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让区块链连接起来的是什么,让区块链连接起来的是hash

发布时间：2023-12-06-06:01:00 来源：网络区块链知识的是区块 version

让区块链连接起来的是什么,让区块链连接起来的是hash

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① How are the blocks in the blockchain connected?

Experts said that the blockchain can be commonly understood as a distributed public ledger. This ledger Each block is connected into a chain. In traditional accounting systems, accounting rights are in the hands of the central server.

On the "ledger" of the blockchain, every point in the chain can record information on it, forming a point-to-point accounting system. Therefore, blockchain technology is considered a decentralized technology.

For example, in a village of 100 people, Zhang San bought a cow from Li Si and paid him 10,000 yuan. In the past, he had to rely on the middleman Zhao Liu to transfer his 10,000 yuan to Li Si.

With the blockchain system, Zhang San can directly record his 10,000 yuan into Li Si’s account book, and at the same time, the transaction information will be transmitted to the whole village, that is, the entire blockchain system. Make the information visible to 98 other people. The system records the entire transaction process, which has the advantage of traceability and prevents problems such as the loss of Zhao Liu's account book or Li Si's refusal to acknowledge the account.

(1) What connects blockchains is version. Extended reading

In 2008, Satoshi Nakamoto first proposed the concept of blockchain The concept, and in the ensuing years, of blockchain became a core component of the electronic currency Bitcoin: serving as a public ledger of all transactions. By leveraging peer-to-peer networks and distributed timestamp servers, blockchain databases can be managed autonomously.

The blockchain invented for Bitcoin made it the first digital currency to solve the problem of repeated consumption. Bitcoin's design has become a source of inspiration for other applications.

② Common blockchain cross-chain technologies

Common blockchain cross-chain technologies include: 1. Ripple Interledger protocol. 2. Side-chain technology BTCRelay. 3. Relay technology Polkadot and COSMOSPolkadotCOSMOS; 4 hash locking technology Lightingnetwork.5 distributed private key control technology WanChain. Among the many problems faced by blockchain, the interoperability between blockchains greatly limits the application space of blockchain. Regardless of whether it is a public chain or a private chain, cross-chain technology is the key to realizing the Internet of Value. It is a good medicine to save the blockchain from scattered islands and a bridge for the blockchain to expand and connect outwards.

③ Components of Blockchain

The components of Blockchain are as follows:

Openness: Blockchain The system data is open and transparent, and everyone can participate. For example, when renting a house, you can know the previous rental information of the house and whether there have been any problems. Of course, some personal private information is encrypted.

Autonomy: The blockchain adopts consensus-based specifications and protocols (such as a set of open and transparent algorithms), and then each node operates according to this specification. This isEverything is done by machines, so there is no human element. This changes trust in people to trust in machines, and any human intervention has no effect.

The information cannot be tampered with: If the information is stored in the blockchain, it will be saved permanently and there is no way to change it. As for the 51% attack, it is basically impossible to achieve.

Anonymity: There is no personal information on the blockchain, because it is all encrypted and is a string of letters and numbers, so your various ID card information and phone number will not appear. Numbers are being resold.

④ Easy-to-understand explanation of blockchain

The popular explanation of blockchain technology is as follows:

To put it simply: blockchain is the use of a package of existing A new generation of network system formed using advanced network technology. This network system has a new structure, a new mechanism, and unprecedented new value. Five major technologies or innovations are specifically used: encryption technology, P2P network technology, distributed storage technology, consensus mechanism, and smart contracts.

Essentially: it is a shared database, and the data or information stored in it is "unforgeable", "full-process traces", "traceable", "open and transparent" and "collectively maintained" ” and other characteristics. Based on these characteristics, blockchain technology has laid a solid foundation for "trust-based sales" and created a reliable "cooperation" mechanism. Yunchun has broad application prospects.

2. Openness.

In addition to the encryption of private information of all parties to the transaction, the blockchain data is open to everyone and provides a flexible script code system. The entire system information is highly transparent and within the rules specified by the system. Nodes cannot deceive each other.

3. Autonomy.

Consensus technology, smart contracts.

