最朴实的区块链技术讲解视频,最朴实的区块链技术讲解课件

区块链技术是一种分布式的记录技术，它将信息存储在一个可验证的共享数据库中，并使用密码学的原理来确保安全性和完整性。它是一种技术，可以用于存储和管理数据，并使用密码学来确保安全性。区块链技术可以用于跨越组织边界的安全交易，以及更快速、更安全的记录和存储数据，这些数据可以是金融交易、智能合约、用户权益等等。

加密货币是一种使用密码学方法加密的数字货币，它是一种新型的货币形式，可以用来作为货币的替代品。它不是政府发行的法定货币，也不能用作法定货币的替代品。它是一种去中心化的货币，可以被任何人使用，而且不受任何法律或政府的监管。它可以用来进行安全的跨境交易，以及更快捷的货币交易。

智能合约是一种基于区块链技术的自动执行代码，它可以用来实现各种合同的自动执行。智能合约是一种可以执行许多操作的自动化程序，它可以用来实现各种合同，包括存储数据、转移资产、执行计算等。智能合约可以被用来实现更安全、更可靠的交易，因为它可以确保参与者都遵守协议，而且每一步都受到公开的确认。

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1. I am a novice in technology. Can anyone explain what is blockchain in an easy-to-understand manner?

Blockchain, for example, Bitcoin, Bitcoin is supported by the blockchain, and the blockchain is what each of us connects to run together

2. How does the blockchain work?

Recently, there are many What kind of technology is the popular blockchain technology? Blockchain technology is considered to be the brightest star in financial technology, and it may continue to develop in the future. It has many characteristics, including the distribution of data and the trust of data. Degree and collective consensus mechanism, the most important ones are openness, transparency, anonymity and privacy, which are very distinctive features. Based on the data in these blockchains, we can derive some basic information about contemporary society.

Blockchain technology is such a secure and scientific database. It can be simply understood as an authoritative database. The basic contents in it are all true and have been verified and reviewed by others. In terms of financial technology, it will be very easy to find some desired data, which is very good for people doing business.

3. What is blockchain technology? What exactly is blockchain?

In a narrow sense, blockchain is a way to block data in chronological order. A chained data structure composed of sequential connections, and a cryptographically guaranteed distributed ledger that cannot be tampered with or forged.

Broadly speaking, blockchain technology uses block chain data structures to verify and store data, uses distributed node consensus algorithms to generate and update data, and uses cryptography to ensure data transmission and access. It is a new distributed infrastructure and computing method that uses smart contracts composed of automated script codes to program and operate data securely.

[Infrastructure]

Generally speaking, the blockchain system consists of data layer, network layer, consensus layer, incentive layer, contract layer and application layer composition. Among them, the data layer encapsulates the underlying data blocks and related basic data and basic algorithms such as data encryption and timestamps; the network layer includes distributed networking mechanisms, data dissemination mechanisms, and data verification mechanisms; the consensus layer mainly encapsulates network nodes Various consensus algorithms; the incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives; the contract layer mainly encapsulates various scripts, algorithms and smart contracts, and is the core of the blockchain The basis of programmable features; the application layer encapsulates various application scenarios and cases of the blockchain. In this model, the chain block structure based on timestamps, the consensus mechanism of distributed nodes, economic incentives based on consensus computing power, and flexible programmable smart contracts are the most representative innovations of blockchain technology.

Extended information:

[Blockchain core technology]

The trust and security issues of transactions that blockchain mainly solves, so it proposed four technological innovations to address this problem:

1. Distributed ledger, which means that transaction accounting is completed by multiple nodes distributed in different places, and each node records Complete accounts, so they can all participate in supervising the legality of transactions and can also jointly testify for them.

The uniqueness of blockchain's distributed storage is mainly reflected in two aspects: First, each node of the blockchain stores complete data according to the block chain structure. Traditional distributed storage generally stores The data is divided into multiple parts for storage according to certain rules. Second, the storage of each node in the blockchain is independent and has equal status, relying on the consensus mechanism to ensure the consistency of storage, while traditional distributed storage generally synchronizes data to other backup nodes through the central node.

No node can record ledger data independently, thus avoiding the possibility of a single bookkeeper being controlled or bribed to record false accounts. Also because there are enough accounting nodes, theoretically speaking, the accounts will not be lost unless all nodes are destroyed, thereby ensuring the security of the accounting data.

