简单介绍区块链和比特币的关系,简单介绍区块链和比特币的区别

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① What is digital currency blockchain

1. Blockchain is a ledger that records digital currency transactions
Take Bitcoin as an example, it has no physical form , but exists in a special ledger. All Bitcoin transactions are recorded in the ledger. Through the transaction records, we can calculate the number of Bitcoins owned by each user. If a person owns Bitcoin, it means that transaction records related to him can be found in the ledger.
The ledger mentioned here is a piece of software, which we can download from the official Bitcoin website, and the underlying technology used in this software is the blockchain. To facilitate understanding, we usually say that the blockchain is the ledger.
The reason why blockchain is used as the underlying technology of the ledger is to achieve the decentralization of digital currency. It can be said that the starting point for a series of problems encountered by digital currencies and the solutions provided comes from decentralization.
2. Blockchain is a technology that ensures the safe use of digital currencies. Everyone knows that blockchain technology has two major characteristics: encryption and non-tamperability, which can reduce the probability of errors during the use of digital currencies. reduced to 0. Since digital currencies have higher requirements for encryption, blockchain technology must be used to support them. Currently, not only many industries in our country are using blockchain technology, but many foreign countries are also actively using blockchain technology. Blockchain technology.
[Extended information]
Blockchain is the underlying technology of digital currency, and Bitcoin is the first successful application of blockchain.. To understand this problem, we must first recognize the facts: not all blockchains require Issuing digital currency, currently our country strongly supports "coinless blockchain". Generally speaking, public blockchain, that is, public chain, needs to issue tokens as "rewards" to motivate users and maintain system operation, while ordinary blockchain , often called a consortium chain, can or cannot be issued. Private blockchains are mostly used for company internal audits and generally do not need to issue coins. The following is a detailed explanation of the differences between the three blockchains:
1. Public block Chain: A blockchain in which anyone in the world can read and send transactions for validity confirmation, and anyone can participate in its consensus process. Bitcoin and Ethereum are typical applications of public blockchains. Public blockchains are a global Distributed blockchain, blockchain data is open, user participation is high, and it is easy to produce network effects, easy to apply and promote. Therefore, this kind of blockchain operation relies heavily on the incentive mechanism, Bitcoin Tokens such as Ethereum and Ethereum are used as "rewards" for incentives, so public chains need to issue tokens to maintain their own development and ecology.
2. Community Blockchain (Alliance Chain): It means that the participation of nodes in the blockchain is selected in advance. There are usually good network connections and other cooperative relationships between nodes. The data on the blockchain can be open It can also be internal. For partial distribution, we can regard it as "partial decentralization". Each alliance in the chain has its own centralized management. For example, R3CEV of more than 40 banks is a typical alliance chain.Chains usually do not require a lot of money, but there are also individual alliance chains that choose to send money to encourage members within the alliance to contribute, so there are no restrictions on the chain.
3. Private blockchain: refers to a node with a limited scope of participation, such as a specific organization’s own users, strict permission management for data access and use.. Write permissions in a completely private blockchain It is only in the hands of the participants, and the read permission can be opened to the outside world or restricted to any extent. It is currently mainly used for internal audit work of the company. Therefore, the private chain does not need to issue currency, and it does not have the characteristics of decentralization. It is a kind of centralization management mechanism.

② Give an example of what is blockchain

Question 1: What is blockchain technology? What exactly is blockchain? What is blockchain? 1. Data blockchain is an important concept in the Bitcoin financial system. It records transaction record data on the entire Bitcoin network, and these data are shared by all Bitcoin nodes. Through the data block, we can query each transaction record. A look at the history of Bitcoin transactions. 2. Example: There are three persons A, B, and C. All funds of A and B are kept by C. And every financial transaction must be recorded by C. Now assume that A and B each have 1 million in custody of C. Then: A spends 80,000 yuan to B, then C's account book record will subtract 80,000 yuan from A's name, and add 80,000 yuan to B's name. If B transfers 50,000 yuan to A, C will add 50,000 yuan to A's name and subtract 50,000 yuan to B's name in the account book. A spends 50,000 yuan to B, then C's account book record will subtract 50,000 yuan from A's name, and add 50,000 yuan to B's name. 3. The role of the data blockchain is similar to that of C’s account record book. It records the user’s ownership of Bitcoin and the records of all users’ Bitcoin transactions. It’s just that this “account record book” is recorded by the mining software of every Bitcoin miner on the network. If a Bitcoin transaction is confirmed by the data blockchain, the relevant information will be recorded in the data blockchain. Bitcoin’s “account record book” is called the data blockchain. All data blockchains on the network form Bitcoin’s distributed network database system. 4. The essence of data blockchain technology is a decentralized and distributed structure of data storage, transmission and certification methods. It uses data blocks to replace the current Internet's dependence on central servers, so that all data changes or transaction items are recorded. On a cloud system, the self-certification of data during data transmission is theoretically realized. In a far-reaching sense, this transcends the traditional and conventional information verification paradigm that relies on a center and reduces the cost of establishing global "credit." This point-to-point verification will produce a "basic protocol", which is a new form of distributed artificial intelligence and will establish a new interface and shared interface between human brain intelligence and machine intelligence.

Question 2: What is the transaction process of the blockchain? Best to give an example 20 points 1. Definition
BlockchainIt's like an open network ledger. It originated from Bitcoin and is the underlying technology of Bitcoin. In a Bitcoin transaction, all the information recorded in the transaction is packaged into a "Block" for storage. With the expansion of information exchange, blocks are linked to each other, forming a blockchain.
2. Characteristics
Digital currency represented by Bitcoin is a peer-to-peer electronic cash system. Among them, each transaction will be broadcast to all participants in the network, and will be recorded in the ledger after multiple confirmations. This ledger is the "blockchain". Each participant will have his own ledger. In this way, when false information occurs, it can be broken through mutual verification, thereby ensuring network security.
In the blockchain, every node is equal, and there is no centralized management organization. This "decentralization" feature makes the blockchain unnecessary to rely on third parties, and its operation does not require any human effort. intervention, capable of independent self-validation. In addition, the blockchain network is open to the world, and anyone can query data through the public port, so the entire system is highly transparent.
3. Application
In short, the blockchain is a trusted database and a reliable "ledger". In the future, it will be used in cross-border payments, securities, loans, voting, etc. For example, in cross-border payments, with the security provided by blockchain, money can be sent to the world anytime and anywhere, thus eliminating many intermediate links and high handling fees.

