区块链需要学哪些内容和知识,区块链需要学哪些内容和技能

区块链技术已经成为当今社会最热门的技术之一，越来越多的企业和个人都在学习和使用它。但是，要想掌握区块链技术，你需要学习和掌握哪些内容和技能呢？

首先，要想学习区块链，你需要具备一定的计算机基础知识，包括计算机网络、数据结构、算法、操作系统等。这些知识对于理解和掌握区块链技术至关重要。

其次，学习区块链需要掌握一些技术知识，比如密码学、共识机制、智能合约、分布式数据库等。这些技术是区块链技术的核心，对于能够深入理解区块链技术至关重要。

此外，学习区块链还需要掌握一些编程语言，比如JavaScript、Go、Python、Solidity等，这些语言可以帮助你更好地开发和使用区块链技术。

最后，学习区块链还需要掌握一些专业知识，比如金融、法律、经济学等，这些知识可以帮助你更好地理解区块链技术在金融、法律等领域的应用。

总之，学习区块链需要掌握计算机基础知识、技术知识、编程语言和专业知识等，只有彻底掌握这些知识，才能更好地理解和使用区块链技术。

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1. How to learn blockchain-related technologies

One of the best ways to learn blockchain technology is to start from practice. You can establish a Simple blockchain projects that use relevant technologies to solve real problems. Then you can learn related technologies, such as Bitcoin, Ethereum, Hyperledger, consensus-based Hu Zhong distributed system, etc. Additionally, more advanced concepts can be learned such as smart contracts, distributed application development, and more. The future prospects of learning blockchain technology are very broad, and many industries are trying to use blockchain technology, such as finance, logistics, procurement, customs, etc.

2. What courses do you need to learn about blockchain?

Main courses: "Blockchain Principles and Applications", "Blockchain and Digital Assets", "Blockchain Technology Principles" and Development Practice", "Blockchain and Innovation and Entrepreneurship", etc.

What do you study in the blockchain engineering major?

Blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it has the characteristics of "unforgeable", "full traces left", "traceable", "open and transparent" and "collective maintenance", etc., and has broad application prospects.

From a technical perspective, blockchain involves many scientific and technical issues such as mathematics, cryptography, Internet and computer programming.

From an application perspective, in simple terms, blockchain is a distributed shared ledger and database that is decentralized, cannot be tampered with, leaves traces throughout the process, can be traced, collectively maintained, and is open and transparent. Features.

Their application fields include: financial field, insurance field, Internet of Things and logistics field, digital version field, and public service field. It can be seen from this that the development prospects and employment fields of the blockchain engineering major are relatively broad.

This major aims to respond to the development of social economy and social informatization, face the demand for blockchain technology talents in the blockchain industry, and cultivate all-round development of morality, intelligence, physical and aesthetics,

Master computer science and technology, basic theories of blockchain technology and blockchain project development methods, have the ability to design and implement blockchain systems, manage and implement blockchain projects, and conceive, design, and implement in corporate and social environments , the ability to run the system.

Have strong professional qualities in teamwork, communication and expression, and information search and analysis, and have the ability to become the backbone of the blockchain industry in the future. In blockchain project system design and development, blockchain project management, and district Application-oriented senior professionals who play an innovative role in blockchain system services and other fields.

3. How to get started with blockchain. This knowledge is not difficult to learn.

1. To learn blockchain knowledge, first learn the necessary concepts of blockchain knowledge.

2. [Blockchain]

The English name blockchain is the underlying technology of Bitcoin and a decentralized accounting method.

3. [Block and Chain]

Block refers to the information block that records transaction information. Each block contains three main factors: This block The ID, the odd number of the transaction, and the ID of the previous block.

The Bitcoin system generates a block approximately every 10 minutes. Each block contains the ID of the previous block, making the blocks form a complete transaction chain. The longest one is The only master blockchain.

4. [Bitcoin]

Bitcoin is a practical application of blockchain technology. It is a peer-to-peer electronic cash payment system. It was first used as Virtual currency exists. Japan has recognized the legality of Bitcoin and can use Bitcoin for shopping.

5. [Satoshi Nakamoto]

The legendary founder of Bitcoin published a paper on a peer-to-peer electronic cash system in 2008, marking the The birth of Bitcoin.

