Block PC chain
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
blockchain technology is considered to be the next generation of disruptive core technology after steam engine, power and Internet. If the steam engine has released people's proctivity, the power has solved people's basic living needs, and the Internet has completely changed the way of information transmission, then the blockchain, as a machine for building trust, may completely change the way of value transmission of the whole human society
first, the essence of blockchain is a distributed public ledger
take a popular example to explain that Mr. w's family, including Mr. W, Mrs. W, Mr. w's grandfather and Mrs. w's grandmother, all record their expenses in their respective books. Because Mr. w's family doesn't trust each other. Mr. W is diligent in raising his wife every month, but Mrs. w may receive 1000 yuan, but she receives 100 yuan. Isn't that a big loss
how to solve this problem with blockchain
if Mr. w gives Mrs. w $1000 one day, he just shouts at the whole family that Mr. w gives Mrs. w $1000. Please write down "Mr. w gives Mrs. w $1000" on their respective account books
so everyone in Mr. w's family becomes a node, and every transaction of Mr. w's family is recorded by everyone (each node)
every night who washes the dishes (proof of workload) can settle the bill in the public ledger, and there is a reward for washing the dishes. A new transaction must be added to the universally recognized ledger of the previous day, and other people will also participate in verifying the transactions of the day
Second, it seems very simple, but blockchain may bring revolutionary changes to human society
1. Machine trust
machine trust is actually trust without trust. For the first time in human history, a large-scale cooperation network unprecedented on earth can be established at near zero cost, which is bound to be a great mass movement
2. Value transfer
the emergence of the Internet has made the means of information dissemination achieve a leap, and information has realized efficient flow, but the efficiency of Internet value transfer is still very slow. At present, e-money on the Internet is still the traditional paper money in essence, and transnational payment is still a big problem
the birth of blockchain is the beginning of human value transmission network. It will enable people to transfer value as conveniently and cheaply as information on the Internet, which can be expressed as capital, assets or other forms
3. Smart contract
smart contract can replace all paper contracts, and more importantly, blockchain can perfectly connect the physical world and virtual world. The perfect combination of blockchain, Internet of things and artificial intelligence makes the imagination more huge
the blockchain itself is actually a super platform. The commercial characteristics of building machine trust, value transfer and smart contract on the blockchain are: ① close to zero trust cost. ② The marginal cost of constructing and trading assets tends to zero
so Mark Anderson, a web browser pioneer, said: in 20 years' time, we will talk about blockchain as we talk about the Internet today.
(1) Technical level. Since 2007, distributed computing has affected technical developers, so it is normal for bitcoin to appear in the field of virtual currency
(2) hardware level. The popularity of PC servers and the exponential growth of computing power (3) commercial level. The three characteristics of blockchain, namely, decentralization, distrust and extremely difficult forgery, just meet the needs of recing the trust cost and speeding up the transaction speed in financial fields such as stock trading and bank settlement (4) political level. Blockchain can rece the transaction cost to a certain extent, but the anonymity and untraceability of blockchain cause huge political risk[blockchain as the underlying technology of bitcoin was proposed at the end of 2008]
< p class = ikqb_ image_ Blockchain is mentioned in this book
Often when we talk about value, we will naturally relate to price. Indeed, price is an important data to measure value. As a blockchain technology, bitcoin's price reached 140000 RMB when it was high, and now it has dropped by about 50%, but it is still as high as 80000 RMB
At this point, you may have understood: if people do not have a common understanding of a thing, and do not give value to a thing, many things will not become "valuable". Just like our understanding of air and food, it is necessary for us to live and survive! This is the "consensus". We all believe that if we want to live, these two are indispensable! Therefore, we can conclude that the essence of value is consensus. What is the value consensus of virtual currency? Most people think that the essence of currency is not consensus, but the credibility and authority of the ruling government. This is not unreasonable. The government can only be one of the sources of value consensus, so most people think it is not comprehensive. In today's society, our consensus on the value of things comes from many ways, such as: Endorsement of authoritative institutions, corporate credit, religious belief, support of scientific theorygenerally, the exchange will have a centralized wallet built in
there are many kinds of wallets. According to the types of wallets, it's between 80000 and 350000.
do you want to do it?