Question 3: What is blockchain? What does it mean in layman’s terms? What is China’s attitude towards blockchain? What can blockchain do? Blockchain, a great technology that accompanied the birth of Bitcoin, is currently being used in the financial field to significantly reduce transaction costs and improve efficiency, which is enough to excite Wall Street. However, this is just the tip of the iceberg. Its potential applications are very broad and will subvert every aspect of our lives in the future.
Blockchain is an important concept of Bitcoin. It is essentially a decentralized database and serves as the underlying technology of Bitcoin. One of the most basic characteristics of Bitcoin is decentralization. In recent months, financial giants have gradually begun to pay attention to Bitcoin's technology and used it in non-monetary fields, such as stock trading, election voting, etc. (1) Art Industry
Artists can use blockchain technology to declare ownership and issue numberable, 100% edition works in digital form for any type of artwork. It even includes a marketplace where artists can buy and sell through their website without the need for any intermediary services.
(2) Real estate industry
Use blockchain technology to solve various problems faced by everyone involved in real estate, including the naming process, land registration, agency intermediaries, etc.
/> (3) Insurance industry
The financial industry has always been the most sensitive to advanced technology. Traditional banking and securities industry giants have been involved in the booming blockchain venture capital investment since 2014, with total global investment reaching US$1 billion within two years.
(4) P2P wallet
Personal assets can be traded through this P2P wallet in the future without going through any central institution, such as Bitcoin.
Most blockchains are in their infancy, mainly overseas. There are very few good domestic blockchain projects, so it is not recommended for any non-professionals to invest in blockchain projects. If you are very interested in blockchain technology and have a technical or financial background, it is recommended that you consider starting a business in this area. In terms of the blockchain protocol system, the lowest layer is the underlying technology of the blockchain, including the technical protocols of the blockchain, as well as some platform routing and basic algorithms; in the middle layer, some application interfaces and some credentials must be solved Issuance and verification, including some industry platform services, big data analysis, etc. This is a very rough classification, and there should be more detailed classifications; the top ones are some applications of blockchain, including finance Some applications and some applications in other aspects, the Internet of Things and so on.
Introduction to Bubi Blockchain
Bubi Blockchain has been focusing on the research and development and innovation of blockchain technology and products since its establishment. It has a number of core technologies and has achieved substantial results in many aspects. Radical innovation has resulted in a number of core technological achievements, such as: mathematically provable distributed consensus technology, fast large-scale ledger access technology, multi-chain general ledger technology that supports business expansion, and interconnection technology between heterogeneous blockchains. wait. On April 25, "Gege Points" introduced the concept of blockchain into the points system, jointly opened it up with multiple parties, issued and redeemed points, and promoted the circulation of points. Each cooperative institution can jointly participate in transaction verification, ledger storage, and real-time settlement; the third-party payment platform of the enterprise points issuer makes the entry and exit of points more flexible. Bubi has developed its own basic blockchain service platform, which has been applied in equity, supply chain, points, credit and other fields. Bubi has been committed to building an open value circulation network with decentralized trust as the core, allowing digital assets to flow freely.
A simple understanding of blockchain is a technology at the bottom of Bitcoin, which is also a peer-to-peer electronic cash system that can realize peer-to-peer value delivery. We should distinguish between Bitcoin, Bitcoin blockchain, blockchain and blockchain. Blockchain technology and other concepts. In countries with relatively developed finance in the past, finance and blockchain technology have a long history, and the legislation of digital currencies and blockchain networks is also very important. With the advent of the financial era, large financial institutions are studying blockchain technology. They have their own teams and conceptual technologies. Slowly, banks in various regions are also participating in digital currency discussions. The application and support of this technology are not only that. The impact of blockchain on enterprises is also huge. For larger domestic enterprises, Bubi Blockchain is also used in various equity, supply chain, points and other fields. Major domestic financial institutions and enterprises have taken a fancy to the value of the new industry and developed their own blockchain platforms. Blockchain has instantly become a domestic New innovative industries. In terms of overseas internationalization, the United States has already obtained 15 blockchain patents at the end of last year compared to China. Blockchain financial applications are entering a new stage in an all-round way. Various applications will become more and more in-depth, and related changes will also become more and more profound. It is attracting more and more attention and will form a huge new trend... >>

Question 4: What is blockchain technology? What is blockchain? How to explain the concept of blockchain? People in each industry have different understandings, and relevant explanations are gradually emerging due to more and more real-life applications. With the popularization of this blockchain technology, the related results are getting bigger and bigger. If we want to understand this technology, we must have an in-depth understanding of reality.
In the past six months, the concept of blockchain has gradually become popular in China, and a blockchain whirlwind has taken off in the financial circle. Blockchain has attracted the attention and favor of more and more people in the industry due to its unique technical advantages. Blockchain technology, which is decentralized (or multi-centered), highly transparent, cannot be tampered with, and has no single point of failure, is entering the field of vision of financial institutions and enterprises. It has at least been used in digital currency, payment exchange, registration and settlement, Digital assets, traceability and anti-counterfeiting, supply chain, Internet of Things and many other fields have moved from theoretical discussions to practical applications.
"Blockchain" was first introduced with "Bitcoin" released in early 2009. Blockchain has become the basic protocol and technical application for the launch, recording, and circulation of Bitcoin. Although Bitcoin has been controversial since its inception and cannot even be regarded as a "currency" by governments and monetary authorities, the blockchain technology used in Bitcoin has been recognized by governments, including governments and monetary authorities. extensive attention.
Why has blockchain become a rapidly heating up hot technology and topic?
The most important of these may be that the launch of Bitcoin based on blockchain technology has opened up a new relationship with traditional society ( The exploration and attempt of new technologies and rule systems such as Internet user identity verification, wealth confirmation, transaction records, notarization and verification, which have little connection with offline) and are completely applied to the online world (online), provide people with the opportunity to adapt to the Internet society. Development provides alternative paths and unlimited imagination.
Judging from its application in Bitcoin, blockchain is a set of new network blocks (BLOCK, also called communities) formed by combining encryption technology with the Internet. Bitcoin configuration, netizen identity verification, and Bitcoin (value) confirmation formed by mining, Bitcoin transaction records, and extended encryption of Bitcoin cross-block flow (value transfer) (added block and transaction time identification, etc. Factors) registration and verification, block connection (Blockchain, that is, blockchain), full encryption, and mutual authenticationInternet protocol rules and accounting (Ledger) system. Precisely because Bitcoin is not a substitute for offline legal currency, but is issued and managed by non-legal currency authorities, mainly imitating the model of gold, and is completely new and decentralized protected and supported by basic Internet protocols and strict encryption technology. Internet currency (virtual currency) has thus formed a new set of currency rules and systems that are different from and not subject to real social laws, and can be bought, sold or exchanged with legal currency. It has been more than 8 years since Bitcoin was launched. There has been no record of funds or user information being stolen. Its security has been verified, and its efficiency and cost of fund settlement also have obvious advantages. This has made people's confidence in the blockchain technology used in Bitcoin continue to increase, and people have become more and more aware that although blockchain is a technology and protocol pioneered and applied by Bitcoin, the blockchain Chain is not the same as Bitcoin, and its application is by no means limited to Bitcoin. The application of blockchain can be decentralized or centralized; it can be a public chain model or a private chain model. Therefore, after Bitcoin, blockchain technology is also constantly developing and innovating, and constantly exploring new application fields, especially in the financial field.
The reason why blockchain is valued highly by more and more people is because the development and widespread application of the Internet have caused more and more economic exchanges and transaction activities to be conducted online, and the online world (or online world) society) is rapidly expanding, enriching and active, and online transactions must solve the efficiency and security protection issues of the parties' identity verification, value verification, transaction records, inspection and verification, etc., and require strict intermediaries and agreements (rules or constitutions). In this regard, traditional thinking and customary practices are to follow the development trajectory of the transfer of offline transactions to online and push the common rules and practices of the real (offline) society to the online (network) society. However, in practice, it is increasingly It is difficult to adapt to the needs of online transactions.
For example, for the identity verification of the parties, the natural choice is to use the information on the identity documents protected by the laws of various countries as the basis, and then add account or transaction passwords, as well as facial recognition, iris, fingerprints and other biometrics to conduct online transactions. Verification, but this method first makes the citizen identity information in the cross-border interconnected online world subject to the administrative jurisdiction of real society... >>

