Topic: In case of a 51% attack, can the damage be reverted? (Read 911 times)

We're starting getting off-topic, someone should make new thread.


Don't forget about decentralized pool such as http://p2pool.org/, even though almost no miners use it.

Edit : forget mention that i don't know much about how p2pool works. You might want check https://en.bitcoin.it/wiki/P2Pool and https://bitcointalksearch.org/topic/1500-th-p2pool-decentralized-dos-resistant-hop-proof-pool-18313, but you probably already check those links.

good point, but this is still about the impact of distribution of hash power among pools in case of 51% attack


thank you for information.
from website: "P2Pool is based on the same peer-2-peer (P2P) model as Bitcoin".

so, receiving job of a blockchain from another sharechain is going to bring transparency in business aspects of internal activities of pools, but I didn't find any difference about preventing a pool from gathering more than 51% power of the entire network. do I understand it right?

this is important everybody knows about the real role of pools and attempt to replace them with something more reliable - my pleasure.


that part related to pools was about analyzing the distribution of hash rate, not the whole hash rate of entire network..

َthanks for mentioning my topic, I just sent you some merits to you because of it:D

You couldn't be true more about pools being major vulnerability and points of failure but I think you need to revise your assumption about them being the only source of information for attackers to analyse hashrate and planning required resources:

Calculating network total hashrate is possible with a reasonable accuracy by taking into account current network difficulty and the time elapsed for generating a sufficiently large number of blocks (100-200 blocks). Actually bitcoin uses this approach for latest 2016 blocks to adjust difficulty target.

I just visit this web site and found it very useful for some risk analysis and possible attacks to PoW. these sort of information are necessary for planning an attack. if you look for amazing stats, just compare bitcoin, bitcoin cash and bitcoin sv:

https://miningpoolstats.stream/bitcoin

UPDATED:
the link above shows many of pools in several coins are (or could simply become) the majority of their network!!
very interesting to see a power outage, a maintenance in major pools could be harmful..

and centralized mining-pools here (because of providing the information about the overall hash-power of the network, that the network protocol is blind about it) are responsible for such damages to the crypto community. you know very well that blockchains set up their block difficulty by timing that they need -  not the hash power of decentralized miners around it. hash power is the sort of information that comes from pools. if someone really wants to perform an attack, needs to monitor the activity of pools and the distribution of processing power among them. the paper bellow (which discusses the selfish miners behavior and their effects on a crypto-currency. based on the paper selfish miners could attack a network by 25% processing power) has some good notes in this area too:

http://www.mixoftix.net/knowledge_base/blockchain/Bitcoin_Mining_is_Vulnerable.pdf

and this is where we could understand the importance of ideas in post entitled "Getting rid of pools: Proof of Collaborative Work":

https://bitcointalksearch.org/topic/getting-rid-of-pools-proof-of-collaborative-work-4438334

Are the parallels to Bitcoin Cash intentional? :3

Currently it definitely seems like social attacks would be the most effective way to damage Bitcoin in the long term.



The miner with 11% of the hashrate is able to check more nonces within the same timeframe, therefore they will find on average more blocks than their competition causing their hashrate superiority to be visible to the public (within a margin of error). That all miners are working in parallel doesn't change that.

Hello Kevin,

these days, there are several videos out there showing you could buy some editions of farm's ASIC devices for 5 Chinese-Yuan (0.72 USD) per pound! but as HeRetiK said above, you can't directly include these parameters in a lets_do_51_attack() function. this need a huge planning for attack - BUT:

I could imagine a consortia of farmers who decide to have their own coin as a new rival to bitcoin. they should be insane to break down the bitcoin and then advertise their new coin, this is not how the market work -  a continuous pumping/dumping in prices of all coins do. do a little math, assume that you have 2000 BTC in your pocket and you also have a farm with 1 PH/s processing power. you are also a member of consortia which enrolls 20 PH/s of the bitcoin.

now when BTC is in 7000 USD, you could sell 1000 of your coins and divert your hash power into a fork that you could buy 10'000 of them at 5 USD. you tell me, what happens if the price of BTC dumps down to 4000 USD and the price of new forked coin pumps up to 15 USD (downgraded hash-power and electricity usage)?

just in the BTC part, you can save 3000 USD x 1000 BTC = 3'000'000 USD for investment in a new fork just by diverting your hash power and by (buying those 1000 BTC back) diverting you hash-power back to BTC when the price is 7000 USD again you could earn another 3'000'000 USD, why you should attack it?! I call it a shadowed social attack to BTC users.

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there is also an interesting note in paper of the byzantine generals problem that includes the number of traitor generals, the paper also is talking about the paths that connect generals to each other. in PoW scheme, I could interpret the path parameter as the distribution of hash power among miner entities. if we have 10 miners in our network, and if 2 of them hold 80% of the hash power of the network (40% for each of them) this is more likely to have double spend transactions in our network than when each of our 10 miners holds 10% of hash power - equally. The distribution of hash power is important and ASIC is against it.

