Ethereum multi signature import

1.

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"

2. 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)

3. GBK
Ethereum is an open source public blockchain platform with smart contract function, which provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency Ethereum. The concept of Ethereum was first inspired by bitcoin by vitalik buterin, a programmer, between 2013 and 2014, and now it's 2.0. Ethereum 2.0 is also something that the whole coin circle is waiting for. In order to celebrate the birth of the genesis block of eth2.0 on December 1, chinacoin officially supports the exchange of eth2.0 verification nodes at 17:00 Hong Kong time on November 20, 2020. It will invest its own eth in the verification node mining and exchange qeth to obtain liquidity. It will participate in the mining as soon as the exchange is received. Now it will give back to the user's welfare. The top 1000 eth enjoy the over exchange of qeth according to the ratio of 1:1.02. Compared with eth2.0, qeth has too many advantages: liquidity is guaranteed, users do not need to bear the technical cost, the threshold of participation does not need 32 eth, as low as 0.1eth, nodes are maintained by the platform, and the revenue is distributed according to eth2.0< br /> < br /> < br /> 

4. Although many people didn't seize the opportunity of bitcoin's boom, it's not too late to invest in virtual currency. Because there are more currency categories in the virtual currency market, investors have more choices, and the market is more standardized< As the originator of virtual currency, bitcoin's investment value still exists although its market situation is far worse than before. On many virtual currency platforms, the share of bitcoin transactions accounts for a large proportion. Take domain kingdom for example, its transaction volume accounts for 75% of the total amount of virtual currency transactions
lightcoin is inspired by bitcoin (BTC) and has the same implementation principle in technology. The creation and transfer of lightcoin is based on an open source encryption protocol and is not managed by any central organization. Lightcoin aims to improve bitcoin. Compared with bitcoin, lightcoin has a significant difference
the token on the Ethereum blockchain is called ether, and its code is eth. It can be traded in many cryptocurrency markets, and it is also the medium used by Ethereum to pay transaction fees and computing service fees
xem is a new type of digital virtual coin based on Java. It adopts the newly invented synchronization solution based on proof of importance poi. It is said that xem is the first cryptocurrency to realize multi signature at the block chain level
in fact, bitcoin, Leyte or ether can be bought and sold in 2019. The important thing is that virtual currency can also be bought and sold in the form of contract transaction
the so-called contract transaction means that no matter whether the market price is rising or falling, as long as the correct trading direction can be judged at the corresponding time, the investors can make profits, and the transaction cost as low as $5 in the realm Kingdom makes it easier for ordinary investors to participate in it
in general, 2019 is full of new opportunities, and some potential digital currencies have also been well developed to a certain extent. But when we invest, we must not be too careless. We must choose a formal and secure platform.

5.

It does not belong to MLM

Ethereum is an open source public blockchain platform with smart contract function, which provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency Ethereum

the concept of Ethereum was first proposed by vitalik buterin, a programmer, from 2013 to 2014, inspired by bitcoin, to the effect of "next generation cryptocurrency and decentralized application platform", and began to develop through crowdfunding in 2014. The market value of Ethernet currency is second only to bitcoin, and it is the second largest encrypted digital currency in the world

extended data

bitcoin has created the first decentralized cryptocurrency, and has fully tested the feasibility and security of blockchain technology in more than five years. In fact, bitcoin's blockchain is a set of distributed database. If a symbol bitcoin is added into it and a set of protocol is specified, the symbol can be transferred safely on the database without trusting a third party. The combination of these features perfectly constructs a currency transmission system bitcoin network

however, bitcoin is not perfect, and the scalability of the protocol is a deficiency. For example, there is only one symbol in the bitcoin Network - bitcoin, and users can't customize other symbols. These symbols can represent the company's stocks or debt certificates, which will lose some functions

In addition, a stack based scripting language is used in bitcoin protocol. Although this language has some flexibility to realize functions such as multi signature, it is not enough to build more advanced applications, such as decentralized exchanges. Ethereum is designed to solve the problem of insufficient scalability of bitcoin

