What are the attributes of blockchain in the technology layer
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 dataso 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
1-contains a distributed database
2-distributed database is the physical carrier of blockchain, blockchain is the logical carrier of transaction, all core nodes should contain full copies of the blockchain data
3-blockchain serializes blocks according to time, And blockchain is the only body of the whole network transaction data
4-blockchain is only effective for addition, but not for other operations
5-public and 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, in the face of a certain amount of contradictions between different nodes, the data will not collapse
8-consensus process can solve the problem of double spending
1 - Decentralization: because the blockchain relies on each node to achieve system maintenance and ensure the authenticity of information transmission, it is based on distributed data storage without centralized management by a certain center, Therefore, the attack and tampering of a node will not affect the healthy operation of the whole network
2-DE Trust: the establishment of a connection between any two nodes does not need to trust each other's identity, and the data exchange between the two sides does not need the basis of mutual trust. Since all nodes in the network can act as "supervisors", there is no need to worry about fraud
3 - extensible: blockchain is an underlying open source technology, on which various kinds of extension, decentralized and distrusted applications can be realized<
4 - anonymization: the two sides of data exchange can be anonymous, and the nodes in the network can exchange data without knowing each other's identity and personal information
5 - Security and reliability: because the activities between any nodes are supervised by the whole network, and the database adopts distributed storage, for hackers, first, they can't disguise and cheat, Second, we can't control the network only by conquering a node.
1-decentralization
2-transparency
3 - openness
4-autonomy
5 - information cannot be tampered with
6 - anonymity.
the top and easiest thing to do is the application layer. I can see two or three such projects every day, accounting for more than 95% of the whole market. But such companies often write a lot of technical things in the white paper. In fact, they also write in vain. This is purely for the purpose of collecting pages, because they don't need to talk about technology at all
the second type is the intermediate operation level, such as quantum chain and ant. This kind of project is similar to the operation procere, called the basic chain, which is used to run the application. This category is relatively small, and the proportion has dropped to less than 5%
the third category is more downward extension and lower level, such as standard chain and arcblock. This kind is even less. It's good to see two or three in a month. And some of them are not necessarily true, because there is really nothing to write about, and all fields are occupied by others, so someone will go in this direction.
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.
first, the meaning of blockchain technology
blockchain technology is a kind of technology that uses decentralized consensus mechanism to maintain a complete, distributed and tamper proof ledger database. It can enable the participants in the blockchain to realize a unified ledger system without establishing a trust relationship. The block is a public account book, which needs multi-point maintenance; Chain is covered with timestamps, which can not be forged. Blockchain is essentially a technology that focuses on security and credibility rather than efficiency
at present, there is a database behind all systems, that is, a large account book. So it's very important who keeps this account book. Now, whose system is who will keep accounts, and the bank accounts are the records of each bank, and Alipay's account is Ali. But now in the blockchain system, everyone in the system can have the opportunity to participate in bookkeeping. If there are new transaction data changes in a certain period of time, everyone in the system can make bookkeeping. The system will judge the fastest and best bookkeeper in this period, write the recorded content into the account book, and send the content of the account book to all other people in the system for backup. In this way, everyone in the system has a complete account book
as a result, the data becomes very secure. Tamperers need to modify more than half of the system node data at the same time to truly tamper with the data. The cost of such tampering is so high that it is almost impossible. For example, bitcoin has been running for more than seven years, and countless hackers around the world have tried to attack bitcoin, but so far there have been no trading errors. It can be considered that bitcoin blockchain has been proved to be a safe and reliable system. Therefore, it can be considered that blockchain technology is a way for the whole people to participate in bookkeeping, and what it will bring is the innovation of bookkeeping.