Python Ethereum alliance chain

1.

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

2.

what is Ethereum:

Ethereum is an innovation based on the application of technologies and concepts in bitcoin to computers. Ethereum itself imitates a lot of bitcoin technology to maintain the computer platform. Blockchain technology is one of them
Ethereum platform can safely run any program users want

advantages of Ethereum over other competitive currencies before Ethereum appeared, some digital currencies imitated bitcoin. However, these projects have their own shortcomings, they can only support one or several specific applications at the same time< However, the reason why Ethereum can surpass the limitations of these projects in the past is because of the core idea of Ethereum

what Ethereum wants to implement is a blockchain protocol with built-in programming language. Since it supports programming language, in theory, any blockchain application can be defined with this language, and then run on Ethereum's blockchain protocol as an application

The design of Ethereum is very flexible and adaptable

Ethereum target sets the advantages of blockchain technology, in order to add the advantages of blockchain, such as decentralization, openness and security, to almost all computing fields

blockchain applications of Ethereum

Ethereum has many blockchain applications, such as digital applications of gold and stocks, financial derivatives applications, DNS and digital authentication, etc

Ethereum has achieved more than 100 blockchain applications by many start-ups

Ethereum has also been closely watched by some financial institutions, banking consortia (such as R3), as well as large companies like Samsung, Deloitte, RWE and IBM. As a result, a number of blockchain applications such as simplified and automated financial transactions, merchant loyalty index tracking, and gift cards designed to achieve decentralization of electronic transactions have emerged

the relationship between Ethereum and blockchain:

Ethereum is a programmable blockchain

Ethereum does not give users a series of preset operations (such as bitcoin transaction), but allows users to create complex operations according to their own wishes

in this way, Ethereum can be used as a platform for various types of decentralized blockchain applications, including but not limited to cryptocurrency

like other blockchains, Ethereum also has a peer-to-peer network protocol. Ethereum blockchain database is maintained and updated by many nodes connected to the network. Each network node runs the Ethereum simulator and executes the same instructions. Therefore, people sometimes call Ethereum "world computer"

3. The digital currency

issued based on Ethereum public chain should be observed according to the price trend of the platform.

4. Ethereum blockchain has exposed three major problems, and its founder vitalik buterin has been unable to interpret them for a long time. The first is the low performance and TPS of Ethereum blockchain as a whole; The second is that resources are not isolated. The event of cryptokitties virtual cat once occupied 20% of the traffic of the whole Ethereum, which directly caused Ethereum network users unable to carry out timely transactions, which is the biggest pain point of resources not isolated; The third problem lies in the embodiment of Ethereum's governance structure. As a decentralized distributed ledger, the founder team of Ethereum has dominated its network development in the past. The over centralized governance mode has led to the bifurcation of eth, etc and ETF in Ethereum, and the Ethereum community is now in a state of fragmented governance. In the view of Ma Haobo, founder and CEO of "aelf", all kinds of disadvantages of Ethereum are unacceptable. Therefore, the positioning of "aelf" is born for the next generation of decentralized underlying computing platform of Ethereum, which focuses on solving the problems of insufficient performance, non isolation of resources and governance structure of Ethereum.

5. Many blockchain projects are developed on the basis of Ethereum's open source technology. Ethereum is a common public chain technology, and the deployment of applications on Ethereum has high requirements for developers. Developers need to consider many technical details and business processing logic, as well as security vulnerabilities such as smart contract overflow
the trust union credit alliance chain is located in the financial public chain, which is oriented to the high-frequency financial application scenarios in the field of credit and assets. It does not use eth, EOS, Neo and other general public chains, but uses the account structure of star network, adopts the lightweight intelligent contract layer, and the whole technical architecture is molarized according to "high aggregation and low coupling", This enables the trust union credit alliance chain to adapt to the requirements of rapid development, rapid implementation and timely response of Internet financial procts.

6. At the top of Ethereum is DAPP. It exchanges with the smart contract layer through Web3. JS. All smart contracts run on EVM (Ethereum virtual machine) and use RPC calls. Below EVM and RPC are the four core contents of Ethereum, including: blockchain, consensus algorithm, mining and network layer. Except DAPP, all other parts are in the Ethereum client. The most popular Ethereum client is geth (go Ethereum)

7. Build / env.sh go run build / ci.go install. / CMD / geth
make: * * [geth] error 1
there is no such directory, or the directory has insufficient permissions

8.

The public chain is open to all, the private chain is open to indivials who meet specific conditions, and the alliance chain is open to authorized organizations or institutions

public chain, also known as public blockchains, refers to a consensus blockchain that can be read by anyone in the world, sent by anyone, and effectively confirmed

private chain, also known as fully private blockchains, refers to the blockchain in which the write permission is completely in the hands of an organization, and all nodes participating in the blockchain will be strictly controlled

alliance chain, or alliance blockchains, refers to a blockchain that is managed by several organizations or institutions. Each organization or institution controls one or more nodes and records transaction data together. Only these organizations and institutions can read, write and send transaction data in the alliance chain

< H2 > extended data:

blockchain has three types: public chain, private chain and alliance chain

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

< H2 > reference: blockchain network

9. The degree of decentralization of public chain. This kind of public blockchain, represented by bitcoin and Ethereum, is not controlled by a third party. All people in the world can read the data records on the chain, participate in transactions and compete for the bookkeeping rights of new blocks
program developers have no right to interfere with users, and each participant (i.e. node) can freely join and exit the network, and carry out relevant operations according to their wishes
private blockchain is on the contrary. The write permission of the network is fully controlled by an organization or institution, and the data read permission is regulated by the organization, either open to the outside world or with a certain degree of access restrictions
in short, it can be understood as a weakly centralized or multi centralized system. Because the participating nodes are strictly limited and few; Compared with public chain, private chain has shorter time to reach consensus, faster transaction speed, higher efficiency and lower cost
the alliance chain is a blockchain between the public chain and the private chain, which can realize "partial decentralization"
each node in the chain usually has its corresponding entity or organization; Participants join the network through authorization and form a stakeholder alliance to jointly maintain the operation of the blockchain.

10. Ethereum is also a proct of blockchain 2.0, which is an open intelligent contract complete solution. Bitcoin is the most important application of blockchain 1.0, which completes currency and payment transactions well. But when we need to record and transfer more complex asset types, we need the third step - a more powerful scripting system - to finally achieve Turing completeness (the ability to run any currency, protocol or blockchain). Ethereum is a blockchain based project, which aims to provide a Turing complete scripting language and Turing complete platform

blockchain 1.0 mainly refers to bitcoin. Blockchain 2.0 extends to all assets, while blockchain 3.0 goes beyond currency, finance, even commerce, and all areas of our lives, including politics, social relations, ecation, medical care, etc. According to the prediction and conception of people in the instry, the era of blockchain 3.0 will be realized in the next five years. At that time, blockchain will be recognized and accepted by all the public like the Internet, thus completely subverting our lives

McKinsey has submitted a technical report on blockchain to the Federal Insurance Advisory Committee of the United States. The report calls 2009-2016 the "Dark Age" and believes that all blockchain solutions ring this period are based on bitcoin, and the new era of blockchain will begin in 2016. At that time, the application of blockchain will become unprecedented. Applying an original sentence in McKinsey report: Based on the current development speed of blockchain, we believe that blockchain solutions may realize their full potential in the next five years.