P.S.

sometimes I think about 10 miners that 8 of them have 10% of hash power and the ninth with 9% and the tenth with 11% and while they all are in parallel processing, why the tenth miner won't be able to hide himself and solve the nonce quicker than the other miners?

Plus, pumping that 1% increases the price too.

That attack cost is calculated using NiceHash's pricing which sounds like a nice metric in theory, but given a sufficiently strong network is completely useless in practice:


BTC being 1% NiceHashable means that purchasing all available hashing power of NiceHash would only yield you 1% of Bitcoin's network making this a rather losing proposition. So no, you can't simply waltz in and buy Bitcoin's majority hashrate.

Thanks for the provided link.

Upon checking it out, I found out that the cost needed to successfully launch a 51% BTC attack is just    $285,785 at the current hash rate of 42,023 PH/s (an one hour attack). Does this mean the attack would work for one hour as soon as someone pays around $300k for rented equipment?

It seems quite cheap in my opinion. For us it might be extremely expensive and unimaginable to spend this much just for a 1hr attack, but what if a millionaire - or billionaire - decides to do this? It's possible, right?

Could someone explain the NiceHash part? It says BTC is 1% NiceHashable, what does that mean?

At what date did 'ANTMINER' go live? That's when BITCOIN entered the 'matrix', you can take the red pill or blue pill, the blue pill you ignore the 500LB gorilla ( china, alibaba, antminer,amazon), red-pill you deal with reality.

since antminer went live, they control 90% of the bitcoin mining, that means that whatever they have been doing since then, they have been in control, as they decide the consensus, and nobody else,

funny thing about these red/blue pills is that this site right here is hosted by amazon-services, who is tied to alibaba, who is tied to jack-ma, who own majority interest in antminer, and jack-ma just got entered into the communist party of china, this is a big-deal

continue on folks, live in the matrix, and this time its brought to you by amazon/alibaba

Another way to use the MATH is apply the 'Kelley Criterion', as the differential eqn, optimized solution for max wealth is all the same, 2P=F, once you hit 50% ( 0.5 ) then your in 1.0, say china ( alibaba/amazon ) control 90% of bitcoin mining ( consensus ), then they're 1.8, ownership/control and some more

More interesting thing about the Matrix, and china's social-score ( facebook ), is why would amazon/alibaba want to control all the digital-money on earth, when they already control all the shopping? Why even ship a product, when you own the printing press? Me thinks this is largely a supplier problem, as suppliers to the GORILLA can be PAID in 'crypto fiat', and of course the sheep who work in the factory's too can be paid in crypto-fiat

The Matrix is Real.

I believe you have already answer the question you asked like you said BTC is bitcoin and there some majority or group of people which may choose to revert the process while there are some which may choose to play along and this is what happened during the time of SegWit if you could remember that the crypto community were divided into two.

let me explain it in another way. look, I have a very good archive from the first days that I have begun coding till now - which means a text file/pdf file that I have in my backup-chain (in DVDs) under e.g. Windows NT in my old 386-XT processor desktop computer is as secure and trusted as a text file that I have written yesterday in my Windows 10 notebook. I have this level of security just because I have upgraded my operating systems regularly. and operating systems sometimes patched/upgraded and sometimes they also changed generation to work with a new hardware.

if my Windows 10 doesn't work properly with a new hardware or malware, I could simply restore (FORK) my data back from my backup-chain (BLOCK-CHAIN) for a while, but this can't long too much -  new operating system (blockchain core) should be available in market very soon. ASIC is the station that makes crypto-currencies to migrate into a new generation.



I'm working on this. I hope you guys do so, then we could share our observations. during these days of drop in prices, I could see a huge downgrade in hash rates of bitcoin and ethereum, but it seems monero (asic-free crypto) hash rate remains unchanged. I think the opinion factor is working in this case.

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UPDATED:
I found this website with amazing collection of coins and the theoretical cost of a 51% attack on each network:

https://www.crypto51.app/

Because we're talking about the hypothetical!

Do you look at a drawing of a Pegasus and are like "Wait a minute, those wings are way too small for a creature of this size, why would someone even draw this it makes no sense!"?



Assuming they are after the coins. Considering all the drama going on I wouldn't dismiss mining attacks out of political reasons (*cough* Bitcoin ABC vs Bitcoin SV *cough*)

The cost of attacking your cash cow is: Electricity + Deprecation of the mined coins + Making your mining equipment useless

The cost of attacking a minority coin is "only": Electricity + Deprecation of the mined coins



Excellent point, but back then all computational power that went into mining simply went into Bitcoin. Nowadays there's massive computational power floating between whatever coins are most profitable to mine at the time.



How does this analogy apply to Bitcoin and PoW? A blockchain is not less stable merely because early blocks were mined at a lower difficulty.