2. Asymmetric encryption and authorization technology. Transaction information stored on the blockchain is public, but account identity information is highly encrypted and can only be accessed with authorization from the data owner. , thus ensuring data security and personal privacy.

3. The consensus mechanism is how all accounting nodes reach a consensus to determine the validity of a record. This is both a means of identification and a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and strike a balance between efficiency and security.

The consensus mechanism of the blockchain has the characteristics of "the minority obeys the majority" and "everyone is equal". "The minority obeys the majority" does not entirely refer to the number of nodes, but can also be the computing power and the number of shares. Or other characteristic quantities that the computer can compare. "Everyone is equal" means that when a node meets the conditions, all nodes have the right to give priority to the consensus result, which will be directly recognized by other nodes and may eventually become the final consensus result.

4. Smart contracts. Smart contracts are based on these trustworthy and non-tamperable data and can automatically execute some predefined rules and terms. Take insurance as an example. If everyone's information (including medical information and risk occurrence information) is true and trustworthy, it will be easy to automate claims settlement in some standardized insurance products.

In the daily business of insurance companies, although transactions are not as frequent as those in the banking and securities industries, the reliance on trusted data continues unabated. Therefore, the author believes that using blockchain technology from the perspective of data management can effectively help insurance companies improve their risk management capabilities. Specifically speaking, it is mainly divided into risk management of policyholders and risk supervision of insurance companies.

Blockchain-Network

4. What is blockchain technology? What exactly is blockchain? What is blockchain

1. The so-called blockchain technology, referred to as BT (Blockchain technology), also known as distributed ledger technology, is an Internet database technology that is characterized by decentralization, openness and transparency, allowing everyone to participate in database records .

Explain in layman’s terms: If we assume that the database is a ledger, reading and writing the database can be regarded as an accounting behavior. The principle of blockchain technology is to find out the accounting information within a period of time. The fastest and best person will keep accounts, and then send this page of information to everyone else in the entire system.

2. Blockchain is a new application model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm.

Blockchain is an important concept of Bitcoin. It is essentially a decentralized database. At the same time, as the underlying technology of Bitcoin, it is a series of cryptographic methods related to each other. Each data block generated contains a batch of Bitcoin network transaction information, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block.

(4) The simplest explanation of blockchain technology for extended reading:

The blockchain system consists of data layer, network layer, consensus layer, incentive layer It consists of layer, contract layer and application layer. Among them, the data layer encapsulates the underlying data blocks and related basic data and basic algorithms such as data encryption and timestamps; the network layer includes distributed networking mechanisms, data dissemination mechanisms, and data verification mechanisms; the consensus layer mainly encapsulates network nodes Various consensus algorithms.

The incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives; the contract layer mainly encapsulates various scripts, algorithms and smart contracts, and is the The basis of the chain's programmable features; the application layer encapsulates various application scenarios and cases of the blockchain.

5. An introduction to the principles and applications of blockchain technology

1. Blockchain is a series of data blocks generated by using cryptographic methods. Each data block contains It collects the information of all Bitcoin network transactions in the past ten minutes and is used to verify the validity of the information (anti-counterfeiting) and generate the next block. It is the underlying technology of Bitcoin, like a database ledger that records all transaction records.

2. Broad definition: Use encrypted chain structure to verify and store data, use distributed node consensus algorithm to generate and update data, use automated script code (smart contract) to convert and operate data A new decentralized infrastructure and distributed computing paradigm.

3. Narrow definition: A decentralized shared account that combines data blocks into a specific data structure in a chain in chronological order, and is cryptographically guaranteed to be non-tamperable and non-forgeable.

4. Characteristics of blockchain: decentralization: blockchain dataProcesses such as verification, accounting, storage, maintenance and transmission are all based on distributed system mechanisms. Pure mathematical methods are used instead of central structures to establish trust relationships between distributed nodes, thereby forming a decentralized and trustworthy system. Distributed Systems.

5. Time series data: Blockchain uses a chain block structure with timestamps to store data, thereby adding a time dimension to the data and having strong verifiability and traceability.

6. Collective maintenance: The blockchain system uses a specific economic incentive mechanism to ensure that all nodes in the distributed system can participate in the verification process of data blocks, and select specific nodes through a consensus algorithm Add new blocks to the blockchain.

