Ethereum test network time bug

1.

There is an essential difference between Ethereum and bitcoin. What is the difference? Bitcoin defines a set of currency system, while Ethereum focuses on building a main chain (which can be understood as a road) to allow a large number of blockchain applications to run on this road

from this point of view, Ethereum's application scenarios are more extensive, which is why we say that Ethereum marks a simple monetary system in the era of blockchain

1.0, and a transformation to other instries and application scenarios in the era of blockchain 2.0

however, there is no perfect thing in the world. Although Ethereum has expanded the application scope of blockchain in all walks of life and improved the speed of transaction processing, it also has some disputes and doubts

first, the solution to the lack of scalability of Ethereum: slicing technology and lightning network

the bottom design of Ethereum, the biggest problem is that Ethereum has only one chain and no side chain, which means that all programs have to run on this chain equally, consuming resources and causing system congestion. Just like last year's very popular Ethereum game "encryption cat", when this game was very popular, it once caused Ethereum network paralysis

to improve the processing capacity, Ethereum proposes two ways: shard and lightning network. Let's introce these two technologies respectively

(1) fragmentation technology

vitalik buterin, founder of Ethereum, believes that the reason why mainstream blockchain networks such as bitcoin process transactions very slowly is that every miner has to process every transaction in the whole network, which is actually very inefficient. The idea of fragmentation technology is: a transaction does not need to be processed by all nodes in the whole network, as long as some nodes (miners) in the network are allowed to process it. Therefore, Ethereum network is divided into many pieces. At the same time, each piece can handle different transactions. In this way, the network performance will be greatly improved

however, the slicing technology is also controversial. As we all know, the important idea of blockchain technology is decentralization. Only when the whole network witnesses (processes) the same transaction can it have the highest authority. The Ethereum slicing technology is similar to the group witness, not all nodes witness together. In this way, it will lose the absolute "decentralization" attribute, and can only achieve the purpose of high performance by sacrificing certain characteristics of decentralization

(2) lightning network

lightning network uses the way of transaction under the chain. What does that mean? It means: when the participants of lightning network transfer money to each other, they do not need to confirm the transaction through the main chain of Ethereum, but create a payment channel between the participants and complete it under the chain

however, lightning network is not separated from the main chain. Before establishing a payment channel, you need to use the assets on the main chain as collateral to generate a balance proof, which indicates that you can transfer the corresponding balance. In the case that both parties of the transaction hold the balance certificate, both parties can make unlimited number of transfers under the chain through the payment channel

only when the off chain transaction is completed and the assets need to be transferred back to the chain, the balance change information of the main chain account will be registered on the Ethereum main chain, and no matter how many transactions occur ring this period, there will be no record on the main chain

another real benefit of lightning network is that it can save the cost of miners for you. At present, when we trade on the main chain of Ethereum, we need to consume gas and pay for miners. Once we move the transaction to the lower chain, we can save this part of the cost

Of course, lightning network is not perfect. When using the lightning network, the assets on the main chain should be used as collateral; And this part of assets as collateral can not be used before the user completes the transaction under the chain. This also determines that lightning trading is only suitable for small transactions

the above is the problem of insufficient scalability of Ethereum, as well as the two main solutions: fragmentation technology and lightning network

Second, there are loopholes in Ethereum's smart contract and the infamous Dao event

Ethereum's smart contract is very powerful, but there are loopholes in any code. The biggest controversy of Ethereum's smart contract lies in the so-called loopholes, that is, security issues. According to relevant research, 34200 (about 3%) of the nearly 1 million smart contracts based on Ethereum contain security vulnerabilities, which will allow hackers to steal eth, freeze assets or delete contracts, such as the infamous Dao incident

(1) what does Dao mean

before introcing the Dao event, let's first introce what Dao is. Dao is the abbreviation of decentralized

autonomous organization, which can be understood as decentralized autonomous organization. From the perspective of Ethereum, Dao is a kind of contract or a combination of contracts on the blockchain, which is used to replace the government's review and complex intermediate proceres, so as to achieve an efficient and decentralized trust system. Therefore, Dao is not a specific organization, that is to say, there can be many Dao, all kinds of Dao