6. < UL >

the first stage: the basic theory of blockchain technology is suitable for students who have various needs for blockchain technology. It is the most comprehensive and up-to-date curriculum system at present. With the rapid appreciation of bitcoin, blockchain technology has become more and more sought after and studied by people from all walks of life, Or from the perspective of technology research and development, this set of courses are very suitable for you to download and learn. Schele: Lesson 1 ICO & amp; EOS understands the risks of ICO and ICO projects, How to judge whether an ICO is reliable lesson 2 the past and present of bitcoin blockchain understand the origin and related background knowledge of bitcoin and blockchain lesson 3 cryptography master the necessary knowledge of blockchain related cryptography lesson 4 bitcoin transaction in-depth discussion of what happened behind bitcoin transaction lesson 5 block generation and link in-depth discussion of how blockchain is generated Lesson 6 bifurcation principle of blockchain and how to operate the coins in hand before and after the bifurcation Lesson 7 how does the wallet know how much money I have and how to hold the coins in hand more safely Lesson 8 mining understanding the history and principle of mining, Experience mining in bitcoin regression test environment Lesson 9 blockchain security, understand the security problems of blockchain, how to "steal" other people's money Lesson 10 smart contract learn the principle of blockchain 2.0 smart contract, understand how the smart contract is written and run

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stage 2: introction to blockchain technology research and development, Blockchain technology is a very popular new technology at present, which is highly praised by large IT companies and experts all over the world. Not long ago, the blockchain technology platform enterprise Ethereum Alliance (EEA) announced its formal establishment, and nearly 30 giants including JPMorgan Chase, Microsoft and Intel joined in. Extremely optimistic about the future of Ethereum. At present, the term blockchain is very popular, but few people really understand blockchain technology. If you no longer want to be a onlooker, you are welcome to learn this course. After learning this course, you can master the following contents: deeply master the blockchain technology, understand what mining is, learn how to build your own blockchain network, how to publish your own applications on your own blockchain network or enterprise Ethernet network, and how to write smart contracts, Blockchain technology applications. This course is based on practical teaching, mainly teaching front-line practical skills, to ensure that students can quickly learn to apply! Timetable: 1. Introction to blockchain 1.1 introction to blockchain technology 1.2 blockchain platform, Ethereum, an open source blockchain technology platform 1.3 Ethereum working principle, Ethereum virtual machine, account 1.4 what can Ethereum do, Blockchain technology application appreciation 1.5 Ethereum white paper 2. Client installation and operation 2.1 client installation 2.2 Ethereum account creation and management 2.3 multi signature account 2.4 Ethereum 3. Ethereum network 3.1 Ethernet network type 3.2 building local private network, User defined Genesis block 3.3 mining on local private network 4. Introction to smart contract programming 4.1 Ethereum multiple private nodes networking 4.2 multiple nodes, Introction to writing, deploying and using smart contracts 4.3 introction to development language solidy 4.4 introction to building development environment 4.5 basic variable types 5.solidy complex variable types 5.1 enumeration 5.2 structure 5.3 mapping 5.4 delete 5.5 common attributes and methods of block and transaction 6.solidy method 6.1 anonymous method 6.2 modifier 7.solidy inheritance and event 8.solidid Y programming practice 8.1 smart contract -- "vote" 9.solidy programming practice 9.1 smart contract -- "create your own token" 9.2 smart contract -- "public auction" 10.decentralized application DAPP project practice 10.1 Ethereum Web3 interface 10.2 building Ethereum online wallet 10.3 building the development framework of truss on Windows

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Level 3 In addition to video tutorials, we have also collected a number of classic e-books for students to learn and understand the knowledge of blockchain technology. These e-books are expensive, and published relatively new, reading format is very rich, not just PDF kind, suitable for mobile phone installation of common reading software. Lesson schele: 1. How blockchain will redefine the world; 2. Blockchain Society: decoding global application and investment cases of blockchain; 3. Blockchain Revolution: how bitcoin underlying technology changes currency, technology and technology Business and the world 4. Blockchain: from digital currency to credit society 5. Blockchain: technology driven finance 6. Blockchain: Reshaping economy and the world 7. Illustrated blockchain 8. The age of artificial intelligence, A book reads block chain finance "(Internet plus era enterprise management real battle Series) 9." block chain technology guide "10." block chain: define the new pattern of future finance and economy "11." business block chain: open a new era of encryption economy "12." Accenture ":" block chain + "13." bitcoin "

