Is 51% attack a double-spending threat to bitcoin?

[Wind_FURY]

Miners are reliable as far as:

1- Provably, they are not inflating the supply of bitcoins by breaching the regulations built into the protocol.

2- There is proof that any incoming fund to a wallet approved by miners, comes with an equal deduction from the ledger maintained by them.

3- There is a safe threshold for the number of confirmations where the costs of rewriting the blockchain outperform any criminal incentive for defrauding users by orders of magnitude.

It's actually because of the full nodes. They secure the network, to make sure the miners are following the rules, and make sure to mine the type of blocks that the full nodes demand.

Plus, https://twitter.com/bitcoinmagazine/status/1197161029832265729

You are rehashing the same argument the old "Don't trust, verify" thing

BUT, it isn't wrong. Full nodes do secure the network FROM bad-actors. Including if the bad-actor is a miner.

which has fed the community up. It'd be a good occasion to make a re-assessment, I suppose and will do my best to help.

The entities who want to co-opt Bitcoin are fed up, not the community. "Don't trust, verify" is, and SHOULD always be part of Bitcoin's ethos.

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[aliashraf]

Now, and please stay focused, if the double-spend is solved in the first place regardless of what is happening in the mining scene, what's actually driving the anti-PoW/anti-miner propaganda/instincts in this community? I'm asking about the rationale behind this phobia and the way it is blocking so many scaling ideas and proposals? If double-spending is not going to happen and bitcoin supply won't ever exceed the cap, what else is at stake that makes people nervous about trusting in PoW?  

Are people concerned about pools to collide and defraud few Satoshis from reckless users who release their assets with one or two confirmations? Please! Just give me a break.

Hello aliashraf. I have seen you be a long time proponent of scaling ideas on bitcoin. I read a lot of your posts about proposing a rigorous solution and the code for some of your ideas but I don't know if you are actively pursuing them in terms of code. Point me in a direction if you are.

Hello, thank you for reading my comments, appreciate it.

About coding, it is complicated, some ideas have been coded for experimental purposes and approval of consistency because nothing is consistent if you just can't translate it to code elegantly but there is no public domain code release for the time being.

To be honest, I'm a bit short of budget right now to do anything more than part-time research and it has been a while since I've exhausted almost all my resources digging literature, writing, ... I'm not a fan of ICO and crowdfunding campaigns myself so it is gonna take a bit more for me to pull more resources together for supporting more serious projects.

There is good news though, as much as jumping to the coding phase is delayed the idea is growing stronger and stronger and I'm absolutely satisfied with the situation right now, no rush.

I don't think there is any anti-PoW/ anti-miner propaganda in this community. Everyone loves PoW. The concern about miner centralization is only related to the fact that you cannot let a specialized group of people be the sole controlling-stakeholders in a decentralized system that we all hope will continue and flourish long after we have gone. Don't you feel it is a genuine and valid concern considering the vision and magnitude of such a system.

No, I don't feel so. I've presented a series of proposals above-thread which are abandoned because of such arguments and concerns.  Blocksize debate was a legitimate debate from the Core side not because of the way they were presenting their argument but because of the proximity premium flaw in bitcoin that makes blocksize increase a centralization nightmare for mining itself. Cenralization of mining is a legitimate concern but centralization because of relying too much on miners? No, it is not!

What exact scaling solutions do you think the community is not thinking of?

Sidechains, UtXO Commitment, Hierarchical Sharding schemes to name few. I started this topic purposedly because all these ideas are pushed back for their legitimate reliance on miners and PoW and right now and in the meantime, taking advantage of Corona situation, I'm doing my best to get some more free time and publish a proposal including all the above fantastic ideas in a package as a scaling proposal for bitcoin. It is not a typical brand new altcoin proposal, neither a two-way pegged sidechain nor a hard/soft fork and it is an ultimate solution for both centralization of mining and bitcoin scaling IMHO. Stay tuned  

"Don't trust, verify" is, and SHOULD always be part of Bitcoin's ethos.

Who says?
...

Actually, I don't care.

[Wind_FURY]

"Don't trust, verify" is, and SHOULD always be part of Bitcoin's ethos.