Question 5: The so-called "district" What is "Blockchain"? Blockchain itself is a tool called decentralization and trustlessness. For example, when you graduate from university, the current practice is to have a certificate recognized and issued by an authoritative agency as your certificate. This setting is more troublesome, because this is a piece of paper, and paper can be forged, so there will be various gaps. The issuing authority is also a person, and there will be various gaps in the middle. As long as it is related to people, whoever There are various possibilities related to media. Blockchain provides a good opportunity. As soon as you graduate, you will be in the districtA record is generated on the blockchain, and no one can change this record. This thing exists objectively. As a physical existence, and then as a data existence, the blockchain is born. In this case, anyone who wants to check where you graduated can easily solve the problem. This is similar to the big data often involved in social networking (WeChat) and payment platforms (Alipay, Yibao).

Question 6: What is blockchain? Can you explain the principle of 10-point blockchain in plain language: decentralized distributed accounting system
Blockchain The core of the technology is that all currently participating nodes jointly maintain transactions and databases. It makes transactions based on cryptographic principles rather than trust, so that any two parties who reach an agreement can directly conduct payment transactions without the participation of a third party.
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Technically speaking, a block is a data structure that records transactions, reflecting the flow of funds for a transaction. The blocks of transactions that have been reached in the system are connected together to form a main chain, and all nodes participating in the calculation record the main chain or part of the main chain. A block contains the following three parts: transaction information, hash hash formed by the previous block, and random number. Transaction information is the task data carried by the block, specifically including the private keys of both parties to the transaction, the number of transactions, the digital signature of electronic currency, etc.; the hash formed by the previous block is used to connect the blocks to realize the past The order of transactions; random numbers are the core of transaction completion. All miner nodes compete to calculate the answer to the random number. The node that gets the answer the fastest generates a new block and broadcasts it to all nodes for update, thus completing a transaction.
1.1 What is Blockchain
Blockchain (BlockChain) refers to a technical solution that collectively maintains a reliable database through decentralization and trustlessness. This technical solution mainly allows any number of nodes participating in the system to associate and generate a series of data blocks (blocks) using cryptographic methods. Each data block contains all the information exchange data of the system within a certain period of time, and generates The data fingerprint is used to verify the validity of its information and chain to the next database block.
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In layman’s terms, blockchain technology refers to a way for all people to participate in accounting. Behind all systems there is a database, which is a big ledger. Then who will keep this ledger becomes very important. At present, it is whoever owns the system who keeps the accounts. Each bank’s account books are kept by each bank, and Alipay’s account books are kept by Alibaba. But now in the blockchain system, everyone in the system has the opportunity to participate in accounting. If there are new transaction data changes within a certain period of time, everyone in the system can do accounting. The system will judge the person who has the fastest and best accounting during this period, write the recorded content to the ledger, and Send the account book contents during this period to the systemBack up everyone else in the system. In this way, everyone in the system has a complete ledger. Therefore, this data becomes very safe. A tamperer needs to modify more than half of the system node data at the same time to truly tamper with the data. Such tampering would be extremely costly, making it nearly impossible. For example, Bitcoin has been running for more than 7 years. Countless hackers around the world have tried to attack Bitcoin, but so far there have been no transaction errors. It can be considered that the Bitcoin blockchain has been proven to be a safe and reliable system.
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1.2 Why is there blockchain innovation?
Human beings need to communicate during their activities, and communication is based on information. In the past, information circulation was not convenient enough to satisfy market participants. There is a demand for information, so intermediaries and centers are born. This centralized system has problems such as high cost, low efficiency, value dispersion, "information islands" and insecure data storage. However, due to technical and environmental factors, this system continued to operate for many years until the emergence of the Internet. The starting point of the first generation of the Internet is the TCP/IP protocol, which is an open code that implements a unified format for peer-to-peer transmission of information by all nodes on the network, and brings the basic values ​​of freedom and equality required by a global unified market into programmed, protocol-based, and reliably Execution. The Internet eliminates low-value, high-cost intermediate chains and achieves low-cost and high-efficiency global information transmission in a decentralized manner.
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However, the first generation of the Internet did not solve the problem of information credibility. Activities that can be decentralized on the Internet must be activities that do not require credit endorsement, and activities that require credit guarantee must be activities involving centralized third-party intermediaries. Therefore, Internet technology that cannot establish global credit has encountered great obstacles in its progress - people cannot participate in any value exchange activities on the Internet in a decentralized manner. To realize value exchange, people still need third-party intermediaries based on credit (such as banks, clearing agencies, exchanges). The global centralized credit system still has problems such as high operating costs, low efficiency, and vulnerability to attacks and damage. For example, each country's legal currency has different credit values ​​and incompatible clearing systems, which adds a lot of cost to global trade.
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Therefore, what the second generation Internet must break through is: how to establish global credit in a decentralized manner? Let...>>

Question 7: Explain clearly what is blockchain in an easy-to-understand manner. The English name for blockchain is Blockchain. Block literally means block, block, and chain means chain, chain. Therefore, together they are translated into blockchain.
1. Use cryptography technology to encrypt and decrypt so that records cannot be tampered with. Common blockchain encryption methods include hash algorithm, RSA algorithm, elliptic curve algorithm, etc.;
2. The huge amount of calculation requires reasonable rewards.Mechanism support. Because every transaction must be recorded, Bitcoin’s blockchain has more than 60 gigabytes so far. Every new transaction requires confirmation of the information related to the trading account to ensure that the transaction is valid. The huge amount of calculation requires a computer with powerful computing power to complete.
In order to encourage the participation of powerful computing power, Bitcoin provides two rewards: one is to issue a certain number of Bitcoins to these computers every day; instead, all transfer fees are awarded to these computers. (The technical term for these computers is "mining machines", and the people who hold the mining machines are called "miners".)
Biying China is working hard on the digitization of assets and has launched the digital currency crowdfunding platform Biying China.