7. Friends who are new to the currency circle are dazzled to see all kinds of digital currencies. What are the origins and characteristics of these cryptocurrencies? Here is a brief introction to some mainstream cryptocurrencies< Bitcoin is the earliest cryptocurrency. In 2008, an Internet geek named Nakamoto Tsung published a paper called bitcoin: a peer-to-peer e-cash system. In 2009, the first creation block was g up by Nakamoto Tsung and has been developing ever since. The original block size of bitcoin was only 1m, and the congestion problem was getting more and more serious. As a result, the block expansion was put on the agenda. The core development group advocated the use of isolation witness and lightning network to realize the expansion, while the big block group advocated the direct expansion of the block. At last, on August 1, 2017, bitcoin cash (BCH) forked from bitcoin (BTC) and expanded its capacity by expanding the block. After this split, bitgold, bitdiamond, super bitcoin, bitgod and many other split coins have sprung up. Later, BCH itself encountered a bifurcation. The Australian CSW, who calls himself Nakamoto Tsung, has to continue to expand the block and lock the underlying protocol of bitcoin. He claims to make a bitcoin that meets Nakamoto Tsung's vision. This time, the bifurcation coin is called BSV

apart from BCH and BSV, most of the other bifurcated currencies have declined. BTC, BCH and BSV represent the exploration of three different directions respectively. BTC is the most conservative and cautious, BSV is the most radical, and BCH is relatively mild and graal. At present, BTC enjoys the name of bitcoin in fact and has the largest market value< br />
< At the end of 2013, vitalik buterin (V God), a gifted programmer born in 1994, published a white paper on Ethereum, proposing the idea of adding various smart contracts to cryptocurrency, which can be used in social networking, trading, games and other fields. The market value of Ethereum has soared all the way, and it will soon be second only to bitcoin, Ethereum with smart contracts is also known as blockchain 2.0

in 2016, Ethereum encountered a serious hacker coin theft incident (DAO), and God V decided to delete the coin theft record by using rollback method. However, some people who insisted that the blockchain should not be tampered with opposed rollback, so Ethereum also split. Unlike bitcoin, the original Ethereum chain has become a minority, known as the Ethereum classic (etc), and the new chain that has been rolled back has become a majority, the de facto Ethereum (ETH)

stable currency system

stable currency is generally anchored legal currency, which can be used to exchange legal currency 1:1 to the issuer. The currency value is relatively stable, but sometimes there will be a small amount of premium in transactions, which is widely used in cryptocurrency transactions. Now the most common stable currency is the usdt issued by tether company, 1 usdt = 1 dollar. Stable currency is generally issued on other cryptocurrency networks, such as bitcoin Omni protocol, Ethereum erc20 protocol, etc< br />


in anonymous currency

on bitcoin, every transaction is clear and searchable, although we don't know who the person behind the address is. Some people think that the privacy of bitcoin is not enough, so some anonymous coins, such as XmR, dash and zcash, which can cover up user information, have emerged. Monroe coin uses ring signature technology, dasey coin adopts mixed coin technology, and big zero coin uses zero knowledge proof, which can play an anonymous effect in different degrees

platform currency system

some digital currency trading platforms often release their own platform currency, and there are certain discounts for trading with platform currency, such as okb of okex, HT of fire currency, BNB of coin security, etc<

some other mainstream currencies

lightcoin (LTC) has copied the code of bitcoin, replaced the consensus algorithm, and shortened the block out time. When bitcoin wants to upgrade, it often does experiments on bitcoin first. Lightcoin is known as "bitcoin, lightsilver"

XRP is currently the third largest currency in market value. It is an Internet transaction protocol, allowing users to transfer money around the world quickly and cheaply

grapefruit coin (EOS), known as blockchain 3.0 and Ethereum upgrade, attempts to introce more functions and application expansion on it

