If Monero Can Suffer 50% Hashrate Risk, Why Can't Bitcoin?

[Quantum_Resolve7987V]

If Monero Can Suffer 50% Hashrate Risk, Why Can't Bitcoin? (And Can LoyceV Save Us?)

Kraken just paused Monero (XMR) deposits after a single mining pool crossed 50% of the network's hashrate (source). This isn't just a "theoretical" 51% attack risk - it's actually happening to a top-tier privacy coin.

So let's ask the uncomfortable question: Could Bitcoin face the same? And if so, would exchanges freeze BTC deposits, grinding everything to a halt?

• Mining centralization is real. Foundry + Antpool already control ~50% of Bitcoin's hashrate. It's just expensive to attack - not impossible.
• Exchanges act first, ask later. Kraken didn't wait for an attack - they froze XMR at the first whiff of risk. Imagine this applied to BTC: chaos.
• The "LoyceV Factor." Maybe the hero we need isn't a miner, but a guy fighting for 0.1 sat/vbyte transactions (thread). If we're all forced to use ultra-low fees during a hashrate crisis, at least Loyce's Electrum server will keep the mempool moving.

Debate Time

• "But Bitcoin has more hashpower!" Sure - but cost ≠ impossibility. A well-funded adversary (cough nation-state cough) could try.
• Would Proof-of-Stake fix this? Or just replace mining barons with staking cartels?
• Should exchanges decide network integrity? Kraken just set a precedent.

☆ Bottom line: XMR's crisis is a stress test for every PoW coin. And if Bitcoin faces a similar scenario, we'll need more than just hopium - we'll need decentralized fallbacks (and maybe LoyceV's low-fee infra). ☆

P.S. LoyceV - if you're reading this, please prioritize your Electrum server over sleep. Bitcoin might need it sooner than we think.

[asriloni]

Bitcoin could, but the problem is whether the attacker can have double digits billion of money to maintain their attack. Even did 51% attack to the Monero could cost double digits of millions in a day.

Impossible to expect there will be a party that can do 51% to the Bitcoin these days. It's only in your imagination.

[Hispo]

Bitcoin could, but the problem is whether the attacker can have double digits billion of money to maintain their attack. Even did 51% attack to the Monero could cost double digits of millions in a day.

Impossible to expect there will be a party that can do 51% to the Bitcoin these days. It's only in your imagination.

I am not very up-to-date with the theory, but... What if the attacker was the owner of the mining pool itself? Does it theorically means the owner of the pool could effectively carry out the attack at a very low cost? Also, they could do such a think without the participants of the pool to be aware of it.
Anyways, for now miners have been very aware of the centralization problems which exist because of pools, so they have stayed away from those who have been dangerously close from 51% percent of hash rate, to move to poll with least hash rate accumulated.

[BitHodlers]

Next time use your brain instead of asking a hallucinating AI for an answer.

Bitcoin could, but the problem is whether the attacker can have double digits billion of money to maintain their attack. Even did 51% attack to the Monero could cost double digits of millions in a day.

Impossible to expect there will be a party that can do 51% to the Bitcoin these days. It's only in your imagination.

There is no way that someone can set up such a massive operation without being detected ahead of time and getting arrested shortly. What people don't understand is that doing a 51% attack is illegal.

I am not very up-to-date with the theory, but... What if the attacker was the owner of the mining pool itself? Does it theorically means the owner of the pool could effectively carry out the attack at a very low cost? Also, they could do such a think without the participants of the pool to be aware of it.

Nobody is stupid enough to nuke a gold mine over proving a point or stealing small amounts of money relatively speaking. The danger of a 51% attack is overblown. You could perhaps revert some transactions and as soon as you do it your operation and you are done for. The Bitcoin blockchain resumes as normal and you get some nice visitors.  

[mrust_mobile]

The hash-attack on monero was never real as far as I know. It was just a bug. Some pool figured out a way to fake its hash-rate that's all. Looks like some exchanges got fooled by it.

[JeromeTash]

OP, you might want to do further research before you just start spread false narratives and speculation because it looks like you are easily excitable

Here, let me help you out with a few links
1. https://www.reddit.com/r/Monero/comments/1mod130/psa_qubic_is_lying_they_dont_have_50_hash_rate/
2. https://shai-deshe.gitbook.io/parallel-thoughts/proof-of-work/the-qubic-minority-report
3. https://x.com/BitMEXResearch/status/1955254320305217726
4. https://www.reddit.com/r/Monero/comments/1ms7oe4/qubic_assault_on_xmr_monero_was_not_a_51_attack/

So before we even jump into the Bitcoin debate, get your facts right.

[BitHodlers]

The hash-attack on monero was never real as far as I know. It was just a bug. Some pool figured out a way to fake its hash-rate that's all. Looks like some exchanges got fooled by it.

Many people fall for this kind of FUD, I think there is some serious monero FUD around every cycle. Never did anything serious materialize.

