What is blockchain and what is lovelorn
blockchain is a shared database. 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
main 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
2. Openness. The foundation of blockchain technology is open source. In addition to the private information of all parties to 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
3. Independence. Based on consensus specifications and protocols, 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
extended data
application direction:
1. Payment: for example, in terms of time, traditional cross-border remittance takes 10 minutes or several days, while blockchain cross-border remittance can achieve remittance in seconds e to decentralization. In terms of convenience, traditional cross-border remittance needs to wait until the next day after 19:00, while blockchain cross-border remittance only needs one mobile phone to realize all-weather remittance
2. Sharing medical records: the medical data blockchain sharing platform can achieve many application scenarios. Patient history data and other information can be linked, and medical history and image data can be viewed by personnel entering the system. These medical data can also be used for modeling and machine learning
source: network blockchain
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
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
(1) running on the Internet
(2) completely distributed< (3) the number of data nodes is changeable and unpredictable< (4) the data is public< (5) anyone can participate anonymously
(6) the operation and maintenance cost is high and depends on the reward mechanism< (7) the transaction speed is slow.