Source of blockchain
blockchain is a digital account book that can be jointly bookkept, and will record all transactions that have occurred and have been unanimously recognized by the system it's the same as the whole family. You're bookkeeping, and your father and mother are also bookkeeping. They can see the general ledger, but the saved information can't be tampered with any more
In 2008, Nakamoto first proposed the concept of blockchain subsequently, blockchain has become the core component of electronic currency bitcoin, which serves as the public account book for all transactions. By using peer-to-peer network and distributed timestamp server, the blockchain database can be managed independentlyextended data:
type of blockchain
1, public blockchain
any indivial or group in the world can send transactions, and transactions can be effectively confirmed by the blockchain, and anyone can participate in its consensus process. Public blockchain is the earliest and the most widely used blockchain. The virtual digital currencies of bitcoin series are all based on public blockchain. There is only one blockchain corresponding to this currency in the world
2, Alliance (instry) blockchain
instry blockchain: multiple preselected nodes are designated as bookkeepers within a group, and the generation of each block is jointly determined by all preselected nodes (preselected nodes participate in the consensus process), and other access nodes can participate in the transaction, However, regardless of the bookkeeping process (in essence, it is still managed bookkeeping, only distributed bookkeeping, how many preselected nodes, and how to determine the bookkeeper of each block to become the main risk point of the blockchain), anyone else can conct limited query through the open API of the blockchain
3, private blockchain
only uses the general ledger technology of blockchain for bookkeeping. It can be a company or an indivial, and enjoys the write permission of the blockchain. This blockchain is not very different from other distributed storage schemes
Blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it is characterized by "unforgeability", "trace in the whole process", "traceability", "openness and transparency" and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects
on January 10, 2019, the state Internet Information Office issued the regulations on the management of blockchain information services. In October 24, 2019, ring the eighteenth collective learning of the Central Political Bureau, general secretary Xi Jinping stressed that "block chain as an important breakthrough in core technology and independent innovation", "accelerating the development of block chain technology and instrial innovation". "Blockchain" has entered the public field of vision and become the focus of social attention
extended data:
related extension: blockchain financial application:
since 2016, the major financial giants have also carried out blockchain innovation projects to explore the possibility of applying blockchain technology in various financial scenarios. In particular, Puyin group took the lead in creating a "blockchain +" standard digital currency
standard digital currency refers to the process of assets identification, evaluation, right confirmation and insurance completed by a third party organization, which is written into the blockchain through careful digital algorithm to form the standard corresponding relationship between assets and digital currency, which is called standard digital currency
in order to realize the great leap forward development of blockchain finance, promote the new development of China's economy, accelerate the circulation of global assets, and realize the dream of rejuvenation that has been struggling for generations, Puyin group will hold the Guiyang strategic development ceremony of Puyin blockchain finance in Guizhou on December 9, 2016
the meeting will discuss the realization of digital circulation of assets by blockchain, the financial transaction mode of blockchain, and the application of blockchain services and social public instry. This conference will mark the beginning of the application of blockchain finance and the change and development of the new financial ecology
on June 1, 2020, Xinhua news agency was authorized to broadcast the "overall plan for the construction of Hainan free trade port" issued by the CPC Central Committee and the State Council, which will "actively participate in the formulation of international rules for cross-border data flow, and establish standards and rules for data rights confirmation, data trading, data security and blockchain finance" as one of the key tasks of Hainan free trade port before 2035
A: first, the connotation of blockchain
blockchain is a distributed shared ledger and database, which is decentralized, tamper proof, traceable, collective maintenance, open and transparent
Agricultural traceability is the most complex and difficult part of food traceability. At present, there is no complete agricultural proct traceability system based on food safety proction and whole process supply chain management2. The most important part of the construction of agricultural traceability system is "one center and three moles", which is a traceability cloud data center and three moles of procers, regulators and consumers
Third, composition of blockchain
blockchain system is composed of data layer, network layer, consensus layer, incentive layer, contract layer and application layer