Who says?
...

Actually, I don't care.

I don't care that you don't care, BUT without it, and without full nodes, INDEPENDENT of the miners, Bitcoin would be a slow, boring, centralized ledger. Or the Federal Reserve all over again. Bitcoin would be pointless.

[Stedsm]

I believe that 51% (or more) is more of a centralization situation rather than being called as an attack for the purpose of double-spending. I've got many reasons to say this, one of which is the fact that at some time when we just began with crypto a decade ago, BTC mining had been both, easier and controllable due to least hash and many companies even tried and did rule the crypto mining industry, and trust me that there will be group of miners who, once all gather at one place (pool) some day, we'll definitely be noticing a drop in number of other mining groups as this single group will be ruling it up to the mark by getting almost all the blocks on its name and others will stop by seeing them gaining everything.

[BrewMaster]

and trust me that there will be group of miners who, once all gather at one place (pool) some day, we'll definitely be noticing a drop in number of other mining groups as this single group will be ruling it up to the mark by getting almost all the blocks on its name and others will stop by seeing them gaining everything.

that is simply not possible without having 90% of the hashrate and the cost of such gigantic hashpower is ridiculously high even if divided among a small group of mining farms. besides even if one pool had that much hasr power it still wouldn't force the 10% to leave because that 10% can still mine 10% of the blocks no matter what. unless that 90% starts performing 51% attacks in which case we will switch to another mining algorithm to brick their billion dollar investment.

the thing about pools is that you may not notice it but their seemingly big hashrate comes from a very large number of miners connecting to them. which means if a pool starts being a little shady, they will all leave.

[Stedsm]

--snip--

the thing about pools is that you may not notice it but their seemingly big hashrate comes from a very large number of miners connecting to them. which means if a pool starts being a little shady, they will all leave.

What if such pools start giving higher rewards per each miner (obviously after dividing their distributed amount of hash power) just to grab a big number (or almost all the miners in the market switch to them due to their competitive business and some contests)? Why won't the miners join them and start gaining even a few bits more than what they get from their ongoing mining group?

[aliashraf]

@Stedsm, @BrewMaster
Centralization of mining is a bad thing, no doubts, and a real threat since 2011, undisputable and it is really a hell of a problem to solve considering the sophisticated situation we are dealing with: so many strong and divergent stakeholders and groups present in bitcoin scene nowadays. But ] got two points to mention here:

1- It is hard but not impossible to mitigate, we need to get rid of centralized pools.

2- It is not an existential threat to bitcoin as a whole because it is irrational to leverage huge mining resources for long-range attacks against bitcoin as @BrewMaster correctly mentioned above.

[Wind_FURY]

@Stedsm, @BrewMaster
Centralization of mining is a bad thing, no doubts, and a real threat since 2011, undisputable and it is really a hell of a problem to solve considering the sophisticated situation we are dealing with: so many strong and divergent stakeholders and groups present in bitcoin scene nowadays. But ] got two points to mention here:

1- It is hard but not impossible to mitigate, we need to get rid of centralized pools.

2- It is not an existential threat to bitcoin as a whole because it is irrational to leverage huge mining resources for long-range attacks against bitcoin as @BrewMaster correctly mentioned above.

Plus,

3 - What Andreas Antonopoulos said, https://twitter.com/bitcoinmagazine/status/1197161029832265729

Thanks to the full nodes validating everything for themselves, and securing the network as an after-effect. I am very confident that that prevents the miners to become dishonest.

[DooMAD]

Miners can raise fees, so you can't afford to move coins.

Have you forgotten how Bitcoin works yet again?  

I know you spend a lot of time playing with that staking rubbish, but that's not really a legitimate excuse for being woefully ill-informed.  But since you clearly need it explained to you like you were still a newbie, I'll happily oblige:

Miners would be jeopardising their income (not to mention their entire business model) if they tried to enforce higher fees.  Users include a fee to effectively bid for priority inclusion in a block.  The miners will naturally select the highest bids first, but it's not practical for them to attempt to force people to bid larger sums.  That's just something people choose to do when the network is congested.  When fees rise, that's the result of users trying to out-bid each other.  It's not the miners causing it.