⑤ Popular explanation of what blockchain is

Question 1: What is blockchain? Can you explain the principle of 10-point blockchain in plain language: decentralization A distributed accounting system
The core of blockchain 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 Payment transactions are carried out without the involvement 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, and all miner nodes compete for calculationWith the answer of 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 contents of the ledger during this period to all other people in the system for backup. 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 require no credit backingBook 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 2: 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 the technology or financeIf you have a financial-related 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 influence 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 new industry. value, they have developed their own blockchain platforms, and blockchain has instantly become a new innovative industry in China. 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 has attracted more and more attention and will form a huge new trend... >>

Question 3: What is blockchain technology? What exactly is blockchain? What is blockchain? 1. Data blockchain is the Bitcoin financial systemThe important concept in , records the transaction record data on the entire Bitcoin network, and this data is shared by all Bitcoin nodes. Through the data block, we can query the history of each Bitcoin transaction. 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 4: What is blockchain: This explanation of blockchain is more understandable. Blockchain refers to a technology that collectively maintains a reliable database through decentralization and trustlessness. plan.
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, everyone in the system can do accounting. The system will judge the person who has the fastest and best accounting during this period, write his recorded content into the ledger, and record this Within a period of time, the contents of the ledger are sent to all other people in the system for backup. In this way, everyone in the system has a complete copy ofLedger. 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.

Question 5: Explain in an easy-to-understand manner what blockchain is. Blockchain can be understood as a database system in a sense. The development of blockchain can be divided into 1.0 and 2.0
1.0 is represented by Bitcoin, and its main application is virtual currency or digital currency application. The blockchain at this time can only be used for simple digital currency transactions.
2.0 is represented by the now popular ethereum (Ethereum) and the upcoming hyperledger. The blockchain at this stage can not only meet the corresponding digital currency transactions, but also use smart contracts to customize currency or asset transactions. If we use the database analogy, the emergence of smart contracts can be understood as allowing users to define functions or stored procedures in the database and call and execute them.
Different from traditional databases, the blockchain introduces consensus mechanism, incentive mechanism, p2p (network), hash and other specific elements, making it open, decentralized and non-tamperable. characteristic.

Question 6: What is blockchain? Can anyone explain it in simple terms? Blockchain is the underlying technology of Bitcoin. It is like a ledger that records all transactions. It is decentralized. What is decentralization? For example, when you buy something on Taobao, you place an order and pay it to Alipay. Alipay will not transfer the money to the seller until you receive the goods. Alipay is the third party in that center. Without it, it means decentralization, just like buying things offline. If you pay with one hand and get the goods with the other hand, there is no third party.
The blockchain itself is a series of cryptographically related data blocks generated.
Look carefully to see if it looks like a ledger. The pieces one by one are blocks, and connected together they are the blockchain.
Many companies are developing this technology, including ours, and its prospects are incredible. For details, you can go to our official website and hope to adopt it, thank you

Question 7: 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 been favored by more and more people in the industry for its unique technical advantages.attention and favor. 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 brand-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 fully applied in 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. Internet protocol rules and accounting (Ledger) system including block chain, full encryption, mutual authentication, etc., including factor) registration and verification. 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 alsoContinuously develop and innovate, and constantly explore new application areas, 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 8: Easy to understand Explain clearly what is blockchain. The English name of 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 needs to be supported by a reasonable reward mechanism. 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 asset digitization and launched the digital currency crowdfunding platform Biying China.

Question 9: What is the so-called "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 human being, and there will be various possible gaps in the process.Take advantage of the opportunity, as long as it is related to people and related to any media, there will be various possibilities. The blockchain provides a great opportunity. As soon as you graduate, you will have a record on the blockchain. No one can change this record. This thing exists objectively. You, as a physical existence , and then as a data existence, the blockchain was 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 10: What does blockchain mean? Regarding blockchain, I think you have already seen the concept on the Internet. Let me explain it based on my understanding!
First, let’s talk about its characteristics: 1. Openness and transparency 2. Decentralization 3. Anonymity 4. Information cannot be tampered with, eliminated 5. No trust cost
Blockchain is like a public ledger , everyone has the right to record and read, and everyone will jointly supervise to ensure its accuracy, and the recorded content will be permanently saved, and can only be added but not deleted! However, as the number of blocks continues to increase, costs will increase and efficiency will decrease. (I’m not sure whether technology can be used to make up for this. I hope someone who understands technology can point it out.)
Blockchain is divided into public chain, private chain, and alliance chain. Public chain: accessible to everyone, everyone has read and write permissions, completely open, transparent and decentralized. Private chain: Open to individuals or institutions, in which the owner of the private chain can set various permissions to make it partially centralized. Alliance chain: Open to specific organizations or groups, it is also "partially decentralized". According to the ledger at the beginning, members can view and transact, but cannot record and confirm bills, or require permission from the alliance. (The latter two do not have cost and efficiency issues)
Regarding blockchain, countries have begun to recruit talents in this area. For this, you can search online for "Central Bank Recruiting Digital Currency R&D Personnel". In addition, you can increase your understanding of blockchain by understanding its existing applications. What we usually refer to generally refers to public chains. Currently, those used abroad include Bitcoin, Ethereum and other domestic blockchains. Chain
1. Open and transparent: Every piece of data is verified by everyone and can be viewed by everyone at any time.
2. Decentralization: For example, when we shop on Taobao, we conduct transactions through the intermediary Taobao, and blockchain allows both supply and demand parties to directly contact each other for direct transactions through blockchain technology.
3. Anonymity: No personal privacy information is required to complete transactions on the blockchain, only your unique alphanumeric signature is required.
4. Information cannot be tampered with or deleted: Once the data has been verified and recorded, no one has the authority to modify it, let alone delete it!
5. No trust cost: The trust crisis in reality will not appear in the blockchain.Blockchain transactions do not require you to trust the other party. They can only be carried out if both of you have enough "digital assets" to trade, and are subject to the supervision of the entire network, so the transaction will not break the contract. If you have no idea about the cost of trust, just think about how many intermediaries there are in your city, or just think about Jack Ma, and you will know how big the cost of trust is.
I am still learning more about blockchain. I am Li Ailin. If you have any questions, you can discuss and learn together!