Question 8: What is blockchain? Blockchain is a new application model of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. The so-called consensus mechanism is a mathematical algorithm that establishes trust and obtains rights and interests between different nodes in the blockchain system.
In May 2016, the Currency Blockchain Research Center published the first book in China that introduces blockchain in simple terms, "Blockchain: Defining a New Pattern of Future Finance and Economics." It introduces the impact of blockchain technology on future finance and economy

Question 9: What is blockchain? For the time being, this is a relatively high-end technology. It connects all nodes (which can be understood as servers) through p2p network technology. Complete data (blocks) are stored on each node. The addition and withdrawal of any node will not affect the normal operation of the chain. Data is embodied in the form of data blocks. Blocks are connected to each other and can be understood as a one-way linked list. The hash value of the nth block is generated based on the hash of the n-1th block, the transaction recorded in the current block, and the random number as parameters. In this way, if you want to modify the data of the historical block, you have to modify all the blocks from the modified block to the final block. The difficulty can be imagined.
The blockchain also introduces a consensus mechanism and an incentive mechanism. There is no way to describe it too comprehensively here. I hope everyone can discuss and learn together

Question 10: What is blockchain: This explanation of blockchain is more understandable. Blockchain (Blockchain) refers to the method of decentralization and trustlessness. A technical solution for collectively maintaining a reliable database.
In layman’s terms, blockchain technology refers to a way for all people to participate in accounting. There is a database behind all systems. You can think of the database as a big ledger. Then who will keep this ledger becomes very important. Currently, whoever owns the system keeps the accounts. Tencent keeps the accounts of WeChat, and Alibaba keeps the accounts of Taobao. But now in the blockchain system, everyone in the system has the opportunity to participate in accounting. If there are any data changes within a certain period of time, the systemEveryone can do accounting. The system will judge the person who has the fastest and best accounting during this period, write the contents of his records into the ledger, and send the contents of the ledger during this period to all other people in the system. Make a backup. In this way, everyone in the system has a complete ledger. In this way, we call it blockchain technology.
Blockchain technology has become the darling of the financial community in China and has become a hot topic. Domestic Puyin Group has launched Puyin, a tea-based digital currency.

③ What is the relationship between Bitcoin and blockchain?

In simple terms:

1. Bitcoin is a digital currency, and blockchain is a technology.

2. Blockchain is the underlying technology of Bitcoin, and Bitcoin is the first application of blockchain technology; as a state-supported and vigorously developed blockchain technology, it will be widely used in the future All walks of life.

3. Blockchain technology is not a new technology, but a new logic of thinking. It just rearranges and combines many previously unrelated algorithmic technologies.

4. Blockchain is a block connected to a block. Thousands of blocks form a chain. To connect the next block, you need to calculate the algorithm. The answer (mining), and the reward for mining is Bitcoin.

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④ What are the differences and connections between blockchain and Bitcoin?

Blockchain technology is a new technology derived with the development of the Bitcoin economy. Blockchain technology can effectively The ground serves the Bitcoin economy, and they are interconnected. Bitcoin is a virtual currency that only circulates in a specific network economic environment. Blockchain technology can not only be applied to the economy, but can also be used in all walks of life. This is their difference.

Blockchain Technology

Because blockchain technology is still an emerging product, it does not yet have an accurate or definite definition and concept. Simply put, blockchain technology is a model for encrypted management of data, which can protect data to a large extent. Blockchain technology has the distinctive characteristics of decentralization, openness, independence, security and anonymity. Its characteristics are well adapted to today's requirements for information protection and information disclosure in all walks of life. On the one hand, it ensures data security and prevents data processing from being interfered by factors such as human subjective emotions and system failures. On the other hand, it is up to the individual data to decide whether to hide their details from the group to the greatest extent possible to achieve the purpose of protecting privacy.

At the same time, there is no doubt that blockchain technology is still in a preliminary state of development. Society's understanding of it is not deep enough, and scholars are still in the stage of continuous exploration. Through correct application, blockchain technology will bring many positive impacts to society.

⑤ What is the relationship between blockchain and Bitcoin?

Blockchain technology is the basic technology of Bitcoin and is also the core and infrastructure of Bitcoin. Bitcoin has always beenThere is no centralized organizational operation and management. Later, Bitcoin technology was abstracted and called blockchain technology, or distributed ledger technology.

(1) Blockchain is the core and infrastructure of Bitcoin:

1. In the Bitcoin system , "currency" is simply the unit of account used in that ledger. The most important thing is not the concept of "currency", but the concept of "ledger" without a central storage organization. For example: I lend 50 yuan to someone else. At this time, I asked the financial staff to help me keep accounts.

2. Blockchain technology is the basic technology of Bitcoin and the core and infrastructure of Bitcoin. Bitcoin has always been operated and managed without any centralized organization. Later, Bitcoin technology was abstracted and called blockchain technology, or distributed ledger technology.

(2) Blockchain is the core and infrastructure of Bitcoin:

1. In the Bitcoin system, “currency” is just the accounting used in the ledger. unit. The most important thing is not the concept of "currency", but the concept of "ledger" without a central storage organization. For example: I lend 50 yuan to someone else. At this time, I asked the financial staff to help me keep accounts. Bookkeeping must be paid, so I need to pay the financial staff.

Because an incentive mechanism has also been invented in the Bitcoin system technology, which is equivalent to what I just said, you can help me keep accounts and I will pay you, but not everyone can keep accounts. rewards. Therefore, the blockchain has designed a corresponding mechanism competition mechanism.

2. The competition mechanism uses a hash algorithm to determine the ownership of rewards. Generally speaking, everyone is given a math problem. The reward is for whoever calculates the result first. The calculation process of the hash algorithm is a process in which a professional computer (we call it a miner) uses the hash algorithm to calculate the results, which is called mining.

For the fastest and best bookkeepers, the system writes the recorded contents into the account books and sends the account book contents to everyone in the system for backup. This way, everyone in the system has a complete ledger called blockchain technology.

(3) The origin of blockchain:

1. The origin of the word "blockchain" is from the original English version of the Bitcoin white paper "Blockchain". When translating this sentence, the Chinese market directly used the word "blockchain" and then directly wrote it as "blockchain", which became a proper noun at the global blockchain technology level.

So, no matter who explains the blockchain, Bitcoin cannot be bypassed. If you want to introduce the history of cars, just like you can't avoid Carl Benz; if you want to introduce the history of airplanes, just like the Wright brothers.

2. Bitcoin "invented" and proved the feasibility of blockchain technology. Bitcoin is not the entire blockchain technology, just one of its applications. But without Bitcoin, or if Bitcoin's applications were not successful, blockchain might not have emerged, or at least not for many years. Therefore, it is difficult for the blockchain to be "isolated" from Bitcoin for a long time.

(5) Brief introduction to blockchain and Bitcoin Extended reading:

Blockchain technology applied to digital currency Disadvantages:

First, "decentralization" does not have a circulation management agency. In essence, blockchain technology is a distributed database system, its logical structure is a one-way linked list, and its design model is based on P2P network, which determines that there is currently no unified virtual currency central control system based on blockchain technology. .

Second, quantity supply is difficult to effectively control. Based on blockchain technology, the issuance amount of virtual currency is fixed. According to the Fisher equation, at a certain price level, the total transaction volume of the whole society in a certain period has a certain ratio to the required nominal amount of money, and a fixed amount of money obviously cannot meet the requirements of the ever-increasing total price of social commodities.