6. [Digital Currency]

It is completely different from the Q coins and other virtual currencies we use to play games in real life. For example, in Japan, although Bitcoin is a digital currency , but it can already be used to purchase goods in real scenarios.

7. [PoW]

A type of consensus mechanism, also known as proof of work. Bitcoin currently uses this consensus mechanism. It is relatively simple and easy to reach consensus, but consumes huge amounts of energy and is prone to bifurcation.

8. [PoS]

A type of consensus mechanism, also known as proof of equity. People with greater equity have a greater probability of becoming bookkeepers, but bookkeeping Human ones are not necessarily professional, don’t consume much energy, and are prone to split ends.

9. [DpoS]

On the basis of PoS, the bookkeepers are changed from unprofessional to professionals, like the EOS we are familiar with. In this consensus method, holders jointly select 21 nodes and 100 reserve nodes to connect the EOS constitution to reach a consensus, and jointly incubate the ecology on EOS.

10. [Public key and private key]

In the world of blockchain, the public key is equivalent to the bank account number, and the private key is equivalent to the bank account number + withdrawal password. The private key is essentially an array of 32 bytes. The private key can generate the public key and address, but this behavior is irreversible, so it is crucial to keep the private key. Losing the private key is equivalent to losing money. And it can never be found back.

11. [Hash value]

It can be simply considered as a set ofThe data is closely arranged together, and no item in the data can be changed, otherwise the calculation results will be very different.

12. [Smart Contract]

It is a promise in digital form. Both parties involved can execute these promised agreements on the consumer network without artificial restrictions. .

13. [Credit Consensus]

Based on the characteristics of blockchain, it is a distributed accounting method that cannot be tampered with and is irreversible. A mechanism of trust that allows many people to form a trust based on digital algorithms.

14. [Public chain and private chain]

Public chain refers to a blockchain that can be participated in by people around the world and can be read, and is open to everyone , while the private chain is only in the hands of an organization and is only open to individuals or entities.

Blockchain is currently a hot topic. Many traditional large enterprises and venture capital are actively participating in the layout and investment of the blockchain industry. As the general public, we must master the necessary blockchain knowledge. , helps us judge and analyze real-world information and protect our investments.

4. Tutorials for getting started with blockchain

However, there are very 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 a best-understood 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 someone wants to add auditing to the blockchain, it cannot be done because itThe design goal is 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), which is 256 bits when converted to binary, 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 to give wayIf the following block can 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 out of 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 an extremely large amount of calculations can the effective hash of the current block be obtained and the new block added 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 of the hash being smaller than that is extremely smallIt's so slim that it might take a billion calculations to count once. 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 block will be produced in exactly ten minutes. Sometimes it can be calculated in one minute, and sometimes it may take several hours. No 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 look at which branch is behind the fork to reach 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 ruleIn other words, 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.

5. How to learn blockchain technology_How to understand blockchain technology

1. Technical language

Python and Go It is a technical language mentioned by many companies in recruitment. Need to prioritize learning. Moreover, these two languages ​​​​also have great applications in the direction of sliding technology outside of the blockchain. For example, Go is used in the background construction of large-scale concurrent systems, and Python is used in the construction of artificial intelligence systems. So learning these two languages ​​is a priority.

2. Technical framework

Master one or more of Bitcoin, ETH and Hyperledger. Needless to say, BTC is written in C at the bottom level. A large number of currency projects, such as Litecoin, Dash, Monero, zcash, etc., all use Bitcoin technology for secondary development.

ETH is the representative of blockchain 2.0, and various application Dapps can be built on the ETH network. Nowadays, a large number of application blockchain projects are developed using the ETH platform.

Hyperledgerfabric is a blockchain development platform strongly promoted by IBM. It is mainly used for the development of alliance chains and is currently the most popular alliance chain development platform.

3. Algorithm

POW (Proof of Work Algorithm), POS (Proof of Stake Algorithm), PBFT (Byzantine Fault Tolerance Algorithm), etc. are all important in the cryptography part of the blockchain Composition, a full understanding of these algorithms will help you have a better understanding of the cryptography part when participating in the underlying development of blockchain projects.

