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Topic: The Vulnerability of PoW in recent 51% attacks on deferent Blockchains (Read 270 times)

member
Activity: 854
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PoS is a lot more secure than PoW because it will be extremely expensive and uneconomical to try to attack a blockchain and when a validator validates a wring transaction it loses its staked coins. This offers more security than that of the PoW blockchain.
PoW vulnerability affects exchanges the most because in a case of an attack, it is hard to detect it as soon as it begins
member
Activity: 431
Merit: 18
All blockchains that run on Pow are vulnerable to a malicious attack called the "51% attack". A 51% attack is possible when a mining pool is able to attain more than 50% of the whole hashrate in a particular blockchain's network. When a mining pool or miner gains this, they will be able to rewrite the blockchain ledger (blockchain reorganization) and then steal the native cryptocurrency of that blockchain through an act called a "double spend".

51% attacks is practically impossible on the ETH blockchain because of how large tge blockchain is and the fact that only a 5% of the 51% hashrate needed for attack the blockchain is available online.

To check the nice hashable percentage of PoW blockchain minibg power available for purchase online check https://www.crypto51.app

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copper member
Activity: 112
Merit: 0
I Came across a blog post from coinbase that addresses  a  51% attack on the ETC (ethereum classic) blockchain between 5th -7th of this month showing chain reorganizations that includes double spends of around $1.1 million dollars.

Before that about $100k of vertcoin, $18 million of bitcoin gold, etc has been stolen in similar manner from different cryptocurrencies.

I am able to understand that this is due to the vulnerabilities in PoW consensus. It has also coincided with some calls for projects to switch to PoS

Here's are my questions:
1. How secure is PoS?
2. If its so secure why are most cryptos still running on PoW?
3. Does this mean that ETH blockchain is not as secure as it is said to be?

I guess the reason why that there occurred a hacked in the ETC is because the miner or the number of miners of ETC is quite small, so that the block chain is control through hashrate that results to inappropriate access of the market.
jr. member
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I heard about this attack. And as it became very scary for all of its assets, in fact, they could drop the network on any of the Altcoins, it’s unprofitable for them to drop top coins Embarrassed
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Activity: 854
Merit: 21
From my understanding I believe proof of stake is a lot more secure than proof of work.
In the PoW theoretically a blockchain can be hacked if a miner can have 51% of the blockchains hash rate, then the blockchain is vulnerable to hacking, block reorg and double spending scams.

This is however not theoretically possible for ethereum because if you check https://www.crypto51.app which shows how much of the 51% hash power is available online to hack a blockchain, you will see that for the ethereum network this figure stands at a mere 5%. But in cases of smaller projects, their blockchains are more vulnerable.

PoS remove this risk as miners will be staking their coins or tokens and a malicious activity will mean they will loose their  tokens.
Also it is practically impossible for such an hack to take place in PoS algorithm because it will require purchase of an unreal amount of coins and this still doesn't guarantee success.
hero member
Activity: 1148
Merit: 528
I am not an expert on PoS so I can't really talk about the PoS aspect of this discussion but the fact is that PoS is giving the load back to people who holds their coins on their wallets and keep the wallet open 7/24 whereas PoW gives the load to miners who already run their rigs 7/24 anyway which means transactions are much faster and much cheaper, the reason PoW is used over PoS in many places is to make transactions much faster and cheaper. However, with the new systems and features coming into PoS that difference is closing quite quickly.

ETH is secure because the amount of PoW it has is insanely high and when it switches to PoS there will be a lot of wallets that's running the node as well. ETC, vert and btc gold was so small compared to ETH that its not even remotely close so no one that holds ETH needs to worry about it. It is a danger to smaller hash PoW coins only.
legendary
Activity: 2800
Merit: 2736
Farewell LEO: o_e_l_e_o

Regarding the popularity of a coin ... wasnt BTC near to an 51% attack in 2017, too? Or am I wrong?
Not sure. Do you have the reference? I always keep eyes on the hashrate distribution of BTC but never encountered any massive threat. Here is the current one...



More or less it's always the same.
sr. member
Activity: 784
Merit: 256
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POS is safe because for an attack of 51% you need to buy a lot of coins and spend a lot of money on it. But the attack might not happen. Therefore, it is extremely risky.
member
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Sorry, but it seems to me that this problem was previously known, which is why there is a constant race of miners, but now it seems to me that when BTC switches to the Lightning network, there will be other problems.
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ETC is different from ETH as you may know already.

In POS, if you are malicious, you will lose your staked stash. So it encourages good behavior unlike POW where if you are malicious, you will be abandoned to continue wasting your hashpower.

The greatest threat I know of now is that of collusion. If people decide in greater power to be malicious, then anything can happen to our beloved chains.

Even considering our biggest chain, the Bitcoin Network, to kill it will require billions of dollars. And we all know it can be popped if people collude to take it down.


The soundness of any blockchain relies on how robust it's cryptoeconomic environment is.
member
Activity: 364
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Killing Lightning Network with a 51% Ignore attack
PoW is seriously flawed. for starters think about what it does. it simply is paying anyone who has the most ASICS !
Only rich people can afford to be PoW miners,  they just sits around and receives profit while wasting electricity and controlling your transactions.
Not to mention what this does to the environment and local energy prices.



FTFY,  Cheesy

What I am saying is:
PoW is an evolutionary dead end,  51% attacks on multiple coins all of the time.