Third, it is difficult for the “mining mechanism” to create recognized value. Bitcoin itself has no value and is not backed by national credit. Some people think that "value is injected into virtual currency by continuously consuming computing power and energy", but in order to find a hash value that meets the requirements, spending millions of calculations is obviously not the most efficient option.

Fourth, producers and early holders can easily obtain high seigniorage taxes. Any virtual currency based on blockchain technology will be held by a small number of people in the early stages of development. Take Bitcoin for example. At first, Bitcoin was just a product of a few people's game. In May 2010, the first transaction to buy Bitcoin was a $25 pizza purchased for 10,000 Bitcoins, and the first transaction completed in July of the same year was $0.04/Bitcoin.

⑥ What are Bitcoin and Blockchain?

1. The difference between Blockchain and Bitcoin:
Blockchain is a technology based on blockchain The technology can have many applications
Bitcoin: one of the most popular and well-known applications
2. What is the essence of blockchain technology?
Blockchain is essentially a decentralized distributed ledger database. Does this sound confusing? Don't worry, I will explain them one by one in the most simple and easy-to-understand way later. Anyone can verify this public ledger, but no single user can control it. Participants in the blockchain system will jointly maintain the update of the ledger: it can only be modified according to strict rules and consensus, and there is a very exquisite design behind this.

⑦ What is blockchain

Let’s talk about some basic concepts first.

The network said that blockchain is a new usage model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanisms, and encryption algorithms. It is essentially a decentralized database, and as the underlying technology of Bitcoin, it is a series of data blocks generated by cryptography.

We try to translate "what is blockchain" into "human language".

The definition refers to the "decentralized database" nature of blockchain3354. This is significantly different from the traditional "centralized database" in terms of storage, update and operation.s difference.

A centralized database can be thought of as having this shape:

For example, if I want to use Alipay to pay a Taobao seller, all data requests from when I make money to when he receives the money will be centrally processed by Alipay. The advantage of this data structure is that as long as Alipay is responsible for the efficient and safe operation of the system, others can unconditionally believe it without worrying; the disadvantage is that if there is a problem with Alipay, such as being hacked, the server being burned, a traitor appearing, and the company running away (Of course, the possibility of the above is extremely low), the balance details and other information in our Alipay will be confused.

Then some people think that this kind of low-probability event can use any technical means to avoid individual risks, and not only hand over the data to a centralized organization. For example, everyone can store and process data.

The database structure may look like this:

This picture is a schematic structural diagram of a "distributed database". Each point is a server, they all have equal rights to record and calculate data, and information is spread point-to-point. At first glance, it seems that it can indeed resist the risk caused by the crash of a certain node, but it is also very confusing and inefficient intuitively. Who will handle my information, and who has the final say on the outcome?

At this time, the "consensus mechanism" in the definition of blockchain comes into play. The consensus mechanism mainly "stipulates" the following things: who will process a data request (what qualifications are required); who will verify the results (to see if he has handled it well); how to prevent processors and verifiers from colluding with each other, etc.

Some people may like to be questioned when a "rule" is made. In order to form a stronger consensus, in addition to making the rules more reasonable, they must also be more attractive so that people are interested and motivated to participate in data processing. This involves the incentive mechanism of the public chain. We will start again later when we discuss the classification of blockchain and the role of digital currencies.

When we hand over a transaction to a distributed network, there is also a "psychological threshold": there are so many nodes that can process information, and I don't know any of them (unlike Alipay, if it hurts me, I can go and file a lawsuit against it). They all have my data, why should I trust them?

At this time, encryption algorithm (the last descriptive word in the definition of blockchain) comes on stage.

In the blockchain network, the data requests we send will be encrypted according to cryptographic principles into a string of characters that the recipient cannot understand at all. Behind this encryption method is the support of a hash algorithm.

Hash algorithms can quickly convert any type of data into hash values. This change is one-way irreversible, deterministic, random, and anti-collision. Because of these characteristics, the person handling my data request could record the information for me, but they had no idea who I was or what I was doing.

So far, the working principle of the decentralized network has been introduced. But we seem to have overlooked one detail. The previous diagram is a net. Where are the pulleys and chains? Why do we call it blockchain?

To understand this matter, we need to clarify a few knowledge points first:

The previous picture is actually a "macro" database perspective diagram, showingIt shows the basic rules and processes for processing information in the blockchain system. And specifically at the "micro" data log level, we will find that the ledger is packaged, compressed, stored in blocks, and strung together in chronological order to form a "chain structure", like this:

Figure Each ring in can be regarded as a building block, and many links are linked together to form a blockchain. Blocks store data, unlike ordinary data storage: on a blockchain, the data in a later block contains the data in the previous block.

In order to academically explain the fields of each part of the data in the block, we tried to use a book metaphor to describe what a blockchain data structure is.

Usually, when we read a book, we read the first page, then the second and third pages. The spine is a physical existence that fixes the order of each page. Even if the book is scattered, the order of each numbered page can be determined.

Inside the blockchain, each block is labeled with a page number, the second page contains the first page's content, the third page's content contains the first and second page's content. The tenth page contains the previous Nine pages of content.

It is such a nested chain that can be traced back to the original data.

This brings up an important attribute of blockchain: traceability.

When the data in the blockchain needs to be updated, that is when new blocks are generated in sequence, the "consensus algorithm" comes into play again. This algorithm stipulates that a new block can only be formed if it is recognized by more than 51% of the nodes in the entire network. To put it bluntly, it is a matter of voting, and it can be elected if more than half of the people agree. This makes the data on the blockchain difficult to tamper with. If I were to force a change, there would be too many people to bribe and the cost would be too high to be worth it.

This is what people often call the "non-tamperable" feature of blockchain.

Another reason why blockchain gives people a sense of trust is because of "smart contracts."

Smart contracts are commitment agreements defined and automatically executed by computer programs. It is a set of transaction rules executed by code, similar to the current automatic repayment function of credit cards. If you turn on this function, you don’t have to worry about anything. The bank will automatically deduct the money you owe when it is due.

When your friend borrows money from you but doesn't remember to pay it back, or makes excuses not to pay it back, smart contracts can prevent breach of contract. Once the terms in the contract are triggered, such as when it is time to repay the money, or there is a limit in his account, the code will automatically execute, and the money he owes you will be automatically transferred back whether he wants it or not.

Let’s briefly summarize. Blockchain technology is mainly decentralized, difficult to tamper with, and traceable, which represents more security and trustlessness. But it also brings new problems: redundancy and inefficiency, which requires many nodes to agree with the rules and actively participate.

This concludes the "drying" section. Next, let’s talk about unofficial history and the official history of blockchain.

A new technology is often used to serve a certain task.

Or goals. So where was blockchain first used, and who came up with it first?

Let's go back to 2008.

