Questions tagged [majority-attack]
A majority attack, or 51% attack, is an attempt at solo-mining a longer chain to outpace the main chain.
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51% attack - apparently very easy? refering to CZ's "rollback btc chain" - How to make sure such corruptible scenario can never happen so easily?
I was shocked to see binance CZ comment to literally "roll back" the bitcoin chain by just "calling" in some favors from "friendly" Asian miners .
This ONE person could effectively do it??? I mean ...
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Can selfish mining work with a leaky pool?
I'm trying to work through an attack scenario (say 20 years in the future when block rewards and fees may be more comparable). A miner with say 10% of the hashrate would like invite others to help ...
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the client's 'invalidateblock' debugging command - possible prevention against majority attack?
there is a 'invalidateblock' debugging command in the btc client. How can this command be used in a situation of majority attack threat and play a part of countering the attack?
I understand that ...
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Can a 51% attack be triggered by any other of these 7 strategies? (and with a quantum computer?)
(I think this question will be blocked for being not specific, so help me edit it, thanks)
(I will present Facts [1] and Facts [2] which will help organize my ideas before my question)
Facts [1]: (the ...
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How could pool-resistant mining change the censorship resistance of Bitcoin?
Researching mining centralization in Bitcoin, I came across Wownero's solo-mining only pool resistance. There do not seem to exist any pool
mining Wownero as shown in miningpoolstats.stream.
Let us ...
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How can an external party be sure that node's response is valid?
Assume that 51% of nodes are honest and 49% malicious. Fur sure, longest chain would make the chains consistent/same all over the world as 51% can outweigh the 49%, but my question is slightly ...
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Attack vectors for difficulty retargeting with BCH and BTC?
Since the existence of BCH, miners can now switch chains to mine on. Assuming they mine greedily based on price and difficulty. Can the following attack happen and how could it be mitigated:
Assuming ...
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What do we mean by honest nodes?
In his recent paper, Vitalik often mentions the term "honest nodes". What do we mean by that exactly?
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How does the network protect itself against attacks where one miner with a lot of hashing power lies that it takes 10 minutes to create a block?
Assume some very "strong" miner that can produce a new block (find a correct nonce) on average every 3 minutes. Everything is fine as long as he sets the right timestamp (the one ...
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Could the Bitcoin network freeze someone's assets?
Strictly as an example, let's say some businessman owns a lot of Bitcoin, and he makes a disparaging comment online about a certain country that happens to have the majority of Bitcoin miners.
Could ...
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Can the two biggest bitcoin mining pools lock out all others?
I just noticed that the two biggest bitcoin mining pools already have more than 52.5% of the hashing power (as of 11/12/23 Foundry USA had 27,7% and AntPool 24.88%) and am wondering about the ...
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Is "fee higher than block reward" attack possible?
Imagine the following scenario:
I send you 1000 BTC.
After 6 confirmations, you give me what I bought.
I create another transaction with 900 BTC to my own wallet and 100 BTC as transaction fee, using ...
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How can Forks and Orphan Blocks be used to attack a Blockchain?
So I'm trying to learn about the security aspects of Blockchains and one of the papers I'm reading (https://arxiv.org/pdf/1904.03487.pdf) states that Forks and Orphaned Blocks can be used to attack a ...
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Can a 'China' or similar actor with more than half of the hash power really destroy Bitcoin?
More of a general question as I've recently gotten into investing in cryptocurrencies. I really love the vision for the future this technology provides, the freedom, ease of use, lack of middlemen, ...
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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, ...
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What can an attacker with 51% of hash power do?
Suppose organization X has 51% of the hash power for a period of 1 week. In this week, what exactly can and can't X do?
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Attack the network by having 51% of full nodes?
Tell me if I'm missing something here:
If a government recognised that an adversery of theirs had a lot of bitcoin reserves, couldn't they just 'crash' the bitcoin network by spinning up enough full ...
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Bitcoin Mining Pools Centralization
I read a couple of articles and watched some YouTube videos, but couldn't find a super convincing argument for why centralized mining pools are not a huge issue. I get that from a Game Theory ...
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Can miners single handedly perform 51 attack toward the network?
Is this true that miners alone cannot do 51 attack even one or a group of miners posses >51% of hashrate of the network?
As far as I know, every block should be accepted by nodes to be added to the ...
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Couldn't Microsoft execute 51% attack?
There are billions of computers out there running Windows O.S., putting aside the reputation risks, technically, Microsoft could add a backdoor to force users hardware to mine BTC.
Is the combined ...
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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 ...
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Could a government or company run thousands of unique nodes?
Let’s say you’re a tech giant or control a tech giant.
So you have access to money, computers & thousands of unique ip addresses.
Could these giants spin up so many unique nodes that they could ...
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Is Bitcoin still uncontrolled with all those mining pools?
It is always stated that Bitcoin is uncontrolled and it does not make sense to cheat and double-spend because you will need more computing power than everyone else combined. Isn't that changed with ...
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Can someone with majority hashing power decide what transactions are included in my block?
I read this paragraph about if a mining pool controls the majority of the hashrate on the network:
Blocking Transactions:
Anyone who controls the majority of the hashing power can decide which
...
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Is it practical to prevent a 51%-attack by having a second mining algorithm?
While miners use special hardware designed to perform only one job (e.g. calculating sha256) changing that job would make all that hardware useless. So, can the bitcoin community use this ...
