How does the blockchain connect to the public chain

1.

blockchain includes public blockchain, joint (instry) blockchain and private blockchain. Public chain point-to-point e-cash system: bitcoin, smart contract and decentralized application platform: Ethereum

blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies

blockchain is an important concept of bitcoin. In essence, it is a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of bitcoin network transaction information, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

extended data

according to the different degree of blockchain network centralization, three kinds of blockchains under different application scenarios are differentiated:

1. The blockchain with the whole network open and without user authorization mechanism is called public chain

2. The authorized nodes are allowed to join the network, and the information can be viewed according to the authority. It is often used in the inter agency blockchain, which is called alliance chain or instry chain

3. All the nodes in the network are in the hands of one organization, which is called private chain

alliance chain and private chain are also called licensing chain, and public chain is called non licensing chain

blockchain features

1, decentralization. Blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain

2. Openness. Blockchain technology is based on open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent

3. Independence. Based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention

4. Safety. As long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily manipulated and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes

5. Anonymity. Unless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information can be transferred anonymously

2. At present, blockchain technology is in the stage of rapid development. In the past two years, China has invested a lot of funds and talents in this area
technical personnel can learn this technology, while non-technical personnel can start from the instry media and instry community
If an enterprise needs to develop blockchain applications, it can entrust a professional third-party company. In Guangzhou, today's technology is good.

3. Guizhou has released some standards, such as the quality model and key elements of blockchain system, the implementation process of data asset transaction of blockchain, the terminology and basic requirements of the implementation process of targeted poverty alleviation of blockchain, etc. now many local blockchain applications have been implemented. Our digital money package is also an application of blockchain technology, and now blockchain applications have been implemented one after another, Changsha high tech Zone has launched a SMIC blockchain service platform project, which is based on the blockchain + public service mode, and is soliciting enterprises to join the chain.

4.

Public chain, also known as "public chain", refers to the blockchain that anyone in the world can enter the system at any time to read data, send confirmatory transactions and compete for bookkeeping. The public chain is generally considered to be "completely decentralized", because no indivial or institution can control or tamper with the reading and writing of data in it. In terms of application, blockchain public chain mainly includes bitcoin, Ethereum, super ledger, most counterfeit currencies and smart contracts. The ancestor of blockchain public chain is bitcoin blockchain, which has the following characteristics:

1, open source code

upload the code to GitHub, and everyone can get complete blockchain data by downloading, Accept the test of the public

2, complete decentralization

anyone can become a node, each node is open, everyone can participate in the calculation of the blockchain, any node is not permanent, but phased, and any center is not mandatory for nodes. Anyone can read and send transactions, and transactions can be effectively confirmed on the blockchain. Anyone can participate in the consensus process. The consensus process determines whether a block can be added to the blockchain and the exact current state. Everyone can get financial reward from it, which is proportional to their contribution to the consensus process. These public chains are generally considered to be "completely decentralized"

3. Developing decentralized applications

through this public chain, developers can easily develop centralized applications. Public chain can protect the rights and interests of users from the influence of program developers

5. The public chain, as the name suggests, has great inclusiveness and fairness. The better the public chain project does in these two aspects, the more prominent it will be. At present, many public chains sacrifice fairness in order to speed up the transaction, which is not optimistic. There is a project called Fanta network. Their DSC technology claims to be safe, democratic and fair, which deserves long-term attention. However, their code will not be open source until the end of the year, and the progress needs to be accelerated

6.

This is two different concepts. According to different standards, blockchain can be classified into three categories:

& # 8195&# 8195; 1) According to the network scope of blockchain, it can be divided into public chain, private chain and alliance chain

 &# 8195; 2) According to the docking type of blockchain, it is divided into single chain, side chain and interconnection chain

 &# 8195; 3) According to the display environment of blockchain deployment, it can be divided into main chain and test chain

the main chain can be understood as a formal online and independent blockchain network, while the public chain refers to a blockchain that can be read by anyone, can send transactions and can be effectively confirmed by anyone, and can participate in its consensus process

7.

Blockchain is strictly divided into three types: public chain, private chain and alliance chain. The core difference between these three types of blockchains is the degree of openness or decentralization of access rights. Generally speaking, the higher the degree of decentralization, trust and security, the lower the transaction efficiency

generally speaking, each type of blockchain has its own specific mode and value, which is better than others. As long as the demand is solved, the blockchain is valuable

8.

According to experts, blockchain can be understood as a distributed public ledger, which is connected by various blocks into a chain. In the traditional bookkeeping system, the bookkeeping right is controlled by the central server

on the "account book" of blockchain, every point in the chain can record information on it, forming a point-to-point accounting system. Therefore, blockchain technology is considered as a decentralized technology

For example, in a village of 100 people, Zhang San bought a cow from Li Si and paid him 10000 yuan. In the past, he had to rely on Zhao Liu, a middleman, to transfer his 10000 yuan to Li Si

with the blockchain system, Zhang San can directly record his 10000 yuan to Li Si's account book, and the transaction information will be transmitted to the whole village, that is, the whole blockchain system, so that other 98 people can see the information. The whole transaction process is recorded by the system, which has the advantage of traceability to prevent the loss of Zhao Liu's account book or Li Si's denial of account

extended data

in 2008, Nakamoto first proposed the concept of blockchain. In the following years, blockchain became the core component of electronic currency bitcoin: as a public account book for all transactions. By using peer-to-peer network and distributed timestamp server, the blockchain database can be managed independently

the blockchain invented for bitcoin makes it the first digital currency to solve the problem of repeated consumption. The design of bitcoin has become a source of inspiration for other applications

9. How can blockchain be connected in sequence
blockchain is composed of a series of blocks generated by cryptographic algorithm. Each block is filled with transaction records, and the blocks are connected in sequence to form a chain structure, which is the blockchain ledger
taking bitcoin as an example, when miners generate new blocks, they need to calculate the new hash value and random number according to the hash value, new transaction block and random number of the previous block. In other words, each block is generated on the basis of the previous block data, which ensures the uniqueness of the blockchain data
because subtle changes in transaction records will completely change the result of hash value, miners can't cheat when competing for computing power. Each miner must wait until the previous block is generated before starting to calculate the qualified random number according to the data of the previous block, which ensures the fairness of mining.

10. The first thing that Java needs to pay attention to in developing blockchain is the hierarchical relationship. Once it's confused, it's difficult to sort out
the difference between blockchain and ordinary mall is that it adds the function of virtual currency. You can see the interface and docking method of virtual currency at other times to avoid mistakes