51% Attack

[Euro1000]

Following scenario: A government would like to destroy Bitcoin. It buys a significant number of ASICs to build up a huge mining farm and carries out a 51% attack.
From my point of view it will not be so easy to buy so many ASICs as once - what do you think?
Another question: Will it be noticed (how?) that somebody buys a big stack of ASICs and/or are we able to identify such a behavior monitoring the network's hashrate?

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[darosior]

Hi,

Following scenario: A government would like to destroy Bitcoin. It buys a significant number of ASICs to build up a huge mining farm and carries out a 51% attack.
From my point of view it will not be so easy to buy so many ASICs as once - what do you think?

Absolutely, that's usually the first argument I make when discussing 51%. Is there enough hashrate available so that it surpasses all the hashrate allocated to Bitcoin ? If so, why not mine Bitcoin ?
Even if it's for trying to hurt, a one (or two?) block(s) reorg won't affect the network that much (if not at all, for one block). Trying to reorg >2 block becomes really difficult..

Another question: Will it be noticed (how?) that somebody buys a big stack of ASICs and/or are we able to identify such a behavior monitoring the network's hashrate?

If the aim is to 51%, then the hashrate won't be allocated to the Bitcoin network. So, no, not by monitoring the hashrate.

[d.kevin29]

Buying ASICs is easy, but a government wanting to destroy Bitcoin means turning against its citizens. The "Bitcoin is used for illicit activity" excuse card means accusing every citizen of sustaining illicit activity. Not a good idea.

But let's hypothetically say they did really want to destroy it. A 51% attack is possible, damage could be done but it could also be reversed by reversing blocks. 51% attack means they have to own 51% of the mining power, so they either do it by slowly adding more and more ASICs into their system to slowly rise the hashrate during a longer term or they would plug all of them in at once and there will be a 110% hashrate spike.

About being noticed, I'm sure there will be lots of people and articles everywhere on the Internet posting screenshots of the hashrate spike. Twitter would be full of them.

Am I missing something? I've never been deep in Bitcoin mining before so this post might contain stupid statements and any correction is appreciated.

EDIT:

-snip

If the aim is to 51%, then the hashrate won't be allocated to the Bitcoin network. So, no, not by monitoring the hashrate.

It won't? Where would it be allocated then? I thought the hashrate charts represented the total Bitcoin mining hashrate.

[stompix]

Following scenario: A government would like to destroy Bitcoin. It buys a significant number of ASICs to build up a huge mining farm and carries out a 51% attack.

First thing, why would a government do that?
And if they are afraid of bitcoin, it means they should be afraid of ethereum once bitcoin is gone, and next about litecoin and them some PoS coins and so on and on. From a government point totally wanting to get rid of cryptos, it makes zero sense to start spending billions in order to pluck only one at a time.

And why kill bitcoin entirely, they could deal with the problem in their country only.
If they are that stupid to plan such an attack first they would put lifetime sentences as punishment people using bitcoin, how many do you think would risk it?

From my point of view it will not be so easy to buy so many ASICs as once - what do you think?

In order to get 51%, you would need roughly 2 million s17, taking into account that while you set them up some miners will drop because of the reward getting smaller, maybe you can do it with 1,2 - 1,5 million, but I doubt Bitmain or Cannan or all the manufacturer together would be able to produce that in a short period of time.

Another question: Will it be noticed (how?) that somebody buys a big stack of ASICs and/or are we able to identify such a behavior monitoring the network's hashrate?

If you don't have an insider at the company selling, you won't know it till the hash rate grows and since the hash rate is normally on an upward trend right now because of better gear and the price increase you will need really good clairvoyance skills to realize it's an evil player adding hash power to the network.

[suzanne5223]

Following scenario: A government would like to destroy Bitcoin. It buys a significant number of ASICs to build up a huge mining farm and carries out a 51% attack.

First thing, why would a government do that?
And if they are afraid of bitcoin, it means they should be afraid of ethereum once bitcoin is gone, and next about litecoin and them some PoS coins and so on and on. From a government point totally wanting to get rid of cryptos, it makes zero sense to start spending billions in order to pluck only one at a time.

