What is blockchain, for example
first, define the
blockchain as an open network ledger. It originated from bitcoin and is the underlying technology of bitcoin. In bitcoin transactions, all the information of transaction records will be packaged into a "block" for storage. With the expansion of information exchange, one block links with another, forming a blockchain
Second, the digital currency represented by bitcoin is a point-to-point e-cash system. Among them, every transaction will broadcast to all participants in the network, and it will be recorded in the account book after repeated confirmation, which is called "blockchain". Each participant will have his own account book. In this way, when false information occurs, it can be broken through mutual verification, so as to ensure network securityin the blockchain, every node is equal, and there is no centralized management organization. This "decentralized" feature makes the blockchain do not need to rely on a third party, its operation does not need any human intervention, and it can independently conct self verification. In addition, the network of blockchain is open to the world, and anyone can query data through the public port, so the whole system is highly transparent
In a word, blockchain is a reliable database and a reliable "account book". In the future, it will be applied in cross-border payment, securities, loans, voting, etc. For example, in cross-border payment, with the security of blockchain, you can remit money to the world anytime and anywhere, which saves a lot of intermediate links and high fees blockchain is a distributed shared ledger and database, which has the characteristics of decentralization, distributed storage, encryption algorithm, whole process trace, traceability, collective maintenance, openness and transparency take taking charge of Department funds as an example, the traditional way is to assign a person in the Department to keep accounts and manage the Department funds. This person can directly manipulate the remaining amount or the amount of each use, and make profits from it by taking advantage of his authority. This is the traditional centralized management and in the blockchain management mode, , everyone in the Department has a fund use book, which is added by relevant personnel, and synchronized to their own book after other personnel check. Each transaction will record the usage time, user, amount and content of funds, and generate corresponding serial number for marking. The serial number of each transaction will be stored together with the usage of the next transaction. Each bookkeeping will be encrypted, and so on. At the same time, the account book of each person in the Department is visible to everyone outside, and anyone can query the use of each fund through the account book in the management mode of blockchain, multi person synchronous bookkeeping is "decentralized management" everyone in the department checks and stores it, which is called "consensus mechanism" everyone records the use of each fund, which is called "distributed storage" the serial number generated by the detailed usage of each fund is called "hash value" store the serial number and the usage of the next fund, which is called "whole evidence chain" everyone's account book is visible to everyone outside, which is called "openness and transparency" to query the usage of each fund is called "traceability" if someone wants to tamper with a certain amount of funds, the serial number of the funds will be changed accordingly, and this person needs to tamper with all subsequent account records on the account book and the account book records of all people. However, this can be realized on the premise that it can crack the encryption processing of everyone's every bookkeeping. Moreover, once the system finds that there is an account book different from everyone's, the blockchain will automatically correct the "wrong" account book. This can fully guarantee the originality and non tamperability of blockchain electronic data 
blockchain is decentralized, tamper resistant and anonymous
the blockchain system is actually a distributed system
bitcoin system is the earliest blockchain system and the simplest blockchain system
the whole bitcoin system is actually a distributed ledger. This ledger is backed up on each node. When a transaction occurs, it will be broadcast to the network. The miner node (the node solving the problem) in the network will mine (the node solving the problem) to record the transaction. The recorded block will be broadcast to the network, and other nodes will verify and synchronize to their own node's account book.
On September 18, 2018, Hangzhou Internet court was officially put on the chain and became the first court in the world to use blockchain for trial
it is understood that prosecutors can submit electronic evidence such as contract, rights protection process and service process details online through online appeal portal, and notarization office, forensic identification center, CA / RA organization, court and other chain nodes can witness and endorse together to provide one-stop service for prosecutors. Hangzhou Internet court of Zhejiang Province made a public judgment on a case of infringement on the right of network dissemination of works' information, and confirmed the legal effect of electronic data with blockchain technology for the first time
2. In the field of logistics
in early 2018, rookie and tmall global jointly announced that blockchain technology has been used to track, upload and verify the logistics full link information of cross-border imported goods
after all nodes of the logistics chain are connected to the blockchain, the goods can be traced from manufacturers to consumers, forming a complete chain; The more links the commodity is missing, the more likely it is to be a fake proct
3. Electronic invoice
on August 10, 2018, Shenzhen International Trade revolving restaurant issued the country's first blockchain electronic invoice. It is understood that this blockchain electronic invoice was led by Shenzhen Taxation Bureau and provided by Tencent with underlying technology and ability
different from traditional e-invoice and simple e-invoice on the chain, this blockchain e-invoice combines "capital flow and invoice flow", combines invoice issuing with online payment, and gets through the whole process of invoice application, invoice issuing, reimbursement and tax declaration
there are still many practical applications of blockchain. You can learn more about relevant information
1、 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. It is essentially a disintermediated 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 the information of a bitcoin network transaction, Used to verify the validity of its information (anti-counterfeiting) and generate the next block
2. Application
1. Art instry
ascribe enables artists to declare ownership by using blockchain technology, issue numbered and limited edition works, and target at any type of digital form of art. It even includes a trading market where artists can buy and sell through their websites without any intermediary services
In recent years, bitproof is the most advanced application in many document time stamp applications, which will make the traditional notarization method become the past. Bitproof offers more services than free versions including blocksgin and originstaemp, including one for intellectual property. Interestingly, bitproof recently cooperated with an it school in San Francisco to put their students' academic certificates on the blockchain, completely redefining how to handle and use diplomas and student certificates Development instry colu is the first enterprise to allow other enterprises to issue digital assets. They can "token" all kinds of assets to impress many people. Although the free bitcoin wallet couperparty also allows simple tokens to be issued and traded among other wallet holders, the tokens of colu can be set with various states and types, can be detached from or returned to the system, and can be stored on BitTorrent's network when the data stored on the blockchain is too large4. Real estate instry
they plan to make the whole instry chain process more modern and solve various problems faced by everyone when participating in real estate, including naming process, land registration, agency, etc
5, Internet of things
a possible application scenario is: generate corresponding behavior through transaction, assign address to each device, inject a certain fee into the address, and perform relevant actions, so as to achieve the application of Internet of things. Similar to: PM2.5 monitoring point data acquisition, server leasing, webcam data call, DNS server, etc
6. Insurance instry in the past two years, the hottest topic in the field of science and technology can not be separated from blockchain technology. This underlying technology, born out of bitcoin, has proved its highly secure and reliable architecture and algorithm design with more than seven years of stable operation. At the same time, with innovative technologies such as distributed ledger and smart contract, it has opened up a huge imagination space for instrial upgrading of many instries. Some instry experts even predict that blockchain technology will set off the second Internet revolution
extended materials:
in 2008, Nakamoto proposed the concept of "blockchain" in the white paper on bitcoin, and established bitcoin network in 2009, developing the first block, namely "Genesis block"
the shared value system of blockchain was first imitated by many cryptocurrencies, and improved in workload proof and algorithm, such as equity proof and scrypt algorithm. Subsequently, the blockchain ecosystem has been evolving all over the world, with the emergence of ICO for the first token sale, Ethereum for smart contract blockchain, "asset token sharing economy with light ownership and heavy right to use" and blockchain countries
at present, people are using this shared value system to develop decentralized applications (DAPP) in all walks of life, and build decentralized autonomous organizations and decentralized autonomous communities (DAS) around the world