Hacker Ethereum

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. 1. What is the ether classic<

etc (Ethereum Classic) is a bifurcated currency that Ethereum hard bifurcates after 1920000 blocks, and its function is very similar to Ethereum. Etc adheres to the concept of decentralization and supports the consensus mechanism of blockchain guarantee. Etc firmly believes that once the blockchain starts to run, its development direction will not be controlled by any central team, but will be determined by the consensus of the people participating in the whole network and the consensus of the computing power of the whole network

the Ethereum blockchain hard branching in July 2016 aims to transfer the Dao funds stolen by hackers to an account controlled by investors, and let the old transaction records be forgotten by history. Most Ethereum developers are involved in the reversal, as are exchanges, startups and other members of the ecosystem. A few days later, the project returned to normal. But not everyone wants to forget the old record. As a result, a small number of miners continued to use the original blockchain as a protest. They described the hard fork as a capital withdrawal for the abandoned project of the Dao. So Ethereum classic (etc) was born

2. Detailed parameters

Chinese Name: Ethereum classic English Name: Ethereum classic English abbreviation: etc

developer: Ethereum Classic team core algorithm: ethash consensus proof: POW

release date: 2016 / 7 / 20 block time: About 15-17 seconds / block

total currency: fixed at 210 million, up to 230 million, Every 5 million blocks decelerate by 20%, and the first proction rection is expected to be in December 2017

main features: independent cryptocurrency

3.

The idea of Ethereum was born in 2013. Vitalik buterin ˙ When he was a programmer in the bitcoin community, he suggested to the core developers of bitcoin to develop a language for application developers to facilitate the development of various applications. Bitcoin core developers disagree. So God V decided to develop a new platform for this purpose

V God wrote the white paper of etheric currency in 2013, in which he explained the goal of building a decentralized program. In 2014, we got development funds through crowdfunding, so we developed the Ethernet system< (better digital currency trading platform "currency exchange")

since its birth, it has carried out four hard bifurcations so far

for the first time, in order to adjust the difficulty

released a stable version of "homeland" for the second time

for the fourth time, in order to prevent DDoS and rece weight

there is only the third hard fork, because of the hacker attack, and forced to fork. This is the Dao event

On July 30, 2015, v-god and Ethereum Foundation created the first smart contract platform and designed the Dao Ethereum contract

on April 30, 2016, the Dao smart contract was officially deployed, and the world's largest crowdfunding was completed, reaching an amazing $150 million As an aside, the biggest crowdfunding event in time is EOS crowdfunding, which has reached an even more amazing $5 billion!)

on June 17, 2016, the Dao was attacked by hackers, who stole about 50 million US dollars of Ethernet currency, and the price also plummeted from US $20 to US $15, causing great harm to Ethereum. In order to recover the loss of investors, the community finally decided to hard fork

therefore, on July 20, 2016, at the block height of 1920000, the hard branching was successful, and the new chain is called Ethereum eth, while the original chain is now Ethereum classic etc

4. This begins with a hermit named "Nakamoto Tsung"
on November 1, 2008, the hermit named "Nakamoto Tsung" watched the sky at night. Seeing that the time was ripe, he announced his new idea of issuing an electronic currency called "bitcoin" on a secret cryptography forum

then, in 2009, bitcoin was born
for a while, there were rumors all over the world:
"what is bitcoin?"
"what's the magic power of bitcoin?"
"can it compare with traditional currency?"

it's just a hermit's "masterpiece left behind". Why did it make such a big stir in the world<

it turns out that this bitcoin has risked the world's great injustice, escaped the high-ranking government control, and set up a "small autonomy" on its own:
bitcoin no longer needs to be issued by a specific institution, but is generated through a set of "institutions" designed by Nakamoto Tsung, which is based on a specific algorithm and through a large number of calculations. Regardless of the world, as long as you have a computer, access system, and operate the "organ", you can become a "coin digger"

a thousand waves were aroused for a while, and an undercurrent was set off in the river and Lake: men, women, old and young were yearning to invest in the "money digging fever"<
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but since ancient times, unique martial arts skills have come out, and most of the onlookers will see through them, but fengmaolingjiao is the one who really understands the mystery