And why kill bitcoin entirely, they could deal with the problem in their country only.
If they are that stupid to plan such an attack first they would put lifetime sentences as punishment people using bitcoin, how many do you think would risk it?

I also dont see any reason why government will do such thing cause they already have enough on their plate rather than focusing on carry out 51% attack on bitcoin and from my experience 51% is usually carry out by miners and i dont see any reason why a miner will want the reason why we are all into crypto today to quench.

Another question: Will it be noticed (how?) that somebody buys a big stack of ASICs and/or are we able to identify such a behavior monitoring the network's hashrate?

If you don't have an insider at the company selling, you won't know it till the hash rate grows and since the hash rate is normally on an upward trend right now because of better gear and the price increase you will need really good clairvoyance skills to realize it's an evil player adding hash power to the network.
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In addition, the work of miners are to maintain/manage the blockchain network and also to get transaction confirm. Which mean they also does the examining job either.

[mpufatzis]

Long before they collect the ASICs for the attack, the government will realize that they can make money mining Bitcoin.
So if they could spend so much money, I thing they would continue the mining and not attacking.
So I believe it is not a possible scenario...

Following scenario: A government would like to destroy Bitcoin. It buys a significant number of ASICs to build up a huge mining farm and carries out a 51% attack.
From my point of view it will not be so easy to buy so many ASICs as once - what do you think?
Another question: Will it be noticed (how?) that somebody buys a big stack of ASICs and/or are we able to identify such a behavior monitoring the network's hashrate?

[DannyHamilton]

Following scenario: A government would like to destroy Bitcoin. It buys a significant number of ASICs to build up a huge mining farm and carries out a 51% attack.

"A significant number"?

They would need to purchase more hashpower than the entire rest of the Bitcoin mining world combined.

The current global hash rate is approximately 120,000,000,000,000,000,000 hashes per second (120 eH/s).

That means that the attacker would need to purchase enough equipment to generate more than 120,000,000,000,000,000,000 hashes per second, and they'd have to do that quickly, since the global hash rate that they are trying to overcome is currently still increasing.  If it took them too long to purchase all their hash power, the global hash rate may have increased, and they'd still need to purchase even more.

The Antminer S17 calculates approximately 67 TH/s and costs $1600 to purchase.

The attacker is going to need to purchase:
120,000,000,000,000,000,000 / 67,000,000,000,000 = 1,791,045 Antminer S17

I'm not sure how long it would take Antminer to manufacture 1.8 million S17 units, but let's pretend they just happen to have them sitting in a warehouse waiting to be sold...

That's going to cost the attacker $2,865,672,000

So, they are going to spend nearly 3 Billion dollars just to acquire the equipment. Then they are going to need to have somewhere to store/operate all this equipment. They'll need to pay some people to set up and maintain everything. They'll also need about 5.8 gigawatts to power the mining equipment (plus the electricity need to cool it all and light the buildings that house it all.

This is almost certainly going to create a noticeable shortage of Antminer S17 units, which will drive up the costs of whatever mining equipment anyone can get their hands on.

After all that money, and all that effort, it's still questionable whether they'd actually "destroy" Bitcoin.  First of all, they won't be able to chnage any of the consensus rules.  The best they'd be able to do is block transactions from being confirmed, keep any other miners from earning any revenue, and/or perform a double-spend (assuming they can find anyone that is willing to engage in a transaction with them).  There is a small chance that an overwhelming majority of users of Bitcoin might decide to fork the code such that all the mining power the attacker purchased could become instantly worthlesss.

Perhaps it would be better/cheaper to just create a law (with penalty of death) that makes it illegal to mine, purchase, sell, hold, or transact with Bitcoin?  Then send a few missles at large mining operations in other countries?  That should significantly reduce participation.  Then once the hash rate drops down below 67 TH/s, they can perform their 51% attack with a single Antminer S17!

[DaCryptoRaccoon]

I actually think there is another way they could take it over. We all know those three letter agency's love a zero-day to get what they want. 
Now what if a exploit in nodes and miners was being tucked away by them they could easy launch an attack to take over the miners already on the network in conjunction with an attack on the nodes this would be the most plausible way for them to take control over the network.

I for one believe that such an attack is highly possible people thinking they would need to buy miners is absurd when they could just exploit the ones that are on the network already.  Second to this is the fact they could also attack pool's to get the desired hash-rate to perform an attack.