(5) What you need to learn about blockchain Extended reading:

Blockchain technology is a distributed accounting technology, and its characteristic is that it is decentralized , open and transparent, so that everyone can participate in the establishment of the database, and each created data cannot be tampered with, everyone participates, and the strangerThe problem of trust between strangers is also solved.

Blockchain technology has emerged. It is an accounting technology that allows all people to participate. The transaction information and data between AB are made public and cannot be tampered with. Everyone knows this. happens, then there is no need for any authoritative third-party C, or everyone in the system plays the role of C. This is also called decentralization.

6. ​ 108 knowledge points for getting started with blockchain

108 essential knowledge points for getting started with blockchain

(Welcome to communicate with fellow fans)

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1. What is a blockchain

The information of multiple transactions and the information indicating the block are packaged together. The verified package is the block.

Each block stores the hash value of the previous block, creating a relationship between blocks, that is to say, a chain. Together they are called blockchain.

2. What is Bitcoin

The concept of Bitcoin was proposed by Satoshi Nakamoto in 2009, with a total number of 21 million. The Bitcoin chain generates a block approximately every 10 minutes, and this block is mined by miners for 10 minutes. As a reward to miners, a certain number of Bitcoins will be issued to miners, but this certain number is halved every four years. Now it's 12.5. If this continues, all Bitcoins will be available in 2040.

3. What is Ethereum

The biggest difference between Ethereum and Bitcoin is the smart contract. This allows developers to develop and run various applications on it.

4. Distributed ledger

It is a database that is shared, replicated and synchronized among network members. To put it bluntly, all users on the blockchain have accounting functions and the content is consistent, which ensures that the data cannot be tampered with.

5. What is quasi-anonymity?

I believe everyone has a wallet, and the wallet address (a string of characters) used to send transactions is quasi-anonymity.

6． What is open transparency/traceability

The blockchain stores all data from history to the present, anyone can view it, and can also view any data in history.

7. What is tamper-proof

Historical data and current transaction data cannot be tampered with. The data is stored in the block on the chain and has a hash value. If the block information is modified, its hash value will also change, and the hash values ​​of all blocks following it must also be modified to form a new chain. At the same time, the main chain is still conducting transactions to generate blocks. The modified chain must always generate blocks synchronously with the main chain to ensure that the length of the chain is the same. The price is too highToo big, just to modify one piece of data.

8. What is anti-DDoS attack

DDoS: Hackers control many people’s computers or mobile phones and allow them to access a website at the same time. Since the bandwidth of the server is limited, a large amount of traffic The influx of data may cause the website to fail to function properly, resulting in losses. However, the blockchain is distributed and there is no central server. If one node fails, other nodes will not be affected. Theoretically, if more than 51% of the nodes are attacked, problems will occur.

9. Definition of main chain

Taking Bitcoin as an example, at a certain point in time, a block is mined by two miners at the same time, and then 6 blocks are generated first. The chain of blocks is the main chain

10. Single chain/multi-chain

Single chain refers to the data structure that handles everything on one chain. The core essence of the multi-chain structure is composed of public chain + N sub-chains. There is only one, but in theory there can be countless sub-chains, and each sub-chain can run one or more DAPP systems

11. Public chain/alliance chain/private chain

Public Chain: Everyone can participate in the blockchain

Alliance chain: Only alliance members are allowed to participate in accounting and query

Private chain: Writing and viewing permissions are only controlled by one person In the hands of the organization.

12. Consensus layer, data layer, etc.

There are six overall structures of the blockchain: data layer, network layer, consensus layer, incentive layer, contract layer, and application layer. Data layer: a layer that records data, belonging to the underlying technology; network layer: a structure for building a blockchain network, which determines how users are organized. Consensus layer: Provides a set of rules to allow everyone to reach agreement on the information received and stored. Incentive layer: Design incentive policies to encourage users to participate in the blockchain ecosystem; Contract layer: Generally referred to as "smart contracts", it is a set of contract systems that can be automatically executed and written according to their own needs. Application layer: Applications on the blockchain, similar to mobile apps. Former Distributed Storage R&D Center

13. Timestamp

The timestamp refers to the time from January 1, 1970 Day 0 hours 0 minutes 0 seconds 0... The total number of seconds from the current time to now, or the total number of nanoseconds and other very large numbers. Each block is generated with a timestamp indicating when the block was generated.

