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

[Crypto123 0]

22 minutes ago, thuongbeng123 said:

A 51% attack is a form of attack that can be performed on the Bitcoin system or other blockchain systems, in which an individual or organization has control over the majority of the hash rates from there. for network interruption. In other words, the 51% attacker possesses sufficient computational power to intentionally alter the order or eliminate transactions.
  Dual spending is money in two parts

Your definition of an attack is 51% correct. As for the definition of double spending, it is incorrect with an apology from you, because double spending is to send or spend the transaction twice for the same person and it is related to an attack of 51%, as whoever has 51% of the network’s power can spend the same transaction twice, which is called By double spending.

[Muskan7816 175]

In words, 51% of attackers possess sufficient strength to deliberately change orders or exclude transactions. Dual Spending The two-part money attack is a series of attacks that can be done on Bitcoin systems or other blockchain systems

[Akasshh 234]

A 51% attack refers to an attack on a blockchain. Double-spending is the risk that a digital currency can be spent twice with digital currencies ,there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original.A double spending attack is a potential attack against cryptocurrency that has happened to several cryptocurrency ,eg- due to the 51% attack.

[Crypto123 0]

1 hour ago, Rieyaz 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.

I think you quote others only without adding any additional information from you? This is against forum rules and you may get a warning point for this reason. So please write well and avoid violating the forum rules.

[fuer44 1083]

Has this case happened before? there is something to be asked about this theory. Did the hacker stop the transaction or cancel (prevent) the existence of new blocks for other miners, it happened before the victim did or after the victim did it so there was confirmation? or it did not confirm once, meaning that the transaction that had already occurred finally never arrived, even though according to the system it had been confirmed?

 

in my opinion this is even more dangerous than hacker exchangers, because this hacker immediately took over the blockchain and could hurt many parties.

[Crypto123 0]

1 hour ago, fuer44 said:

Has this case happened before? there is something to be asked about this theory. Did the hacker stop the transaction or cancel (prevent) the existence of new blocks for other miners, it happened before the victim did or after the victim did it so there was confirmation? or it did not confirm once, meaning that the transaction that had already occurred finally never arrived, even though according to the system it had been confirmed?

 

in my opinion this is even more dangerous than hacker exchangers, because this hacker immediately took over the blockchain and could hurt many parties.

Yes, this attack happened several times before and here are some cases:

June 2013: Feathercoin (FTC) attacked for ~ $ 1,400.
April 2018: Electroneum (ETN) attacked for unknown losses.
April 2018: Verge (XVG) attacked for a loss of ~ $ 1.1 Million.
May 2018: Verge (XVG) attacked again for a loss of ~ $ 1.75 Million.
May 2018: Bitcoin Gold (BTG) attacked for a loss of ~ $ 18 Million.
June 2018: ZenCash (ZEN) attacked for a loss of ~ $ 550,000.
December 2018: Vertcoin (VTC) attacked for a loss of ~ $ 100,000.
January 2019: Ethereum Classic attacked for a loss of ~ $ 1.1 Million.

 

Source: https://komodoplatform.com/51-attack-how-komodo-can-help-prevent-one/

 

[Crypto123 0]

1 hour ago, Ahmadu12 said:

You gave skillful in rank about less significant exact first-class for individuals who are liability that.but mining is fantastically dear and essential a grouping funds of investment and not for little investors.

Thank you, dear, for describing these kind words, I try as much as possible to provide useful and good information and present it in a simple way so that everyone understands it and there is the most benefit in the forum.

[khan22 3478]

The 51% attack is the attack on the blockchain and so many time the hackers will attack on the Blockchain but they are fail and they are not do this to hack the BTC or other coins from the blockchain and they have good security.

[Crypto123 0]

1 hour ago, khan22 said:

The 51% attack is the attack on the blockchain and so many time the hackers will attack on the Blockchain but they are fail and they are not do this to hack the BTC or other coins from the blockchain and they have good security.

They have not yet succeeded with bitcoin, but they have succeeded with other currencies such as BTG, ETC, ETN and others as well. 51% attack on these currencies has been carried out and millions of dollars have been stolen in the past two years.

[Crypto123 0]

32 minutes ago, thangvn00lc said:

The 51% attack (51% Attack) is known as an attack on the Blockchain system in the cryptocurrency market. This attack is performed by a group of miners who use control of more than 50% of the network's mining power.
 

You and several other people have quote these words and write them as they are without changing and without reference to the source, this is shameful and contrary to the rules of the forum, please stay away from transcription and such violations that cause harm to you and the forum.

