Bitcoin Forum

I read a few hours ago about the suspension of the movement of Ethereum Classic by a major crypto exchange Coinbase, alleging that it detected a possible confidence- breaking attack on the cryptocurrency's blockchain which led to a double spend of about $500,000 worth of ETC on the network by some malicious party.

 I don't know exactly how that was possible, and I'm wondering if such a malicious attack could happen in the networks of other major coins like Bitcoin, Ether, Bitcoin cash, etc?

I think this calls for a serious concern in the cryptospace.

Meanwhile, Ethereum Classic (ETC) Developers Deny 51% Attack, Double Spend (https://ethereumworldnews.com/ethereum-classic-etc-developers-2019/)

51 percent attack is possible especially if the network hash rate is relatively small and thus will be easier for someone with enough resources and malicious intent to orchestrate such attack. You only need to control 51 percent of the total hashrate. That will be very difficult for for bigger network like that of bitcoin and maybe ethereum. This is one of the reasons why PoS is being proposed.where your control is based on the quantity of coin you own,someone who owns so much coins will not want to destroy the integrity of the network as he will end up being the one being hurt by such attack.

I think there is any possibility. If there is a serious loophole in BTC or ETH, it may be hacked and collapsed. However, it has not yet been found whether they have serious problems, so it is safe for the time being.

Therefore, if that defence is valid I expect Coinbase to come out with another version of its earlier claim by clearing the air with a further explanation that would re-instate the confidence of investors on the coin. Despite the developer's defence, the exchange is yet to restore trading activities on the ETC on its platform.

I don't think PoS could do better than PoW in stopping such a malicious activity. This is because if a party owns more than 50 percent of the total quantity of the coin in circulation then it is possible that such party could dictate and manipulate what goes on in the network. This may compromise the confidence trust of the network.

ETC will surely drop the price after a day or three because of this attack. Its supporters and investors will lose its confidence to ETC which may cause a price dump because of panic selling. I hope that the team will immediately cover its losses specially their credibility to its supporters. If that type of attack happens to bitcoin, the whole crypto space is doom and another bloody market will follow.

I think there is always a risk because hackers learn and develop quickly. But the platforms aren't standing still, they're also moving forward and developing newer high-tech protection.
But, Husam Abboud, a FECAP analyst at Brazil's FECAP University, has demonstrated that mobilizing only $1.5 million is enough to launch a network attack on Ethereum Classic (ETC) with a market capitalization of more than $2 billion, and if you have $55 million, you can bankrupt this cryptocurrency and make a profit of $1 billion.
The researcher calculated the cost of the 51% attack on Bitcoin Cash (250 Bitcoins per day, or $2 million) and Bitcoin Gold (26 Bitcoins per day, or $200,000). Abboud says the attacks may continue until the developers take the appropriate code update, or until the price of the cryptocurrency becomes so low that the attack becomes unprofitable.
Abbud notes that Satoshi Nakamoto was developing a consensus protocol without assuming that the miners would carry out attacks that would reduce the market price of the cryptocurrency and make it unprofitable for everyone.
There are large stock exchanges with solid liquidity, which allow you to trade with leverage from 1:2.2 to 1:100. However, the market is becoming more liquid for those who are trying to benefit from lower prices.
Concerns about the reliability of the PoW cryptocurrencies are getting bigger and bigger: recently, attacks have been launched on Verge, Electroneum, Bitcoin Gold and Monacoin. Experts believe that there are many ways to combat the attack. These can include security measures for existing PoW blockchains, upgrading to Proof-of-Stake, increasing the number of required confirmations, and improving hashing algorithms. Of course, it is foolish for cryptocurrency networks with billions of dollars of capitalization to save on their own security.

It was unfortunate that Ethereum Classic is been attacked! Etheteum Classic was suppose to be the most decentralized form of ethereum but Ethereum classic is yet to attain that status. I hope this does not affect Ethereum and etheteum based projects!

now they seem to deny this attack and do not give official confirmation that the network was hacked.

Any problem can happen, the ETH network, BTC can be attacked at any time. Even at the present time everything is still under control,
but we absolutely can not affirm the safety of the BTC network, eth ... is absolute.

Someone sent approximately $400k-$500k and they reversed the transaction, basically removed the transaction
from the blockchain and made double spending . Coinbase blocked all ETC activities until this situation is resolved.
And Yes, such malicious attack could happen to ETH as well but it would be much more difficult as there is 17x time
 more hash power which is securing the ETH chain. (the mining algorithm is the same with ETC so it is worrying for ETH as well)

It has been called as a double spend, when there was a party gets more than 51% hash power in the blockchain and that makes it possible to do a double spend. Not only ETC but bytecoin was also getting it. It can be called as an attack to the blockchain

This is correct, and another problem that ETC will face if this issue is not solved yet.
the transaction can be reversed and they can halt every transaction on the chain, this is why 51% attack is the worst.


Every project with POW system has a probability to get 51% attack, Bitcoin included too. Do not worry about ETH, because they are going to change it into POS in the near future.

They can defend themselves but its also spreaded that 51% attack, double spend was real.

People will trust Coinbase rather than the devs of ETC.

That's really unfortunate for them to deny such facts when clearly anyone can check that the double spent was done and was inevitable to reverse back.

Hope they make a quick fix to such solutions by bringing in more members and making it evenly decentralized.

I think that Ethereum Classic turned out to be a failed project. Projects do not use ETC, some of the developers left the project, double spending is now taking place. I'm not saying that Ethereum Classic is a scam but this is a very bad and not successful project.

This is of course a very bad news for all investors of this coin, but as you know, any company is not insured against scammers today they can hack any project. The main thing for the team of this coin to pay damages.

While denying, I guess they are looking for the fault of the attack.

And I've read into a report that the source was from someone who owns more than half of the network's hash power.

If this news is true, it will really hit the crypto world, hopefully it will not affect other large coins so that prices do not fall deeper

That is real news, not fake. I have a coinbase account and yesterday I received their notice of this attack. Certainly, the price of ETC will be greatly reduced after this attack

https://www.trustnodes.com/2019/01/08/1-1-million-worth-of-etc-double-spent-in-a-51-attack

This means that the 51% attack would not making the ethereum classic developer gone hacked.

Honestly etc is a big coin and all that but it is not really that hard to find mining power anymore. There are COMPANIES that rent out their mining power for stuff like this. People are not using mining power to only mine anymore.

Look at where Craig Wright found its hashing power, he has no miners at all and yet he was capable of mining so much bitcoin cash blocks with the mining power he rented, that person who rented to craig was not looking to make money from his hash power and mining rewards, he is just natural evil who is willing to sell his hashing power whoever wants to regardless of what they will use it, it kinda is similar to renting your gun to whoever wants it regardless of if the use will be hunting or murder. Hence, if anyone wants to do 51% attack on any coin they will be capable of finding proper hash power if they want to. Of course its impossible to do so in bitcoin, ethereum and similar level ones.

This problem has long been known. To implement this action, you need a huge opportunity and power.

It's terrible and this information can impact other crypto prices. Hopefully it will be resolved quickly and not too far away when the price is still low as it is now