Questions tagged [majority-attack]

A majority attack, or 51% attack, is an attempt at solo-mining a longer chain to outpace the main chain.

Filter by
Sorted by
Tagged with
1
vote
1answer
109 views

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 ...
0
votes
0answers
30 views

Pissing Attack / adversarial blocks attack

How do the ones of you familiar with the protocol and game theory suggest dealing with potential 'empty block attacks' (a majority of miners collaborate to slow down Bitcoin transactions by producing ...
2
votes
1answer
138 views

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 ...
0
votes
2answers
214 views

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'...
0
votes
3answers
75 views

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 ...
1
vote
2answers
107 views

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 ...
1
vote
1answer
79 views

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 ...
-1
votes
1answer
45 views

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 ...
1
vote
2answers
127 views

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 ...
1
vote
1answer
76 views

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 ...
1
vote
0answers
122 views

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 ...
0
votes
1answer
50 views

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 ...
1
vote
1answer
36 views

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 ...
1
vote
2answers
44 views

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 ...
2
votes
2answers
1k views

Why is a 51% attack guaranteed to outpace the rest of the network's miners? Doesn't 51% hashing power give only a slightly higher chance?

I thought hashing power is an expression of the probability of being the one to solve the cryptographic puzzle and placing a new block on the network. If that's true, owning 51% of the hashing power ...
0
votes
1answer
34 views

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 ...
0
votes
2answers
71 views

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 ...
0
votes
2answers
125 views

What are some potential scenarios that a state actor can harm bitcoin if they control more than 51% of the hashing power?

As reported recently, China controls more than 51% of the hashing power and just in one province in China controls 54%. Assuming China has bad intentions and forces all these mining operators to ...
2
votes
1answer
99 views

Can attackers change transactions during a 51% attack?

If in a 51% attack transactions can be reversed, isn't it possible that the chain with more hash rate also changes transactions (for example if x sent 5 btc to y, they would change it to x sent 500 ...
2
votes
1answer
131 views

transactions and 51% attack?

I have a very basic understanding of how the bitcoin blockchain works and am trying to understand how manipulating transactions in a 51% attack works. I just watched a video which stated 51% attacks ...
0
votes
1answer
88 views

Can collective mining pools refuse to recognize a mining block mined by a specific miner?

This is a continuation to the question: Can a bitcoin transaction from a specific bitcoin address be banned? (via mining pools). Suppose Satoshi Nakamoto sends bitcoins from one address to another, ...
0
votes
1answer
57 views

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 ...
3
votes
2answers
96 views

Can a bitcoin transaction from a specific bitcoin address be banned? (via mining pools)

Can a bitcoin transaction from a specific bitcoin address be banned? (via mining pools) Suppose Satoshi Nakamoto wants to send some bitcoin from one of his bitcoin address, can the mining pools ...
1
vote
1answer
58 views

Why one miner can dig out many blocks continually in one moment?

I am new to bitcoin and blockchain, I browed the website just now. There is a question confusing me, I find that one miner dig out blocks many times even in one hour. For example, this miner dig out ...
3
votes
3answers
105 views

Don't miners control who is allowed to make transactions?

Simple question really, considering theres a very small group of miners controlling the chain ATM. Whats to stop them from being forced by the goverment to disallow certain transactions or just mining ...
0
votes
2answers
98 views

Is the 51% attack the only technical reason no country will adopt Bitcoin as a state currency? [closed]

Is the 51% attack the only technical reason no country will adopt Bitcoin as a state currency? Lets suppose a country with GDP size less than 300 Billion USD adopt the Bitcoin as an official currency. ...
0
votes
2answers
105 views

Robustness of bitcoin

I am wondering about the consequences of a potential 51% CPU attack on the bitcoin blockchain. Imagine that a state invests enough computational power to rewrite from scratch an entire blockchain, ...
0
votes
2answers
102 views

What are the chances bitcoin big mining pools to unite and do 51% attack?

Looking at this bitcoin hash rate distribution chart (https://www.blockchain.com/en/pools), it only takes 3-4 mining pools to unite and do a 51% attack. With this possibility, how can people still ...
21
votes
6answers
7k views

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 ...
-1
votes
1answer
53 views

If there are 20 nodes in network and all are receiving transaction and after 10 min

Question 1) If there are 20 nodes in network and all are receiving transaction and after 10 min all will pick transaction from their transaction pool and start creating block, now will all nodes will ...
0
votes
0answers
42 views

Is 10K full nodes enough to bitcoin to avoid 51% attack?

