How to calculate the transaction time of Ethereum data

1. You can choose to trade in the digital currency exchange. At present, the mainstream digital currency exchanges in the market are coin security, fire currency and bitnet.

2.

At present, there are many channels for domestic users to buy Ethereum. Here are some common channels:

< H2 > 1. Coincola is an over-the-counter trading platform for indivials to trade bitcoin

coy Cola is affiliated to Hong Kong coincola limited, which is developed and operated by a professional international team, focusing on providing convenient and reliable blockchain services for global users. Coincola gathers global users and is committed to building a world-class blockchain asset platform

in coy cola, people from different countries can buy bitcoin with their own currency. The seller of the website publishes the advertisement of selling bitcoin, and explains the payment method and exchange rate. You can choose to trade directly online according to the content of the advertisement. Bitcoin is stored in Ke Ying Cola's Internet wallet. You can transfer bitcoin directly

2. How to buy eth

< UL >

register the coincola account, and then click "buy" in the top menu of the home page to enter the advertisement list page

select the appropriate advertisement from the advertisement list and click "buy eth" to enter the transaction page

enter the amount of money to be purchased or the number of digital currency (please understand the message information of the other party, payment method, and transaction instructions of the platform before entering), click buy now, and the order confirmation pop up. After checking and confirming the information, click confirm purchase to enter the order page

in the chat box of the platform, you can inquire whether the other party is online according to the template statement, and make offline payment according to the collection information and collection method provided by the other party

after the completion of offline payment, click the mark that the payment has been completed at the first time (please complete this operation within 15 minutes at the beginning of placing an order, so as to avoid the payment cannot be recovered e to the cancellation of the order e to overtime), and then customize the input information in the chat box to confirm the payment and ask the seller to confirm the collection and release the digital currency

the progress bar in the top column shows that the goods have been received, indicating that the digital currency has arrived in the wallet. Make comments according to the seller's behavior, and click submit to complete the transaction

< / UL > < H2 > 2. C2C trading on trading platform

with the rapid increase in the number of trading platforms and competitive pressure, many trading platforms will have their own C2C trading. Here we take the relatively large ZB trading platform as an example to illustrate

What is C2C

C2C transaction is a customer to customer transaction, which is guaranteed by the transaction platform. There are many such platforms, such as: Fire coin, otcbtc, bitpai OTC, etc., which are guaranteed by the platform and traded between users. We can simply understand it as: our shopping situation on Taobao is the same as that. In case of dispute, the platform will arbitrate. As long as the transaction is carried out according to the normal process, the security of the transaction is guaranteed

2. ZB's C2C business

ZB platform has two choices: QC and usdt. The basic logic is the same. There are many usdt platforms. QC is the feature of ZB, EXX and other platforms. Here we focus on QC

< H2 > about QC

QC is a token. At present, you may know more about usdt and bitcny. At present, there is a special area for QC transaction on ZB. Simply put, QC can buy all other digital currencies (BTC, ETH, EOS, etc.) on ZB. Therefore, after purchasing QC with RMB recharge, you can conct currency transaction on ZB station

The advantage of the < H2 > QC token is that the exchange ratio between the < H2 > < UL >

and RMB is 1:1, which is easier to convert

purchasing other tokens with QC can be directly understood as purchasing RMB, and has an intuitive understanding of the currency price

it takes about half an hour to get to the account. It will take about two hours to get to the account in congestion

ZB platform is relatively reliable, and the reputation of ZB is still very good in the past

How to operate C2C of ZB

< UL >

log in to ZB trading platform and click "C2C trading" on the page

to get to the QC transaction page, you need to first bind your bank card. Then, in the buy QC interface, enter the quantity of QC you want to buy. At present, the ratio of QC to RMB is 1:1. Enter the purchase quantity and click "buy now"

after clicking "buy now", you will be prompted to complete the payment within 30 minutes. At the same time, payment information is generated. Please note that the payment must be made according to the prompt