14. Block/block header/block body

Block is the basic unit of blockchain, and block header and block body are components of blockchain. The information contained in the block header includes the hash of the previous block, the hash of this block, timestamp, etc. The block body is the detailed data in the block.

15. Merkle tree

Merkle tree, also called binary tree,It is a data structure for storing data. The bottom layer is the original data contained in all blocks. The upper layer is the hash value of each block. The hash value of this layer is combined in pairs to generate a new hash value to form a new one. layer, and then layer by layer, until a hash value is generated. Such a structure can be used to quickly compare large amounts of data, and you can quickly find the bottom-level historical data you want without downloading all the data.

16. What is expansion?

The size of a Bitcoin block is about 1M and can save 4,000 transaction records. Expansion means making the block larger so that more data can be stored.

17. What is a chain?

Each block will save the hash of the previous block, creating a relationship between the blocks. This relationship is a chain. Data such as block transaction records and status changes are stored through this chain.

18. Block height

This is not the height mentioned in terms of distance. It refers to the total number of blocks between the block and the first block on the chain. This height indicates which block it is, and is just for identification purposes.

19. Fork

Two blocks were generated at the same time (the transaction information in the block is the same, but the hash value of the block is different), and then in Two chains are forked from these two blocks. Whoever generates 6 blocks from these two links first will be the main chain, and the other chain will be discarded.

20. Ghost Protocol

Mining pools with high computing power can easily generate blocks faster than mining machines with low computing power, resulting in most of the blocks on the blockchain being generated by these mining pools with high computing power. However, the blocks generated by mining machines with low computing power are not stored on the chain because they are slow, and these blocks will be invalid.

The ghost protocol allows blocks that should be invalidated to remain on the chain for a short time, and can also be used as part of the proof of work

. In this way, miners with small computing power will contribute more to the main chain, and large mining pools will not be able to monopolize the confirmation of new blocks.

21. Orphan blocks

As mentioned before, orphan blocks are blocks generated at the same time. One of them forms a chain, and the other does not form a chain. Then this block that does not form a chain is called an orphan block.

22. Uncle block

The orphan block mentioned above, through the ghost protocol, makes it part of the proof of work, then it will not be discarded and will be saved in the main chain superior. This block is next

23 replay attack

The hacker resends the message that has been sent to the server. Sometimes this can defraud the server of multiple responses.

24. Directed acyclic graph

Also called data set DAG (directed acyclic graph), DAG is an ideal multi-chain data structure. Most of the blockchains mentioned now are single chains, that is, one block is connected to another block, and DAG is multiple blocks connected. The advantage is that several blocks can be generated at the same time, so the network can process a large number of transactions at the same time, and the throughput will definitely increase. However, there are many shortcomings and it is currently in the research stage.

25. What is mining

The mining process is to perform a series of conversions, connections and hash operations on the above six fields, and continue to try them one by one. The random number you are looking for, and finally successfully find a random number that meets the conditions: the value after hashing is smaller than the hash value of the preset difficulty value, then the mining is successful, and the node can broadcast the area to neighboring nodes. block, neighboring nodes receive the block and perform the same operation on the above six fields to verify compliance, and then forward it to other nodes. Other nodes also use the same algorithm to verify. If there are 51% of nodes in the entire network If all verifications are successful, even if this block is truly "mined" successfully, each node will add this block to the end of the previous block, delete the list in the block that is the same as its own record, and resurrect again. the above process. Another thing to mention is that regardless of whether the mining is successful or not, each node will pre-record the reward of 50 Bitcoins and the handling fees of all transactions (total input-total output) in the first item of the transaction list (this is " The most fundamental purpose of "mining" is also the fundamental reason to ensure the long-term stable operation of the blockchain), the output address is the address of this node, but if the mining is unsuccessful, the transaction will be invalidated without any reward. Moreover, this transaction called "production transaction" does not participate in the "mining" calculation.

26. Mining machines/mines

Mining machines are computers with various configurations, and computing power is the biggest difference between them. A place where mining machines are concentrated in one place is a mining farm

27. Mining pool

Miners join together to form a team, and the computer group under this team is a mining pool. Mining rewards are distributed based on your own computing power contribution.