[nelson4lov]

Moreno is a relatively small network that one can easily manipulate to gain 51% of network hash rate. This would've been possible on bitcoin as well but ONLY in the early days. At that time, the price was dirt cheap and mining was even more cheaper to come by so a well positioned entity could have done it. You people underestimate the cost it would take to gain 51%of Bitcoin's network. Bitcoin isn't Monero. Try taking your fud elsewhere.

[TastyChillySauce00]

Different scale of hashrate, different difficulty, just because both uses PoW doesn't mean bitcoin is as vulnerable as Monero.
You should observe more about the current bitcoin's hashrate distribution. It's entirely different thing and honestly, to do 51% attack on bitcoin would take significantly much much more the resources needed to attack monero.

[Quantum_Resolve7987V]

OP, you might want to do further research before you just start spread false narratives…

Thanks for your response. I respect that you linked some sources, but I’ll stick with the ones that convinced me otherwise:  

1. Kraken halts Monero deposits, citing Qubic seizing 51% hashrate  
2. Cryptodnes: Kraken suspends Monero deposits after 51% attack linked to Qubic Pool  

For me, the fact that a major exchange like Kraken reacted the way it did is enough to take the 51% narrative seriously.  

And regarding LoyceV — I know he didn’t bother to reply directly, since he agreed with your post and simply merited it as a “carbon copy” of his thoughts. That’s fine, but I’ll admit I’m curious: what does it take to earn a merit from Loyce himself? 🙂

[FinneysTrueVision]

The hash-attack on monero was never real as far as I know. It was just a bug. Some pool figured out a way to fake its hash-rate that's all. Looks like some exchanges got fooled by it.

Fake hashrate wouldn’t explain the six block reorg. Although they didn’t have 51%, like some media organizations with low journalistic standards might have claimed, they did have enough to cause some serious disruption for a short while.

It’s not impossible to do a similar attack on Bitcoin, but having millions of ASICs securing the network makes it more resilient against external bad actors who can’t just acquire such a significant share of hashpower overnight. In theory, a big pool like Foundry, might be able to do this kind of attack, but in practical terms it would be very difficult because individual miners would defect to other pools and the financial damage would be devastating. It would be counterproductive and illogical to attack the network that your multi-billion dollar business relies upon.

[pooya87]

So let's ask the uncomfortable question: Could Bitcoin face the same? And if so, would exchanges freeze BTC deposits, grinding everything to a halt?

The nature of Proof of Work is in a way that 51% attack is a real attack vector but it depends on a big "if". IF one entity can gain control of such a large hashrate they can theoretically carry out such an attack.

2 more things, you can't really compare any altcoins with bitcoin.
Also this already happened a long time ago in bitcoin as well. The mining pool was called GHash.io back in 2014 and it briefly gained more than 50% of the total hashrate (for real) and nothing was halted and nothing broke. The miners left that pool (switched to other pools) and its hashrate came down.

• Mining centralization is real. Foundry + Antpool already control ~50% of Bitcoin's hashrate. It's just expensive to attack - not impossible.

I haven't verified how much hashrate these pools control to verify your 50% claim but you are forgetting that FoundryUSA is a US based mining pool while Antpool is a Chinese based mining pool! That is not called centralization.
In fact this is the exact opposite since these pools are located in completely different jurisdictions.

A well-funded adversary (cough nation-state cough) could try.

And what would they gain by spending such a massive amount of their taxpayers money? Specially while they can "fight" bitcoin using much cheaper tactics like simply banning it!

• Would Proof-of-Stake fix this? Or just replace mining barons with staking cartels?

PoS is a broken algorithm that died as soon as it was invented (ie. ~2012). The only reason why it is still used by shitcoins is that it is a cheap way of getting a coin that has lost the community to stay alive.

• Should exchanges decide network integrity? Kraken just set a precedent.

They should not and they are not.

[UchihaSarada]

The nature of Proof of Work is in a way that 51% attack is a real attack vector but it depends on a big "if". IF one entity can gain control of such a large hashrate they can theoretically carry out such an attack.

2 more things, you can't really compare any altcoins with bitcoin.
Also this already happened a long time ago in bitcoin as well. The mining pool was called GHash.io back in 2014 and it briefly gained more than 50% of the total hashrate (for real) and nothing was halted and nothing broke. The miners left that pool (switched to other pools) and its hashrate came down.

Two big ifs are like

No entity owns enough dominant hashrates to do 51% attack on the network.
Another bigger if is, when an entity has that dominating hashrate and is able to do 51% attack on the network, will that entity do this?

The answer is clear.
After spending a lot of money for owning such dominating hashrate that can help to mine many Bitcoin blocks (in this example about Bitcoin blockchain and 51% attack on it), and get very good revenue for the mining business, why that entity need to attack the network with very unavoidable high risk that Bitcoin price will crash?

There is no need like this, and intelligent Bitcoin miners will never do this.
There were times with dominating mining pools like this but they did not make 51% attack and they surely had big reasons.
https://hal.archives-ouvertes.fr/hal-03610424/document
https://petra.isenberg.cc/publications/papers/Tovanich_2020_VAO.pdf

[Rgram]

The nature of Proof of Work is in a way that 51% attack is a real attack vector but it depends on a big "if". IF one entity can gain control of such a large hashrate they can theoretically carry out such an attack.