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"bitkangaroo" is the first digital currency financial service platform in the world that allocates theoretical revenue from its own mines and machines without power failure. The platform is mainly based on cloud computing procts, and the theoretical revenue is allocated by "1tash" of Wanyou computing power's professional mine, a strategic partner, on a regular basis every day, integrating high-yield, security, liquidity, transparency and professionalism

High Yield: the platform aims at "increasing users' assets", and customers can choose a variety of derivatives to prevent systemic risks

Security: the team stores the standby digital assets in the cold multi signature wallet, and in case of any accident, the reserve fund will be used to distribute revenue to customers

Liquidity: the platform allocates income every day, and can withdraw as soon as it reaches the minimum currency withdrawal standard

transparency: mine data and mine logs are open and transparent, and users can monitor the actual computing power of the mine at any time through the data center monitoring system

Professional: the mine is operated and managed by professional personnel who have been engaged in deep mining for many years. Each unit is isolated by professional network interruption to prevent virus invasion. Multiple standby networks are used in the computer room to eliminate non systematic risks in an all-round way

8. At present, there are many digital currency wallets, some of which have good personal experience

light wallets are good for imtoken, geekwallet, kcash, Cobo, etc.

Hardware wallets are good for ledger, trezor, etc., which involve large amount of digital currency or hold for a long time. Generally, hardware wallets are recommended

big body introces these personal good light wallets

1. Imtoken:

is a mobile light wallet app, which supports Eth and Ethereum erc2.0 standard tokens (such as EOS, DGD, SNT, qtum)

advantages: as Ethereum series light wallet, mtoken supports all the tokens of Ethereum erc2.0 standard, can control the miner's fee of each coin, can set the collection amount, and has convenient transaction record query, refreshing interface and easy operation, so it is suitable for ICO investors who need to receive a variety of erc2.0 standard tokens and trade infrequently

disadvantages: 1. The "discovery" mole of the wallet is not intuitive enough. 2. The tokens that can only be stored on the Ethereum platform, such as BTC and Neo, can't be stored. At the same time, the bifurcations of bitcoin can't be stored

2. Geek wallet

geek wallet is a simple and convenient light wallet, which supports the storage and management of mainstream digital currency assets such as bitcoin (BTC), lightcoin (LTC), Ethereum (ETH), EOS, usdt, etc. Using bip44 mnemonics, local private key, off-line signature and other security mechanisms, as well as mobile phone and computer al backup strategy, completely solve the loss of digital currency assets caused by hacker attacks, virus infection, mobile phone loss, forgetting mnemonics and other ways, and provide users with online Multi Chain digital assets one-stop management service. The platform also has tiaoshao market, which can carry out token trading of physical assets on the chain

advantages: it has high security factor, adopts local private key security mechanism, as well as mobile phone and computer al backup strategy, supports the current mainstream currency, and has a jump market on the platform, which can carry out token trading of physical assets on the chain

disadvantages: usdt transaction must use 0.0001 BTC as transaction handling fee, does not support some small currencies, page optimization is good, but the function is relatively few

3. Kcash

kcash is also a light wallet. At present, it supports BTC, ETH, LTC, etc, act and digital currency based on Ethereum and achain smart contract platform. Kcash has cross chain and cross contract technology, and the supported currencies are still increasing

advantages: as a Multi Chain Wallet, kcash supports multiple types of digital currencies and is very friendly to users who invest in multiple series of digital currencies. In addition, kcash also has the function of sending red packets, and in the future, it will launch currency transaction, bank card connection and other functions

deficiency: too many features lead to poor usability. In addition, there are some compatibility problems with Android versions. Some Android models will flash back when opening apps< Cobo

4. Cobo

Cobo is a professional digital asset management wallet, which can help you store your assets safely. The unique POS gain can help you increase the value of your assets. It supports more than 20 kinds of digital assets including eth, EOS and TRX, as well as more than 500 kinds of tokens

advantages: Cobo security is in the lead in the same level, using multiple security verification, hot and cold separation storage, HSM multi signature, Cobo provides you with stable income through intelligent voting, dpos vote pool, POS mining digital asset gain matrix

disadvantages: poor page optimization, complex functions, a little difficult to get started, and there is also a flash back problem of Android version