28. Mining difficulty and computing power

Mining difficulty is to ensure that the interval between generating blocks is stable within a certain short time, such as Bitcoin is issued in 10 minutes

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Block 1. The computing power is the configuration of the mining machine.

29. Verification

When verification in the blockchain is a confirmation of the legality of the transaction, each node will verify the transaction once when the transaction message is propagated between nodes. Whether the transaction is legal. For example, verify whether the syntax of the transaction is correct, whether the transaction amount is greater than 0, whether the entered transaction amount is reasonable, etc. After passing the verification, it will be packaged and handed over to the miners for mining.

30. Transaction broadcast

That’s itNodes send information to other nodes over the network.

31. Mining fees

For the blockchain to work non-stop like a perpetual motion machine, miners need to maintain the system. Therefore, the miners must be given favorable fees to make it sustainable.

32. Transaction confirmation

When a transaction occurs, the block recording the transaction will be confirmed for the first time, and will be confirmed in every area on the chain after the block. Block is reconfirmed: When the number of confirmations reaches 6 or more, the transaction is generally considered safe and difficult to tamper with.

33. Double transaction

That is, I have 10 yuan, I use the 10 yuan to buy a pack of cigarettes, and then instantly use the 10 yuan that has not yet been paid. Bought another cup of coffee. So when verifying the transaction, you need to confirm whether the 10 yuan has been spent.

34. UTXO unspent transaction output

It is a data structure containing transaction data and execution code, which can be understood as digital currency that exists but has not yet been consumed.

35. Transactions per second TPS

That is throughput, tps refers to the number of transactions the system can process per second.

36. Wallet

Similar to Alipay, it is used to store digital currencies, and blockchain technology is more secure.

37. Cold wallet/hot wallet

A cold wallet is an offline wallet. The principle is to store it locally and use QR code communication to prevent the private key from touching the Internet. A hot wallet is an online wallet. The principle is to encrypt the private key and store it on the server. When it is needed, it is downloaded from the server and decrypted on the browser side.

38. Software Wallet/Hardware Wallet

A software wallet is a computer program. Generally speaking, a software wallet is a program that interacts with the blockchain and allows users to receive, store, and send digital currencies and can store multiple keys. Hardware wallets are smart devices that specialize in handling digital currencies.

39. Airdrop

The project sends digital currency to each user’s wallet address.

40. Mapping

Mapping is related to the issuance of blockchain currency and is a mapping between chains. For example, there are some blockchain companies that have not completed the development of the chain in the early stage. They rely on Ethereum to issue their own currency. The issuance and transactions of the early currency are all operated on Ethereum. With the development of the company, the company's own chain development has been completed. The company wants to map all the previous information on Ethereum to its own chain. This process is mapping.

41. Position

Refers to the ratio of the investor’s actual investment to the actual investment funds

42. Full position

Buy all the funds in Bitcoin

43. Reduce the position

Sell some of the Bitcoins, but not all of them

44. Heavy positions

Compared with Bitcoin, Bitcoin accounts for a larger share of funds

45. Short position

Compared with Bitcoin, the share of funds is larger

46. Short position

Sell all the Bitcoins you hold and convert them all into funds.

47. Stop loss

After obtaining a certain profit, sell the Bitcoin held to keep the profit

48. Stop loss

After losses reach a certain level, sell the Bitcoins you hold to prevent further losses

49. Bull market

Prices continue to rise and the outlook is optimistic

50. Bear market

Prices continue to fall, and the outlook is bleak

51. Long (long)

The buyer believes that the currency price will rise in the future, buys the currency, and waits for the currency price After rising, sell at a high price to take profits

52. Short position (short selling)

The seller believes that the currency price will fall in the future, and sells the currency he holds (or borrows it from the trading platform) (coin) sell, wait for the price of the currency to fall, buy at a low price to take profits

53. Open a position

Buy virtual currencies such as Bitcoin

54 . Cover the position

Buy Bitcoin and other virtual currencies in batches, for example: buy 1 BTC first, and then buy 1 BTC later

55. Full position

All funds are purchased at one time to buy a certain virtual currency

56. Rebound

When the currency price falls, the price rebounds and adjusts because it falls too fast

57 .Consolidation (sideways)