⑥ Blockchain technology

Background: After the birth of Bitcoin, it was discovered that the technology was very advanced, and blockchain technology was discovered. Bitcoin and blockchain technology were discovered at the same time.

1.1 The purpose of the birth of Bitcoin:

①Currency transactions have records, that is, ledgers;

②The disadvantages of centralized institution accounting - it can be tampered with; Yi Chaofa

Bitcoin solves the first problem: anti-tampering - hash function

1.2 hash function (encryption method)

① Function: convert any A string of length, converted to a fixed-length (sha256) output. The output is also called a hash value.

② Features: It is difficult to find two different x and y such that h(x)=h(y).

③Application: md5 file encryption

1.3 Blockchain

①Definition

Block: Split the general ledger into zones Block storage

Blockchain: On each block, add a block header. It records the hash value of the parent block. By storing the hash value of the parent block in each block, all blocks are connected in order to form a blockchain.

②How does the blockchain prevent transaction records from being tampered with?

After the blockchain is formed, tampering with any transaction will cause the hash value of the transaction block to be different from that of its sub-blocks. , tampering was discovered.

Even if you continue to tamper with the hash value in the sub-block header, the hash value in the sub-block will be different from that in the grandchild block, and the tampering will be discovered.

1.4 The essence of blockchain

①The essence of Bitcoin and blockchain: a big ledger visible to everyone, only recording transactions .

②Core technology: Through cryptographic hash function + data structure, it ensures that the ledger records cannot be tampered with.

③Core function: Create trust. Fiat currency relies on government credibility, and Bitcoin relies on technology.

1.5 How to trade

① To conduct transactions, you need an account number and password, corresponding to the public key and private key

Private key: A string of 256-bit binary numbers. No application is required to obtain it, and you don’t even need a computer. You can generate a private key by tossing a coin 256 times.

The address is converted from the private key. The address cannot reverse the private key.

The address is the identity, which represents the ID in the Bitcoin world.

After an address is generated, it can only be known by everyone if it enters the blockchain ledger.

②Digital signature technology

Signature function sign (Zhang San’s private key, transfer information: Zhang San transfers 10 yuan to Li Si) = signature of this transfer

< p> Verify Korean verify (Zhang San’s address, transfer information: Zhang San transfers 10 yuan to Li Si, signature of this transfer) = True

Zhang San uses his own signature function sign() The private key signs this transaction.

Anyone can verify whether the signature was issued by Zhang San himself who holds Zhang San's private key by verifying the Korean vertify(). It returns true, otherwise it returns false.

sign() and verify() are cryptographically guaranteed not to be cracked. ·

③Complete the transaction

Zhang San will provide the transfer information and signature to the entire network. Under the premise that the account has a balance, after verifying that the signature is true, it will be recorded in the blockchain ledger. Once recorded, Zhang San's account will be reduced by 10 yuan, and Li Si's account will be increased by 10 yuan.

Supports one-to-one, one-to-many, many-to-one, and many-to-many transactions.

In the Bitcoin world, private keys are everything! ! !