As I know bitcoin has about 10K full nodes. And the question is in my mind is that: This number is not huge! If someone has 6K servers, Can control the bitcoin via 51% attack? I was thinking if ...
0
votes
1answer
40 views

51% attack + ignore blocks not mined by yourself [duplicate]

If you own 51% of the mining power and decide to ignore all blocks not mined by yourself. You would eventually end up having the longest chain, and would eat up the 49% of block-reward you werent ...
-1
votes
1answer
105 views

How to do a 51% attack on my own altcoin [closed]

recently I have been curious about 51% attacks so I created a fork of litecoin and want to do a 51% attack on the coin but don't know how to. please can you tell me how to do it. Thanks,
1
vote
1answer
48 views

How do I know that the majority of bitcoin miners are not XYZ government's facilities? [closed]

Even if "Satoshi Nakamoto" is/was actually a real person, how can I be sure that XYZ government (XYZ can be US, or China, or ...) does not have now (or will not have in the future) 51% of the hashing ...
0
votes
1answer
82 views

Do you really need more than 50% mining power in order to attack Bitcoin blockchain?

My question is about concept, so code is not related, however, do you really need 51% of the mining power in order to attack/replace the real bitcoin Blockchain? For example, a blockchain has a ...
1
vote
1answer
72 views

double spend attack: Is this actually true for the more time progress the higher the probability of success for attacker

I'm new here. I have a question here. Some experts keep saying that this assumption isn't formally correct and I don't really understand why or why they might be wrong. In the double spend attack; ...
0
votes
1answer
62 views

Is a 51% attack on bitcoin likely?

Given that the majority of bitcoin processing is done in China (source: https://bitcoinmagazine.com/articles/report-links-74-bitcoin-mining-china-sees-threat-network/), is it possible for a single ...
3
votes
1answer
175 views

Bitcoin is attacked by China miners by screwing with the network, what will Bitcoin do?

There was a report recently (https://arxiv.org/pdf/1810.02466.pdf) that stated that China controls 74% of the hashing power. They can choose to collude and attack the network by either doing a 51% ...
0
votes
2answers
694 views

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?
-1
votes
1answer
109 views

Other people mining my coin without my permission, how to avoid this? [closed]

I have created an altcoin and i wanted to solo mine all coins myself. I disabled generate function in wallet, hidden the source code as private in github. I run one main node and i mine in my laptop. ...
2
votes
1answer
246 views

Is there a limit to how many blocks can be rolled back from a 51% attack?

I was wondering if we where to ever face a 51% attack is there some sort of limit as to when the longest chain doesn't matter? For example if I owned 51%+ of the network, mined 1000 blocks privately ...
0
votes
1answer
19 views

Are smalltime block chains susceptible to brute force liars?

My understanding is that the integrity of the bitcoin block chain is dependent on the consensus of the masses - that no single actor can write entries at will unless they. controlled over 50% of the ...
15
votes
2answers
5k views

Why do we call it a 51% attack instead of a 50% attack?

From the Bitcoin paper: p = probability an honest node finds the next block q = probability the attacker finds the next block qz = probability the attacker will ever catch up from z blocks behind qz ...
3
votes
1answer
77 views

Why is it more profitable for a node with more than 51% computation power to abide by the rules in the bitcoin network

The Bitcoin whitepaper states - "The incentive may help encourage nodes to stay honest. If a greedy attacker is able to assemble more CPU power than all the honest nodes, he would have to choose ...
1
vote
1answer
55 views

How prevalent are coin attacks with botique altcoins?

I have deployed several altcoins using various PoW algorithms on my LAN for my buddies and I to mine/learn from. We ultimately want to go the distance of deploying an altcoin to the world, writing the ...
2
votes
1answer
65 views

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). ...
2
votes
2answers
137 views

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 ...
0
votes
2answers
87 views

Why can a 51% attacker not change the block reward?

It is said that in the case of an attacker having a sustained 51% power, the attack still cannot change the block reward. Why? My naive understanding is that, since consensus is controlled by the ...
9
votes
1answer
1k views

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 ...
3
votes
2answers
218 views

Is possible to destroy the Bitcoin for just $500K? (51% attack)

Everytime I read about the 51% attack the answer was something like: is really expensive to get 51% of power on BTC and nobody will invest so much so to destroy the bitcoin. But I found this site ...