The price fluctuation is small and the currency price is stable

58. Yin fall

The currency price declines slowly

59. Diving (waterfall)

The currency price fell rapidly and to a large extent

60. Cutting meat

After buying Bitcoin, the currency price fell, as Avoid expanding losses and selling Bitcoin at a loss. Or after borrowing the currency to go short, the currency price rises, and then buying Bitcoin at a loss

61. Holding up

Expecting the currency price to rise, but unexpectedly the currency price falls after buying; or expecting the currency price to rise. fell, but unexpectedly, after selling, the currency price rose

62. Unwinding

After buying Bitcoin, the currency price fell, causing a temporary book loss, but afterwards the currency price fell.The price rebounded and turned losses into profits

63. Going short

After selling Bitcoin because of the bearish market outlook, the price of the currency continued to rise. I was unable to buy it in time, so I failed to make any profit. Profit

64. Overbought

The currency price continues to rise to a certain height, the buyer's power is basically exhausted, and the currency price is about to fall

65. Oversold

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The currency price continues to fall to a certain low, the seller's power is basically exhausted, and the currency price is about to rise

66. Lure bulls

The currency price has been consolidating for a long time, and it may fall The risk is relatively high. Most of the short sellers have sold Bitcoin. Suddenly the short sellers raise the price of the currency, inducing the bulls to think that the currency price will rise and buy one after another. As a result, the short sellers suppress the currency price and lock the bulls.

< p> 67. Short-selling

After buying Bitcoin, bulls deliberately suppress the price of the currency, making short sellers think that the price of the currency will fall and sell them one after another. As a result, they fall into the trap of bulls

68. What is NFT

The full name of NFT is "Non-Fungible Tokens", which is non-fungible tokens. Simply put, it is a token on the blockchain. This kind of indivisible copyright certificate mainly serves to confirm and transfer the rights of digital assets. The difference from digital currency is that it is unique and indivisible. In essence, it is a unique digital asset.

69. What is the Metaverse

The Metaverse is a collection of virtual time and space, consisting of a series of augmented reality (AR), virtual reality (VR) and the Internet (Internet) Composed of digital currency, which carries the function of value transfer in this world.

70. What is DeFi

DeFi, the full name is Decentralized Finance, which is "decentralized finance" or "distributed finance". "Decentralized finance", as opposed to traditional centralized finance, refers to various financial applications based on open decentralized networks. The goal is to establish a multi-level financial system based on blockchain technology and cryptocurrency. As a basis, re-create and improve the existing financial system

71. Who is Satoshi Nakamoto?

Satoshi Nakamoto is the developer and founder of Bitcoin. Satoshi Nakamoto published the Bitcoin white paper on November 1, 2008, and mined Bitcoin for the first time on January 3, 2009. Whoever can use the Bitcoin in the genesis block is Satoshi Nakamoto himself, so who Is it Satoshi Nakamoto? There have been many "Satoshi Nakamotos" in history: In 2013, someone revealed that Mochizuki Shinichi, who had made outstanding contributions in the field of mathematics, was Satoshi Nakamoto, but no direct evidence was provided. In 2014, hackers broke into the mailbox used by Satoshi Nakamoto and found the owner of the mail, Dorian.; Dorian Nakamoto. Later, Dorian stated that he only obtained the email address and password by chance and was not Satoshi Nakamoto. In 2016, Craig Wright said that he was Satoshi Nakamoto and could provide Satoshi Nakamoto's private key. But later, Wright withdrew his statement because he could not face everyone's doubts.

72. Bitcoin is different from Q Coin

Bitcoin is a decentralized digital asset with no issuing entity. Q Coin is an electronic currency issued by Tencent. It is similar to electronic points, but it is not actually a currency. Q Coin requires a centralized issuing institution. Q Coin can only be recognized and used because of the credit endorsement of Tencent. The scope of use is also limited to Tencent's games and services. The value of Q coins is entirely based on people's trust in Tencent.

Bitcoin is not issued through a centralized institution, but it is widely recognized around the world because Bitcoin can self-certify its trust. The issuance and circulation of Bitcoin are jointly accounted for by miners across the entire network, and are not A central authority is also needed to ensure that no one can tamper with the ledger.

