Ethereum multi signature
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"
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 />
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
in terms of cloth storage and mining, I recommend Heshu hardware wallet and jiajiabao intelligent home miner. The core advantage of the proct is safety
take sum hardware wallet as an example. The advantages of sum hardware wallet are as follows:
1. The private key seed is encrypted layer by layer, physically isolated and never touched the Internet.
firstly, when creating the wallet, the seed password is generated and stored in the local encryption chip, and the 10 bit payment password is required
then, the transaction is made in the wallet. At this time, the user needs to enter the payment password to obtain the private key to digitally sign the transaction, and the transaction is completed. In addition, the private key seed is permanently stored in the chip, which is physically isolated and never touches the Internet. There is no need to worry about my password being stolen by hackers
Second, the bank system verifies the financial level motherboard and encryption chipuses the bank system to verify the financial level motherboard, and the private key seed is stored in the chip. If the proct is stolen or lost, and destroyed by malicious violence, the chip will trigger a self destruct circuit, and immediately permanently and irrecoverably delete all the information in the area
Third, it supports the withdrawal of global bitcoin ATM, which is convenient and fastthe reason why digital assets attract the attention of many fields in the world is that it is creating a global fast circulation, and the larger the circulation field is, the wider the scope is, and the higher its use value is. The core of digital assets is the medium it acts on among currencies. The Heshu wallet has built-in many mainstream exchanges in the world. It can trade digital assets anytime and anywhere. With one machine in hand, it can walk around the world without worry, and no longer have to worry about exchanging foreign currency
Different from conventional digital wallets, multi signature wallets need the authorization of multiple key holders to transfer digital currency, so the security of multi signature wallets is higher. Ordinary Wallet: a wants to transfer a bitcoin to X. A only needs his signature (using the private key) to complete the transaction. Sum Wallet: if a wants to transfer a bitcoin to x, a multi signature verification is set (at least two signatures of Abc3 indivials are required to transfer the money), then a needs B or C to complete the signature (using the private key) when a wants to transfer the money to X. I hope I can help you. Thank youIt's said that the currency circle has been going on for one day and the stock market has been going on for one year. Although it's a bit exaggerated, it's not unreasonable. In recent days, bitcoin has gone up sharply, but it has come down slightly today. It's estimated that no one can match the speed of the bull bear conversion in the currency circle. However, among many virtual currencies, how can we find high-quality projects? Xiaobian thinks that the bull market is not surprising. The key point is that the bear market still insists on giving weekly reports, at least for the projects with reliable teams. Today Xiaobian still brings you weekly reports of some high-quality projects. The following is the latest weekly project progress report (April 9-April 15, 2018) released by ubtc team. The specific information is as follows:
pre upgrade of Ub smart contract:
smart contract is one of the major milestones of the technology roadmap of bit fed project. In order to prepare for the implementation of smart contract on UB, the UB team made some adjustments on April 10, 2018, as follows:
1. The block speed was adjusted from 10 minutes to 1 minute
2. The difficulty adjustment cycle was once for 10 blocks
3. Block reward was adjusted to 1 ubtc
The total amount of ubtc was adjusted from 21 million to 20 million The mature period of reward was 7200 blocksthis adjustment requires users to download the latest version of the wallet to ensure that subsequent use will not be affected
wallet download link: https://www.ub.com/project/wallet
R & D:
1
2. Ubtc contract function continued internal test and bug repair
3. Ubtc contract function test documents continue to improve
4. Gjavac, gsharpc, uvmassassembler, uvmpackagegpc organize the code and open source on GitHub
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Market:
1. Anybit mobile wallet charging UB award UB activity starts at 8:00 p.m. Beijing time on April 4, 2018, and ends at 8:00 p.m. Beijing time on April 15, 2018. During the activity, users who download anybit and recharge ubtc will get 1% reward, up to 1 ubtc. The event is limited to the top 1000
the reward is calculated based on the balance of ubtc at 8:00 p.m. Beijing time on April 15, 2018. The reward ubtc will be uniformly distributed to the corresponding ubtc address on April 16
