Multiple topics of blockchain

1. Jinwowo analysis believes that blockchain mainly solves the trust and security problems of transactions. Once the information is confirmed and added to the blockchain, it will be permanently stored. Unless more than 51% of the nodes in the system can be controlled at the same time, the modification of data on a single node cannot be realized. Therefore, the data stability and reliability of blockchain are very high
e to the use of Distributed Accounting and storage, there is no centralized hardware or management organization, the rights and obligations of each node are equal, and the data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system.

2. Is this the college entrance examination?

3. At present, there are three application deployment types of blockchain: public chain, private chain and alliance chain. What's the difference between them? What are the typical applications<

public chain: open to all, anyone can participate

private chain: open to indivial indivials or entities

alliance chain: open to specific organizations

4. In one sentence, it is decentralization
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 obtain interests between different nodes in the blockchain system
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data< Advantages:
1) the algorithm is simple and easy to implement
2) there is no need to exchange additional information between nodes to reach a consensus
3) it takes a lot of cost to destroy the system< Disadvantages:
1) waste of energy
2) it is difficult to shorten the block confirmation time
3) the new blockchain must find a different hash algorithm, otherwise it will face bitcoin attack
4) it is easy to generate bifurcation and needs to wait for multiple confirmations
5) there is no finality, and checkpoint mechanism is needed to make up for it.

5. 1-contains a distributed database

2-The distributed database is the physical carrier of the blockchain, and the blockchain is the logical carrier of the transaction. All core nodes should contain the full of the blockchain data

3-The blockchain serializes the blocks according to time, and the blockchain is the only body of the whole network transaction data

4-The blockchain is only effective for adding, Invalid for other operations

5-public-private key verification based on asymmetric encryption

6-accounting node requires that Byzantine general problem can be solved / avoided

7-consensus progress is evolutionarily stable, that is, it will not collapse in the face of a certain amount of contradictory data of different nodes

8-consensus process can solve the problem of double spending

five characteristics of blockchain:
decentralized
e to the use of Distributed Accounting and storage, there is no centralized hardware or management organization, the rights and obligations of any node are equal, and the data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system
thanks to the decentralization of blockchain, bitcoin also has the characteristics of decentralization [6]
openness
the system is open, in addition to the private information of all parties to the transaction is encrypted, the data of the blockchain is open to all, and anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
autonomy
blockchain adopts consensus based specifications and Protocols (such as a set of open and transparent algorithms) to enable all nodes in the whole system to exchange data freely and safely in a de trusted environment, so that the trust in "people" is changed into the trust in machines, and any human intervention does not work
information cannot be tampered with
once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid, so the data stability and reliability of the blockchain are extremely high<
anonymity
since the exchange between nodes follows a fixed algorithm, their data interaction does not need trust (the program rules in the blockchain will judge whether the activity is effective by themselves), so the counterparties do not need to let the counterparties generate their own trust by disclosing their identities, which is very helpful for credit accumulation.

6.

Although the current blockchain technology is still in the initial stage, the advantages of this technology have begun to be reflected. In many fields, blockchain can proce great value, and I believe there will be more landing application scenarios in the future,

blockchain + cross border payment

at present, the mainstream way of cross-border remittance is wire transfer, and its cycle is generally as long as three to five working days. In addition to certain handling charges, intermediary banks will charge certain handling charges, Swift (Global Interbank Financial Telecommunication Association) will also charge a higher fee for the message exchange of its system. In China, a single fee of 150 yuan will be charged for cross-border remittance through the Bank of China

and the use of blockchain technology allows the remitter and the payee to pay and settle directly, eliminating all intermediate costs, so that cross-border payment and settlement can be completed point-to-point quickly. While improving the speed of settlement, it can also achieve all-weather payment, real-time arrival, simple embodiment and no hidden cost