1.6 Centralized Accounting

① Advantages of Centralized Accounting:

a. No matter which center keeps accounts, don’t worry too much

< p> b. Centralized accounting, high efficiency

②Disadvantages of centralized accounting:

a Denial of service attack

b Stop service after getting tired

c Central institutions are vulnerable to attacks. For example, destroying servers and networks, committing self-intrusion, legal termination, government intervention, etc.

All attempts at confidential currencies with centralized institutions in history have failed.

Bitcoin solves the second problem: how to decentralize

1.7 Decentralized accounting

①Decentralization: Everyone can keep accounts. Everyone can keep a complete ledger.

Anyone can download open source programsProgram, participate in the P2P network, monitor transactions sent around the world, become an accounting node, and participate in accounting.

② Decentralized accounting process

After someone initiates a transaction, it is broadcast to the entire network.

Each accounting node continues to monitor and continue transactions across the entire network. When a new transaction is received and the accuracy is verified, it is put into the transaction pool and continues to be propagated to other nodes.

Due to network propagation, the transactions of different accounting nodes at the same time are not necessarily the same.

Every 10 minutes, one person is selected from all accounting nodes in a certain way, and his transaction pool is used as the next block and broadcast to the entire network.

Other nodes delete the transactions that have been recorded in their own transaction pool based on the transactions in the latest block, continue accounting, and wait for the next selection.

③ Features of decentralized accounting

A block is generated every 10 minutes, but not all transactions within these 10 minutes can be recorded.

The accounting node that obtains the accounting rights will be rewarded with 50 Bitcoins. After every 210,000 blocks (approximately 4 years), the reward is halved. The total amount is about 21 million, and it is expected to be mined in 2040.

Recording the reward of a block is also the only way to issue Bitcoin.

④ How to allocate accounting rights: POW (proof of work) method

Compete for accounting rights by calculating mathematical problems on several accounting points.

Find a random number that makes the following inequality true:

There is no other solution except traversing the random numbers starting from 0 and trying your luck. The process of solving the problem is also called mining.

Whoever solves the problem correctly first will get the accounting rights.

If a certain accounting node finds the solution first, it will announce it to the entire network. After other nodes verify that it is correct, a new round of calculation will start again after the new block. This method is called POW.

⑤ Difficulty adjustment

The generation time of each block is not exactly 10 minutes

As Bitcoin develops, the computing power of the entire network does not increase.

In order to cope with changes in computing power, the difficulty will be increased or decreased every 2016 blocks (about 2 weeks), so that the average time for each block to be generated is 10 minutes.

