0 to build Ethereum environment

1. ethereum is a new and open blockchain platform, which allows anyone to build and use decentralized applications running through blockchain technology in the platform
just like bitcoin, Ethereum is neither controlled nor owned by anyone - it is an open source project created by many people around the world. Different from bitcoin protocol, Ethereum's design is very flexible and adaptable. It is very easy to create new applications on the Ethereum platform. With the release of homestead, anyone can use the applications on this platform safely
Ethereum is a programmable blockchain. It does not give users a series of preset operations, but allows users to create complex operations according to their own wishes. In this way, it can be used as a platform for many types of decentralized blockchain applications
in a narrow sense, Ethereum refers to a series of protocols that define a decentralized application platform. The core of Ethereum is Ethereum virtual machine (EVM), which can encode any complex algorithm. In computer science terminology, Ethereum is "Turing complete.". Developers can use the existing JavaScript and python as the model of other friendly programming languages to create applications running on the Ethereum simulator.

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. 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)

4. The first part: build your own blockchain directory from 0 to 1:
1.1 start with imitation, First knowledge of blockchain
1.2 basis of blockchain: analysis of consensus mechanism
1.3 design principle and method of consensus mechanism
1.4 how to quickly clone a blockchain
1.5 how to turn bitcoin into its own private chain - bifurcated bitcoin
1.6 how to turn Ethereum into its own private chain - bifurcated Ethereum
1.7 how to turn ripple into its own private chain - bifurcated Ripple
1.8 how to turn stellar into a private chain of its own, How to develop your own blockchain wallet (windows and MAC) 1.11 how to develop your own blockchain wallet (Android and IOS) 1.12 how to develop an online wallet similar to blockchain.info 1.13 how to increase the security and robustness of your own blockchain network 1.14 how to use coin to handle recharge withdrawal business
1.15 How to use the fund pool to build a mixed currency service
1.16 how to design a new mining algorithm
this process is generally used, but it is also very difficult for ordinary people to complete. The mature projects of blockchain include Ethereum, decent, bitcoin and so on.

5. 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

6. My computer - & gt; Attribute - & gt; Advanced - & gt; Environment variables - & gt; Add the following environment variables to the system variables:
java_ The home value is: the directory where JDK is installed, and mine is C: &# 92; Program Files\ Java\ jdk1.6.0_ 34
the classpath value is:;% JAVA_ HOME%\ lib\ tools.jar;% JAVA_ HOME%\ lib\ dt.jar;% JAVA_ HOME%\ bin;( Pay attention to the & quot& quot; To add)
Path: append at the beginning.;% JAVA_ HOME%\ bin;% JAVA_ HOME%\ jre\ bin;( Pay attention to the & quot& quot; To add)

after the installation, you can check whether the JDK is installed successfully. Open the CMD window and enter Java – version to view the version information of JDK.

7. Yes, but it is better to use overseas servers. In addition, the server configuration should be medium or above.

8. Ethereum is a distributed computing platform. It generates an cryptocurrency called ether. Programmers can write "smart contracts" on the Ethereum blockchain, and these Ethereum smart contracts will be executed automatically according to the code

what is Ethereum
Ethereum is often compared with bitcoin, but the situation is different. Bitcoin is a kind of cryptocurrency and distributed payment network, which allows bitcoin to be transferred between users

related: what is bitcoin? How does it work

Ethereum has a bigger goal. As Ethereum says, "Ethereum is a distributed platform running smart contracts.". These smart contracts run on "Ethereum virtual machine", a distributed computing network composed of all devices running Ethernet nodes

"distributed platform" means that anyone can set up and run an Ethereum node just as anyone can run a bitcoin node. Anyone who wants to run "smart contracts" on nodes must pay the operators of these nodes in ether, which is a cryptocurrency related to Ethereum. Therefore, the person running the Ethernet node provides computing power and gets paid in the Ethernet, which is similar to the way that the person running the bitcoin node provides hash power and pays in bitcoin

in other words, although bitcoin is only a blockchain and payment network, Ethereum is a distributed computing network, and its blockchain can be used for many other things. Details are provided in the Ethereum white paper

what is ether
Ethernet is a digital token (or cryptocurrency) related to Ethereum blockchain. In other words, Ethereum is the token and Ethereum is the platform. But now people often use these terms alternately. For example, coinbase allows you to buy Ethereum, which stands for Ethereum

this is technically "altcoin", which actually means a non bitcoin cryptocurrency. Like bitcoin, ether is supported by distributed blockchain - in this case, Ethereum blockchain

developers who want to create applications or Ethereum smart contracts on Ethereum blockchain need Ethernet token to pay for nodes to host it, while users of Ethereum based applications may need Ethernet to pay for services in these applications. People can also sell services outside the Ethereum network and accept Ethernet payments, or they can sell Ethernet tokens in cash - just like bitcoin

9.