7. Programmable: Blockchain technology provides a flexible script code system to support users in creating advanced smart contracts, currencies or other decentralized applications.

8. Safe and trustworthy: Blockchain technology uses asymmetric cryptography principles to encrypt data, and at the same time uses the powerful computing power formed by consensus algorithms such as workload proof of each node of the distributed system. To resist external attacks and ensure that blockchain data cannot be tampered with or forged, it has high security.

9. Blockchain application scenarios: Digital currency: Represented by Bitcoin Damin Coin, it is essentially a digital currency generated by a distributed network system. Its issuance process does not rely on a specific centralized institution. .

6. How to interpret blockchain in the simplest way

Everyone hears the word blockchain every day recently, so what is blockchain? Explanations such as "distributed, difficult to tamper, and consistent storage" are too technical and dry. Let me give you some popular science here: Blockchain is mainly designed to solve the trust problem between individuals who do not trust each other.

To give a popular example: It is said that Lao Li and Lao Wang live in the same village. Lao Li is a little short of money recently and wants to borrow some money from Lao Wang. As for Lao Wang, he was worried about what would happen if he defaulted on the loan after borrowing money from Lao Li, so he called in the "highly respected" village chief. But thinking about it, the village chief couldn't be trusted either. The village chief had even stolen other people's sweet potatoes in the past! what to do?

The blockchain method is: After Lao Wang borrowed 1,000 yuan from Lao Li, he then used a loudspeaker to shout in the village, "I, Lao Wang, borrowed 1,000 yuan from Lao Li today. Everyone Record it quickly." So everyone in the village recorded it in their own account books and kept it carefully. This is good, Lao Li can't rely on him anymore. Even if there are dishonest people in the village, there are still many good people. Lao Li can't find everyone in the village to secretly erase his loan records. In this way, the blockchain solved the trust problem of borrowing money between Lao Wang and Lao Li, who did not trust each other.

Before the emergence of blockchain, how did we solve the problem of trust between individuals who did not trust each other? It's simple, just find a "witness" who is "highly respected" and trusted by both, such as the villagers in the story.Long, such as Alipay between buyers and sellers, such as notary offices, etc. However, it is possible that such "witnesses" may not always be honest, so the blockchain simply allows everyone to act as a witness.

Lao Wang is relieved, but Lao Li has a headache! Lao Li has to wait until everyone in the village has recorded the money before he can get the money lent to him. There is no uncle or aunt in the family who is slower. Therefore, there is still a certain distance between blockchain and application, and efficiency issues need to be significantly improved.

Recall how you usually trade with others: you can choose a beautiful dress in a physical store, confirm that the other party’s clothes are of good quality, and the other party confirms that your money is real money. , then we will pay and receive the goods face to face.

What if we are thousands of miles apart and neither know nor trust each other but still want to trade? Then there needs to be a third party that we all trust, which is the so-called consensus mechanism. For example: you can complete the transaction through a third-party witness guarantee on Taobao. The money is first given to Alipay - Alipay collects the payment and lets the seller deliver the goods - the seller delivers the goods - you confirm receipt - Alipay then gives the money to the seller.

However, what if this centralized organization does evil, and Dad Ma tears up the account books and refuses to admit that you gave the money, or joins forces with the seller to defraud you of money?

Or maybe the government lends you 1 million, and finally pays you back by issuing extra currency. The 1 million shrinks to 10,000, and you bear the loss of inflation. What should you do? ?

Is there a third party that is not controlled by any government or organization, can complete arbitration in an open and transparent manner, has records that will not be tampered with, and has no risk of running away?

Don’t worry, our protagonist blockchain technology solves this problem - the transactions between you can be witnessed by everyone in this blockchain system, and everyone’s small ledger will be recorded Your deal. If B denies receiving money from A, or if A says that he borrowed 300 yuan, passers-by A, B, B, and D will question him. How exactly is it done?

1) The system issues a small ledger to everyone, so that everyone has the right to keep accounts. We call it distributed accounting.