5. Ledger

Hardware wallet, which supports eth, BTC, zcash and other mainstream currencies, uses encryption chip technology to build security solutions for users, and is used to protect users' digital assets and block chain application security. This is a hardware bitcoin wallet specially designed for consumers. It provides enterprise level security hardware moles and hardware procts supporting the Internet of things

6, ledger

Hardware wallet, support eth, BTC, zcash and other mainstream currencies; Using encryption chip technology to build security solutions for users to protect users' digital assets and block chain application security. This is a hardware bitcoin wallet specially designed for consumers. It provides enterprise level security hardware moles and hardware procts supporting the Internet of things.

9. The ideal state cannot be modified, and the blockchain can only be added, not modified or deleted. Although Ethereum can modify and delete account data, it is only at the state machine level. It is a state transition through transaction or event. The previous state will not be modified or deleted
if it is POW algorithm: such as bitcoin. Users tend to synchronize the new chain with the best computing power. And each trade has a delay of six blocks. So every time we make a fake block, we usually need to make all the POWs of the first six blocks at the same time, and the accumulated POWs of these six blocks need to be higher than those of the real main chain (the main chain is jointly maintained by honest users) to ensure success every time, so we need to master 51 computing power

10. There are many digital currency wallets. Here are some wallets
anmao wallet
anmao wallet is a light wallet developed by Hangzhou anmao blockchain Technology Co., Ltd., which saves storage space compared with full node wallet. And it is a multi currency Cross Chain Wallet, which supports BTC, BCH, LTC, ETH, etc, dash and erc-20 series of tokens. At present, it is the most complete currency digital currency wallet in the true sense
anmao wallet is the only digital currency wallet that supports Chinese mnemonic words. It is composed of 12 Chinese characters, which is convenient for memory and in line with Chinese reading habits
the biggest feature of anmao wallet is that it well applies the scalability of light wallet. While managing a variety of digital assets, it has embedded DAPP list and anmao fishpond mining game. The tokens are directly stored in the wallet, which is convenient, labor-saving and interesting. It can be said that it is a money making wallet
with embedded Android block browser, each transaction can be queried in real time by using transaction address, block height and transaction ID, which is accurate
there are also market and information DAPP, a multi-functional digital currency wallet
bitpai
bitpai wallet is a new generation of blockchain asset integrated service platform developed by bitpai team. It is based on HD wallet technology, multi signature and on chain transaction. It can easily and safely use digital currency and easily send and receive bitcoin on bitpai. At present, the main supported currencies are BTC, BTC, ETH, some erc2.0 tokens, qtum, HSR, dash, safe, LTC, LCH, Zec, etc and Doge
bitpai supports multi address coin issuing, built-in OTC and exchange (third-party service), and can trade with users from all over the world, which is more suitable for professional users with frequent transactions and OTC trading needs
in terms of security, the user controls the private key. After the transaction is completed, the coin is directly kept by the user. If it does not operate for a long time, bitpie will automatically lock, further improving the security of the wallet
disadvantages: for initial users, too many and complex functions are a kind of burden. They only need to send and receive digital currency simply. Too many complex functions increase the learning time cost of users and affect the experience of wallet users
atoken
atoken is a mobile wallet supporting multi currency cross chain exchange, which is safe and convenient. At present, it supports BTC, LTC, ETH, etc, Doge, EOS and other main chain currencies; BCD, BTG, BCH, SBTC, etc; Support all tokens of Ethereum erc20
users hold their own private key, which is stored in app with multiple encryption. They do not access the server in any form, and no one else can touch your digital assets; The wallet adopts 5-layer HD, horizontal isolation and vertical defense architecture; Pbkdf2, sha-512 and other encryption algorithms are used. At the same time, atoken implements the transaction acceleration function of wallet and supports the transaction acceleration of bitcoin and Ethereum.