All Questions
Tagged with majority-attack proof-of-work
11 questions
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Why does an attacker need 51% mining power to overtake the blockchain?
I am really struggling to understand this thing about the 51% attack.
Usually whoever mines a block first wins.
My understanding is that mining is like a race. In a race, an athlete does not need to ...
0
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1
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112
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Potential fork from genesis block using enormous computational power
51% attacks are commonly discussed where one entity could potentially mine blocks ahead of the network. The assumption is that the attacker manages to acquire 51% of computational power.
However, ...
- 279
2
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1
answer
516
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51% attack, miners, nodes or both
If 51% of the hashrate was controlled by bad actors mining invalid blocks, this would become the longest chain. Where do nodes come into the 51% attack? The canonical chain is the longest chain. Is ...
- 193
1
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2
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447
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Why can't a 51% attack change past blocks on the blockchain?
I have read that it is not possible to reverse transactions already added to the blockchain but I do not understand why that is not possible in a 51% attack.
If an attacker was to change the ...
- 11
0
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2
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109
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Incentive for miners to keep mining once reward get very low [duplicate]
Currently each winning miner receive 12.5 bitcoin or 12.5*10 000 dollar per successfully mined block and the amount of bitcoin receive is divided by 2 approximately each 4 years.
The incentive to ...
- 2,820
2
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1
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99
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On a low level, how are long chains kept secret and later broadcast during 51% attacks?
I've been reading about the vulnerabilities of PoW crypto, and there's a part of it that I don't understand.
Suppose I wanted to stage a 51% attack on Bitcoin (not really feasible, but bear with me). ...
- 123
4
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1
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146
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POW based blockchains systems Majority Attack
TL;DR: With only 30% of network power a Majority Attack is possible and profitable. Am I missing anything?
Generally speaking, blockchains based on Proof-of-Work authentications are using amount of ...
0xasker
6
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2
answers
1k
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51% attack and rewriting to the latest checkpoint
This is not a question about the consequence of a 51% on the price nor as to the motivation of the attacker. Let say we don't care that it's not realistic and we don't care that the attacker wouldn't ...
- 316
1
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351
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Why don't the miners just take profit from our coins and make the coin worthless?
You own a very valuable thing and you want to go to holiday without it, but there is nobody who you trust and who can look after the thing. So you take somebody unknown to guard it. You pay him a fee ...
user65934
4
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3
answers
399
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Egoistic miners combined with large transactions destroy PoW?
EDIT
There is a clearer description of some parts of the problem in the link questions.
If there is a transaction value much higher than the payment for mining 10 new blocks, how can you trust this ...
user65934
4
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1k
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Why does an adversary have to control 50% of the computing power to double spend?
If transactions in a block are valid, in order to add that block in the block chain, a proof of work needs to be found. I have read the bitcoin paper by Satoshi.
If the difficulty of the proof of ...
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