Blockchain and consensus network

1. There are many consensus mechanisms in the blockchain. The advantage of the pow consensus mechanism behind bitcoin, the most influential one, is that it is secure and can not be tampered with. The disadvantage is that it is too slow to process only seven transactions a second

2. Blockchain is a decentralized distributed ledger system, which can be used to register and issue digital assets, property rights certificates, points, etc., and transfer, pay and trade in a point-to-point manner. Compared with the traditional centralized ledger system, blockchain system has the advantages of complete disclosure, tamper proof, multiple payment prevention, and does not rely on any trusted third party
e to the high network delay in peer-to-peer network, the transaction order observed by each node can not be completely consistent. Therefore, the blockchain system needs to design a mechanism to reach a consensus on the sequence of transactions that occur in the same time. This algorithm to reach consensus on the order of transactions in a time window is called consensus mechanism
-- chainknow

3. The so-called "consensus mechanism" is to complete the verification and confirmation of the transaction in a very short time through the voting of special nodes; For a transaction, if several nodes with unrelated interests can reach a consensus, we can think that the whole network can also reach a consensus. More generally speaking, if a Chinese microblog big V, an American virtual currency player, an African student and a European tourist do not know each other, but they all agree that you are a good person, then you can basically conclude that you are not bad
as a data structure that stores data in chronological order, blockchain can support different consensus mechanisms. Consensus mechanism is an important component of blockchain technology. The goal of blockchain consensus mechanism is to make all honest nodes keep consistent blockchain view, and satisfy two properties at the same time:
1) consistency. The prefix part of the blockchain saved by all honest nodes is exactly the same
2) effectiveness. The information released by one honest node will be recorded by all other honest nodes in their own blockchain.

4. POW: proof of work (POW), a simple explanation is a proof to confirm that you have done a certain amount of work. Because the whole process of monitoring work is usually extremely inefficient, and it is a very efficient way to prove that the corresponding workload has been completed through the certification of the work results. For example, in real life, graation certificate, driver's license and so on, are obtained by means of test results. That is to say, how much money you get depends on your effective contribution to mining. Simply understand, the better your computer performance, the more revenue you will get. This is to allocate money according to your workload. Most digital currencies, such as bitcoin, lightcoin, etc., are virtual currencies based on POW mode (the higher the computing power, the longer the mining time, the more coins you get)
pos: POS is a consensus algorithm in the public chain, which can be used as a replacement of pow algorithm. POW is a mechanism to ensure the security of bitcoin, Ethereum and many other blockchains, but POW algorithm is criticized for destroying the environment and wasting power in the process of mining. POS tries to solve these problems by replacing the concept of mining with a different mechanism
POS mechanism can be described as a kind of virtual mining. POS mainly relies on the token in the blockchain itself. In pow, a user may buy a computer for 1000 dollars, join the network to mine and proce new blocks, and get a reward. In POS, users can buy tokens of equal value with us $1000 and put them into the POS mechanism as deposit, so that users have the opportunity to generate new blocks and get rewards. In pow, if users spend $2000 on hardware equipment, they will of course get twice the computing power to mine, thus getting twice the reward. Similarly, if you invest twice as much token as the deposit in the POS mechanism, you have twice as much chance to get the right to generate new blocks.

5. How to reach a consensus on decentralized networks
in the blockchain system, there is no centralized bookkeeping institution like a bank, so it is very important to ensure the consistency of each transaction on all bookkeeping nodes, that is, to make the whole network reach a consensus. The consensus mechanism solves this problem
at present, the main consensus mechanisms are workload proof mechanism POW and equity proof mechanism POS
POW determines your chances of getting bookkeeping rights by evaluating your workload. The greater the workload, the more likely you will get this bookkeeping opportunity
POS determines your chances of getting bookkeeping rights by evaluating the number and ration of tokens you hold. This is similar to the stock dividend system, holding a relatively large number of shares can get more dividends
the principle of dpos is similar to that of POS, except that some "deputies to the National People's Congress" are selected. The main difference from POS is that the node elects several agents, which are verified and recorded by the agents
with the development of technology, more advanced consensus mechanisms may emerge in the future.

6. In bitcoin and other blockchain currencies, there is also the problem of how to reach a consensus. In other words, the core issue of bitcoin or other blockchain currencies is how to reach a consensus in a decentralized environment

blockchain is not only the core technology behind bitcoin, but also the infrastructure supporting bitcoin. Therefore, when talking about the consensus of blockchain, we must talk about the consensus of bitcoin

the core breakthrough of bitcoin is to reach a consensus on transaction events in the case of decentralization, that is, to reach an agreement on the effectiveness of a transaction without a central organization<

bitcoin's method to achieve this consensus mainly includes two parts:

incentive; That is, each block generates a certain amount of new bitcoin to motivate participants
introce external resources to ensure safety; That is, to ensure the security of consensus through a large number of external calculations, that is, proof of power

this is also the method adopted by almost all POW currencies. For example, dent, Wright coin, sand coin, dog coin and so on.

7. Jinwowo network analysis: consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering.

8.

1、 The types of mobile phones are not exactly the same: g9700 belongs to 4G / 3G mobile phones; G9730 belongs to 5g mobile phone

Second, the screen size and resolution are different: the main screen size of g9700 is 5.8 inches, the narrow frame is 3.42mm, and the screen proportion is high 84.49%, the main screen resolution is 2280 x 1080 pixels; G9730 home screen size 6.1 inches, narrow frame 04mm, screen ratio The resolution of the main screen is 3040x1440 pixels

Third, the camera configuration is different: g9700 has three cameras, including two rear cameras, which are 16 million pixels + 12 million pixels, and the front camera is 10 million pixels; G9730 has four cameras, one more 12 megapixel rear camera than g9700

Fourth, the overall size and weight of the mobile phone are different: the size of g9700 mobile phone is 142.2x69.9x7.9mm, the weight is not the same 150g The size of g9730 mobile phone is 149.9x70.4x7.8mm, and the weight of g9730 mobile phone is 157g

(5) the color of mobile phone is different: g9700 mobile phone has four colors: bright jade white, carbon crystal black, glass green and lime yellow; G9730 has one less lime yellow color than g9700

9. The reasons are as follows: 1. The United States does not allow the suspect to be punished personally, that is to say, if the person does not speak, there is no way! American suspects have the right to silence. Therefore, no one can help him if he doesn't speak. 2. In the United States, there is always a law of egg pain, which can be used to account for the whereabouts of the victims and demand a light sentence! That's why the suspect didn't speak. I didn't hurt anyone, no body! So this can be a lighter sentence. 3. What's more painful is that there is no death penalty in the state where Zhang Yingying went. The reason why the case is not closed is that there are no bodies! According to the law of the United States, it may be the one who got off the bus half way and lost himself!! Because there's no body! Therefore, only Chinese law is just!

10. Jinwowo uses a vivid metaphor to illustrate: if consensus is the basis of blockchain, then consensus mechanism is the soul of blockchain
when explaining what a blockchain is, we can use a simple and clear decentralized distributed ledger to summarize it. However, in this ledger, how to sort the things generated in almost the same time is related to the consensus mechanism of the blockchain network
therefore, jinwowo network technology believes that consensus mechanism is an algorithm to reach consensus on the sequence of things in a period of time.