The core idea of blockchain is

1.

From the perspective of technology and architecture, I will tell you my understanding of blockchain in common language

what is blockchain? In a word, blockchain is a storage system. To be more specific, blockchain is a distributed storage system without an administrator and each node has all the data

What are the common storage systems like

first, how to ensure high availability

the common storage system usually uses "rendancy" to solve the problem of high availability. As shown in the figure above, if the data can be copied into several copies and rendant to multiple places, high availability can be guaranteed. The data in one place is hung, and there is data in other places. For example, the master-slave cluster of MySQL is the same principle, and the raid of disk is also the same principle

two points need to be emphasized in this place are: data rendancy often leads to consistency problems

1. For example, in the master-slave cluster of MySQL, there is actually a delay in reading and writing, which means there is a inconsistency in reading and writing in a short period of time. This is a side effect of data rendancy

The second point is that data rendancy often reces the efficiency of writing, because data synchronization also consumes resources. If you add two slave libraries, the write efficiency will be affected. The common storage system is to use rendancy to ensure the high availability of data

so the second question, ordinary storage system, can write more

the answer is yes, for example, take this graph as an example:

in fact, MySQL can do a master-slave synchronization of al masters, master-slave synchronization of al masters, two nodes can be written at the same time. If you want to do a multi room multi live data center, in fact, multi room multi live data synchronization. What we should emphasize here is that multi-point writing often leads to the consistency problem of writing conflicts. Take MySQL as an example, suppose that the attribute of a table is self incrementing ID, then the data in the database is 1234 now. If one of the nodes writes and inserts a piece of data, it may become 5, and then these 5 pieces of data are synchronized to another master node, Before synchronization, if another write node inserts a piece of data, a piece of data with self incrementing ID of 5 will be generated. Then, after the generation, synchronize to another node, and the synchronized data will conflict with the two local 5's after it arrives, which will lead to synchronization failure and write consistency conflict. This problem will occur in the case of multi-point writing

how to ensure consistency in multi-point writing

the reform "Swan class" gives you more technical work

2. Compared with the traditional centralization scheme, blockchain technology has the following three characteristics:
1) the core idea of blockchain is decentralization
2) the biggest subversion of blockchain lies in the establishment of credit
3) the collective maintenance of blockchain can rece the cost.
in a word, blockchain touches money, trust and power, which are the fundamental basis for human survival.

3. It is understood that compared with the traditional centralized scheme, blockchain technology mainly has the following three characteristics:

the core idea of blockchain is decentralization

in the blockchain system, the rights and obligations of any node are equal, and all nodes have the ability to vote with computing power, Thus, the result recognized by more than half of the nodes is guaranteed. Even under serious hacker attacks, as long as the number of nodes controlled by hackers does not exceed half of the total number of nodes in the world, the system can still operate normally and the data will not be tampered with

block chain's biggest subversive nature is the establishment of credit

theoretically, block chain technology can make WeChat payment and Alipay no longer exist value. The economist makes an image metaphor for blockchain: in short, it is "a machine for creating trust". Blockchain enables people to cooperate with each other in the case of mutual distrust and no neutral central institution. The fight against counterfeit money and financial fraud will not be needed in the future

the collective maintenance of blockchain can rece the cost

under the centralized network system, the maintenance and operation of the system depend on the operation and maintenance of platforms such as data center, and the cost cannot be omitted. Anyone can participate in the nodes of the blockchain. Each node can verify the correctness of the results of other nodes' records while participating in the records, which improves the maintenance efficiency and reces the cost

in a word, blockchain touches money, trust and power, which are the fundamental basis for human survival.

4. Yes, decentralization, which is the core of blockchain. It is a new application mode integrating distributed data storage, transmission, identification, encryption, trust and security technologies. At present, it is mainly used in electronic currency

5. Many relationships between people are based on trust, such as friend relationship, cooperation relationship, transaction relationship, etc
take trading activities as an example. In the past, the two sides who did not trust each other usually chose an intermediary to guarantee a transaction. In the mobile Internet era, we chose Taobao shopping because Alipay provided us with an intermediate guarantee. We chose to drop dripping because it provided us with information matching.
however, these intermediaries are centralized and have their own interests. Sometimes they are not so reliable and trustworthy. Theoretically, Alipay's centralization of accounting has been artificially falsified. Part of the reason for Didi's troubles is that they only think from their own standpoint
what blockchain does is the machine of trust, which replaces the role of trust intermediary with code, ensures the fairness and justice of the whole system through consensus mechanism and distributed accounting, and provides a trust without trust
for example, in the future, people can abandon the intermediate platform and realize point-to-point docking and free trading through blockchain. Shopping does not need to go through an intermediary, and taking a taxi does not need to go through Didi. In this way, we can really achieve "no middleman to earn the price difference" and rece the cost.

6. 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
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 to be trusted (the program rules in the blockchain will judge whether the activity is effective by themselves), so the counterparties do not need to trust themselves by disclosing their identities, which is very helpful for credit accumulation

7. From the market, to the market, with the correct method, do useful research.

8. In a narrow sense, blockchain is a kind of chained data structure that combines data blocks in chronological order in a way of sequential connection, and it is a distributed account book that can not be tampered with and forged by cryptography. In a broad sense, blockchain technology is a new distributed infrastructure and computing paradigm, 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.

9. The core significance of blockchain technology is to build a social trust network that does not rely on a third party and runs by itself, so as to promote the value interconnection of the whole society. Its mark is not only that today's material assets, financial assets, information assets, human resources and so on can better reflect the value, but also that today's social relations, personal background, time and energy, ideological sparks, enterprising spirit and so on, which can not be simply valued and quantified, can graally become social assets that can be valued and quantified, It has comprehensively promoted the development of social proctive forces and pushed human society to a new level
black horse programmers are going to offer the course of "Internet of things + blockchain". Those who want to learn can pay attention to it.