in the same way, this "coin digger" who creates miracles is not something ordinary people can do at will. Even if everyone has a computer and computing tools, it depends on talent and hard work to generate a new bitcoin

if every "digger" wants to dig bitcoin, he has to go into many "mechanisms" of Nakamoto Tsung and use computers to solve a complex mathematical problem through huge calculation. This is far from enough. Whether we can understand the secret is not only related to the ability of the "coin digger", because the "mechanism" will automatically adjust the difficulty of the questions, so that the whole system will get a qualified answer every 10 minutes, while the vast army of "coin diggers" are crazy computing. Who can understand the secret depends on the nature

it's like buying lottery tickets. Everyone is crazy to generate various combinations of numbers with computing tools in hand. Whoever can guess the same string as the big prize will be the winner

in the end, the lucky person who was lucky enough to get a specific solution successfully created a bitcoin, and the reward for him was a total of 50 bitcoins

at this time, someone will ask, is bitcoin hard to get out of the endless mining
this is the true wisdom of Nakamoto's seclusion

like all kinds of gold, silver, iron and copper veins, bitcoin will be g out one day. A total of 21 million mathematical problems have been designed in the "mechanism" and 21 million corresponding qualified answers have been matched. In other words, the upper limit of bitcoin mining is controlled at 21 million
Where is the mystery

we know that the reason why the government calls the wind and the rain is precisely because it has the power to issue currency. Increasing and recing issuance are "fierce moves" to regulate the economy

and Nakamoto's restriction on the total amount of bitcoin has cut off the way for bitcoin market to be regulated, which is obviously the opposite

which is better? There are two schools in the world:
"supporters" think that eliminating intervention is a sign of social progress
the "losers" feel that fixed aggregate may lead to deflation, which in turn will lead to a series of market weakness and "bone breaking" of the overall economy
the merits and demerits will be left to future generations

since there is a reward for digging coins and the total amount is limited, isn't the mine going to be g through in just a few days
How could the "mechanism" that he had painstakingly researched be easily manipulated by the world<

Nakamoto has two rules under the "agency" neutrality:

first, the more bitcoin, the less reward
- when the total amount reaches 10.5 million hours (50% of 21 million), the reward will be halved to 25. When the total amount reached 15.75 million (5.25 million new output, or 50% of 1050), the bounty was further halved to 12.5. And so on

secondly, the more the total number of "coin diggers", the lower the efficiency
in this way, bitcoin will be proced more slowly in the later stage. According to the plan, from the birth of bitcoin in 2009, mining will last more than 100 years, and it will not reach the upper limit until 2140
today, the total amount of bitcoin mined out in the world is just over 16 million

all of the above are just a set of "mechanisms" carefully arranged by master Nakamoto. There is another set of "mechanisms" with such precision

bitcoin is a rare thing in the world, so how to trade it? How to manage
after living in seclusion for many years, Nakamoto studied cryptography, a unique security process for bitcoin circulation

the transaction behind bitcoin is very complicated. Bitcoin can generate bitcoin addresses randomly, and each address has a corresponding private key, which is equivalent to the bank card number and the corresponding password. Only when you have both can you manage your money
but is the complexity of this address comparable to that of ordinary bank cards

how confidential is the bitcoin address
each address is made up of a string of letters and numbers about 33 bits long, always starting with 1 or 3
how many such random addresses are there? The answer is: probably more than the sand on earth
it's not easy to break such a complex "secret protection system"

in this way, with the second "organ" blessing of Nakamoto Tsung, bitcoin circulation has more security than ordinary currency

it's no wonder that with the advent of bitcoin, the currency world is shaking, and a new fight is in the dark

bitcoin, like countless secret lone Rangers, grows savagely under the authority of the government. According to the legend, bitcoin is free (decentralized, tax-free, regulatory free), strong (relying on P2P network, external can not be closed), omnipresent (cross-border, borderless), and anonymous

you can understand, "freedom", "coming and going without name" and "omnipresent", which means that bitcoin can not only be tracked and supervised by the government, but also grow wildly in the world. It's a great way for hackers to blackmail
moreover, since last year, bitcoin has been rising wildly, and hackers all over the Internet know this information well

