Yee blockchain
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
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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
Chinese Mahjong: the world's earliest blockchain project
first of all, a initiates an application. I want to play mahjong and set up a mahjong Bureau, which is equivalent to creating a block, and this block will be broadcast to B, C, D, a, B, C, C, C, C, C, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D D...
in the process of playing mahjong, the above four people constantly play cards, which can be understood as mining, through what to mine? Mahjong machine can understand the mineralization machine. These four miners are the so-called miners. These four miners collide from 144 mahjong, and any right card can be Hu card. We can understand the 144 mahjong as a series of hash values (numbers). The process of Hu card is called computational power. Until Hu card, it means that the right hash value is collided and you can get a reward, Each person will pay the corresponding chips to C and put them in the blockchain. The reward is bitcoin or other virtual coins
Why do the other three people take the initiative to reward C? That's because these people have automatically reached a consensus that C has indeed won, and everyone has recorded the account, including the family members who are sitting next to buy horses. It's not good to deny it, otherwise when it comes out that the character is not good, no one will play with him again. After all, the circle is very important
when we reached a consensus, we didn't see any intermediary or third party judging that C had won, and the rewards given to C didn't need to be transferred to C through the third party. All of them were direct point-to-point transactions. This process was decentralization. The card players (miners) recorded their own achievements in the first game, and the third team won the first game, After the record is completed, a complete block is generated. But remember, this is only the first round. In the whole blockchain, this is just a node. The first eight rounds are finished, that is, eight nodes (blocks). Eight blocks are connected together to form a complete account book, which is the blockchain. Because everyone has one account book, it is a distributed account book. The purpose is to prevent someone from tampering with records. In the end, it is clear who wins or loses.
blockchain is a decentralized distributed ledger database . The advantage of this distributed ledger is that buyers and sellers can trade directly without any intermediary. Everyone has a backup, even if you lose this, it will not be affected
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blockchain application field
1, financial field
blockchain has potential huge application value in international exchange, letter of credit, equity registration, stock exchange and other financial fields. The application of blockchain technology in the financial instry can save the third-party intermediary link and realize the point-to-point direct docking, so as to greatly rece the cost and quickly complete the transaction payment
2. The Internet of things and logistics
blockchain can also be naturally combined in the field of Internet of things and logistics. Through blockchain, we can rece logistics costs, trace the proction and delivery process of goods, and improve the efficiency of supply chain management. This field is considered as a promising application direction of blockchain
3. The data stored on the public welfare field
blockchain is highly reliable and tamperable, which is naturally suitable for social public welfare scenarios. The relevant information in the public welfare process, such as donation project, collection details, fund flow, recipient feedback, etc., can be stored on the blockchain, and can be made transparent and public, which is convenient for social supervision
4. In the field of insurance
in terms of insurance claims, insurance institutions are responsible for fund collection, investment and claims settlement, and often have higher management and operation costs. Through the application of smart contract, there is no need for the applicant to apply or the insurance company to approve. As long as the claim conditions are triggered, the automatic claim settlement of the policy can be realized
The application prospects of blockchain are mainly in the fields of finance, Internet of things and logistics, public services, digital rights and insurance
1. Blockchain has great potential applications in international exchange, letter of credit, equity registration, stock exchange and other financial fields. The application of blockchain technology in the financial instry can eliminate the third-party intermediary link and realize the point-to-point direct docking
2. Blockchain can also be naturally combined in the field of Internet of things and logistics, which is considered as a promising application direction of blockchain. The establishment of credit resources in the blockchain can double improve the security of transactions and improve the convenience of Internet of things transactions. It can save time and cost for the application of intelligent logistics mode
3. Blockchain is closely related to people's proction and life in public management, energy, transportation and other fields. The decentralized and fully distributed DNS service provided by blockchain can realize the query and resolution of domain name through the point-to-point data transmission service between nodes in the network
4. Through blockchain technology, works can be authenticated to prove the existence of text, video, audio and other works and ensure the authenticity and uniqueness of ownership. After the works are confirmed on the blockchain, the subsequent transactions will be recorded in real time to realize the full life cycle management of digital rights, and can also be used as a technical guarantee in judicial evidence collection
5. In terms of insurance claims, insurance institutions are responsible for fund collection, investment and claims settlement, and often have higher management and operation costs. Through the application of smart contract, there is no need for the applicant to apply or the insurance company to approve. As long as the claim conditions are triggered, the automatic claim settlement of the policy can be realized
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the core technology of blockchain
1. Consensus mechanism, through the voting of special nodes, completes the verification and confirmation of transactions in a very short time; For a transaction, if several nodes with unrelated interests can reach a consensus, it can be considered that the whole network can also reach a consensus. The goal of blockchain consensus mechanism is to make all honest nodes keep consistent blockchain views
2. Asymmetric encryption requires two keys for encryption and decryption, which are public key and private key. The public key corresponds to the private key. The public key is used in the process of data encryption, and only the corresponding private key can be used to decrypt; On the contrary, the private key is used to encrypt the data, and only the corresponding public key can be used to decrypt the data
bitcoin is a consensus network, contributing to a new payment system and a fully digital currency. It is the first decentralized peer-to-peer payment network, which is controlled by its users without a central management organization or middleman. From the user's point of view, bitcoin is much like Internet cash. Bitcoin can also be regarded as the most outstanding three style bookkeeping system
New bitcoin is proced through "mining", which is a competitive and decentralized process. This process involves indivials serving the bitcoin network and getting paid for it. Bitcoin miners use dedicated hardware to process transactions and protect bitcoin networks, and collect new bitcoins ring transactions< At present, bitcoin mining needs professional ASIC bitcoin mining equipment, and the mainstream domestic bitcoin mining equipment is Avalon III miner.
The disadvantages of the Internet of things are:
1. Security: the Internet of things systems are interconnected and communicate through the network. Despite any security measures taken, the system hardly provides any control, and can trigger a variety of network attacks
2. Privacy: the Internet of things system can provide the most detailed personal data even if it does not actively participate in users
Complexity: it is quite complex to design, develop, maintain and support large-scale technology to Internet of things system
the advantages of the Internet of things:
1. Efficient resource utilization: if you understand the function and working mode of each device, you can improve the effective utilization of resources and monitor natural resources
2. Minimize manpower: when IOT devices interact with each other and communicate with each other and complete a large number of tasks, they can minimize manpower
Save time: because it reces manpower, it definitely saves time. Time is the main factor that can be saved through the Internet of things platform4. Enhance data collection: network and collect relevant data
5, improve security: the system can connect all these contents, then it can make the system more secure and efficient