2) In order to encourage everyone to help others keep accounts, the system code is set to reward tokens such as Bitcoin to the keepers. In order to prevent a group of people from being blocked in keeping accounts, the tokens are also set to There are only a limited number of A, B, C and D who need to be calculated through the mechanism specified by the system. Only the fastest and best calculation can obtain the right to keep accounts. After recording, it is broadcast to everyone through the system. Everyone copies the same ledger. This is obtained through calculation. The reward process is called mining, and passers-by A, B, C and D who keep accounts are the miners.

3) One day, the person who originally recorded the transaction Game Over, but the ledger still exists in other people’s books.In the ledger, neither A nor B can deny it. We have written in code how to arbitrate and distribute, without the need for banks, governments, enterprises and other centralized organizations to serve as third-party witnesses (decentralization), and the direct point-to-point (P2P) transaction method is called decentralization.

4) The system packages multiple transactions into blocks and links them in chronological order to become the final ledger that everyone has. This is the blockchain technology

In fact, the block chain The simple understanding of blockchain as a ledger is only the simplest interpretation. If each of its characteristics is separated, it can be applied in many fields.

Now the traditional financial industry, securities firms, and investment institutions are rushing to enter the Internet of Things, games, storage, copyright, anti-counterfeiting, credit reporting, payment, prediction markets (gambling, etc.), communities and many other fields. The exploration and application of blockchain has already begun.

The Internet allows everything to be connected. Can blockchain make everything connected trustworthy?

Let me explain the blockchain using the natural stones of heaven and earth:

All science, philosophy, morality... heaven and earth are included. Every thing and every culture is related to the Taoism of heaven and earth.

Blockchain naturally cannot escape the fate of heaven and earth: that is, smooth, random, infinite, and impermanent.

It is this strange stone, and the overall data movement on its surface. First, the whole is intangible. Second, the lines and points adhere to a pattern: the path of impermanence. That is to say, every line and every point they pursue is not a closed goal or a limited purpose. I can understand it better when I say this: when a painter paints a chicken, it has a purpose and an ending, while strange rocks, when created by nature, have no ending. Therefore, the phase is not closed, and the line and point data are not terminated. The technology of block connection is this way of destiny. Impermanence is invisible and has no end. (No centralization means formlessness, no closed form, no closed structure, no closed mind... just like "stone" to do things).

Confucius Lingshi Museum in Qufu, Shandong

Hello everyone, I am Pippi. I will use a few life examples to explain to you what blockchain is?

A decentralized, tamper-proof, distributed storage data block linking system that uses encrypted information as the link address is called blockchain

This thing is originally There are many high-tech composite products that cannot be simplified. No matter how simple it is, it takes a long paragraph, and it may not be clear.

The strict definition of blockchain refers to the design based on cryptography technology. Consensus mechanism method, multiple nodes in the peer-to-peer network jointly maintain a continuously growing, a distributed database technology of linked list ledgers constructed from timestamps and ordered record data blocks. This technical solution allows any number of nodes participating in the system to calculate and record all information exchange data in the system over a period of time into a data block (block) through cryptographic algorithms, and generate the fingerprint of the data block for linking ( chain) and check the next data block, all participating nodes in the system jointly determine whether the record is true.

Blockchain is a general term for technical solutions similar to NoSQL (non-relational database). It is not a specific technology. Blockchain technology can be implemented through many programming languages ​​and architectures. . There are also many ways to implement blockchain. Common ones currently include POW (Proof of Work), POS (Proof of Stake), DPOS (Delegate Proof of Stake), etc.

The concept of blockchain was first proposed in the paper "Bitcoin: A Peer-to-Peer Electronic Cash System" by the author who calls himself Satoshi Nakamoto (Satoshi Nakamoto) individual (or group). Therefore, Bitcoin can be regarded as the first application of blockchain in the field of financial payments.

[Popular explanation]

No matter how big the system or how small the website, there is usually a database behind it. So who will maintain this database? Under normal circumstances, whoever is responsible for operating the network or system will maintain it. If it is a WeChat database, it must be maintained by Tencent's team, and Taobao's database must be maintained by Alibaba's team. Everyone must think that this approach is natural, but this is not the case with blockchain technology.