On September 21, Wall Street investment banks collapsed one after another, and the Federal Reserve announced that it would retire the two remaining investment banks (Goldman Sachs Group and Morgan Stanley) into commercial banks; hoping to survive the financial crisis by absorbing savings. On October 3, the Bush administration signed a $700 billion financial rescue package.

Twenty-eight days later, on November 1, 2008, a new post appeared in a cryptography mailing group: "I am developing a new electronic currency system that is completely peer-to-peer and does not require a third party. Three-party trust institution." The text of the post is a paper titled "Bitcoin: A Peer-to-Peer Electronic Cash System", signed by Satoshi Nakamoto.

The paper explains the design of this peer-to-peer electronic cash system with a more rigorous logic. It first discusses the problem that financial institutions are subject to "trust based" (based on credit), and then explains step by step how to achieve "no third-party agency" , and cleverly solved the technical problems left by the predecessors.

Two months later, Satoshi Nakamoto released the first version of the open source Bitcoin client and mined 50 Bitcoins for the first time. The block that generated the first batch of Bitcoins is called the "Genesis block". The genesis block was compiled into block 0 and was not uploaded to the chain. It took Satoshi Nakamoto 6 days to mine this block. This also sparked discussion in the bitcointalk forum. Bitcoin "believers" thought of the Bible, "God created the heavens and the earth in six days, and then rested on the seventh day."

Although concepts such as decentralized, token, and economy did not appear in the paper, Satoshi Nakamoto explained in detail the role of blocks and chains in the network. working principle. So, there is Block Chain.

This paper later became the "Bible" of the "Bit Cult", technology became the cornerstone of faith, and developer documentation became the "Code of Hammurabi".

After that, Bitcoin realized the first real-life payment by exchanging pizza, WikiLeaks, whose account was blocked by the US government, miraculously survived by relying on Bitcoin, Satoshi Nakamoto's "decentralization" and retirement, and the appearance of the real and the fake A series of legends such as and refutation of rumors, combined with the expectations, imagination and speculation of later generations, became "Bible stories".

There are also people who are not satisfied with the world described in the "Old Testament" and start new sects, write the doctrines into white papers, and tell the story of their faith in the ten years after Bitcoin. Just like the writing of the 66 books of the Bible spanned 1,500 years, and after 2,000 years of interpretation, Christianity has divided into 33,000 branches.

CoinMarketCap shows that there are more than 4,900 types of digital currencies, and the overall digital currency market size is nearly 140 million yuan. Bitcoin still leads the entire digital currency market with a market share of 66%, and the recent price has been hovering around US$7,200 per coin.

So many currencies have different functions and are divided into differentCategories: Digital currencies represented by Bitcoin are positioned as "digital gold" and have certain store-of-value and hedging properties; digital currencies represented by Ethereum have become the "operational fuel" in their network systems; Stablecoins represented by USDT and Libra have good payment capabilities due to their low volatility; central banks represented by DCEP issue digital currencies, which to a certain extent replace M0, allowing commercial institutions and ordinary people to survive when they have no cash and are disconnected from the Internet. time, and there is no delay in collection and payment.

It can be seen that after 10 years of development of blockchain technology, the first and largest application is digital currency.

Digital currency has also become an attractive reward for participants to maintain the public chain.

So besides digital currency, where else can blockchain technology be used?

Let us recall what the essence of blockchain is—a decentralized database, and its corresponding characteristics: traceability, publicity, anonymity, and tamper-proofing. In theory, you can try to use blockchain to transform traditional scenarios that use centralized databases to see if they are suitable.

Next, let’s talk about several industries and scenarios where blockchain has been successfully implemented:

Blockchain can prove the existence of a certain file or digital content at a specific time through hash timestamps, providing judicial authentication, Identity proof, property rights protection, anti-counterfeiting traceability, etc. provide perfect solutions

In the field of anti-counterfeiting traceability, blockchain technology can be widely used in various fields such as food and medicine, agricultural products, alcohol, and luxury goods through supply chain tracking.

Give two examples.

Blockchain can allow government data to be run, greatly streamlining service processes

The distributed technology of blockchain can allow government departments to be centralized on one chain, and all service processes are delivered to smart contracts, and the workers only need to be in one department Through identity authentication and electronic signature, smart contracts can be automatically processed and transferred, and all subsequent approvals and signatures can be completed in sequence.

Blockchain invoices are the earliest use of blockchain technology in China. The tax department launched the "Tax Chain" platform for blockchain electronic invoices. The tax department, the issuer, and the payee join the "Tax Chain" network through unique digital identities, truly realizing "instant invoicing for transactions" and "instant reimbursement after invoicing" - in seconds Level invoicing and minute-level reimbursement accounting significantly reduce tax collection and management costs, and effectively solve problems such as data tampering, over-reporting of one ticket, and tax evasion.

Poverty alleviation is another practical application of blockchain technology. Utilize the characteristics of openness, transparency, traceability, and non-tampering of blockchain technology to achieve transparent use, precise investment, and efficient management of poverty alleviation funds.

Give two examples as well.

The eID network identity operation agency guided by the Third Research Institute of the Ministry of Public Security is jointly developing a "digital identity chain" with Gongyilian, which will be issued to Chinese citizens based on the citizen's identity number as the root and cryptographic algorithm. Since it was put into operation, the eID digital identity system has served the full life cycle management of 100 million eIDs, effectively alleviating the problems of personal identity information being fraudulently used, abused and privacy leaked.

Odaily Planet Daily compiled 5 identity chain projects registered with the Cyberspace Administration of China

Blockchain technology naturally has financial attributes

In terms of payment and settlement, under the blockchain distributed ledger system, multiple market participants jointly maintain and synchronize a "general ledger" in real time, which can be completed in just a few minutes Completing payment, clearing, and settlement tasks that currently take two or three days to complete reduces the complexity and cost of cross-bank and cross-border transactions. At the same time, the underlying encryption technology of the blockchain ensures that participants cannot tamper with the ledger, ensuring that transaction records are transparent and safe. Regulators can easily track transactions on the chain and quickly locate high-risk capital flows.

In terms of securities issuance transactions, the traditional stock issuance process is long, costly and complicated. Blockchain technology can weaken the role of underwriting institutions and help all parties establish a fast and accurate information exchange and sharing channel. The issuer can handle the issuance on its own through smart contracts. , regulatory authorities conduct unified review and verification, and investors can also bypass intermediaries for direct operations.

In terms of digital bills and supply chain finance, blockchain technology can effectively solve the financing difficulties of small and medium-sized enterprises. It is difficult for current supply chain finance to benefit small and medium-sized enterprises in the upper reaches of the industrial chain, because they often do not have direct trade relations with core enterprises, and it is difficult for financial institutions to evaluate their credit qualifications. Based on blockchain technology, we can establish a consortium chain network covering core enterprises, upstream and downstream suppliers, financial institutions, etc. The core enterprises issue accounts receivable vouchers to their suppliers. After the bills are digitized and uploaded to the chain, they can be uploaded to the supplier Transfer between them, each level of supplier can realize the corresponding amount of financing with the digital bill certificate.

