Ethereum code vulnerability

3.

Ethereum energy coin is not MLM

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

in 2013, vitalik buterin, 19, first mentioned the idea of Ethereum in a book entitled "Ethereum white paper: next generation intelligent connection and decentralized application platform". Then, in 2014, the algorithm and protocol of Ethernet coin were officially implemented, and $150 million was raised. The system itself was finally completed on July 30, 2015

as the representative of blockchain 2.0, the mainstream currency Ethernet is regarded as the wind vane of crypto digital currency market. However, over the past week, the price of ether currency has continued to fall. On August 14, 2018, the ethereal currency plummeted by 20%, reaching a record low of $257 this year. Compared with this year's peak of $1295, the price of Ethernet currency has shrunk by more than 80%. Affected by this, on August 15, 2018, none of the top ten mainstream currencies in the digital money market was spared, falling across the board, with a number of single day declines exceeding 10%

extended data

Ethereum started planning almost in 2013, and started to implement the project in 2015. Before that, there were many digital currencies imitating bitcoin in the market, and they made various modifications on the basis of bitcoin code. In this way, it is very difficult to develop a new blockchain application, to re deploy a new chain, and then to develop an application on this chain. Using a consensus mechanism of pow alone is a huge maintenance workload. It's like developing an app on a mobile phone and developing the Android system together

after Ethereum comes out, it is equivalent to the underlying operating system of the blockchain. On Ethereum, it is very convenient to develop various dapps without considering the underlying development, and it can also share the computing power and storage of Ethereum. For programmers, the threshold of blockchain development is lowered instantly. The emergence of Ethereum has played a very important role in the development and popularization of blockchain applications. That's why Ethereum is called blockchain 2.0

4.

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

5. Ethereum blockchain has exposed three major problems, and its founder vitalik buterin has been unable to interpret them for a long time. The first is the low performance and TPS of Ethereum blockchain as a whole; The second is that resources are not isolated. The event of cryptokitties virtual cat once occupied 20% of the traffic of the whole Ethereum, which directly caused Ethereum network users unable to carry out timely transactions, which is the biggest pain point of resources not isolated; The third problem lies in the embodiment of Ethereum's governance structure. As a decentralized distributed ledger, the founder team of Ethereum has dominated its network development in the past. The over centralized governance mode has led to the bifurcation of eth, etc and ETF in Ethereum, and the Ethereum community is now in a state of fragmented governance. In the view of Ma Haobo, founder and CEO of "aelf", all kinds of disadvantages of Ethereum are unacceptable. Therefore, the positioning of "aelf" is born for the next generation of decentralized underlying computing platform of Ethereum, which focuses on solving the problems of insufficient performance, non isolation of resources and governance structure of Ethereum.

6.

Ethereum is an implementation of blockchain. In Ethereum network, many nodes are connected with each other to form Ethereum network:

Ethereum node software provides two core functions: data storage and contract code execution

in each Ethereum node, complete blockchain data is stored. Ethereum not only saves the transaction data on the chain, but also saves the compiled contract code on the chain

At the same time, a virtual machine is provided to execute the contract code

Ethereum virtual machine

Ethereum blockchain not only stores data and code, but also contains a virtual machine (EVM) in each node to execute contract code - it sounds like a computer operating system

in fact, this is the core difference between Ethereum and bitcoin: the existence of virtual machine has brought blockchain into the era of 2.0 and made blockchain a friendly platform for application developers for the first time

the above content comes from the introction course of Ethereum DAPP development

7.

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

8. Ethereum is not a scam, but there are countless scams designed by criminals around Ethereum. The best way to avoid Ethereum scams is not to trust the guaranteed return on investment and manage your own money bag. Choose a formal digital currency exchange to invest. At present, the mainstream digital currency transactions in the market are all coin security, fire coin network, bitnet, etc.

9. Contract code of Ethereum. If the WPS document is used to analyze the , it's not clear.
I haven't touched it