#欧易OKEx# #BTC[超话]# #digital currency#

⑦ Tutorial for getting started with blockchain

However, There are few simple and easy-to-understand introductory articles. What exactly blockchain is and what makes it special is rarely explained.
Next, I will try to write the best articleUnderstand the blockchain tutorial. After all, it is not difficult. The core concept is very simple and can be explained clearly in a few sentences. I hope that after reading this article, you will not only understand the blockchain, but also understand what mining is, why mining is getting more and more difficult, and other issues.
It should be noted that I am not an expert in this area. Although I have been paying attention to it for a long time, my detailed understanding of blockchain started at the beginning of this year. You are welcome to correct any errors or inaccuracies in the article.
1. The essence of blockchain
What is blockchain? In a word, it is a special distributed database.
First of all, the main function of blockchain is to store information. Any information that needs to be saved can be written to the blockchain and read from it, so it is a database.
Secondly, anyone can set up a server, join the blockchain network, and become a node. In the world of blockchain, there is no central node. Every node is equal and stores the entire database. You can write/read data to any node, because all nodes will eventually be synchronized to ensure that the blockchain is consistent.
2. The biggest features of blockchain
Distributed databases are not a new invention, and there have been such products on the market for a long time. However, blockchain has a revolutionary feature.
Blockchain has no administrator, it is completely centerless. Other databases have administrators, but blockchain does not. If one wanted to add auditing to the blockchain, it would not be possible because it is designed to prevent the emergence of a central authority.
It is precisely because it is unmanageable that blockchain can be uncontrollable. Otherwise, once big companies and large groups control the management, they will control the entire platform, and other users will have to take orders from them.
However, without an administrator, everyone can write data into it. How can we ensure that the data is trustworthy? What if it is modified by a bad person? Please read on, this is the wonderful thing about blockchain place.
3. Block
Blockchain is composed of blocks. Blocks are much like database records. Every time data is written, a block is created.
Each block contains two parts.
Head: records the characteristic values of the current block
Body: actual data
The block header contains multiple characteristic values of the current block.
Generation time
Hash of the actual data (i.e. block body)
Hash of the previous block
...
Here, you need to understand what a hash is , which is necessary to understand blockchain.
The so-called hashing means that the computer can calculate a characteristic value of the same length for any content. The hash length of the blockchain is 256 bits, which means that no matter what the original content is, a 256-bit binary number will be calculated in the end. And it can be guaranteed that as long as the original content is different, the corresponding hash must be different.
For example, the hash of the string 123 is (hexadecimal), converted to binaryThat's 256 bits, and only 123 can get this hash. (Theoretically, it is possible for other strings to get this hash, but the probability is extremely low and can be approximated as impossible.)
Therefore, there are two important inferences.
Corollary 1: The hash of each block is different, and the block can be identified by the hash.
Corollary 2: If the content of the block changes, its hash will definitely change.
4. The non-modifiable nature of Hash
Blocks and hashes have a one-to-one correspondence, and the hash of each block is calculated based on the block header (Head). That is to say, the characteristic values of the block header are connected together in order to form a very long string, and then the hash is calculated on this string.
Hash = SHA256 (block header)
The above is the calculation formula of block hash. SHA256 is the hash algorithm of the blockchain. Note that this formula only contains the block header and not the block body. In other words, the hash is uniquely determined by the block header.
As mentioned before, the block header contains a lot of content, including the hash of the current block body. , and the hash of the previous block. This means that if the content of the current block body changes, or the hash of the previous block changes, it will definitely cause the hash of the current block to change.
This point has great significance for blockchain. If someone modifies a block, the hash of the block changes. In order for subsequent blocks to still be connected to it (because the next block contains the hash of the previous block), the person must modify all subsequent blocks in sequence, otherwise the modified block will be removed from the blockchain . Due to the reasons mentioned later, hash calculation is very time-consuming, and it is almost impossible to modify multiple blocks in a short period of time, unless someone controls more than 51% of the computing power of the entire network.
It is through this linkage mechanism that the blockchain ensures its own reliability. Once the data is written, it cannot be tampered with. This is just like history, what happened happened, and it can’t be changed from now on.
Each block is connected to the previous block, which is where the name blockchain comes from.
5. Mining
Since synchronization between nodes must be ensured, the adding speed of new blocks cannot be too fast. Just imagine, you have just synchronized a block and are preparing to generate the next block based on it, but at this time, another node generates a new block, and you have to give up half of the calculations and synchronize again. Because each block can only be followed by one block, you can only generate the next block after the latest block. So, you have no choice but to sync as soon as you hear the signal.
So, the inventor of the blockchain, Satoshi Nakamoto (this is a pseudonym, and his true identity is still unknown) deliberately made it difficult to add new blocks. His design is that on average, the entire network can generate a new block every 10 minutes, which is only six per hour.
This output speed is not achieved through commands, but by deliberately setting up massive calculations. In other words, only through extremely large amounts of calculations can weGet the valid hash of the current block to add the new block to the blockchain. Because the amount of calculation is too large, it cannot be done quickly.
This process is called mining, because the difficulty of calculating a valid hash is like finding a grain of sand that meets the conditions among the sand in the world. The machine that calculates hashes is called a mining machine, and the person who operates the mining machine is called a miner.
6. Difficulty coefficient
After reading this, you may have a question. People say that mining is difficult, but isn’t mining just about using a computer to calculate a hash? This is the strength of computers. How could it be? It becomes very difficult, why can’t it be calculated?
It turns out that not just any hash can be used, only hashes that meet the conditions will be accepted by the blockchain. This condition is particularly harsh, causing most hashes to fail to meet the requirements and must be recalculated.
It turns out that the block header contains a difficulty coefficient (difficulty), which determines the difficulty of calculating the hash. For example, the difficulty coefficient of the 100,000th block is 14484.16236122.
The blockchain protocol stipulates that the target value (target) can be obtained by dividing the difficulty coefficient by a constant. Obviously, the greater the difficulty coefficient, the smaller the target value.
The validity of the hash is closely related to the target value. Only hashes smaller than the target value are valid, otherwise the hash is invalid and must be recalculated. Since the target value is very small, the chance that the hash is smaller than this value is extremely slim, and it may be calculated 1 billion times before it is considered a hit. This is the fundamental reason why mining is so slow.
As mentioned earlier, the hash of the current block is uniquely determined by the block header. If the hash of the same block needs to be calculated repeatedly, it means that the block header must keep changing, otherwise it is impossible to calculate different hashes. All feature values in the block header are fixed. In order to make the block header change, Satoshi Nakamoto deliberately added a random item called Nonce.
Nonce is a random value. The role of the miner is actually to guess the value of Nonce so that the hash of the block header can be smaller than the target value so that it can be written to the blockchain. Nonce is very difficult to guess. At present, we can only use trial and error one by one through exhaustive methods. According to the protocol, Nonce is a 32-bit binary value, which can reach a maximum of 2.147 billion. The Nonce value of the 100,000th block is 274148111. It can be understood that the miner started from 0 and calculated 274 million times before obtaining a valid Nonce value so that the calculated hash can meet the conditions.
If you are lucky, you may find Nonce in a while. If you are unlucky, you may have calculated it 2.147 billion times without finding the Nonce, that is, it is impossible to calculate a hash that meets the conditions for the current block body. At this time, the protocol allows miners to change the block body and start a new calculation.
7. Dynamic adjustment of difficulty coefficient
As mentioned in the previous section, mining is random and there is no guarantee that a zone will be produced in exactly ten minutes.Block, sometimes it comes out in a minute, sometimes it may take several hours to get the result. Overall, with the improvement of hardware equipment and the increase in the number of mining machines, the computing speed will definitely become faster and faster.
In order to keep the output rate constant at ten minutes, Satoshi Nakamoto also designed a dynamic adjustment mechanism for the difficulty coefficient. He stipulated that the difficulty factor should be adjusted every two weeks (2016 blocks). If the average block generation speed in these two weeks is 9 minutes, it means that it is 10% faster than the legal speed, so the next difficulty factor will be increased by 10%; if the average block generation speed is 11 minutes, it means It is 10% slower than the legal speed, so the difficulty factor of the next step must be lowered by 10%.
The difficulty coefficient is adjusted higher and higher (the target value is getting smaller and smaller), which makes mining more and more difficult.
8. Forks of the blockchain
Even if the blockchain is reliable, there is still an unresolved problem: if two people write data to the blockchain at the same time, that is to say, two people write data to the blockchain at the same time. Blocks join because they are connected to the previous block, forming a fork. Which block should be adopted at this time?
The current rule is that new nodes always adopt the longest blockchain. If there is a fork in the blockchain, it will be seen which branch is behind the fork and reaches 6 new blocks first (called six confirmations). Based on a block calculation of 10 minutes, it can be confirmed in one hour.
Since the generation speed of new blocks is determined by computing power, this rule means that the branch with the most computing power is the authentic blockchain.
9. Summary
Blockchain, as an unmanaged distributed database, has been running for 8 years since 2009 without major problems. This proves it works.
However, in order to ensure the reliability of data, blockchain also has its own price. The first is efficiency. You have to wait at least ten minutes to write data to the blockchain. All nodes synchronize the data, which requires more time. The second is energy consumption. The generation of blocks requires miners to perform countless meaningless calculations. This is Very energy consuming.
Therefore, the applicable scenarios of blockchain are actually very limited.
There is no management authority that all members trust
The written data does not require real-time use
The benefits of mining can make up for its own costs
If the above conditions cannot be met, then the traditional database is Better solution.
Currently, the largest application scenario (and possibly the only application scenario) of blockchain is the cryptocurrency represented by Bitcoin.

