Ethereum private key signature

1. 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)

2.

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 chip

uses 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 fast

the 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 you

3. If it's lost, it's better to post the lost advertisement

4. 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.

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although the place is large,
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it won't let you go around.
moreover,
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that's where it's a little scary

6. Return the result of ifconfig
eth0 to awk for processing
where - F & # 39;:|< br />+'
this is a separator defined by awk and then matched with "BCAST & quot;, Take the content of the fourth column
since your command is not universal, you can't output the result here, but you should intercept the broadcast address

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10.

Transaction

the behavior of blockchain transaction follows different rule sets

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e to the distributed and unlicensed nature of public blockchain, anyone can sign the transaction and broadcast it to the network

according to different blockchains, traders will be charged a certain transaction fee, which depends on the needs of users rather than the value of assets in the transaction

blockchain transactions do not require any central authority verification. It only needs to use the digital signature algorithm (DSA) corresponding to its blockchain to sign it with the private key

once a transaction is signed, broadcast to the network and mined into a successful block in the network, the transaction cannot be recovered

Ethereum transaction structure

Ethereum transaction data structure: transaction 0.1 eth

{
& 39; nonce':&# 39; 0x00', // Decimal: 0
& 39; gasLimit': &# 39; 0x5208', // Decimal system: 21000
& 39; gasPrice': &# 39; 0x3b9aca00', // Decimal system: 10000000000
& 39; to': &# 39;&# 39; ，// Sending address
& 39; value': &# 39; 0x16345785d8a0000',// 100000000000000000 ，10^17
' data': &# 39; 0x', // Decimal representation of null data; chainId': 1 / / blockchain network ID
}

these data have nothing to do with the transaction content, but have something to do with the execution mode of the transaction. This is because when you send a transaction in Ethereum, you must define some other parameters to tell miners how to handle your transaction. Transaction data structure has two attribute designs & quot; gas": & quot; gasPrice",& quot; gasLimit"

" gasPrice": The unit is Gwei, which is 1 / 1000 eth, indicating the transaction cost

& quot; gasLimit": The maximum gas charge allowed for the transaction

these two values are usually filled in automatically by the wallet provider

in addition, you need to specify which Ethereum network to execute the transaction (chainid): 1 represents the Ethereum main network

ring development, tests are usually carried out locally and on the test network, and transactions are carried out through the test eth issued by the test network to avoid economic losses. After the test, enter the main network transaction

in addition, if you need to submit some other data, you can use & quot; data" And & quot; nonce" Attach as part of a transaction

a nonce (number used only once) is the value used by Ethereum to track transactions, which helps to avoid double spending and replay attacks in the network

Ethereum transaction signature

Ethereum transaction involves ECDSA algorithm. Taking JavaScript code as an example, the popular ethers.js is used to call ECDSA algorithm for transaction signature

const ethers = require(' ethers')

const signer = new ethers.Wallet(' Wallet address

signer.signTransaction({

' nonce':&# 39; 0x00', // Decimal: 0

& 39; gasLimit': &# 39; 0x5208', // Decimal: 21000

& 39; gasPrice': &# 39; 0x3b9aca00', // Decimal 10000000000

& 39; to': &# 39;&# 39; ，// Sending address

& 39; value': &# 39; 0x16345785d8a0000',// 100000000000000000 ，10^17

' data': &# 39; 0x', // Decimal representation of null data

& 39; chainId': 1 / / blockchain network ID

})

. Then (console. Log)

you can use the online application composer to deliver signed transactions to Ethereum. This is known as "offline signature.". Offline signatures are particularly useful for applications such as status channels, which are smart contracts that track the balance between two accounts and transfer funds after a signed transaction is submitted. Offline signature is also a common practice in dexes

you can also use online wallet to create signature verification and broadcast through Ethereum account

with Portis, you can sign a transaction to interact with the gas station network (GSN)

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