there is no doubt that bitcoin is a safe and profitable way to blackmail

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or like this< But all the martial arts in the world are strong. Bitcoin also has weaknesses

there are three pithy formulas:
first, bitcoin network is not broken, and trading platform is fragile
Second, the "black market" trading, speculation rampant, price roller coaster day by day
thirdly, it is difficult for ordinary people to understand the secrets of nature because of their profound martial arts
in particular, the third point is that although the Kung Fu is good, the threshold is too high, which is lamentable

then, if you look at China today, where is bitcoin going
to be fair, in the eyes of the mother of the central bank, it is not too much to say that bitcoin is a barbaric growth: in the past year, with the devaluation of RMB, bitcoin has once again become the target of investors' speculation, and its value has increased by 120%

smart passers-by have already seen through everything
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coupled with the emerging bitcoin virus, it seems that it is time for bitcoin to be subject to a wave of regulation.

5.

at present, the vast majority of digital currency transactions are concted in exchanges. Among the numerous exchanges, bitfinex, binance, okex and so on are well-known

However, bitcoin and other digital currencies, as decentralized assets, have to be traded in a centralized exchange, which seems to have hidden contradictions and dangers

1. Problems and challenges of stock exchanges=“ https://iknow-pic.cdn.bcebos.com/fd039245d688d43fdf16c83b761ed21b0ff43bbf ">

in February 2014, Mt. GOx, the world's largest bitcoin exchange at that time, was stolen 850000 bitcoins, and the price of bitcoin suffered a" cliff "crash on that day. Later, it was revealed that Mt. GOx was in fact a thief, and only 7000 bitcoins were actually stolen

in August 2016, bitfinex, the largest U.S. dollar bitcoin trading platform, suffered a security vulnerability, resulting in the theft of 120000 bitcoins, which was worth $65 million at that time. If converted into the price in December 2017, it would be worth nearly $2 billion

on December 19, 2017, South Korea's youbit exchange was attacked by hackers and lost 4000 bitcoins, and the exchange declared bankruptcy

on December 21, 2017, the Ukrainian liqui exchange was stolen 60000 bitcoins, and the unit price of bitcoin plummeted by US $2000

in 2018, such a drama will only continue

in addition to the threat of hackers, traditional exchanges also have some inherent shortcomings, such as lack of supervision and inefficiency. The security of the exchange for investors can only rely on its own credit, and the cost of running is very low. The stock exchange is regulated at the national level, but there is no such sword of Damocles on the top of the digital currency exchange. Moreover, in an exchange, the same order can only be submitted to one exchange. After the user places an order, the funds used for the transaction will be frozen and can only wait for the completion or cancellation of the transaction. These are undoubtedly inefficient

All in all, the problems of exchanges are the problems of centralization

2. Decentralization of exchanges=“ https://iknow-pic.cdn.bcebos.com/86d6277f9e2f070889a173c9e224b899a801f257 ">

(1) the progress of the exchange itself

the upgrade of security means is various. At present, the best use is cold wallet, that is, to keep the digital currency in the offline U disk. At the end of 2017, when the YouTube exchange was attacked, 75% of its assets were withdrawn into the cold purse in time to avoid greater losses. However, it seems to be a helpless way to protect the online assets by offline means. Of course, there should be many other methods, which will not be repeated here

(2) the representative of cross ledger transaction is ripple network, and the operating company is ripple labs, which is a semi centralized system. Ripple is a decentralized clearing agreement. In order to solve the high cost and delay of inter-bank clearing, its base currency is XRP. Ripple network can connect all kinds of assets, such as US dollar, RMB, Japanese yen, bitcoin, etc. to its own network. In this system, U.S. dollars or bitcoin can be converted into reborn currency, and then reborn currency can circulate freely in the network, just as a highway is built between various assets. Due to the support of major banking institutions, the reborn currency achieved nearly 300 times growth in 2017