Why develop digital currency? From the perspective of the central bank, there are six advantages:

first, to improve the convenience and transparency of economic transactions; second, to rece the high cost of the issuance and circulation of traditional paper money; third, to better support economic and social development; fourth, to help the comprehensive realization of Inclusive Finance; fifth, to rece money laundering, to promote the development of the economy and society Sixth, improve the central bank's control over money supply and circulation

steps of digital currency development:

the first step,

first, we need to download the source code of a blockchain system from git, such as choosing the backbone code of bitcoin to download the relevant source code

At the same time, prepare the corresponding compiling environment (c + + is recommended in Linux) and install the corresponding development environment and tools

the second step and

code all need to be compiled, so you need to prepare the compilation environment and tools, download the environment compilation tools, configure

system environment variables, QT environment and other files, and compile commands are described in detail in the files in ITC source code

however, the construction of the system and development environment, program compilation and other processes are cumbersome, so it is not recommended for ordinary users to make their own. For developers, it may take 2-3 days to install and configure for the first time

the third step,

take bitcoin development as an example, it is the development environment of Q. after downloading the source code and configuring the environment, open the source code of the bitcoin core in qtcreator, configure relevant files and compilers, and start to try to compile the client of the bitcoin core

Step 4,

transform into your own digital currency, open each source file, find the corresponding local adjustment parameters, such as adjusting

the number of coins in each block, the total output, the adjustment difficulty, and so on. Then the most critical point is to change the name to your own currency

name as you want, and don't forget to replace the related icons in the resource folder. If all goes well, after re compiling, your new coin will be invented successfully

for the development of this digital currency, the technology is relatively professional, so it is better to have a professional team to assist

framework for digital currency development:

1. Build Ethereum private chain test environment and public chain node environment configuration

2. Ethereum transaction and confirmation principle

3. Ethereum JSON RPC interface

4. Ethereum transfer and withdrawal principle

5. The server connects Ethereum public chain interface, and its own server stores business data, Public chain storage transaction anonymous data

6, private key security processing

the following is the development code example:

for example, the common digital currency wallets in the market are:

app class: kcash Imtokenweb: myethereumwallet Google browser plug-in: metamask

one of the most commonly used is imtoken

blockchain transaction technology concept:

let's take a look at how blockchain transaction is handled with bitcoin as an example. In order to send a certain amount of bitcoin to another wallet, you need the following information: the address to send the funds to your wallet, the amount of cryptocurrency you want to send

the ID of the recipient's wallet

each transaction is signed with a unique confidential private key. Once the payment is signed by the sender, it becomes publicly available. The transaction still needs to be confirmed so that the payee can get the money. In order to confirm the transaction, it is necessary to generate a new chain block

these blocks are generated by complex mathematical calculation to find the unique key. It takes 10 minutes to create a new block, and the person who finds the key gets a certain amount of coins as a reward. Once a new block of the chain is created, it is not possible to remove it from the database or change the information in some way. Therefore, blockchain transaction is final and irreversible

three core advantages of digital currency:

first, digital currency is a fair currency

digital currency has no specific issuing institution, is not issued by a country, only depends on a specific algorithm, which means that digital currency can not be manipulated by manipulating the number of issues, so digital currency is a free, non-state currency

we can see that there are many countries that directly recognize the virtual currency, so if there is a demand, it needs a trading platform

many investors who want to build a virtual currency trading platform now, why can't they go to these areas to build a trading platform? Building a virtual currency trading platform is a good business opportunity, isn't it

Second, the security factor of digital currency is higher.

although the emergence of paper money facilitates the transactions in our daily life, there are risks of being stolen and received. Although e-money can avoid these risks, there will be new problems such as theft and swiping

digital currency can avoid the above problems. And broadcast every transaction record on the network. Yes, all nodes save all the currency circulation information, so that any node can easily find the currency circulation before the transaction

Thirdly, the transaction of digital currency can realize anonymous transaction. Although you can query the flow information of each account according to the local complete transaction records

but we can't know who the owner of this account is, and no one has the ability to manipulate the digital currency on other people's accounts, which protects the privacy of users

if you also hold trading digital currency, foreign exchange gold, crude oil, contract Futures: