What is a 51% attack? What is dual spending?

[Captain Karim 0]

On 4/1/2020 at 8:55 AM, Crypto123 said:

I don't think so. The fear of an attack of 51% in this way is exaggerated. Yes, it could happen and has already happened on networks other than Bitcoin, but it is not destroyed, meaning everything there is. Attackers steal millions of dollars and then the network returns to normal.

But if an attack of 51% of bitcoin occurs, it will be a disaster for the whole market because all cryptocurrencies are affected by bitcoin, if an attack of 51% hits a network other than bitcoin, this network will only be affected and the market will not be affected, but if the attack hits the bitcoin network, then it will be devastating Bitcoin is closely related to the rest of the cryptocurrency in the market, when bitcoin drops all cryptocurrencies are bleeding, and bitcoin is only supported by investor confidence in its safety, so why will investors keep bitcoin if they think that their money is in danger?

[Razan alikac 1899]

This is an interesting and very dangerous topic if it happened, and this attack threatens the security of Bitcoin and cryptocurrency investors, and there must be solutions to it .. I do not hope that such an attack will happen, it will be very bad

[Crypto123 0]

2 hours ago, Razan alikac said:

This is an interesting and very dangerous topic if it happened, and this attack threatens the security of Bitcoin and cryptocurrency investors, and there must be solutions to it .. I do not hope that such an attack will happen, it will be very bad

Such an attack has already occurred before on the ETC, BTG network and several other currencies but it has not happened on the Bitcoin network, this attack is very dangerous and could affect the Bitcoin network and the attackers can steal millions of dollars.

[Crypto123 0]

15 hours ago, Preadator889 said:

An attack of 51% is an attack on the blockchain, so hackers attack the blockchain very often, but they fail and do not do this to crack BTC or other coins from the blockchain, and they have good security.

They have failed to attack Bitcoin because they have very strong encryption protection and very large mining difficulty so they need to have massive power to attack it, but they have succeeded in attacking other coins and stole millions of dollars.

[Crypto123 0]

On 4/5/2020 at 8:31 AM, UT2001 said:

I think that three was one of these attacks on the ethereum classic block chain not too long ago which created some major discussions about the security of that block chain.

Your words are absolutely correct, it was one of the dangerous attacks carried out on the ETC coin and the attackers were able to steal millions of dollars from this attack, also there was another on the BTG coin as well as millions of dollars were stolen.

[Crypto123 0]

6 hours ago, Nutu18 said:

It's very impotent things because if anyone got 51% of control then easily can crash and boost but this is not possible because every country have good amount in crypto.

Getting 51% of the power of the network to carry out the attack is not an easy thing and needs a huge group or company to do it and it is difficult for individuals to do and in the event that it happens the password or encryption will not help in the protection because the network is in their hands.

[Thekingcallme 1975]

51% attack is considered one of the most dangerous hacking and control attacks and is carried out by miners to acquire half of the currency

[Shaza Ahmad 1682]

Good topic! I think the problem with this attack is the biggest problem for bitcoin because it will mean its destruction, but the bitcoin network is getting more secure with the increase of mining strength (hash) day by day.

[Crypto123 0]

2 hours ago, Shaza Ahmad said:

Good topic! I think the problem with this attack is the biggest problem for bitcoin because it will mean its destruction, but the bitcoin network is getting more secure with the increase of mining strength (hash) day by day.

Thank you, it is true that 51% attack is the most serious problem for the bitcoin network but it does not mean destroying it ever, the attackers will steal millions of dollars but the network will not collapse, the more miners increase the network protection, also full nodes have a big role in protecting the network.

[Rezort 846]

Well, it looks like this attack hasn't been ever implemented on the bitcoin market which is the biggest right now, so I don't think that it can be dangerous for the market.

[Crypto123 0]

On 4/29/2020 at 11:05 AM, Rezort said:

Well, it looks like this attack hasn't been ever implemented on the bitcoin market which is the biggest right now, so I don't think that it can be dangerous for the market.

It is not a risk at the present time, but there will be a great risk in the event that the price of the Bitcoin decreases and the rewards fall, and therefore that the miners can follow and leave the mining. In this current, the Bitcoin network will be at great risk from an attack of 51%.

[Hasmizara 64]

I don't think there will be any risk for transactions in bitcoin networks and blockchain technology at a 51% attack. It will not affect the market. As Bitcoin is not a stable currency, its price rises, and falls. There is no risk in Bitcoin investment transactions.