⑧ What exactly is NFT

What is NFT? NFT consists of the first letters of the three English words Non, fun, and token. When translated into Chinese, it is worthless Token.

In fact, even if it is translated directly, I don’t think you can understand what a valueless token is. Let me give you a simple example and you will understand immediately.

If I have a 100 yuan note in my hand and you have a 100 yuan note in your hand, IIf I want to switch with you, you will think, no problem, then just switch. Because two hundred dollars are of the same value. So, if the 100 yuan in your hand is signed by Jay Chou, when I want to exchange the 100 yuan in my hand, you will not exchange it with me, because the value of the 100 yuan in your hand may be worth 100,000.

This is the point of having tokens with different values. It looks like the same thing, but the value is different. The ones signed by Jay Chou are unique.

Why has NFT received special attention from the entire technology and fashion circles in recent years?

Because Christie's held an unprecedented digital art auction on March 11 last year, in the past, there was no way for digital art to enter the auction house for auction. A very important reason is that digital files are easily copied and there is no way to verify their origin and authenticity.

Everyone should have seen this work on the screen by now. This piece comes from an American artist named Pimple. He spent fourteen years uploading a digital art creation on his social network every day, so this work was auctioned at Christie's on March 11, 2011. The title of the work is "5000 Days", and the final auction price was US$69 million.