If we imagine the database as a ledger: Alipay, for example, is a typical ledger, and any change in data is an accounting type. We can think of database maintenance as a very simple accounting method. The same is true in the world of blockchain. Everyone in the blockchain system has the opportunity to participate in accounting. The system will select within a period of time, maybe within ten seconds, or maybe ten minutes, to select the person with the fastest and best accounting during this period. This person will do the accounting, and he will combine the changes in the database during this period with Changes in the ledger are recorded in a block. We can imagine this block as a page of paper. After confirming that the record is correct, the system will link (chain) the data fingerprint of the past ledger to this paper, and then This piece of paper is sent to everyone else in the entire system. Then the cycle starts over and the system looks for the next person who can do the accounting quickly and well, and everyone else in the system gets a copy of the entire ledger. This also means thisEveryone in the system has an identical ledger. This technology is called blockchain technology, also known as distributed ledger technology.

Since everyone (computer) has exactly the same ledger, and everyone (computer) has exactly the same rights, there will be no problem due to a single person (computer) losing contact or going down. The entire system collapses. Since there are exactly the same ledgers, it means that all data is open and transparent, and everyone can see the digital changes in each account. Its very interesting feature is that the data in it cannot be tampered with. Because the system will automatically compare, it will consider the account books with the largest number of the same number as the real account books, and the small number of account books with different numbers as others are false account books. In this case, it makes no sense for anyone to tamper with their own ledger, because unless you can tamper with most of the nodes in the entire system. If the entire system has only five or ten nodes, it may be easy to do, but if there are tens of thousands or even hundreds of thousands of nodes, and they are distributed in any corner of the Internet, unless someone can control most of the computers in the world , otherwise it would be unlikely to tamper with such a large blockchain.

[Elements]

Combined with the definition of blockchain, we believe that it must have the following four elements to be called a public blockchain technology. If it only has the first three points elements, which we will consider as private blockchain technology (private chain).

1. Point-to-point peer-to-peer network (peer-to-peer power, physical point-to-point connection)

2. Verifiable data structure (verifiable PKC system, non-tamperable database)

3. Distributed consensus mechanism (solve the Byzantine generals problem and double payment)

4. Nash equilibrium game design (cooperation is an evolutionarily stable strategy)
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[Characteristics]

Combined with the definition of blockchain, blockchain will realize four main characteristics: decentralized, trustless, Collectively maintained (Collectively maintained), reliable database (Reliable Database). And the four characteristics will lead to two other characteristics: open source (Open Source) and privacy protection (Anonymity). If a system does not possess these characteristics, it will not be considered an application based on blockchain technology.

Decentralized: The entire network has no centralized hardware or management organization. The rights and obligations between any nodes are equal, and the damage or loss of any node will not affect it. operation of the entire system. Therefore it is also possibleThe blockchain system is believed to be extremely robust.

Trustless: Each node participating in the entire system does not need to trust each other for data exchange. The operating rules of the entire system are open and transparent, and all data contents are also public. , therefore within the rule range and time range specified by the system, nodes cannot and cannot deceive other nodes.

Collectively maintain: The data blocks in the system are jointly maintained by all nodes with maintenance functions in the entire system, and these nodes with maintenance functions can be participated by anyone.

Reliable Database: The entire system will be divided into databases so that each participating node can obtain a copy of the complete database. Unless more than 51% of the nodes in the entire system can be controlled at the same time, modifications to the database on a single node are invalid and cannot affect the data content on other nodes. Therefore, the more nodes and stronger computing power participating in the system, the higher the data security in the system.

Open Source: Since the operating rules of the entire system must be open and transparent, for the program, the entire system must be open source.

Privacy protection (Anonymity): Since nodes do not need to trust each other, there is no need to disclose their identities between nodes. The privacy of each participating node in the system is protected. protected.

[One of the meanings of blockchain: Solving the Byzantine Generals Problem]

The core problem solved by blockchain is not "digital currency", but information asymmetry and inconsistency. Under a certain environment, how to establish a "trust" ecological system that satisfies the occurrence and development of economic activities. This problem is called the "Byzantine Generals Problem", also known as "Byzantine Fault Tolerance" or the "Two Armies Problem". This is a difficult problem faced when information machines interact in a distributed system, that is, any point in the entire network When nodes cannot trust the other party they are communicating with, how can they create a consensus basis for secure information exchange without worrying about data being tampered with. Blockchain uses an algorithmic proof mechanism to ensure the security of the entire network. With it, all nodes in the entire system can automatically and securely exchange data in a trustless environment. For more introduction, please see "Bitcoin and the Byzantine Generals Problem".

