Has Ethereum ever been attacked
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 transactionsthe 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 meanbefore 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 stabilityEthereum is an open source public blockchain platform with smart contract function. It provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency ether (also known as "Ethereum")
The token on theblockchain is called ether, and the code is eth. It can be traded in many foreign exchange markets of cryptocurrency, and it is also the medium used to pay transaction fees and computing services on Ethereum
the concept of Ethereum was first proposed by vitalik buterin, a programmer, from 2013 to 2014, inspired by bitcoin, with the general meaning of "next generation cryptocurrency and decentralized application platform", and began to develop through ICO crowdfunding in 2014. As of February 2018, Ethernet is the second highest cryptocurrency in market value, second only to bitcoin
extended data:
Ethereum platform has no characteristics and value. Like programming languages, it's up to entrepreneurs and developers to decide what to use. However, it is clear that some application types benefit more from the functions of Ethereum than others. Ethereum is especially suitable for those applications that automatically interact directly between points or promote group coordination activities across networks
for example, coordinate the application of point-to-point market, or the automation of complex financial contracts. Bitcoin enables indivials to exchange money without the help of financial institutions, banks or governments. The impact of Ethereum may be more profound
in theory, any complex financial activities or transactions can be automatically and reliably carried out on Ethereum with coding. In addition to financial applications, any application scenario with high requirements for trust, security and persistence, such as asset registration, voting, management and Internet of things, will be affected by Ethereum platform on a large scale
It does not belong to MLM
Ethereum is an open source public blockchain platform with smart contract function, which provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency Ethereum
the concept of Ethereum was first proposed by vitalik buterin, a programmer, from 2013 to 2014, inspired by bitcoin, to the effect of "next generation cryptocurrency and decentralized application platform", and began to develop through crowdfunding in 2014. The market value of Ethernet currency is second only to bitcoin, and it is the second largest encrypted digital currency in the world
extended data
bitcoin has created the first decentralized cryptocurrency, and has fully tested the feasibility and security of blockchain technology in more than five years. In fact, bitcoin's blockchain is a set of distributed database. If a symbol bitcoin is added into it and a set of protocol is specified, the symbol can be transferred safely on the database without trusting a third party. The combination of these features perfectly constructs a currency transmission system bitcoin network
however, bitcoin is not perfect, and the scalability of the protocol is a deficiency. For example, there is only one symbol in the bitcoin Network - bitcoin, and users can't customize other symbols. These symbols can represent the company's stocks or debt certificates, which will lose some functions
In addition, a stack based scripting language is used in bitcoin protocol. Although this language has some flexibility to realize functions such as multi signature, it is not enough to build more advanced applications, such as decentralized exchanges. Ethereum is designed to solve the problem of insufficient scalability of bitcoinThe 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 contracton 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
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 dangers1. Problems and challenges of stock exchanges=“ //www.yuanxue365.com/en/img_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 centralization2. Decentralization of exchanges=“ //www.yuanxue365.com/en/img_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 centralizationon cryptokitties, you can buy virtual cats. By 17:00 Beijing time on December 6, 2017, the cheapest kitten had reached 0.037eth. Equivalent to 110 yuan per piece
then the kittens have some opinions about the generation. For example, Gen 12 indicates that it is the 12th generation, while Gen 20 indicates that it is the 20th generation. Generally speaking, the smaller the algebra, the more valuable it is. And you can make your kittens slap each other. For example, a Gen 1 kitten and a Gen 1 kitten will give birth to a Gen 2 kitten
you can sell your kittens and their offspring for money
but what if you don't have two kittens? If you only buy one kitten, you can use your kitten to have fun with other people's high-quality kittens. The fee also depends on the kittens of your spouse (to be honest, this mechanism is very evil, similar to borrowing chickens to have children?) The quality of the proct. If your kitten is of high quality, you can also use your kitten to mate other people's kittens, and then you get Ethereum income
but kittens also have special fertility rates
every time a kitten gives birth to one generation, it will have a certain cooling time, ring which it can not regenerate kittens,
the cooling time is divided into several grades
fast: 1 minute
swift: 2 – 5 minutes
snappy: 10 – 30 minutes
brisk: 1 – 2 minutes
plodding: 4 – 8 minutes
slow: 16 – 24 minutes
sluggi Sh (lazy kitten): 2 – 4 days
catatonic (nervous kitten): 1 week
so the price of your cat also depends on its birth time
and generally speaking, the larger the algebra is, the higher the gen value is, and the slower their growth rate is
but I want to make complaints about it because CryptoKitties is too hot! Ethereum network has a little bit of a crash, the official recommended that every time you buy a cat, the minimum handling charge is 21000. 400000 fuel = 0.01eth. However, it is irritating that I raised the procere to 1.6 million fuel, which is 0.04, and Ethereum still failed. 0.04 Ethereum. That's more than 120 yuan. It's too dark.