[Crypto123 0]

3 hours ago, Fahad Ali said:

Thanks for sharing this information article i was not aware of these things but this article is very useful and informative for me your platform is really great platform to learn more and new things about crypto

There is no need to thank my friend, this is our duty here in this forum to provide useful information and exchange opinions, ideas and experiences so that the benefit prevails to all members and the forum, I hope everyone thinks about providing the things that benefit the forum and members.

[Crypto123 0]

3 hours ago, HorbiDJ1 said:

No one is immune from such attacks. Many are mistaken, especially those who only introduce cryptocurrency. But you must be careful with yourself and your investments.

Yes, no one is immune to these attacks, a 15% attack has already occurred many times before on several coins and the attackers have stolen millions of dollars so strong protection and encryption methods must be followed to prevent such attacks.

[lifelline1262 15]

This is absolutely very bad for the blockchain, and I hope that they are not existence now, because the blockchain will be in trouble

[Crypto123 0]

1 hour ago, jitu123321 said:

Great ! the post you created has full of information actually it helps me i forgot the terms and there defination of of all these term and the prcatical 51% i have been faced on XVG coin's blockchain in 2017 during crypto boom

Thank you, in fact, I always try to write topics that are useful, simple and easy to understand so that most members of the forum can understand them and the benefit is general to everyone. The example you gave about "51%  have been faced on XVG coin's blockchain in 2017" is correct and it is a 51% attack.

[babaji 1228]

That is real nice explanation of 51% attack, and that is what we need to discuss, topics that deal with crypto. 51% attack has been instrumental in disturbing the workings of lot of exchanges. I read a few months ago Bitcoin Gold was recipient of 51% attack and 72000$ were used in double spent. All of us should be aware of 51% and work to avoid it. 

[Crypto123 0]

6 hours ago, Gidakwano said:

you gave high-quality in sequence about insignificant identical fine for individuals who are burden that.but mining is extremely exclusive and requisite a fortune currency of investment and not for slight investors.
 

I didn't quite understand what you want to say, but we are talking here about a 51% attack, which is an attack that some groups of people use a large mining force to control currency conversions and then do the so-called dual spending, i.e. sending the same currency twice.

[Crypto123 0]

On 3/6/2020 at 3:36 AM, Foridul22 said:

They try to ‘double spend them, hence the name. The goal of this isn’t always to double spend crypto’s, but more often to cast discredit over a certain crypto or blockchain by affecting its integrity. But the block chain is becoming more hard to be hacked.

 

Yes, it has become more difficult to hacked, but nevertheless this inevitability still exists. There are coins other than Bitcoin. The difficulty is not great and therefore 51% attack on it will be much easier as it happened in the attack on the ETC coin.

[Crypto123 0]

2 hours ago, jekichchan said:

51%? This is just an unrealistic number, what farms should be in order to control most of the hash power. It’s almost impossible to have such an amount of interest. After all, there are a lot of miners in the world.

No my friend this number is 51% realistic and this attack has already happened before on several networks such as ETC and other currencies, there are many mining companies able to reach this number and more. Also, new quantum computers may be able to reach this number on their own.

[Karani 99]

Note that the 51% attack remains theoretical. Some of the ways to counter it include increasing blockchain security and controlling mining pool sizes.

[Crypto123 0]

10 minutes ago, Rezoan91 said:

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

Yes, the main risk from an attack of 51% is double spending. If attackers manage to penetrate the network by attacking 51%, they will be able to spend a single transaction twice. Each transaction needs to be confirmed by 50% of miners to be accepted.

[Crypto123 0]

14 hours ago, vekll5 said:

The 51% attack, also known as the 51% attack, refers to an attack on blockchain, in which such an attack is still a hypothesis - because a group of operators controls more than 50% of the function. amount of network mining, or computing power.

Not just a hypothesis, dear, I mentioned before that a 51% attack happened several times before on several coins and the most famous was the ETC coin. There are other currencies, too, that have been attacked and stolen millions of dollars. You can review the topic to see the links.

[iloveyobit 6599]

I did not know this before, thank you for the useful information, but what is the degree of protection of the blockchain from this attack, can this hack be implemented simply?

[Efs 164]

Recently there were 51 attacks on the ethereum classic coin. a very risky event the money in your wallet can disappear at once. nothing is guaranteed

[nickoman987 1040]

How is it possible to carry out such an attack? After all, no one can hold 51% in the same hands. Only some simply unrealistic miner who has more plants than the fair. It’s unrealistic just ...

[Crypto123 0]

24 minutes ago, Arati123321 said:

In 51% attack a hacker can control full mining power by hacking attack and this kind of attack was seen on the xvg coin last in the 2017 whicj is get controlled by team

It is not controlling the mining force but controlling the network transactions, where the transaction needs to confirm half of the mining force on the network so the attacker can make these required assurances and do double spending.