So, before we speak today, let us give you a gift worth $69 million!

What I provide are high-definition pictures. Please use your fingers to download this image or save it quickly.

Do you think the pictures saved on your phone are exactly the same as those at the auction? The answer is that it looks exactly the same, but if we were to sell this picture to others today, would anyone be willing to buy it? I didn't want to buy it, just like I wanted to exchange it for the 100 yuan signed by Jay Chou in your hand. You wouldn't want to exchange with me because the value is not the same and because there is no unique signature.

This is why digital art can enter auction houses from now on with NFT technology, because we can know the source and we can make it a unique creation.

The technology behind NFT has several cores. The first is of course blockchain technology. Blockchain technology is not the focus of today’s discussion, but it must be mentioned briefly.

Throughout the NFT distribution, there will be a publisher role. The publisher must launch his products through some platform on the blockchain. For example, the artistic creation just mentioned is a casting process that must go through the cooperation between Christie's and the blockchain. So it must have a platform through which smart contracts are released. This clever contract records that the artwork is unique across the entire blockchain. How do we verify that it is unique?

I think this is the most confusing point for everyone. Please take a closer look, clap your hands and take a closer look.

Because the blockchain has a feature called a ledger, it is not recorded in a centralized company host like traditional works or computers. It is not composed of one computer, but is recorded by millions of computers throughout the blockchain, so this record will be thrown to different computers for recording. We call these records nodes. .

The creations of these people will be recorded on different nodes. existIn each node, it will be written: "Today, a pair of creations generated this contract through this platform, and then left a piece in it." These blocks are called blocks, and each next transaction will pass through the next Blocks are connected in series, so after each block is connected, we call it a blockchain. This is the origin of the blockchain.

We can imagine what would happen if someone today tried to tamper with or steal this work. This can only be achieved if the records on so many computers can be modified at the same time. However, this style is actually not feasible because there are millions of such nodes around the world recording this ledger. It is precisely because of this feature that Xiang Ming Gun can Only in this way can the uniqueness of this distribution mechanism be guaranteed.

This is not the most critical point of smart contracts. The next most important feature that smart contracts give an NFT is that it can execute automatically and continue to distribute value and benefits during the creation process.

If a buyer wants to buy the NFT made by this publisher from me today, if we say the buyer bids 1 million, we will have to pay the platform's 2.5% handling fee for each transaction. For example, it is 25,000 yuan, but in this step, I have to pay 100,000 yuan in royalties to the publishing house, plus 875,000 yuan for the works that the buyer bought from me. These three amounts constitute the total amount distribution of the buyer's 1 million transaction. In this step, I have to pay a royalty of 100,000 yuan to the publisher.

In fact, for NFT, the impact of smart contracts is definitely not just artwork. Imagine if you were a real estate agent today and you were building houses, and when the first house I built was sold to Seller A, it was a traditional transaction. However, if seller A sells the house to seller B and returns 10% of the transaction amount to you, the logic of building a house will be different at this time, because you will consider how to build the house.

Of course it's not just the physical thing. As I said just now, the logic of building a house and trading are different. Rather than just calculating the return on my first home purchase minus my costs, I hope to approach it in a way that keeps trading and even increasing in value. Because every value-added transaction I make will return a certain amount of royalties to my account, I hope that my house can be used for a long time and increase in value in the long term. We need to think about it.

The same goes for insurance. Current insurance must rely on the policies of these insurance companies before they decide whether to insure you.

Jin, there is no need for it in the future. In the future, these insurance brokers will only need to create a smart contract, which can construct which insurance portfolios to use according to the buyer's own conditions. When something happens to you, the smart contract Funds will be automatically transferred to your account, and it can even extend the value of your smart policy to your next generation.

So the same is true for insurance practitioners. Your current job is to maintain this series of protection, but the protection of the next generation in the future can also be passed on to your children to inherit, because smart contracts can automatically help you make such transactions. , it will generate a period of continuous income.

Of course, you can think ofFor example, lawyers and medical professionals carry smart electronic devices with them every day, which may collect your sleep data.

But have you ever thought about it, your sleep data can actually be sold for money. When some research institutions conduct sleep studies, they need to collect a lot of people's information into their database to connect the data. But your data itself is NFT, you can sell it to research institutes that really need your sleep data, and then by using it, you can receive a certain amount of money every time you use it for research, so this time smart Contracts can be used in many, many different areas, not just artistic creation.

NFT has changed the shape of the entire transaction value chain.