Give me an example.

The China Enterprise Cloud Chain, jointly launched by ICBC, Postal Savings Bank of China, 11 central enterprises, etc., has covered 48,000 companies since its establishment in 2017, with the amount of rights confirmed on the chain reaching 100 billion yuan, and factoring financing of 57 billion yuan. , cumulative transactions reached 300 billion yuan. After receiving the loan application, financial institutions can verify the authenticity of the contract on the chain and whether the contract has been verified multiple times (multiple loans); the smart contract automatically clears and settles, reducing costs and increasing efficiency; at the same time, the accounts payable of core enterprises can have The corresponding vouchers will be split by the first-level suppliers and handed over to the second- and third-level suppliers in the chain to help them with financing; core enterprises can also use this to understand whether the entire chain is operating normally and avoid emergencies. Redemption pressure.

Blockchain technology will greatly optimize the existing use of big data and play a huge role in data circulation and sharing

The aforementioned areas are areas that we are relatively familiar with. As more new technologies develop, blockchain may be able to be combined with them and play a role in unexpected cross-fields and new scenarios that are currently unforeseen.

In the future, the Internet, artificial intelligence, and the Internet of Things will generate massive amounts of data. The existing centralized data storage (computing model) will face huge challenges. Edge storage (computing) based on blockchain technology is expected to become a future solution. Furthermore, the non-tampering and traceability mechanism of blockchain ensures the authenticity and high quality of data, which becomes the basis for the use of all data such as big data, deep learning, and artificial intelligence.

Finally, blockchain can realize multi-party collaborative data computing under the premise of protecting data privacy, and is expected to solve the problem of ""Data Monopoly" and "Data Island" issues to realize the value of data circulation.

In view of the current blockchain development stage, in order to meet the blockchain development and use needs of general business users, many traditional cloud service providers have begun to deploy their own BaaS ("Blockchain as a Service") solution. The combination of blockchain and cloud computing will effectively reduce the cost of enterprise blockchain deployment and promote the implementation of blockchain usage scenarios. In the future, blockchain technology will also be used in charities, insurance , energy, logistics, the Internet of Things and many other fields.

During this trial process from traditional technology to blockchain, we found that when certain scenarios require traceability, tamper-proof, and decentralization It is stronger and does not have high requirements for the weaknesses of blockchain (such as performance). Such a field is quite suitable for combining blockchain.

At the same time, in the process of evolution, blockchain has also evolved from a The accessible, highly decentralized public chain has developed a consortium chain with different permissions and maintained by multiple centers, which balances the advantages and disadvantages of the two systems to a certain extent.

Typical cases of consortium chains include: FISCO BCOS jointly developed by WeBank and the Golden Alliance Open Source Working Group, Fabric, a major contribution from IBM, and Ant Alliance Chain led by Ant Blockchain, etc.

These trustless systems represent more secure data authentication and storage mechanisms where data is effectively authenticated and protected. Businesses or individuals can exchange or sign contracts digitally, where these contracts are embedded in code and stored in transparent, shared databases where In the database, they will not be deleted, tampered with, or revised.

It is boldly predicted that in the future, contracts, audits, tasks, and payments will all be digitized with unique and secure signatures, and digital signatures will be permanently identified. Authentication, legalization and storage, and cannot be tampered with. There is no need for an intermediary to guarantee each of your transactions. You can conduct transactions without knowing the basic information of the other party. While improving information security, it is effective Reduce transaction costs and improve transaction efficiency.

In general, there has been a lot of progress in the implementation of blockchain compared to two years ago.

Many improvements are at the bottom of the system, and users cannot directly It can be seen that the blockchain has been used and it has actually benefited from it; some uses are still in pilot and users have not yet been able to experience it. In the future, blockchain is expected to be used on a large scale and become one of the Internet infrastructure.

Hope Seeing this, you already have a general understanding of what blockchain is and what blockchain can do.

Related Q&A: What is blockchain

Blockchain is actually equivalent to a disintermediation The database is composed of a series of data blocks. Each of its data blocks contains information about a Bitcoin network transaction, and these are used to verify the validity of the information and generate the next block.< p>In a narrow sense, blockchain is a chain data structure that combines data blocks in a sequential manner in chronological order, and is cryptographically guaranteed to be non-tamperable and non-forgeable. Distributed ledger.

And CongguangIn a nutshell, blockchain is actually a distributed infrastructure and computing method that is used to ensure the security of data transmission and access.

Blockchain infrastructure:

Blockchain is composed of six infrastructures: data layer, network layer, consensus layer, incentive layer, contract layer and usage layer.

⑧ The difference between blockchain and digital currency

When it comes to blockchain, digital cash comes to mind. In fact, the two are different. What is the difference between blockchain and digital cash?

The organic combination of digital cash and block chain is closely related. Block chain is the most basic technology and the most important technical means of digital cash. The most successful practice of block chain is innovation in the currency field. As a One of the technologies of digital currency, the use of digital currency includes mobile payment, reliable cloud computing, cryptographic algorithms, etc. The popularity of Bitcoin has informed the technical framework and broad application prospects of the blockchain.

< p>The block chain is actually the digital bookkeeping book of Xinxingqianma Chain. This bookkeeping book has powerful functions and is equivalent to the cloud storage function. Every time a transaction is completed for a certain period of time, all transactions within that period of time will be recorded and Completely copied on all nodes. This is a block. Therefore, there is almost no possibility of information being tampered with, as long as almost all nodes cannot be invaded. A block is connected head to tail to form a block chain.

Digital Cash It is a form of encrypted cash. Because this kind of digital cash requires encryption, digital cash requires the support of blockchain technology. Blockchain technology is also the most advanced technology in the world. Many famous companies in the world are studying this technology. This technology The development prospects are unlimited

Common misunderstandings

1. The blockchain is Bitcoin

Since Bitcoin is more popular than its underlying technology blockchain, many People confuse the two. Blockchain is a technology that records peer-to-peer transactions on a distributed ledger across the entire network. These transactions are stored in blocks, and each block is linked to the previous block, thus making a link.

Bitcoin is digital cash and can be traded directly between two people without going through a third party like a bank.

2. The only application of blockchain is digital cash

< p>Blockchain and digital cash are like peanut butter and jelly. They are great together and they are great on their own. Blockchain is more than just a purpose. Every business and industry can use the underlying technology of distributed ledgers .

3. Information on Wuchi blockchain activities cannot be made public

⑨ Blockchain and Bitcoin (1)

Blockchain is A concept that has been proposed by academic circles for a long time but has only become popular with Bitcoin in recent years. Bitcoin is an implementation based on blockchain technology. Bitcoin is a cryptocurrency, or a digital currency. Let’s start with Bitcoin and talk about how Bitcoin uses blockchain technology.

Suppose that during the 2006 World Cup finals, two football fans who did not know each other met. Italy played France. The French fans said that we have France.Zidane will definitely beat Italy. Italian fans are not convinced and say that Italy is invincible. If you don't believe it, let's bet 100 euros. In the real world, what should we do?