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If the longest chain is considered the valid blockchain by nodes, what happens if a future supercomputer alters the entire blockchain?
Let's say that the computational power from the genesis block to the current block becomes a trivial computation in the future by some supercomputer using a new technology exclusive to it. Perhaps ...
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51% attack on a small network of nodes?
Not all the nodes in the bitcoin network are connected. So that means the computational power required to attack a smaller network would be comparatively easier.
So, say we start a 51% attack on a ...
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Why does Bitcoin no longer have checkpoints?
I've read that checkpoints in Bitcoin were removed because they were not preventing any meaningful attack.
Why should a regular checkpoint not prevent majority attacks? For instance, if a checkpoint ...
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Why wouldn't a state level actor be able to centralize Bitcoin?
I was reading this question:
What can an attacker with 51% of hash power do?
According to that, the 3 "powers" obtained through controlling 51% or more would be:
Reverse transactions that ...
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Do nodes receive information from which they can discern how long a miner has withheld publishing a block from the time it found it?
In a recently Medium article, Joe Kelly described an attack that he calls "Monopoly Mining" in which a state actor or some other very well resourced party that obtains majority hashpower ...
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Bitcoin 51% majority miner attack - question on the role of user activated soft forks as defense tactic
If one mining entity has alone 52% hash power of the overall network, then this party can block transactions for example and try to "build" up a forked, longer chain while time passes, right?. As I ...
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Can the 51% attack be made to become 81% attack or 91% attack?
Since the 51% attack happens if there are more than 50% of nodes that fake the data on the blockchain, can it be actually 81% or 91% that is needed to fake the data, because it would be much harder if ...
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Could miners create a cartel to raise transaction fees?
Could miners with enough mining powers (say >95% of all blocks) form a cartel where they demand absurdly high transaction fees? Of course, I still could could hope for a miner not in that cartel to ...
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51% attack inevitable [closed]
I think the assumption of a 51% attack is not worth the effort is wrong. Eventually the price of Bitcoin will stabilize. Let’s say at 1 million USD then a diminishing block reward and the transaction ...
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Noob question: Why is there not a limit of the number of blocks in a chain revision?
I have a noob idea and I want to understand where I'm going wrong :)
Say nodes agreed on a block revision limit, say, 6. This would mean that if they see an incoming chain that is longer than the ...
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Can a 51% attacker earn mining rewards on the blocks they tampered with?
This article gives an example of a 51% attack in theory as:
In a 51% attack the hacker will typically mine in private to attain a
longer chain than the publicly seen chain in hopes of double-spending
...
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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 ...
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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 ...
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How does the bitcoin core protect against initial DNS seed changes?
While the bitcoin network is essentially P2P, one still needs to identify an initial node to connect to. I understand that a method for such initial connections is connecting to known DNS seeds, e.g ...
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Is there any software available for testing of Bitcoin security?
I'm currently in the process of working on my thesis about Bitcoin security and I'm wondering if there's any software available for testing of Bitcoin security? For example, are there any programs ...
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Miners forego revenue in order to 51% attack the Bitcoin protocol by rejecting blocks
I was recently listening to Mike Green and Anthony Pompliano debate the future of Bitcoin on RealVision. And Mike raised an interesting point regarding Bitcoin (I'm paraphrasing). "Scenario: Let'...
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Did Satoshi Nakamoto (in his blogs or the whitepaper) forecast that mining pools would exist?
Mining pools are common today where users pool their resources together and share profits accordingly. Such pools today can account for significant proportions of a network's hash power and they're ...
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How exactly are Bitcoin's consensus rules enforced?
There are some rules called consensus rules, for example the block generation amount.
And it is said that "a change to consensus rules is a hard-fork".
But how exactly are the consensus ...
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What will happen on creating a transaction with negative amount?
Bitcoin in short is a public ledger guided by consensus of its nodes.
In theory, if there is no validation of transaction amount, if we were to create a transaction with negative amount, that would ...
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What are the benefit of mining an empty block
Something peculiar just happened on the newly mined block number 655534, it contain only the coinbase transaction, nothing else.
I have searched for a similar question but only found this one Why ...
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Attacker Changing Address to Receive Block Reward [duplicate]
A miner creates a block B which contains address α, on which he wants to receive his rewards. An attacker changes block B, such that instead of α it defines a new address α’, which is controlled by ...
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Two threats to Bitcoin: Quantum Computing and Mining farm seizures - what new BIPs are needed before it is too late? [closed]
How resistant is bitcoin blockchain against physical attacks? Contrary to other consensus mechanisms, Bitcoin's PoW model is dependent on massive Mining Farms with tons of ASIIC hardware. These farms ...
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Why would more confirmations help in a 51% attack scenario?
After the 51% attack on Bitcoin Gold. The developers of the cryptocurrency recommended the exchanges to increase the confirmations. I don't understand why increasing the confirmations would help if ...
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How does longest chain propagation take place in bitcoin?
Let's say the valid blockchain that Node A has is: B1->B2->B3
Now, I am gonna cheat since I have lots of computing power. What I do is I download the above blockchain that Node A has and start ...
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Reversing network hashpower
I'm reading this article by Vitalik Buterin on Problems in Cryptocurrency and don't quite understand what this means:
Ideally, after some number of blocks (perhaps logarithmic in the total size of ...
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