[The second meaning of blockchain: realizing cross-border value transfer]

At the beginning of the birth of the Internet, the earliest core problem to be solved was information production and transmission. We can transfer information through the Internet Rapidly generated and copied to every corner of the world with a network, but it still cannot solve the problem of value transfer and credit transfer.shift. The so-called value transfer here refers to a method that everyone in the network can recognize and confirm, accurately transferring a certain part of the value from a certain address to another address, and it must be ensured that when the value is transferred, the original address is reduced The transferred portion, while the new address increases the value transferred. The value mentioned here can be a monetary asset, or some kind of physical asset or virtual asset (including securities, financial derivatives, etc.). The results of this operation must be recognized by all participating parties, and the results cannot be manipulated by any one party.

There are also various financial systems in the current Internet, and there are also many payment systems provided by government banks or third parties, but they still rely on centralized solutions. The so-called centralized solution is to put all value transfer calculations on a central server (cluster) through the endorsement of a certain company or government credit. Although all calculations are automatically completed by the program, this centralization must be trusted. person or institution. In fact, through centralized credit endorsement, credit can only be limited to certain institutions, regions or countries. It can be seen from this that the fundamental problem that must be solved is credit. Therefore, the core issue of value transfer is transnational credit consensus.

In such a complicated global system, it is difficult to establish a global credit consensus system out of thin air. Due to the different political, economic and cultural conditions of each country, it is difficult for two countries to It is almost impossible for enterprises and governments to completely trust each other. This means that whether it is endorsed by the credit of individuals or corporate governments, even if the value exchange between countries can be completed, there will be huge time and economic costs. But in the long history of mankind, no matter how different the religion, politics and culture of each country are, the only thing that can reach consensus is mathematics (basic science). Therefore, it is no exaggeration to say that mathematics (algorithms) is the greatest common denominator of global civilization and the basis for the greatest consensus among human beings around the world. If we use mathematical algorithms (programs) as endorsement, all rules are based on an open and transparent mathematical algorithm (program), which can allow all people with different political and cultural backgrounds to gain consensus.

[Future Development]

The Internet will make global interactions closer and closer, accompanied by a huge trust gap. Currently, the existing mainstream database technology architecture is private and centralized. On this architecture, the problems of value transfer and mutual trust can never be solved. Therefore, blockchain technology may become the next generation database architecture. Through decentralized technology, it will be possible to complete the huge progress of mathematical (algorithm) endorsement and global mutual trust on the basis of big data.

As a specific distributed access data technology, blockchain technology uses multiple nodes participating in calculations in the network to jointly participate in the calculation and processing of data.records, and mutually verify the validity of their information (anti-counterfeiting). From this point of view, blockchain technology is also a specific database technology. The Internet has just entered the era of big data, but from the current point of view, big data is still in a very basic stage. But when it enters the blockchain database stage, it will enter the big data era of real strong trust endorsement. All data here has acquired indestructible quality, and no one has the ability or need to question it.

Perhaps we are now at a major turning point - the early stages of a major transition that is almost as profound as the changes brought about by the Industrial Revolution. Not only are new technologies exponential, digital and combined, progress and changes, but more surprises may be ahead of us. In the next 24 months, the planet will grow more computing power and record more data than it has in all of history combined. In the past 24 months, this value increase may have exceeded 1,000 times. This digital data information is growing faster than Moore's Law. Blockchain technology will not only be used in the field of financial payments, but will expand to all current applications, such as decentralized Weibo, WeChat, search, renting, and even taxi-hailing software may appear. Because blockchain will allow humans to collaborate on a large scale in a trustless manner without geographical restrictions.

Blockchain is a technology based on which many applications have been produced, including all industry businesses related to data and information. Bitcoin is one of the most well-known applications. The popular explanation of blockchain is that if you buy a lipstick online, you first find the product you like and place an order with the seller. You first give the money to the intermediary platform. After the seller ships the goods and the buyer confirms receipt, the intermediary platform then transfers the money. Transfer it to the seller, because of the trust issue, both buyers and sellers rely on the intermediate platform, and the blockchain, as a decentralized distributed ledger database, focuses on removing this intermediate platform while solving the trust issue at the same time. In the blockchain, everyone has their own ledger to record everything that happens. If a seller takes money but does not deliver the goods during the transaction, this record will exist permanently and cannot be modified, and there is no need to interact with each other. To exchange information, the blockchain world will select the person's ledger that records the fastest and best quality at the same time node to copy, send and connect in series, and finally stack it up to form a block.