[BrolySSJ 7899]

This is very intense to see that they will be able to reverse the existing completed transaction and they will then be able to use those funds again. This will seem as if the payment would not have gone through whereas the payment has been successful and then both parties will get what they want with just one payment. This could severely affect businesses and could even cripple the economy in all honesty.

[TimopheyKa 3900]

Thank you very much for this information. I believe that 51 percent of the attack is a very critical situation. They say that you can hack bitcoin, but it seems to me that this will not happen soon, because bitcoin is a very hidden system, as well as quantum computers, which are unlikely to be able to help in any way!

[Virgil dijk 1431]

This is dangerous and I think miners are actually working hard to prevent such attack because if it happens will cause damage and miners will lose most of the reward there are supposed to get in return.

[Crypto123 0]

42 minutes ago, Virgil dijk said:

This is dangerous and I think miners are actually working hard to prevent such attack because if it happens will cause damage and miners will lose most of the reward there are supposed to get in return.

Miners keep the Bitcoin network safe, there are also FullNodes and Nodes interested in keeping the network safe, the Bitcoin network is very strong and difficult to breach with this attack but other currencies have been hacked.

[Virgil dijk 1431]

 Well last year many was really expecting much from this year 2020 but entering the year 2020 there have been many uncertainties due to the heavy attack of the pandemic, but crypto has recovered fully from the attack and now in few months time I think our expectations will come to pass.

[Omar Ommeish 4872]

On 12/22/2019 at 9:18 AM, Ardian1206 said:

This is very dangerous for the network and will cause the collapse of bitcoin, especially with more severe damage is very dangerous.

Yes, this is dangerous for Bitcoin and all cryptocurrencies because many investors are afraid to pay their money to invest in these currencies for fear of being attacked by hackers.

[Raqeebzy 6456]

Good and interesting topic. I don't think the Bitcoin network can be 51% attacked anymore taking into account the cost needed for the attack; the hardware and electricity and cooling costs, it won't be feasible to launch such attack, difficulty will even increase with time. 

[malik6314193 5449]

On 12/21/2019 at 3:05 PM, Crypto123 said:

It is an attack on a blockchain designated by a group or organization of miners to try to control more than 50% of the hash rate or the computing power of the network.

 

I don't know about that but thanks for sharing this useful information with us. It's mean that they can hack crypto easily. But how now it is very hard to hack crypto specially bitcoin. 

[Ridam 7455]

Well you have provided really interesting information and talking about the cost for 51% attack it's really high for Bitcoin as owning 50 % of miners would cost them huge and i don't think they would able to manage profit and that's why altcoins are more vulnerable to it.

[Crypto123 0]

On 6/14/2020 at 4:59 AM, Ridam said:

Well you have provided really interesting information and talking about the cost for 51% attack it's really high for Bitcoin as owning 50 % of miners would cost them huge and i don't think they would able to manage profit and that's why altcoins are more vulnerable to it.

Yes, true, because of the very large bitcoin mining difficulty, it is difficult for attackers to possess 51% of the network strength and therefore the possibility of attack on bitcoin is very weak. As for the rest of the altcoins it is easier and has already happened on several currencies.

[Iriswolfgang 200]

On 12/21/2019 at 6:05 PM, Crypto123 said:

The 51% attack:
It is an attack on a blockchain designated by a group or organization of miners to try to control more than 50% of the hash rate or the computing power of the network.

Dual spending:
A type of attack on the bitcoin network. so that it can be defined as the spend of Bitcoin several times
 This would be by sending a certain value to two wallets at the same time, the first is the victim's wallet and the second is the hacker wallet, and this attack needs a large hash force from mining

What is the risk of attack 51%:
If this attack occurs, attackers will prevent new transactions from obtaining assurances, they can stop payments or transactions between most users.
They will also can reverse completed transactions and this means that they can do double spend.
By controlling most of the computing power on the network, they can interfere with the process of registering new blocks. Then prevent the other miners from completing the blocks, which in theory They take over mining new bitcoin blocks and earn all the rewards.

Thank you for this information and I think that this will help so many people here in cryptocurrency because they will be now be wary about the 51 attack which might target them if they are not cautious they could be targeted by the attackers

[BTC Future 3946]

On 6/14/2020 at 4:48 AM, malik6314193 said:

I don't know about that but thanks for sharing this useful information with us. It's mean that they can hack crypto easily. But how now it is very hard to hack crypto specially bitcoin. 

Not actually easily, but some coins have really low requirements. Bitcoin can't be hacked as the power required to amass is not something that is available. Bitcoin is being mined in thousands of different locations and miners use warehouses full of special equipment called ASICs to produce as much hashrate as possible. It is not possible for anyone to make a successful 51% attack on Bitcoin.