2 more things, you can't really compare any altcoins with bitcoin.
Also this already happened a long time ago in bitcoin as well. The mining pool was called GHash.io back in 2014 and it briefly gained more than 50% of the total hashrate (for real) and nothing was halted and nothing broke. The miners left that pool (switched to other pools) and its hashrate came down.

Two big ifs are like

No entity owns enough dominant hashrates to do 51% attack on the network.
Another bigger if is, when an entity has that dominating hashrate and is able to do 51% attack on the network, will that entity do this?

The network has grown so robust to allow for any entity to have that 51% hashrate and even in any eventuality like Pooya already exemplified from 2014, the likely scenario would be they did nothing with it and it only takes few minutes for this to happen. You’ll find miners switching other pools and not have the integrity of the network compromised.
These attacks also count as short term gains and mining though a rewarding activity, miners are more interested in the technology than these short term gains from attacks.

If Monero Can Suffer 50% Hashrate Risk, Why Can't Bitcoin? (And Can LoyceV Save Us?)

Kraken just paused Monero (XMR) deposits after a single mining pool crossed 50% of the network's hashrate (source). This isn't just a "theoretical" 51% attack risk - it's actually happening to a top-tier privacy coin.

Monero haven’t come by much sophistication as we have in Bitcoin and to compare any of the occurrences in Monero with Bitcoin is placing interest in the wrong places as, Bitcoin is more decentralized and has a stronger network than we can see or have in any altcoin.

[o48o]

There is no way that someone can set up such a massive operation without being detected ahead of time and getting arrested shortly. What people don't understand is that doing a 51% attack is illegal.
-cut-

Hold on, despite the fact that 3 mining pools already hold the 51% of the hash power and that they could easily coordinate it (it just wouldn't make any sense).

Explain to me how doing 51% attack is "illegal", because that sounds like BS to me. It's not hacking or cracking the system. It's nothing but having 51% of the hash power and using power of majority as they wish. Code is the law.

[Quantum_Resolve7987V]

Update - Monero (XMR) deposits have been re-enabled and now require 720 confirmations before crediting. 
Given the current uncertainty around the security of the Monero network due to major hash rate consolidation under a single entity, Kraken may halt deposits at any time and delay crediting at its discretion. 
Source: Kraken status page (Aug 18, 2025 - 04:30 UTC)

720 confirmations?! 😳 That sounds like forever! 

And yet… withdrawals are still allowed?? That’s wild. Seems crazy strict on deposits but somehow you can still send your XMR out. 

Honestly, the whole thing makes me wonder — if something like this happened to Bitcoin, the panic would be off the charts. 

[Mpamaegbu]

The hash-attack on monero was never real as far as I know. It was just a bug. Some pool figured out a way to fake its hash-rate that's all. Looks like some exchanges got fooled by it.

You concluded it was a bug but the Monero team knows better. It felt the grief of panic and anger while all that was going on. The dude behind Qubic, (Twitter handle – Come-from-Beyond @c__f__b), said what he wanted to do with Monero before embarking on it. So, it wasn't as if it wasn't planned ahead. CFB actually didn't mean to destroy Monero but to prove to the community what just played out. The Monero team would've lost it if it was an attack from the various writeups, the back and forth, that I read. Monero just got rattled. The same dude is now contemplating another challenge on Dogecoin.

I made a post on this similar issue a few days ago here.

[zeuner]

And yet… withdrawals are still allowed?? That’s wild. Seems crazy strict on deposits but somehow you can still send your XMR out.  

The withdrawers' own decision whether to take the risk or not...

[OgNasty]

Bitcoin could, but the problem is whether the attacker can have double digits billion of money to maintain their attack. Even did 51% attack to the Monero could cost double digits of millions in a day.

Impossible to expect there will be a party that can do 51% to the Bitcoin these days. It's only in your imagination.

I wouldn't say it is impossible, but expensive and unlikely to be profitable.  You'd have to be involved in scamming some pretty massive players for this to payoff.  Even then, I'd find it doubtful that you could get away with it.

The only reason I think we could see a 51% attack on Bitcoin is if someone is doing it for research purposes.  That seems like something the government would waste money on.  I could see them performing a successful 51% attack to discredit Bitcoin, seed doubt, or just prove it can be done.

[pooya87]

That seems like something the government would waste money on.  I could see them performing a successful 51% attack to discredit Bitcoin, seed doubt, or just prove it can be done.

But it won't discredit Bitcoin though, not for long term. It may cause some disruption in the market short term but won't be permanent. Not to mention the backlash since that would be a type of attack such a government can carry out only once. Kinda like the attack US regime carried out on Iran back in June, they could do it only once and since it failed the Iranian retaliation was very deadly for them.

If a government actually does this, first of all the mining pools that they'd use become discredited and all miners would abandon them for good. Secondly no miner would be willing to have their operation in that jurisdiction since that country would become a pariah in Bitcoin World...