Block chain technology principle the first mock exam in Wuxi

1. blockchain does not belong to any instry. Blockchain is a new application mode of computer technology, such as distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and so on. In a narrow sense, blockchain is a kind of chain data structure that combines data blocks in a sequential way according to the time sequence, and it is a distributed account book that can not be tampered with and forged by means of cryptography.

2. Blockchain technology uses mathematical methods to achieve distributed accounting and solve the trust problem, so as to complete the decentralization, which will bring far-reaching influence in many fields such as communication, finance, Internet of things, government management and so on
blockchain refers to the technical solution of collective maintenance of a reliable database through centralization and distrust in the past, and it is a technical way for the whole people to participate in bookkeeping. Previous bookkeeping methods were all centralized and needed centralized intermediary, whether it was traditional government, financial institutions, notarization institutions or emerging e-commerce platform and online payment platform
in economic hypothesis, information is sufficient. In fact, it is precisely because of insufficient information that there are very large intermediaries. The existence of intermediaries increases the transaction cost and raises the transaction threshold. In essence, blockchain technology is a large-scale collaboration tool. It makes direct value transfer possible by using pure technology for the first time, and continues the trend of Internet decentralization and disintermediation. Disintermediated blockchain technology will greatly subvert the information intermediary instry
blockchain technology is the basic technology for building bitcoin data structure and encrypted transmission of transaction information, which realizes the issue and transaction of bitcoin. The core of blockchain technology is that all the current participating nodes jointly maintain the transaction and database, so that the transaction is based on the principle of cryptography rather than trust, so that any agreed parties can directly carry out payment transactions without the participation of a third party
technically, a block is a data structure for recording transactions, reflecting the capital flow of a transaction. In the system, the transaction blocks are connected to form a main chain, and all the nodes participating in the calculation record the main chain or part of the main chain
a block contains the following three parts: transaction information, hash formed by the previous block and random number. Transaction information is the task data carried by the block, including the private keys of both parties, the number of transactions, the digital signature of electronic currency, etc; The hash hash formed by the previous block is used to connect the blocks and realize the sequence of past transactions; Random number is the core of the transaction. All nodes compete to calculate the answer of the random number. The node that gets the answer the fastest generates a new block and broadcasts it to all nodes for updating, so as to complete a transaction.

3. From the perspective of data, blockchain is a kind of distributed database or distributed shared general ledger. The "distributed" here is not only reflected in the distributed storage of data, but also reflected in the distributed records of data. From the perspective of effect, blockchain can generate a set of time sequence, tamper proof and trustworthy database
blockchain has four core technologies. The first one is block + chain, which is the most core and basic technology in blockchain. The second core technology is distributed structure. The ingenious design of blockchain structure is to let every node participating in data transaction record and store all data. The third core technology is asymmetric encryption algorithm, and the fourth core technology is script, which can be understood as a programmable smart contract.

4. Let's take bitcoin as an example:
blockchain is an important concept of bitcoin, which is essentially a decentralized database and serves as the underlying technology of bitcoin. Blockchain is a series of data blocks generated by cryptography. Each data block contains the information of a bitcoin network transaction, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block
blockchain is public on the network and can be queried in every offline bitcoin wallet data. The function of bitcoin wallet depends on the confirmation with the blockchain. An effective inspection is called a confirmation. Usually, a transaction needs to obtain several confirmations. The lightweight bitcoin wallet uses online confirmation, that is, it will not download the blockchain data to the device storage
many of bitcoin's competitors also use the same design, but the workload proof and algorithm are slightly different. For example, the use of proof of interest and scrypt and so on
in addition, digital cryptocurrencies such as Laite coin, Ethereum, Weimeng coin, doggy coin and Ruitai coin also use blockchain technology.

5.

In a narrow sense, blockchain is a kind of chain data structure that combines data blocks in a sequential way according to the time sequence, and it is a distributed account book that can not be tampered with and forged by means of 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 contracts composed of automated script code to program and operate data

working principle

blockchain system is composed of data layer, network layer, consensus layer, incentive layer, contract layer and application layer. Among them, the data layer encapsulates the underlying data blocks and related basic data and algorithms such as data encryption and timestamp; The network layer includes distributed networking mechanism, data transmission mechanism and data verification mechanism; The consensus layer mainly encapsulates all kinds of consensus algorithms of network nodes; The incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives; The contract layer mainly encapsulates all kinds of scripts, algorithms and smart contracts, which is the basis of the programmable characteristics of blockchain; The application layer encapsulates various application scenarios and cases of blockchain. In this model, chain block structure based on timestamp, consensus mechanism of distributed nodes, economic incentive based on consensus computing power and flexible and programmable smart contract are the most representative innovations of blockchain technology

6.

Seeing some answers to the debate on the definition of blockchain, I suddenly realize that my answer to this explanation principle has always been directed at bitcoin. There is no specific and unique answer in the instry between the definition of blockchain. Here I first summarize the characteristics of "blockchain" according to the papers I read:

1; Hash chain & quot There are several nodes participating in the system operation (distributed)

3. Reach a consensus on the consistency of basic data (consensus agreement / algorithm) through a certain protocol or algorithm

since bitcoin is currently one of the most typical and influential applications of blockchain, it will be much easier to understand how bitcoin uses blockchain before understanding other forms of blockchain applications

7. At present, there are a variety of books on blockchain, each with its own merits. However, it is necessary to choose books with better quality. I have been in touch with blockchain for two years. According to my personal opinion, I recommend you books with high basic quality. The titles of the books are as follows: Xu Mingxing's Illustrated blockchain, Changxia's blockchain: from digital currency to credit society, blockchain: technology driven finance and so on. I hope they can be helpful.

8. Blockchain is a technology, but it is not a single technology, but the result of the integration of a variety of technologies, including cryptography, mathematics, economics, network science and so on. You can think of it as a distributed shared accounting technology, or as a database, but the database is jointly maintained by all nodes in the chain, and each node has an account book. Because the account books of all nodes are consistent, different nodes can trust each other, and there is no doubt about the data, so we all say that the blockchain has realized trust technically. For detailed professional technology, you can consult some professional technology companies, such as Jinbo technology, which focuses on the development of blockchain related procts, professional R & D team and perfect after-sales service, and you can consult by telephone.