Commercial miners will usually be able to mine much cheaper than hobby miners, due to economics of scales. So while a hobby miner may be willing to mine less profitably, commercial miners are able to stick around longer due to larger profit margins. Therefore I don't think hobby miners are necessarily more likely to keep mining during a bear market than commercial miners. I do think that hobby miners are more likely to hold onto their mined coins than commercial miners though, due to the latter's requirement to keep a consistent (fiat) cashflow.

and let me add another note here.. the incentives are different among FARMERS (huge facilities of mining) and MINERS (rigs at home). miners do mine for fun, opinion, curiosity, learning or investment. miners also 100% own their tools (paid in cash) and usually have no employees and are loyal to some coins. but farmers are a group of stakeholders who invest in setting up huge mining facilities (paid by loans) just for PROFIT and have employees for physical security, accounting, operation, etc. farmers also are not loyal to a specific coin - even if they equip their farms by ASIC devices.

therefore these two group of miners show different reactions in pricing crisis. it seems we always could count on MINERS group.

unfortunately, coin price is not always the VALUE that attackers look for.


I do so. the Bullwhip Effect exactly addresses this situation too.
granted ranges of tolerance around a miner hash power should be considered - of course not by software tricks.

Security in PoW is not guaranteed by hash power. It is about resource consumption and costs involved in mining. Although opportunity costs (depreciation of investment and interest rates) are important and should be considered too, they are not the most important cost factor, electricity is , while human resources and other costs are involved too.

A drop in bitcoin price eventually causes an oversupply of hash power in the market but its rental price won't fall significantly because the operational costs remain the same. Let's put it to be like 20 percents for bitcoin plunging to its darkest price thresholds. Now let's look at the other side of the story: A drop in bitcoin price decreases the stakes involved (and the incentives to attack the network) proportionally. Now do the math: bitcoin drops to 1K$ and as a result incentives to attack it decrease almost five times (proportional to its value) while costs to carry out such attacks are corrected just like 20%. Bingo! we got a network almost four times more secure than now!

Unlike what you propose, in terms of security measures, I'm more concerned about the situations when price skyrockets and we are short of hashrate, in such cases, I'm hopefully counting on short supply of rental hashrates and the increase in their prices.

Edit:
I just realized that I've overlooked the drop in hashrate and its consequence on decreasing the amount of power needed to attack the network, and it is not a small issue. Though, I think it won't change the situation in opposite direction, hashrate never drops in a complete linear and proportionally equal rate with price.

Well, there is one thing that we should consider: "genesis block mined by CPU". This obviously influences the early consensus estimations of PoW. Just like the effect of center of mass in Pisa Tower, the granted tolerance of forces is important to the final stability. Even adding equal huge amounts of forces in different direction of Pisa Tower may still preserve its stability, but this time they are far above the granted tolerance and absence of one force in one moment will break down that beautiful tower..

The PoW has passed from the GPU and ASIC - and I think ASIC is out of granted tolerance of genesis block in many ways - (and who knows when we will access the quantum computing in market). Miners invest in their farms to earn PROFIT, and PROFIT could mislead by many kinds of motivations. The way we talk about economy around PoW is like we write a code that pulls two digits inside a function and divide digit 1 on digit 2 while we insist on: "lets do not check digit 2 for division by zero! because there is no motivation for end user to do so.."

look at this scenario: "bitcoin price goes down and main farms turn off their machines. then hash rate goes down too and DIFFICULTY follows them down. now bad guys RENT those farms for 1 month and do what they want to do to crash the TRUST to one coin/all coins". this could be a kind of supply chain Bullwhip Effect in crypto ecosystem:

https://en.wikipedia.org/wiki/Bullwhip_effect

to RENT and not to INVEST in farms to access huge amounts of process will be a real threat. we need to find out how to adjust the tolerance in forces (hash power), and not in the way Monero tries to do..

bitcoin is safe now, and will be. what we are talking about may bring extra strength to the network.

Sure they will but why ignoring economics? It is all about economics isn't it? Bitcoin is not a mere technical system, it is a monetary system based on the most promising mathematical model for economics: game theory.

Obviously, you don't want to give such a credit to so-called "shitcoins" to be counted as secure cryptosystems. I do agree there me be wholes/glitches in some of them in terms of code or design principles and this makes them suspicious to be considered comparably secure but it is not about network hash rate and 50%+1 attack.

Your arguments about the attacker switching back to another coin after ruining the one under attack is correct, but does not lead to anything new, once he leaves everything is restored and he has been rewarded by a bunch of now worthless coins, given he has not managed to fool some reckless merchant or exchange to buy a reverted transaction.

And please note, bitcoin started with a few desktop computers and took almost a decade to reach the current state in which like 200k$ a day (at least) worth of electricity is  being spent for its security and yet it has been always secure against 50%+1 attack from the first day because of the beauty of PoW and the equilibrium state between incentives and costs involved in such an attack.