Right now I think the focus should be on the centralization of the mining power with less and less home miners and small farms shutting down and being pushed out dew to power hungry 3kw units that are no use for home miners. 

This should be on the minds more than a state coming in and shutting it down lose the home and small farms and it's basically china and  the east than own bitcoin that should be more of a concern that anything also the number of pools that are about on the brink of shutting down will give the large players more of a the hashrate so the above becomes very relevant,  and quickly..

[DaveF]

Kinda sorta quoting myself here, but I changed the numbers a bit.
You can screw with bitcoin with a lot of money and a fake PPS pool(s).

6 blocks an hour  * 24 hours in a day  * 12.5 coins per block (for now) = 1800 BTC generated per day

1800 * 8750 (USD value of BTC at the moment) = 15,750,000 USD Lets round that up to 17,500,000 a day

Let’s give everyone a 20% bonus so $21 Million USD a day in our PPS pool in outgoing BTC

Let’s do this for a quarter so 90 days. That is just shy of 2 Billion USD out of pocket if this killer pool mines 0 blocks and has to buy all the BTC that they are giving out.

Since it’s a PPS pool that they control, they can point the hash to ANY SHA coin. Kiss every SHA coin that is not BTC goodbye. Then they point it back to BTC for 2 or 3 difficulty increases. And then in the end they point the hash rate nowhere. And the block chain comes to a crashing halt. Are you seriously going to mine at CKpool or Slush or P2Pool when it’s going to take forever to find a block because difficulty spiked because with an extra 20% marginal hardware gets turned back on, or are you going to mine here and get your extra 20% all day every day.

And then they shut off and go away. How long will it take us to recover?

Who would do this? I don’t know. Do you think if I went to Chase / Bank Of America / HSBC / CitiBank / Western Union / Wells Fargo and said “Hey, each of you cough up $350 million and I’ll set Bitcoin / crypto back 5+
years.” They would ask how or just write me a check? It's also petty cash for just about any government. Even after the divorce settlement Bezos probably still has it in cash in his safe at home

-Dave

[DaCryptoRaccoon]

That is very true DaveF,  I think also the fact that there are very few pools out there people plump for the ones that have the largest hash rate leaving out the likes of ck pool and kano now both are struggling now kano's last bock being mid December and ck's some time before that we also lost johnny bravo's pool and have seen may other fold under the conditions now.

It will be a true shame if we lose these pools the more I look at this the more it's looking like a whitewash by the large players to keep the small guys out the market but thing is if this happens and say something happens to the large players if there are no fallback pools and miners left out there your right the chain come's to a horrific stalemate.

It's concerning that the small pools are being forced out now this will only continue we really need more pools and better distribution of hashrate to resolve this or we will end up with 3 of 4 very very large pool basically the mining mafia.

[NeuroticFish]

That pool will have a too big hash rate. People will notice and start crying. Smarter miners may understand that something is fishy and go out.

Keep in mind that other SHA coins have only a small fraction of Bitcoin hash rate.

I think that the trick will not work.

[Welsh]

If a pool did turn rogue, then a lot of hashrate contributors would switch to a different pool to combat it. The 51% attack isn't a genuine threat from my eyes. I think a 51% attack could potentially be made in a short period of time, but once everyone else is aware, and the expenses start to rack up the attack will subside. The government don't really need to attack the Bitcoin network as much as everyone likes to pretend that Bitcoin is a threat to the governments of the world or the banking systems it just isn't currently.

Bitcoin was never meant to be a direct attack on the government, and I can't see them getting involved especially when they can control it from less expensive, and invasive ways via media coverage.

[JollyGood]

~snip~

The Antminer S17 calculates approximately 67 TH/s and costs $1600 to purchase.

The attacker is going to need to purchase:
120,000,000,000,000,000,000 / 67,000,000,000,000 = 1,791,045 Antminer S17

I'm not sure how long it would take Antminer to manufacture 1.8 million S17 units, but let's pretend they just happen to have them sitting in a warehouse waiting to be sold...