(2) the infamous Dao event

however, when we talk about Dao now, we basically refer to the Dao event, that is, the infamous hacker attack event we just mentioned. As we know, the English word "the" refers to "the Dao event". The Dao event

refers to "the Dao event", because we just said that Dao is not a specific organization, there can be many Dao, all kinds of Dao

in 2016, slock.it, a German company focusing on "smart locks", launched the Dao project on Ethereum in order to realize decentralized physical exchange (such as apartments and ships). Since April 30, 2016, the financing window has been open for 28 days

unexpectedly, this Dao project is very popular. It raised more than US $100 million in just half a month. By the end of the whole financing period, it raised a total of US $150 million. Therefore, it has become the largest crowdfunding project in history. However, it didn't last long. In June, hackers took advantage of the loopholes in the smart contract to successfully transfer more than 3.6 million Ethernet coins and put them into a Dao sub organization, which has the same structure as the Dao. At that time, the price of Ethernet currency fell directly from more than $20 to less than $13

this event shows that there are loopholes in smart contracts, and once the loopholes are exploited by hackers, the consequences will be very serious. This is why many people criticize Ethereum and say that its smart contract is not smart

to solve this problem, many foreign companies begin to provide code audit services in order to solve the vulnerability problem of smart contract. From a technical point of view, some teams are currently testing smart contracts. Most of these teams are led by professors from Harvard, Stanford and Yale, and some of them have obtained investment from leading institutions

in addition to the problems of insufficient expansibility and loopholes in smart contracts, the controversy over Ethereum lies in the POS consensus mechanism it pursues, that is, the proof of equity mechanism. Under the proof of equity mechanism, if anyone holds more money and holds it for a longer time, he will get more "rights" (interests) and have the opportunity to get bookkeeping power, Bookkeeping can also be rewarded. In this way, it is easy to create the oligarchic advantage of "the stronger the stronger"

Another problem is the chaos of ICO. ICO is a common way to raise funds for blockchain projects, which we can understand as pre-sale. The outbreak of ICO projects on Ethereum has caused illegal activities such as fund allocation and money fraud under the banner of ICO, which has caused security risks to social and financial stability

2.

Hangzhou Ethereum Information Technology Co., Ltd. is a limited liability company (invested or controlled by natural person) registered in Yuhang District, Hangzhou City, Zhejiang Province on March 20, 2017. Its registered address is room 2003, building 3, Xinyuan jinzuo, Nanyuan street, Yuhang District, Hangzhou City, Zhejiang Province (entrusted by Tianze commercial secretary)

the unified social credit code / registration number of Hangzhou Ethereum Information Technology Co., Ltd. is 91330110ma28n029xm, and the enterprise legal person is Zhang Shoukun

Hangzhou Ethereum Information Technology Co., Ltd. has a general registered capital in the province

view more information and information of Hangzhou Ethereum Information Technology Co., Ltd. through network enterprise credit

3.

First of all, we need to understand what is MLM:

MLM refers to the illegal behavior of organizers and development personnel to obtain wealth by calculating and paying remuneration to the developed personnel based on the number or performance of the personnel directly or indirectly developed, or requiring the developed personnel to pay certain fees to obtain the qualification to join. The essence of MLM is "Ponzi scheme", that is to say, the money of later comers is distributed to the income of former comers

However, the new type of MLM does not restrict personal freedom, does not accept ID cards and mobile phones, and does not take classes collectively. Instead, it uses capital operation as a banner to pull people to cheat money, drives luxury cars, wears gold and silver, and uses money to attract your relatives and friends to join in, and finally makes you lose all your money

then judge whether the ether coin is a kind of MLM, whether you need membership fee, whether you need to ask your relatives and friends to join

extended materials:

Ethereum is an underlying technology platform on which developers can create distributed applications. With the application, there will be transactions. With a transaction, you need money to complete the transaction. In this way, money has value, and investors' investment has a return. If the transaction volume on the platform is larger and larger, the demand for money will be higher and higher, and the money will be more and more valuable

from the perspective of image, bitcoin creates a kind of digital gold, while Ethereum creates a country, and Ethereum is the credit currency of the country

after bitcoin, there are thousands of digital virtual currencies in the world, many of which are completely deceptive in the guise of "digital currency". Previously, Haikou Municipal Public Security cracked down on a pyramid selling organization called "Eurasian currency", which operated on the internet pyramid selling platform, making more than 40000 investors cheated, involving 4.06 billion yuan. The field of virtual currency has just started, so we need to be cautious

resources : Ethernet money network

4.

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

5.

The price of Eth and other virtual currencies is determined by the following aspects: 1. Frequency of use; 2. Actual use; 3. Number of participants

as for how much room to go up, the current price of Ethereum is about 6600. Recently, e to the frequent use of Ethereum private placement, Ethereum has risen to more than 10000. Ethereum is a smart contract, and there are countless tokens developed based on Ethereum. Therefore, as the underlying public chain of smart contract, its prospect changes with the popularity of blockchain, However, some time ago, the disadvantages of Ethereum were exposed. The main chain was congested and the handling fees were extremely expensive. The development of Ethereum was close to the bottleneck. Therefore, the room for its growth was whether the developers could improve the main chain environment according to the disadvantages. As for the number of participants, it was not a big problem now. Pay more attention to the current development progress of the developers and focus on doing things, There is a bright future ahead

at present, the websites that can trade Ethereum include: btctrade international station, Huo coin, coin an, etc.

6. As a bitcoin trading platform, fire coin has won a round of 10 million RMB capital investment from Zhenge fund, Dai Zhikang, Sequoia Capital (shareholders of many global well-known companies such as apple and Alibaba). Fire coin implements strict risk control management and operates stably. As of the end of 2016, the accumulated turnover of fire currency reached 200 billion yuan
on September 15, 2017, huoyuan.com announced that registration and RMB recharge services will be suspended from now on, and all users will be informed before September 30 that they will stop trading. At the same time, all transactions of digital assets against RMB will be graally stopped before October 31. Fire money network said it will stop virtual currency trading on October 31, 2017. You can contact the fire coin net official consultation refund question
response time: March 11, 2021. Please refer to the official website of Ping An Bank for the latest business changes
[Ping An Bank I know] want to know more? Come and see "Ping An Bank I know" ~
https://b.pingan.com.cn/paim/iknow/index.html

7. Generally speaking, ETF will rise when the stock goes up, and ETF will fall when the stock goes down. On Friday, the stock rose sharply, so ETF should not fall, but it also depends on what kind of proct you buy.

8. 1. The first feature of blockchain is decentralization. How to understand it? Taking the trading book of the foreign exchange trading platform as an example, through the comprehensive and in-depth application of blockchain technology, the foreign exchange trading platform can record all relevant information in a distributed account book, making it difficult for traders to tamper with their trading records, and investors can clearly understand their own capital status and each order transaction, It also changes the opaque trading status of the foreign exchange instry in the past, and is concive to strengthening the competitiveness of the formal and high-quality foreign exchange trading platform
2. The second feature of blockchain is security. Because the blockchain is composed of each encrypted data mole, it has a specific defensive. When the blockchain technology is applied to the safe operation of procts and the management and operation of the platform, this natural security defense mechanism will rece the operation cost of the platform, and the risk coefficient of the platform will be greatly reced
3. When the security and trust are highly solved through blockchain technology, the transnational settlement and transaction efficiency of transactions will undoubtedly be greatly improved. At this time, compared with the past, the foreign exchange trading platform with block chain technology has higher technology content, which can provide more professional service requirements for investors. It's a wonderful thing for investors.

9. may not!!!

10. Maybe it's the timing problem between FPGA and PHY. Add an SDC to constrain the port timing.