle's website, including finance, proction, ecation, media, entertainment, government, retail business, health, medical care, supply chain, insurance and public utilities. Is it very tall? But what I want to say is that these application scenarios, in front of real high-energy blockchain applications, can only hide in the corner and shiver

now the real high-energy application scenario of blockchain is Ponzi application, commonly known as "Ponzi scheme". It is a smart contract type Qianbao, a blockchain game for rolling in and out of money, an ICO for trading, and a global pension platform

Ponzi scheme is one of the oldest application scenarios of our human beings. After Internet plus, the Ponzi scheme has upgraded the Internet + "Internet plus Ponzi scheme". The Internet enabled the Ponzi scheme, so there was an event similar to the 10 billion level of Qianbao. Before the Internet era, there were few Ponzi schemes on such a large scale. They were enabled through the Internet, and paid through mobile app. Finally, they rolled for several years and reached the 10 billion level

the Internet has broken the geographical restrictions, physical restrictions, capital flow restrictions and communication restrictions. As long as you have a mobile phone, you can play Qianbao app. Everyone participates in it, everyone gets into the money, and everyone gives out the money. According to the data of the people involved, it has reached the level of one million. Relatively speaking, the online pyramid scheme (Ponzi scheme 1.0), which still stays on the top of the list, has meetings every day, can't stop brainwashing, and uses violence and illegal means. It's simple and weak. With the rise of blockchain technology, the Ponzi scheme enabled by "blockchain +" can no longer be described as adding wings like a tiger. It is like a chicken changing into a tiger. Like the Internet, the "block chaining +" technology is a solid application to enhance the application scenario. Ponzi's fraud is further upgraded in the two generation of the Internet plus, because of the major improvement and improvement of the scene, turning into Ponzi scheme 3, whose characteristics are mainly in the following aspects:

1, centralization and no summit. The smart contract of blockchain runs automatically, and it does not need human intervention, nor can it be interrupted by human. Code rules are dead and cannot be tampered with. In terms of scene improvement, it solves the biggest pain point of Ponzi scheme for thousands of years, that is, the problem of head running away. Because the head is a program and code, the program of blockchain can exist forever, and no one can delete it. I think this is the biggest breakthrough. This virtual leader is always there. He can't run away, he can't run, he can't change. The rules will never change. He will stick to the Ponzi line for 100 years, 1000 years and 10000 years. It may be said that smart contracts can be iterated, and they can also be manipulated to leave a back door. Yes, but it can be done without iteration. Even if iteration is transparent and visible, it can be seen at a glance with a back door. This is the characteristic of the blockchain smart contract. If you cheat on it, you will get out a under the teacher's eyes. No one will participate in such a smart contract when it is online. Therefore, after technical review and verification, there is no backdoor, fair rules and irreversible smart contract, which can be realized by using blockchain technology. Such reliability, once verified, will never change. This is the certainty of the smart contract. A program or a character's code will not change. It will run one million times and one trillion times, and the result will be consistent and certain

2. The process was transparent. The number, address, account number, amount and time of deposit; Number, address, account number, amount and time of payment; All visible. Blockchain has a public ledger function, which can be viewed by everyone in the world, and the ledger data viewed by everyone is completely consistent. Why does Qianbao burst? Because we can't see his background account, how much money he goes in and how much money he comes out every day, and the details of each transaction. In this way, you can see the assessment of cashing ability before you pay in, and the assessment result is absolutely certain, that is, it will not change after you pay in

3. Complete anonymization. If you've ever heard of zero proof of knowledge. This part can be skipped. In short, some of the things we used to have in the mathematical knowledge base did not have application scenarios after many inventions. Later, it was found that it was easy to use these knowledge for anonymization. The cryptography technology in the blockchain can achieve identity hiding. As we all know, Zhihu can't achieve anonymity in a real sense in terms of technical structure, and blockchain can

The rules are open and fair to all. One yuan in gold, ten yuan in rebate. Everyone is the same rule. It will never change. If you pay one yuan, go to the front and pay for it, then the back will pay for it, and then pay for it. Fair, right? I have reflected on this many times, and I think it is fair

5. Sustainable iteration. In the low-level Ponzi scheme, the leader, proct designer, benefit distributor and benefit receiver are often four in one, while the blockchain Ponzi scheme can completely logically separate the four roles. Achieve sustainable iteration. Through collaboration based on socialization, these projects can be iterated on forever. There are now 400 senior engineers who are developing around bitcoin and constantly updating the code. These people can not know anyone. As long as the application is valuable, they can continue to iterate. Which centralized project can be achieved? Even bat level companies can't employ so many professionals scattered around the world. This kind of social iteration is not affected by the changes of a specific person or organization

"blockchain" enabled Ponzi scheme uses different range of blockchain technology, because the technology in this field is still constantly updated, and the application of smart contract has only increased in the past two years. The earliest application of blockchain is bitcoin. Some people think that bitcoin itself has the characteristics of Ponzi scheme. In 2013, I wrote a reply and implicitly pointed out that this new type of Ponzi scheme will have great lethality, because it has the characteristics of no head, open account book, no running away, open and fair rules. Later, I also found that many people around me like Ponzi scheme much more than blockchain technology. As soon as I hear that bitcoin is not a Ponzi scheme, before I start talking about blockchain technology, I usually walk away in silence. On the contrary, you tell him it's a Ponzi scheme, and then they will ask, where can I buy it? Of course, there is a lot of controversy about whether bitcoin is a Ponzi scheme, because the practical application scenarios of bitcoin have been expanding