I have said before that we who work on computers spend more than 90% of our time dealing with abnormal situations. If humans were very trustworthy, the world might not be what it is now. The 600 miles that Qin promised King Huai of Chu were no longer 6 miles. Maybe it would be Chu who unified China. If you hand over the money to a third party, what if the third party also runs away? He stole the money. Therefore, in the real strange world, relying solely on a kind heart is unreliable. There must be means to firmly guarantee this commitment, legal contract, etc. Nowadays, a very common approach is for the third party to find an authoritative institution, such as the government, a bank, etc., or to find a reputable person or organization. In the final analysis, it is still to find an institution or person with credibility. But under normal circumstances, this third party will definitely "pluck out hair" and charge a certain percentage of handling fees.

So is there any way to solve this problem? This is one of the original intentions of Bitcoin's original design, to solve the trust problem between two strangers.

Encryption algorithm + multi-person accounting

Let’s talk about the encryption algorithm first. Here we need the asymmetric encryption I mentioned before, that is, the public key and private key. Everyone can have one or more pairs of public and private keys, but a public key can only have a corresponding private key, and vice versa. The principle is that two very large prime numbers (p and q) are multiplied to get a number (n). If you want to crack the private key based on the public key, you must theoretically crack it violently and figure out which two large prime numbers the number is multiplied by. Got it. Currently, there is no published private key in the world that can crack more than 1024 bits, so it is very safe to use a private key of 1024 or 2048 or even longer.

Then with the public key and private key, I as an individual can encrypt with the private key, and then publish the public key. Anyone can use my public key to decrypt to determine that this is what I published. . In the same way, when someone transfers money to me, I can also use his or her public key to decrypt it and determine that this is someone's identity. This is also called a digital signature. The principles are the same, they are all encryption algorithms, obtained by using mathematical Euler's formula, prime number multiplication and other principles. This is a very great algorithm called RSA, proposed by three mathematicians. As long as we ordinary people understand the concept and use of public keys and private keys.

In the previous traditional model, banks or government agencies had their own separate ledgers. For example, if Zhang San transferred 100 yuan to Li Si, how would it be recorded in the ledger? 100 is deducted from Zhang San’s account and 100 is added to Li Si’s account, right?

The same is true for multi-person ledgers, except that the previous centralized institution has become a distributed, decentralized multiple institutions and even individuals. For example, Li Bai transferred 100 taels of silver to Du Fu.It is the Ministry of Finance's accounting. In the blockchain, it is Tang Taizong, Yang Yuhuan, Zhang Xiaojing, He Zhizhang and many other people who are keeping accounts together. It is recorded that Li Taibai transferred 100 taels of silver to Du Zimei. This is used as evidence. Li Bai's name is attached at the back. seal. In this way, with multiple ledgers, it would be extremely difficult to tamper with them. Li Bai could safely transfer them to Du Fu without worrying that he would tamper with the amount or deny it.

This can solve the problem of fans betting mentioned at the beginning, but there is another question, why should others help us keep accounts?

The answer is to be paid, which is in line with human nature. Otherwise, who would be willing to help keep an account that has nothing to do with them?

But there is only one person who can ultimately keep accounts, otherwise everything will be in chaos.

On the premise that it is beneficial, how to ensure who will keep the accounts? There is a mathematical knowledge involved here. Everyone who wants to keep accounts, in fact, the so-called miners, must solve a mathematical problem when keeping money. There is no trick to this mathematical problem. The only way is to put the numbers into the formula. In hard calculation, the algorithm is a Hash algorithm, which is similar to calculating a series of numbers. Miners can only guess, but there is no other way. Moreover, the current probability of guessing in Bitcoin is one in a trillion. It would take an ordinary computer to guess this number continuously for about a year.

But there are thousands of computers in the world, and if they are calculated together, the speed will be much faster, because from a probability point of view, one computer will definitely calculate it, and this is indeed the case. Let’s look at a real-life example of Bitcoin.

In addition, you can also see who the Miner is and how many transactions (Number of Transactions) are included in this block.

What if this miner is an individual with ulterior motives, and after calculating the calculation, he tampered with the transfer record and amount privately?

A. Tampering with transaction records/amount

We introduced the public and private key encryption technology earlier. The miners themselves theoretically do not have the private keys of the sender or payee. Therefore, the transaction record that he tampered with will make errors when decrypted with the correct public key, and will eventually be deemed illegal (the author is not sure at what point in time the identification was made, but he is sure that this record can be falsified) ).

B. Delete transaction records

Assume a scenario where Zhang San wants to buy a two-bedroom, one-living house in Beijing’s 4th Ring Road, but Zhang San doesn’t want to pay for it. Occupying the house for free, I thought of a sneaky way to tamper with the transaction records. Theoretically, after Zhang San paid, this record was generated but not confirmed.The record needs to wait until a miner solves the puzzle. Assuming that the miner is one of his own, he will ask the miner to erase the record, no problem. But there are several ways to do it:

As we all know, Bitcoin mining takes a long time because of the troublesome math problems. The current cycle is about 10 minutes. This is based on the world Under the premise that hundreds of thousands of mining machines are working at full capacity at the same time. That is to say, tens of thousands of transactions will be uniformly confirmed and put into an immutable block every ten minutes, and these hundreds of thousands of mining machines will update their local records at the same time.

2.1 If the transaction is just generated and the landlord sees it, and then transfers the property rights to Zhang San the next second, then if Zhang San wants to tamper with the payment record, he must meet several conditions:

The difficulty of success depends on how many confirmed blocks follow the tampered record. If there is only one, it is too simple, because the blockchain algorithm defaults to miners using the first received longer block when publishing a new block. So after this modification, it will be done once and for all, because all the ledgers will be synchronized, but there is also a problem, that is, this synchronization will be recorded. If the landlord cannot check the account, Zhang San will eventually be arrested. If there are many, for example, after Zhang San transfers the money, the landlord only transfers the property rights 1 hour after confirming the transfer, then Zhang San must tamper with the previous block information of about 6 blocks, which is very troublesome, because every block All will point to the previous block, and each block will have a digest (Hash), which is a summary of all transaction records in the current block. So if you try to modify a block that was written a long time ago, the digests of subsequent blocks will be changed. This is the hash tree (MerkleTree). Other nodes can report information that the blockchain has been tampered with. This involves the most important point. The 51% computing power that is often mentioned means that if Zhang San owns more than 50% of the ledgers and acknowledges this modification, then other nodes will also acknowledge this modification according to the algorithm design. . However, let’s not talk about the fact that almost no one in the world can do the above two things at the same time. Even if you can do it, if someone has questions about this, you can still force the system to be repaired. Similar problems have occurred in Ethereum before, and the outcome is Ethereum Entire blocks were tampered with and stolen property was recovered. Ethereum fork event.

The above is only a superficial introduction to the characteristics of Bitcoin implemented by applying blockchain technology. It can achieve openness, fairness, neutrality and equality. Any two strangers in the world can rely on Bitcoin or other blockchain technologies to trust each other.