Consensus, simply understood, means that everyone is in agreement. In the blockchain, it is actually a rule, each node according to this rule to confirm their own data, and finally maintain the database of the whole network to keep consistent.

1. What is the consensus mechanism of blockchain

How can decentralized networks reach consensus? In the blockchain system, there is no centralized accounting institution like a bank. To ensure the consistency of every transaction on all accounting nodes, it is crucial to reach a consensus across the network. The consensus mechanism solves this problem. At present, the main consensus mechanisms include proof-of-work mechanism PoW and proof-of-interest mechanism PoS. PoW evaluates your workload to determine your chances of getting the billing. The more work you do, the more probably to get the billing chance. The PoS determines your odds of getting billing rights by assessing how many tokens you hold and how long you hold them. 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" are selected. The main difference with PoS is that a node elects a number of agents, who verify and keep accounts. More advanced consensus mechanisms are likely to emerge in the future as technology evolves.

What problem does blockchain solve

In a word: decentralized. Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. The so-called consensus mechanism is a mathematical algorithm to establish trust and gain rights and interests between different nodes in the blockchain system. Narrowly speaking, blockchain is a kind of chained data structure that combines blocks data sequentially connected in a chronological manner, and cryptographically guaranteed tamper-proof and unforgeable distributed ledger. Broadly speaking, blockchain technology is a new way to distributed infrastructure and computing which using block chain data structure to verify and storage data, using distributed node consensus algorithm to generate and update data, using cryptography to ensure the security of data transmission and access, programming and manipulating data using smart contracts composed of automated script code.

Advantages: 1) The algorithm is simple and easy to implement; 2) Consensus can be reached between nodes without exchanging additional information; 3) Destroying the system requires great cost.

Disadvantages: 1) Waste of energy; 2) It is difficult to shorten the confirmation time of the block; 3) New blockchain must find a different hashing algorithm or face Bitcoin's computational attack; 4) Easy to bifurcate and need to wait for multiple confirmations; 5) There is never finality, and checkpoints are needed to compensate for finality.

What kind of problems can blockchain technology solve

Blockchain technology can solve the trust problem with a relatively lower cost, which plays an important role in reducing the burden of the real economy and reducing transaction costs, and has great social value. At the same time, for the blockchain technology itself, there is still a need for continuous exploration, I believe that the independent and controllable intellectual property rights and patents can be integrated with the technology in the future.

As a decentralized database, block chain has the characteristics of openness, distribution and irreversibility. As an electronic data storage platform, it has the advantages of low cost, high efficiency and stability. At present, block chain has been applied in many fields and brought many changes to life. Now many electronic contract platforms, such as the University of Law, legal data chain, etc., have applied this blockchain technology, and the blockchain technology certificate has also been accepted by the court.

Block chain requirements on the books of each join points in common distributed accounting every transaction, every time after trading, information will inform to all of the "point", the "dot" (the people) according to the preset rules to confirm transactions independently of the entire process, transparency and unified, participant qualification permission to complete equivalence. Most of the "points" confirmed are the final conclusion, and the system will automatically correct your data to the accepted result. You want to cheat or insist on a different point of view unless you can get more than 51 percent of the dots to agree with your conclusion, which is practically impossible when there are enough dots involved. After a transaction is confirmed, the transaction records and various kinds of data are packaged into blocks, timestamp, encoded into the chain, and then the next round of transactions (blocks) are initiated, and the old and new blocks are followed together to form a "chain". The transaction records stored in each block can be traced back indefinitely, ready for reference at any time and cannot be changed. If you want to cheat, lie and conceal the truth, there is no chance to take advantage of it, and the trust between people is thus established! The second generation of blockchain also introduces the "smart contract" mechanism, adding a contract that can be automatically performed in the program. Once the agreed conditions are met, the system will automatically implement compulsory delivery, and all the connection points will also witness and confirm this process, and the occurrence of perfidious behavior is not allowed.