in the ICO boom, there are a lot of air coins, such as the bogus Ponzi scheme, which has no application scenarios. The buyers probably know that these air coins are Ponzi schemes, but they buy them because the packaging is good. It is estimated that there are hundreds or thousands of such air coins. The scope of the case is all over the world, and the amount involved is more than 10 billion. These ICOS use smart contracts for subscription and distribution, and then circulate in the secondary market by themselves. In this case, there is no guarantee that the money will be paid out, and some people will lose all their money. Many people, blockchain professionals, have always wanted to draw a clear line with these applications, because although these air coins use part of the blockchain technology, they are still a centralized organization or indivial behind them. There are few network nodes, and users directly converge to a certain organization or indivial when they are paid (so they will be swept away), but there is no doubt that, Air money still uses blockchain to make money and raise funds, which solves part of the problem of running away and improves the scope and communication ability of Ponzi scheme. This is an objective situation

and from this year, with the development of technology, the Ponzi scheme, which uses smart contracts to achieve more decentralization, began to surface. Smart contract locking is used for fund in and fund out to complete a complete closed loop of fund in, fund subscription and fund out. It can already be a very pure blockchain application. Some blockchain games can freely admit that they are a Ponzi game after their release. He said: you see, the rules are transparent, the code is visible, the gold entry contract is locked, they can't run away, no one intervenes, and the gold is automatically paid. Early play, early gain. This is a key breakthrough. It's a way to publicly admit that you are a Ponzi scheme, which can't be done by Ponzi scheme 1.0 and Ponzi scheme 2.0 before. Great. It's simple and rough

this solves the major obstacles in the promotion process of Ponzi scheme, which used to rely on brainwashing, but now it depends on code. You see, "this program doesn't run on its own. There's no back door in it, right? Is the leader gone? The capture of Nakamoto does not affect the continued implementation of the program, does it Therefore, the first batch of blockchain Ponzi scams are hooked by code farmers who can understand the code, and then these code farmers stand up again and say that after technical verification, it is really such an effect, driving other people who do not read the code to join

in addition to realizing the Ponzi scheme application scenarios of entertainment, gambling and fraud, blockchain also has the opportunity to make a big show in the Ponzi scheme application scenarios involving the national economy and the people's livelihood and public utilities, which can even greatly enhance people's sense of gain and happiness, and actually improve people's life. For example, the application of national or global public pension platform based on blockchain can solve several major drawbacks of pension: fund misappropriation. The account book is open, the funds are not centralized and locked, and no one can unlock it, except the recipients who meet the rules can pay out the money. There is no possibility of misappropriation

2. Inflation. The current pension system adjusts the coefficient every year according to a series of complex algorithms such as inflation. After adjustment, the recipients are often dissatisfied because the total amount has increased, but the purchasing power has decreased. Using the feature that virtual currency can't be issued, we can control the inflation rate and ensure that we get real money

3. Unpredictable problems. It is very difficult for us to predict the pension payment after 30 years, and we can predict it in advance through smart contract. Stimulate the enthusiasm of paying

4. Policy loopholes and fairness. There will be unfairness in the diversification of groups that any pension policy faces. Everyone wants to pay less and get more, pay later and raise earlier. The transparency of blockchain is refined to each account, rather than a set of general policies to plug the loopholes in the implementation process. Everyone is the same, pay more, pay earlier, pay earlier. It can even be inherited and never lost

this has greatly reced the burden and cost of the state's pension management. What the existing pension system can do, after using the blockchain technology, can still be done, such as the state subsidies, just pay money into the contract, lock it in, there will be no fake, such as compulsory payment, and every record is real and traceable. In a word, all the existing systems and rules can be linked to the chain. On the basis of not affecting the existing effect, the efficiency and output level are improved, and fairness is guaranteed. Moreover, because the cost of the huge management system is reced, the absolute number that everyone can get may be increased by a large part. This has played a real effect on improving people's lives, and also has a positive effect

5. Sum software blockchain technology is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. The so-called consensus mechanism is a mathematical algorithm to establish trust and obtain interests between different nodes in the blockchain system
in a narrow sense, blockchain is a kind of chained data structure, which is composed of data blocks connected in sequence according to the time sequence, and is a distributed account book that can not be tampered with and forged by cryptography. In a broad sense, blockchain technology is a new distributed infrastructure and computing paradigm, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data.

6. Shanghai Heshu Software Co., Ltd. is a professional blockchain technology service provider in China. The smart contract seems to be a script that can be executed accurately. It can also be realized with traditional technology. Why must we use blockchain technology? Personal understanding of blockchain has two characteristics: 1. Data can not be modified or deleted, but can only be viewed and added; 2. Decentralization.

7. Generally, as long as the enterprise has good credit and stable supply of goods, it can obtain different amount of financing credit of accompanying payment contract logistics. For example, some small and medium-sized logistics enterprises, which are located in remote areas and whose credit system is not perfect, can not get credit from traditional institutions. They can also get the help of collateral free financing credit.

8. General banks can exchange, but limited to Monday to Friday, I suggest you can go to Bank of China and Bank of communications, especially Bank of China, this business is very perfect, you can also use RMB to exchange US dollars in the future.

9.

1. Learning conditions:

level above 45, each player can only learn two life skills at the same time. If you reach level 90, you should be able to learn the third life skill

10. ? In short,? Is it accompanied? Combined with their own offline energy? Strength, strength? What can technology do? The regional chain technology is used to build the? A complete one? Credit system,? Can we solve this problem effectively? Small and medium sized contracts? What are the characteristics of logistics enterprises? Financing difficulty? What is harmony? It's expensive.