73. What is a mining machine?

Taking Bitcoin as an example, a Bitcoin mining machine is a professional equipment that competes for accounting rights by running a large amount of calculations to obtain new Bitcoin rewards. It is generally composed of a mining chip, a heat sink and a fan, and only performs A single calculation program consumes a lot of power. Mining is actually a competition between miners for computing power. Miners with more computing power have a greater probability of mining Bitcoin. As the computing power of the entire network increases, it becomes increasingly difficult to mine bits with traditional equipment (CPU, GPU), and people have developed chips specifically for mining. The chip is the core part of the mining machine. The operation of the chip will generate a large amount of heat. In order to dissipate heat, Bitcoin mining machines are generally equipped with heat sinks and fans. Users download Bitcoin mining software on their computers, use the software to assign tasks to each mining machine, and then start mining. Each currency has a different algorithm and requires different mining machines.

74. What is quantitative trading?

Quantitative trading, sometimes also called automated trading, refers to the use of advanced mathematical models to replace human subjective judgments, which greatly reduces the impact of investor sentiment fluctuations and avoids extreme fanaticism or pessimism in the market. make irrational investment decisions. There are many types of quantitative trading, including cross-platform trading, trend trading, hedging, etc. Cross-platform trading means that when the price difference between different target platforms reaches a certain amount, sell on the platform with a higher price and buy on the platform with a lower price.

75. Blockchain asset over-the-counter trading

Over-the-counter trading is also called OTC trading. Users need to find their own counterparties and do not need to match the transaction. The transaction price is determined by negotiation between the two parties. The two parties can fully communicate through face-to-face negotiation or telephone communication.

76. What is a timestamp?

The blockchain ensures that each block is connected sequentially through timestamps. Timestamps enable every piece of data on the blockchain to have a time stamp. Simply put, timestamps prove when something happened on the blockchain and cannot be tampered with by anyone.

77. What is a blockchain fork?

Upgrading software in a centralized system is very simple, just click "Upgrade" in the app store. However, in decentralized systems such as blockchain, "upgrading" is not that simple, and a disagreement may even cause a blockchain fork. Simply put, a fork refers to a disagreement when the blockchain is "upgraded", resulting in a fork in the blockchain. Because there is no centralized organization, every code upgrade of digital assets such as Bitcoin needs to be unanimously recognized by the Bitcoin community. If the Bitcoin community cannot reach an agreement, the blockchain is likely to form a fork.

78. Soft fork and hard fork

Hard fork means that when the Bitcoin code changes, the old nodes refuse to accept the blocks created by the new nodes. Blocks that do not comply with the original rules will be ignored, and miners will follow the original rules and create new blocks after the last block they verified. A soft fork means that old nodes are not aware of the changes to the Bitcoin code and continue to accept blocks created by new nodes. Miners may work on blocks they have no understanding of, or validation of. Both soft forks and hard forks are "backwards compatible" to ensure that new nodes can verify the blockchain from scratch. Backward compatibility means that new software accepts data or code generated by old software. For example, Windows 10 can run Windows XP applications. Soft forks can also be "forward compatible".

79. Classification and application of blockchain projects

Judging from the current mainstream blockchain projects, blockchain projects mainly fall into four categories: Category 1: Currency; The second category: platform category; the third category: application category; the fourth category: asset tokenization.

80. USDT against the US dollar

USDT is Tether USD, a token launched by Tether that is against the US dollar (USD). 1USDT=1 US dollar, users can use USDT and USD for 1:1 exchange at any time. Tether implements a 1:1 reserve guarantee system, that is, each USDT token will have a reserve guarantee of 1 US dollar, which supports the stability of the USDT price. The unit price of a certain digital asset is USDT, which is equivalent to its unit price in US dollars (USD).

81. Altcoins and alternative coins

Altcoins refer to blockchain assets that use the Bitcoin code as a template and make some modifications to its underlying technology blockchain, among which Those with technological innovations or improvements are also called alternative coins. Because the Bitcoin code is open source, the cost of plagiarism in Bitcoin is very low, even just copying the code of BitcoinCode and modify some parameters to generate a brand new blockchain.