< / UL > < H2 > official statement:

business processing time 9:00-21:00. Non processing time orders will be processed at 9:00 the next day, and the payment will be completed within 24 hours after receiving the order

this means that the merchant you paid will transfer QC coin to your account within 24 hours. According to my experience, you can get to the account in 2 hours ring the day

< H2 > the following points should be paid attention to:

1) make sure to use the newly bound bank card for transfer and payment

2) note information (that 6 digit) must fill in

3) do not use Alipay, WeChat and other transfers. p>

4) do not fill in the opposite account incorrectly

< UL >

about 1-2 hours, you can check whether your QC has arrived in the financial center

after the account is received, you can trade in the "QC" zone of the "spot trading". You can choose the transaction you want to buy and buy the order

3.

If you want to query the transaction records on the main network, you can use Etherscan. However, if you build your own private chain, how should you query the transaction records

the answer is that you need to listen to the logs on the chain, save them in the database, and then query them in the database. For example:

< pre t = "code" L = "Java" > varaddr = & quot& quot;< br />varfilter=web3.eth.filter({fromB lock:0 ,toBlock:' latest', address:addr });< br />filter.get(function(err,transactions){
transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});

Web3. Eth. Filter() is used to monitor the log on the chain, and Web3. Eth. Gettransaction() is used to extract the information of the specified transaction. Once the transaction information is obtained, it can be stored in the database for query

recommend a practical introction, you can see: Ethereum tutorial

4. With bitpie wallet, this is the largest bitcoin wallet in China. It can buy and sell bitcoin with one click, which is much more convenient than the exchange.

5. Note that Ethereum is 2.0 now. As of 13:57 on the 4th, the current deposit contract address of Ethereum 2.0 has received 1000098eth, and 31252 addresses have completed the mortgage of 32eth. With the increasing number of mortgage, the annual yield of mortgage will graally decrease. After the mortgage amount reaches 1 million eth, the current annualized yield is about 15.7%. Zhongyuan, a well-known exchange, has taken the lead in opening the mining channel of eth2.0 verification node, and then launched qeth. Users can invest their own eth in verification node mining and exchange qeth to obtain liquidity, and then participate in mining. Compared with the disadvantages of eth2.0, qeth has too many things: the liquidity is guaranteed, the user does not have to bear the technical cost, the threshold of participation does not need 32 eth as low as 0.1eth, the nodes are maintained by the platform, and the income is distributed according to eth2.0.

6. Search Ethereum blockchain browser or bitcoin blockchain browser. If it is based on other chains, search other browsers to view

7. Many people are optimistic about the decentralized exchange. The private key is in their own hands and they enjoy complete control over the user's assets. However, e to the congestion of Ethereum's public chain, the trading experience of the decentralized exchange on Ethereum is not very good and slow. At present, the most promising is the X protocol, but if the problem of Ethereum is not solved, its application problems can not be started at all
in comparison, the decentralized exchange based on EOS is much better, because its TPS is fast enough to handle the decentralized application at the present stage, and its speed is much better than that on Ethereum. Whaleex, in particular, is very smooth in use, with fast transactions. It is not inferior to those centralized exchanges. Among all decentralized exchanges, whaleex is excellent
therefore, I think the decentralized exchange on EOS may break out faster than that on Ethereum, especially the whale exchange, which will be a dark horse. The smart contract of their home is also the only one that has passed the slow fog security audit. The security is particularly high and the use is assured.

8. Gas & gt; ethestimateGas({ from:ethaccounts [1], to: ethaccounts[2], value:50000000000000 }) 21001 > Ethgasprice 2000000000, as shown above, shows this account [1] = & gt; The transaction of account [2] needs 21001 gas, and the current gasprice is 2000000000. How many gas does it take to send transaction / call contract method in Ethereum

9. Introction: the company is a subsidiary of China Galaxy Securities Co., Ltd. in Hong Kong.

10.

Transaction

the behavior of blockchain transaction follows different rule sets

< UL >

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)

< / UL >

the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system