(3) decentralized exchange

some teams try to use blockchain technology to build a decentralized exchange. This kind of decentralized exchange, to some extent, is an extension of cross ledger trading

bitshares is the most representative of early rising projects. It builds a blockchain development platform with servers scattered all over the world. Even if some of them are attacked, the system will not collapse. Anyone can transfer money and borrow money freely on this platform, and can also quickly build a centralized exchange based on this platform. In order to ensure stable value, bitstocks also require three times of digital assets as collateral. At present, bitstocks are running fairly well

later, with the development of Ethereum and smart contract, the x x protocol came into being. This is an open protocol running in the Ethereum blockchain and a decentralized exchange in the Ethereum ecosystem. The agreement has attracted many investors. At present, it has completed financing and started to build open source software tools and infrastructure. Of course, there are many competitors. Ether Delta, IDEX and oasis DEX are trying to provide similar functions. Moreover, it is a smart contract system based on Ethereum, which only supports erc20 token. If other smart contract public chains start to rise, the demand will be reced

in addition, there are some teams that are entering, such as the domestic road seal agreement, looping (LRC) in English. They adopted a design similar to the X protocol, and also introced a fast payment function similar to the lightning network. It is characterized by trying to match multiple exchanges, the user's order can be broadcast to multiple exchanges, and completed by different exchanges. Moreover, the user can still use the account funds after placing an order, and the user's behavior of transferring part or all of the funds is equivalent to partial or total cancellation. To some extent, it improves the breadth and timeliness of the transaction. However, this system seems to have damaged the "power" of the existing exchanges. Whether we can persuade everyone to play together will be a difficult problem

At present, there is still a long way to go for the construction of decentralized exchange. In 3-5 years, traditional exchange will still be the main battlefield of digital currency

However, in the future, it is worth looking forward to let the decentralized digital currency get rid of the shackles of centralization

6. EMule uses both e2dk and kad networks. The former is server based and the latter is decentralized. The two complement each other to find more sources

eMule is better than BT's decentralization and more suitable for sharing resources.

7. It depends on the unit or the indivial. There are about 20 or 30 units in the unit and about 10 units in the indivial family. Of course, there are also games to watch.

8. Freundlich adsorption equation can be applied to both monolayer adsorption and heterogeneous surface adsorption. Freundlich adsorption equation, as an empirical adsorption isotherm of heterogeneous surface, can well describe the adsorption mechanism of heterogeneous surface, and is more suitable for low concentration adsorption. It can well explain the experimental results in a wider concentration range. However, the disadvantage of Freundlich adsorption equation is that it can not get a maximum adsorption capacity and estimate the adsorption beyond the concentration range of parameters

9. After investigation and confirmation by professional network security companies, gatecoin, a bitcoin platform, publicly declared that its system had been hacked and 15% of its digital asset deposits had been stolen

another platform closed down e to hacker intrusion. Is bitcoin still in spring< Bitcoin (BTC): originally proposed by Nakamoto, it belongs to a kind of digital currency. It is based on a specific algorithm and generated through a large number of calculations. Therefore, the issuance of bitcoin is not manipulated by any government, bank, organization or indivial. The total number of bitcoins is very limited. In the past four years, there were only less than 10.5 million, and in the future, the total number of bitcoins will always be limited to 21 million

Hot Wallet: it can be connected to the Internet, has strong circulation, can be used for daily consumption, and is vulnerable to hackers

cold Wallet: it won't connect to the Internet and has poor circulation, but it is not easy to be attacked by hackers

gatecain explained in an official article that the server intrusion occurred between May 9 and May 12. On the night of May 9, the service was interrupted e to the restart of a server. Associated with the time node, I strongly feel that the hacker intrusion event has an indispensable relationship with this service interruption

on the evening of May 13, gatecoin detected some suspicious transactions, so it immediately suspended the service for investigation to prevent more unauthorized access to Eth and BTC hot wallets<

loss

the hacking incident caused huge losses to gatecoin, with 185000 Ethernet coins and 250 bitcoins, with a total value of US $2 million, accounting for 15% of gatecoin's total digital assets

the security company investigated and found the hackers' Ethernet and bitcoin addresses, and gatecoin is raising funds to make up for the losses

Wright coin, Ruitai coin, doggy coin, Ethereum, bitstock and other digital currencies are also excellent.

10. I don't know where the landlord said that he was attacked by hackers, but it's not impossible. Although blockchain is very popular at present, there is no absolute security for anything, even bitcoin