Proof of Stake is currently the only consensus that makes sense and has been around since 2013,
it continues to survive and thrive despite the ignorant PoW fanatics that can't see that PoS is the superior design.  


 Cool
legendary
Activity: 1946
Merit: 1137
the problem is that unfortunately because of false advertising done by malicious people in addition to some idiots, now many think that the solution for 51% weakness in PoW is to switch to PoS while they all ignore the problems that PoS has!

the thing is, 51% attack is not a serious one for serious projects. look at your own examples.
Vertcoin: practically a dead coin
BTG: a useless fork coin with a gigantic premine and a filthy history of scams, malware distributed by the developers team,...
ETC: the leftover of ETH hard fork that has been under attack by the ethereum foundation which has been spending millions of dollars from their premine free money. and it is pretty small and weak.

PoS is seriously flawed. for starters think about what it does. it simply is paying anyone who has the most amount of money! a rich person doesn't even have to do anything. he just sits around and receives profit. not to mention what this does to inflation and consequently the price.

what i am trying to say is that whether there are weaknesses in PoW or not, you shouldn't run to PoS just because it has been advertised.
legendary
Activity: 2674
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I think there are good arguments on both sides of PoS and PoW, but as Gwapo already said, it's not really comparable directly. PoW for me is a lot more secure because of consensus rules that favor most hashpower, as Satoshi intended and this is still ideal.

Most coins staked as in PoS is always a bit weird for me and because there is less economic cost in mining, less incentive to secure the network.

But everything is changing and Ethereum is also moving to PoS so let's see.
sr. member
Activity: 1372
Merit: 322
Regarding the popularity of a coin ... wasnt BTC near to an 51% attack in 2017, too? Or am I wrong?
It may happen when group of miners give up. Otherwise, it's not possible to get 51% hashing power by someone although those can be rent. I assumed most of the miners as honest.
legendary
Activity: 2296
Merit: 2721
Quote

ETH and ETC are different. The PoW attack occurred on ETC blockchain. PoW attacks generally occurs when major involvement and popularity is not there in a project.
Regarding the popularity of a coin ... wasnt BTC near to an 51% attack in 2017, too? Or am I wrong?
member
Activity: 448
Merit: 15
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I think POS is a superior form of network verification to POW and it certainly inolves an awful lot less power consumption. POW has been the defacto standard since Blockchain began but I think that is slowly changing.
sr. member
Activity: 1372
Merit: 322
It's nothing about stolen, for your info. A 51% attack means more than 51% hashing power is controlling by an entity who likely to spend a coin for twice. They can spend a single coin for two times. First time they send it and reverse the transaction. That's it. Also, most of the times, it is done for lessening the price of that coin. Anyway, it mostly happen on those which have less active nodes. And that's why PoS is better.
member
Activity: 364
Merit: 13
Killing Lightning Network with a 51% Ignore attack
I Came across a blog post from coinbase that addresses  a  51% attack on the ETC (ethereum classic) blockchain between 5th -7th of this month showing chain reorganizations that includes double spends of around $1.1 million dollars.

Before that about $100k of vertcoin, $18 million of bitcoin gold, etc has been stolen in similar manner from different cryptocurrencies.

I am able to understand that this is due to the vulnerabilities in PoW consensus. It has also coincided with some calls for projects to switch to PoS

Here's are my questions:
1. How secure is PoS?
2. If its so secure why are most cryptos still running on PoW?
3. Does this mean that ETH blockchain is not as secure as it is said to be?

1.
PoS is more Secure than PoW.
Look at Blackcoin, it is a very secure PoS coin and it blocks all reorgs over 500 confirms.
So anything over 500 can't be reorg no matter how many coins someone owns.
Also after staking those coins go dormant for a specific time, making sure no PoS holder can dominate a PoS indefinitely like a PoW miner can.

2.
Greedy PoW miners don't want to give up control over those coin networks,
they don't care about the coin's users only their profit in fiat from selling their PoW generated coins.

3.
ETH hashrate is ~20X the ETC hashrate, but in all PoW coins, it all depends on the collusion of 51% can dominate any PoW coin.
Higher PoW Hashrate is no guarantee, enacting a rolling checkpoint similar to blackcoin would guarantee no reorgs past the rolling checkpoint limit.
full member
Activity: 234
Merit: 100
1. How secure is PoS?

POS is distributing coins by staking. Although it's quite secure than POW but it doesn't have a real consensus in it's true sense.

2. If its so secure why are most cryptos still running on PoW?

PoW is the vanilla form of mining since its derived from bitcoin. PoW has it's deterministic way of assessing supply vs demands.

3. Does this mean that ETH blockchain is not as secure as it is said to be?

ETH and ETC are different. The PoW attack occurred on ETC blockchain. PoW attacks generally occurs when major involvement and popularity is not there in a project.
jr. member
Activity: 123
Merit: 3
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I Came across a blog post from coinbase that addresses  a  51% attack on the ETC (ethereum classic) blockchain between 5th -7th of this month showing chain reorganizations that includes double spends of around $1.1 million dollars.

Before that about $100k of vertcoin, $18 million of bitcoin gold, etc has been stolen in similar manner from different cryptocurrencies.

I am able to understand that this is due to the vulnerabilities in PoW consensus. It has also coincided with some calls for projects to switch to PoS

Here's are my questions:
1. How secure is PoS?
2. If its so secure why are most cryptos still running on PoW?
3. Does this mean that ETH blockchain is not as secure as it is said to be?
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