Anyone who has watched this video congratulates you for earning 200,000 US dollars, because this 24-second video of James slam dunk, the transaction price of NFT on the NBA Top Shot blockchain in 21 years has been to over $200,000.

But I personally suggest that when everyone doesn’t know much about the true ideology of NFT, there are many risks or technical considerations hidden in it that you don’t know about.

The first one is that you must have a virtual currency wallet, which is a wallet. A virtual currency wallet is a bit like everyone's bank account, but the biggest difference is that the blockchain is decentralized, so it does not have a bank or a central regulatory unit to manage these virtual currencies. But through each person's different computer, we call it a node, or the people who provide computing power in mining, we call it miners, and they save the computing data of these virtual currencies.

Our virtual wallets are divided into three main types. The first one is called a centralized wallet. It is more like a traditional institution, which is a virtual currency that can be traded in an exchange or a certain company. Then it will Provide you with a trading account.

The second type is a cold wallet, which is a hardware device that is not connected to the network at any time. Maybe it is a USB disk, which records the password of your public and private keys, which you need to access. Plug it into your computer or device to access your wallet.

The third type is an app or a web browser program. It may be in your mobile phone or computer. When you need it, you can use the password of your private key to access your currency. .

Of course there are differences in security and convenience. In short, we need a place to store virtual currency.

The second step is to purchase these cryptocurrencies. There are several ways to buy them. For example, the centralized exchange I just mentioned, the New York Stock Exchange or the foreign exchange trading market, one place can directly To exchange, for example, I use one Ether coin now, which is about 50,000 yuan, so you can use 60,000 Taiwan dollars to exchange for one yuan of Ether currency. You can use this exchange rate to exchange. The second You can also set a price you want to buy like buying and selling foreign exchange or stocks, and then the buyer and seller can make an agreement on a centralized exchange.Synthetic intercourse.

Of course, you can also use P2P. If you find it particularly troublesome, if someone around you has Ethereum, I will buy it from you. Of course, this is also possible. You directly transfer the RMB to me and I will use my Cryptocurrency wallet, transfer Ethereum to your cryptocurrency wallet, and you're done.

The third part is that we need to choose a platform for issuing NFT. For example, as mentioned earlier, you can build a public chain yourself on the blockchain, like NBA Top Shot, which is built on flow. On the blockchain, or if we choose the mainstream Ethereum as the issuance, there are some public issuance platforms, and then I can issue my NFT on it by paying the casting fee through the cryptocurrency wallet.

Of course, if we hope that NFT can be bought and the transaction is completed, the most important thing is actually marketing. I wonder if you have heard that many celebrities have recently begun to issue their own NFTs. For example, the founder of Twitter posted his first NFT in history. One's twitter has also become an NFT for sale on the blockchain, and sold for more than two million US dollars, so it is a unique mark accumulated over a long period of time, and it is the proof of time stamp and unique value. .

Regarding the future development of NFT, if you go to Google, many people will say that it will bubble or simply be a scam, huh? In fact, it is not wrong, because the value of NFT increases too fast, and there are too many reasons for it. People who want to profit from speculation and hype are just like the dot-tom crisis in 2000, so there will definitely be a wave of bubbles in the future.

However, this technology will still be left behind after the bubble, and will be used by people in more different industries.

Not only for commercial use, in the future, the graduation certificate we get when we go to school will also be an NFT, because there are already a lot of fake graduation certificates and work permits, so how do you verify it? It is no longer possible to use manual methods, but to verify with the issuing unit through the time stamp on the blockchain.

In fact, MIT has done something like this two or three years ago, but it will become more popular in the future, and the government will use more blockchain and NFT.

For example, many trees can only be cut down by the government. If each tree is labeled with a unique label, the market can determine who has been illegally cut down when purchasing. This can serve as many possibilities for commercial or legal use. Although there is a risk of bubbles in the future, the use of this technology will continue now.

Perhaps if you put it in the open world of the Metaverse, everything will make sense.

The movie "Ready Player One" once made a wonderful prediction about the future world. In the world of Oasis, everyone has a free role. Here, classic characters from film and television games from different dimensions gather together, and rich digital content and items can also be circulated at will. In this flashy virtual worldHere, a loser in the real world can also become a superhero.

"Behind every dream is an energetic and adventurous person. They expect nothing but surprises."

What Hal Finney said may be the best explanation of the current NFT craze.

In the next issue, I will tell you about the story of the Metaverse and NFT, so stay tuned.

The title picture comes from Unsplash, based on the CC0 protocol