2. The UB team held a fan meeting in Genesis block, Wanchai, Hong Kong from 7:00 to 9:00 p.m. on April 9. Mr. Wouter van der schagt, director and project CEO of Ub foundation, introced the project progress and planning to the fans. UB's major fan communities (wechat group, telegraph group, QQ group, beechat group, microblog, twitter, etc.) carried out real-time live picture push
3. On April 9, the microblog of "UB global support association" held a comment lottery to send UB customized hat and coat. Under the supervision and notarization of Weibo official lottery tool @ Weibo lottery platform, an enthusiastic fan in Ningbo was lucky to win. The fan has already received the prize, and in the microblog @ quiet style quiet style sun out the picture
4. On the 14th, UB team sent representatives to participate in the [chaine] blockchain Technology Salon Hosted by Babbitt and had interactive exchanges with the guests present. The salon was held in Yulong international building, Huli District, Xiamen city
5. Enthusiastic fans made the relevant expression pack (animation) for UB's upgrade and adjustment on the 10th, and spread it on wechat group
6, UB subscription number WeChat official account will be on the way to sign the lottery every day. Please look forward to it! p>
community release:
1. The last snapshot of issuing ubtc to Eth and LTC communities was completed on April 11, and the qualified addresses were released on May 2. Please refer to UB website for details www.ub.com The announcement in the news section on March 18
about ubtc:
unitedbitcoin, referred to as UB, code ubtc. UB is not only an upgraded version of bitcoin, but also a leading global blockchain ecosystem. UB is headed by Jeff garzik, a veteran of bitcoin, a core developer of bitcoin and a leader in the blockchain field
UB 100% inherits bitcoin's blockchain and upgrades and optimizes it. The upgrade and optimization of Ub include expanding the block size to 8MB, supporting segwit isolation witness, adding smart contract and lightning network, etc
UB is committed to bringing the inactive bitcoin credit into full play. Finally, based on these credits, we can issue stable currency anchored by legal currency, which can be used in a wide, fast, efficient and intelligent business society
at present, UB team has developed anybit mobile wallet app (anybit is a decentralized multi currency wallet APP), core, core QT and electrum wallet (electrum is a lightweight wallet supporting multi signature), and released a complete blockchain browser
more than 18 trading platforms around the world support ubtc trading
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 "
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.
according to whether to run the whole node, it can be divided into full node wallet and light wallet. The full node wallet refers to the wallet that synchronizes all the blockchain data, while the light wallet only retains part of the data related to itself. We usually use the light wallet
according to whether the wallet is connected to the Internet, it can be divided into hot wallet and cold wallet. Hot wallets are wallets that stay online, also known as online wallets. A cold wallet is a wallet that is not connected to the Internet, also known as an offline wallet. It is usually a computer, hard disk or paper with a private key written on it that is not connected to the Internet. Generally speaking, a cold wallet is more secure than a hot one because it is not connected to the Internet and the private key can hardly be stolen
according to the different ways of private key storage, wallet can be divided into decentralized wallet and centralized wallet. Decentralized wallet means that the private key is not stored and managed by a third party, but generated and managed by users themselves. If the private key is lost, it will not be retrieved. The storage of the private key of the centralized wallet is managed by the platform. Users log in with their accounts, and the exchange wallet belongs to this category
at present, the well-known wallets on the market include Bitian, imtoken, Galaxy wallet, Cobo wallet, etc.
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
XTT (Xin time token), based on Ethereum erc20 platform, is a decentralized digital currency carrier based on blockchain as payment technology
Ethereum is an open source public blockchain platform with smart contract function, which provides decentralized Ethernet virtual machine to process point-to-point contract through its special cryptocurrency ether (ETH)
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 ICO crowdfunding in 2014
extended data:
background
bitcoin has created the first decentralized cryptocurrency, and has fully tested the feasibility and security of blockchain technology in more than five years
the blockchain of bitcoin is actually 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 bitcoinreference source: network Ethereum