That's going to cost the attacker $2,865,672,000

Have to take my hat off to you, there are some serious calculations there 

The reality is the only winner in any such scenario would the Antminer manufacturing company

[gmaxwell]

Indeed, assuming a very powerful attacker then limiting them to weird technical attacks is unimaginative.

'just have to catch some miners, gather them up on stage and shoot them in the head. (Or more realistically put them in prison). Don't hypothesize weird technical attacks when boring things will do.'

https://buildingbitcoin.org/bitcoin-dev/log-2012-05-17.html#l-642

Even outlaws don't have that much use for an outlaw currency. Actually destroying bitcoin would be very hard but depriving it of almost all of its value would be much easier for a major nation state attacker.  But why would people want to do such a thing? -- in general, they wouldn't.

[naska21]

Sometimes this happens ... the last 51% attacks  have succeeded in stealing of   $19K +  $53K = $72K  worth of BTG.

Bitcoin Gold (BTG) Suffers 51 Percent Attack with Barely Anyone Noticing

[DaveF]

Indeed, assuming a very powerful attacker then limiting them to weird technical attacks is unimaginative.

'just have to catch some miners, gather them up on stage and shoot them in the head. (Or more realistically put them in prison). Don't hypothesize weird technical attacks when boring things will do.'

https://buildingbitcoin.org/bitcoin-dev/log-2012-05-17.html#l-642

Even outlaws don't have that much use for an outlaw currency. Actually destroying bitcoin would be very hard but depriving it of almost all of its value would be much easier for a major nation state attacker.  But why would people want to do such a thing? -- in general, they wouldn't.

That is overt. People will see and know what happened. Some of what was posed could be done covertly. No public bad actors, no acknowledgement, just oh look BTC was around for this many years then that happened and it and other cryptos went away. People would point fingers and everything else but w/o proof it would all be speculation.

I seriously do not think it could really happen in just about any of the ways listed, but that does not mean that it can't happen some way.

-Dave

[HeRetiK]

Sometimes this happens ... the last 51% attacks  have succeeded in stealing of   $19K +  $53K = $72K  worth of BTG.

Bitcoin Gold (BTG) Suffers 51 Percent Attack with Barely Anyone Noticing

That's the downside of running on an "ASIC-proof" PoW algorithm -- more easily available hashing power that can just as easily be reused for another coin so you don't even have to shoot your own foot when running an attack.

BTG having relatively small hashing power to begin with didn't make things much better.

[Harlot]

Being in line with your scenario, what the government would be doing is illegal. The 51% attack would mean fraud when it comes to transactions happening in Bitcoin's blockchain even the disruption of the system alone will make the government commit a crime what more if they try to double spend in some transactions? This alone would simply make them liable in several criminal things and the worst thing that could happen to them is that the international body would intervene with the sick thing they are doing. Also if they want to destroy Bitcoin and the entire industry wouldn't it be much easier for them to do it by creating unfavorable laws and regulations under their country which will be much cheaper for them to do.

[pooya87]

Sometimes this happens ... the last 51% attacks  have succeeded in stealing of   $19K +  $53K = $72K  worth of BTG.

Bitcoin Gold (BTG) Suffers 51 Percent Attack with Barely Anyone Noticing

you can't really post that in a topic that is discussing about bitcoin! and if you compare the two hashrates you will understand how ridiculous that comparison is. in chart form it is this: https://bitinfocharts.com/comparison/hashrate-btc-btg.html#3m the red line at the bottom which can't even be seen belongs to BTG.
in numbers the values are like this (first one is bitcoin hashrate and second is BTG both in h/s):

102,205,774,869,465,923,584
                  2,745,036

[stompix]

~
you can't really post that in a topic that is discussing about bitcoin! and if you compare the two hashrates you will understand how ridiculous that comparison is. in chart form it is this: https://bitinfocharts.com/comparison/hashrate-btc-btg.html#3m the red line at the bottom which can't even be seen belongs to BTG.
in numbers the values are like this (first one is bitcoin hashrate and second is BTG both in h/s):

102,205,774,869,465,923,584
                  2,745,036

I'm the last person defending shitcoins but you can't compare the hash rate of two different algorithms.
Ethereum's hash rate is ~160 Th, while an S17+ is doing 67Th but I doubt you can launch an attack with 3000$ worth of equipment.