82. Three major exchanges

Binance

Okex

Huobi

83. Market software

Mytoken

Non-small account

84. Information website

Babbitt

Golden Finance

Coin World News

85. Blockchain Browser

BTC

ETH

BCH

< p> LTC

ETC

86. Wallet

Imtoken

Bitpie

MetaMask (Little Fox)

87. Decentralized exchange

uniswap

88. NFT exchange

< p> Opensea

Super Rare

89. Ladder

Bring your own, buy a reliable ladder

90. Platform currency

Digital currency issued by the platform, used to deduct handling fees, transactions, etc.

91. Bull market, bear market

Bull market: rising market

Bear market : Falling market

92. Blockchain 1.0

A currency trading system based on distributed ledgers, represented by Bitcoin

93. Blockchain 2.0 < /p>

The contract blockchain technology represented by Ethereum (smart contract) is 2.0

94. Blockchain 3.0

The era of intelligent Internet of Things, beyond the financial field , providing decentralized solutions for various industries

95. Smart Contract

Smart Contract is a contract designed to spread, verify or execute in an information-based manner Computer protocol, simply put, an electronic contract is set in advance, and once both parties confirm it, the contract is automatically executed.

96. What is a token?

The token economy is an economic system with Token as the only reference standard, which is equivalent to a pass. If you own Token, you have rights and interests, and you have the right to speak.

97. The difference between big data and blockchainDon't

Big data is the means of production, AI is the new productivity, and blockchain is the new production relationship. Big data refers to a collection of data that cannot be captured, managed and processed within a certain time range using conventional software tools. It is a massive, high-growth and high-volume data set that requires new processing models to have stronger decision-making power, insight discovery and process optimization capabilities. Diverse information assets. Simply understood, big data is massive data accumulated over a long period of time and cannot be obtained in the short term. Blockchain can be used as a way to obtain big data, but it cannot replace big data. Big data is only used as a medium running in the blockchain and has no absolute technical performance, so the two cannot be confused. (A simple understanding of production relations is labor exchange and consumption relations. The core lies in productivity, and the core of productivity lies in production tools)

98. What is ICO?

ICO, Initial Coin Offering, is the initial public offering of tokens, which is crowdfunding in the blockchain digital currency industry. It is the most popular topic and investment trend in 2017, and the country launched a regulatory plan on September 4. Speaking of ICO, people will think of IPO, and the two are fundamentally different.

99. Five characteristics of digital currency

The first characteristic: decentralization

The second characteristic: having open source code

The third feature: independent electronic wallet

The fourth feature: constant issuance

The fifth feature: global circulation

100. What is decentralization?

It has no issuer, does not belong to any institution or country, and is a publicly issued currency designed, developed and stored on the Internet by Internet network experts.

100. What is measurement (scarcity)?

Once the total amount of issuance is set, it is permanently fixed, cannot be changed, cannot be over-issued at will, and is subject to global Internet supervision. Because the difficulty of mining and mining changes over time, the longer the time, the greater the difficulty of mining, and the fewer coins are mined, so it is scarce.

101. What is open source code?

The alphanumeric code is stored on the Internet. Anyone can find out the source code of its design, everyone can participate, can mine it, and it is open to the world.

102. What is anonymous transaction? Private wallet private?

Everyone can register and download the wallet online without real-name authentication. It is completely composed of encrypted digital codes. It can be sent and traded globally in real-time point-to-point without resorting to banks or any institutions. It cannot be traced by anyone without my authorization. ,Inquire.

103. What is a contract transaction?

A contract transaction refers to an agreement between the buyer and the seller to receive a certain amount at a specified price at a certain time in the future.A protocol for trading certain assets. The objects of contract trading are standardized contracts formulated by the exchange. The exchange stipulates standardized information such as commodity type, transaction time, quantity, etc. A contract represents the rights and obligations of the buyer and seller.

104. Digital Currency Industry Chain

Chip manufacturers, mining machine manufacturers, and mining machine agents mine and export to exchanges for retail investors to speculate in coins< /p>

105. Who is Bei Feng?

Beifeng: Digital currency value investor

Investment style: Steady

106. Build a community?

Beidou Community (high-quality price investment community)

Combining long and short, focusing on price investment, no contracts, no short-term play< /p>

Reasonable layout, scientific operation, prudent and conservative, earning periodic money

Welcome currency friends and seek common development.