When everyone talks about virtual currencies, they often cannot do without the concept of blockchain. So what is the magic of blockchain?

Blockchain is an underlying technology, essentially a decentralized distributed ledger database. It sounds very high-end and out of reach, but it is actually very easy to understand.

For example, if you want to buy something on Taobao, the first thing you usually have to do is to open Taobao, find the product you want, place an order and pay the money to Taobao, which is the transaction intermediary. Wait for the goods to be received and confirm receiptTaobao will then transfer the payment to the seller. This was originally just a transaction between me and the seller, but it has an additional "center", namely Taobao.

During the transaction process, this "center" has unlimited power and can even modify the bill at will. Therefore, the “center” often needs a strong backend to endorse it.

So, a man named Satoshi Nakamoto wanted to get rid of this center with infinite power. He wanted to create a decentralized system in which everyone is the center and everyone is the center. Have the authority to keep accounts. So, he created Bitcoin.

In the Bitcoin system, everyone has a small ledger to record every transaction that occurs. A transaction is only valid after being confirmed by a majority of people. If the seller doesn't deliver the goods, everyone's little ledger will record it, leaving him nowhere to escape.

At this time, you may have questions. Since it is just a public ledger, why is it called a blockchain? This involves the issue of consensus. The blockchain system is a system composed of many "centers". The entire blockchain belongs to all individuals participating in accounting. At this time, new problems arise. A system must be in order to survive in the long term. If the bookkeeper can act recklessly regardless of the cost, it may happen that he originally just bought a mobile phone, but received a Tesla instead.

So, Satoshi Nakamoto invented a consensus method called PoW. This method increases the cost of bookkeeping for bookkeepers and prevents them from doing evil easily. PoW uses cryptography to require bookkeepers to compete for computing power to obtain accounting rights. The first bookkeeper to calculate the result can obtain the accounting rights of a block packaged from several transactions. At the same time, you will receive certain tokens as rewards. This is what we commonly call "mining".

Now that the bookkeeper has recorded a block containing several transactions, the system needs to be organized and sorted. It is impossible to have countless blocks distributed in the system in an orderly manner. So it is necessary to link all blocks end to end in chronological order. At this time, the blockchain was born. The core of blockchain is technology.

7. Popular explanation of blockchain technology

Blockchain is a new application model of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. Blockchain is an important concept of Bitcoin, which is essentially a decentralized database. At the same time, as the underlying technology of Bitcoin, it is a series of data blocks generated by cryptographic technology. Each data block contains a batch of Bitcoin network transaction information, which is used to verify the validity of its information (anti-counterfeiting) and generate the next data block.
First of all, it is a special distributed database that is essentially readable and writable. The unit then entered into the database is a "block", which is decentralized.
Explain it this wayIt doesn't seem that easy to understand, so let's give a simple example.

When we shop on Taobao, because neither the buyer nor the seller knows each other's credit, we need to introduce a third-party platform - Alipay. Alipay is a trustworthy platform. The buyer first gives money to Alipay. After the seller delivers the goods, the buyer receives the money and notifies Alipay, who then lends the money to the seller. In this way, there is no need to worry about credit issues in the transaction.

8. Briefly talk about what "blockchain" technology is

Blockchain is a permanent and irreversible modification generated by superimposing encrypted data (blocks) in chronological order (chain) record of.
Blockchain is a technology that can completely change the underlying design of the financial system. Because it can achieve undifferentiated records of the ownership and transaction records of all assets in the market by all market participants, it can completely eliminate clearing and custody. These are the intermediate links that confirm ownership before, during and after the transaction; in addition, the blockchain, as an electronic information record, can be combined with computer algorithms to realize the automation of transactions, that is, smart contracts. Blockchain has many derivative applications combined with other financial technologies, each of which can replace a type of market intermediary. Blockchain is to financial services what TCP/IP is to the Internet: once the underlying standards are recognized and popularized, specific applications like Bitcoin and R3 will appear in every corner of financial services.