If miners began en-masse to reject transactions based on lower fees, they're effectively just "leaving money on the table".  It's basic supply and demand.  

[aliashraf]

@Khaos77
I'm not used to saying this but @Doomad is right (exceptionally tho  ) ...
Centralization of mining is a nightmare but not an existential threat for bitcoin: neither short-range nor long-range attacks are feasible in bitcoin because of the game-theoretic force behind the scenes.

The problem with @Doomad and guys like him (including @Wind_FURY) is their paradoxical positions:

Firstly they incorrectly believe that it is because of decent full nodes and not the game theory that mining centralization is not a serious threat to bitcoin. It is a totally wrong assumption and is nothing more than blindly repeating baseless rumors and slogans. For instance, I could imagine a bitcoin ecosystem solely consisted of SPV wallets and yet immune to such attacks in the real world. Any dishonest move from miners would trigger panic and drop the price drastically and ruin the mining business in the first place, wouldn't it?

Secondly, they follow the same miner-phobic discourse when it comes to advanced scaling proposals that need a bit more reliance on PoW and miners at the same time that they say there is no practical threat because of the centralized situation with miners!

Thirdly, they don't feel any obligation to engage in any project or support it by any means or at least remaining neutral about any proposal that involves changing the situation with mining and pools in bitcoin, instead, these guys are among the firsts to show up trying to shut down any serious idea by accusing it of being disruptive, out of the holly road map, requiring hard-fork, blah, blah, ...

Such a complex type of people our friends are  

[Wind_FURY]

Miners can raise fees, so you can't afford to move coins.

Have you forgotten how Bitcoin works yet again?

He's trolling. Allow him. It helps open the newbies eyes to the truth.

I know you spend a lot of time playing with that staking rubbish, but that's not really a legitimate excuse for being woefully ill-informed.  But since you clearly need it explained to you like you were still a newbie, I'll happily oblige:

Miners would be jeopardising their income (not to mention their entire business model) if they tried to enforce higher fees.  Users include a fee to effectively bid for priority inclusion in a block.  The miners will naturally select the highest bids first, but it's not practical for them to attempt to force people to bid larger sums.  That's just something people choose to do when the network is congested.  When fees rise, that's the result of users trying to out-bid each other.  It's not the miners causing it.

If miners began en-masse to reject transactions based on lower fees, they're effectively just "leaving money on the table".  It's basic supply and demand.  

Plus newbies, miners will also NEVER "delay transactions for fun", or waste energy to double-spend. Any dishonest miner will be kicked out of the network by the community of full nodes, and Bitcoin will continue moving along.

What the dishonest miner could have done was mine Bitcoin, and receive a block reward.

The troll overlooked the game theory.

The troll is also saying that LN will steal the majority of transaction fees from the miners. Does he want Lightning to be successful? OK! Hahaha.

@Khaos77
I'm not used to saying this but @Doomad is right (exceptionally tho  ) ...
Centralization of mining is a nightmare but not an existential threat for bitcoin: neither short-range nor long-range attacks are feasible in bitcoin because of the game-theoretic force behind the scenes.

The problem with @Doomad and guys like him (including @Wind_FURY) is their paradoxical positions:

Firstly they incorrectly believe that it is because of decent full nodes and not the game theory that mining centralization is not a serious threat to bitcoin. It is a totally wrong assumption and is nothing more than blindly repeating baseless rumors and slogans. For instance, I could imagine a bitcoin ecosystem solely consisted of SPV wallets and yet immune to such attacks in the real world. Any dishonest move from miners would trigger panic and drop the price drastically and ruin the mining business in the first place, wouldn't it?

I never said that they were not a threat. I said, the entities that actually secure Bitcoin are the full nodes.

In your imagined Bitcoin ecosystem, the full nodes are centralized towards the miners? They can change the rules without community consensus?

[aliashraf]

{snip}
I never said that they were not a threat. I said, the entities that actually secure Bitcoin are the full nodes.

In your imagined Bitcoin ecosystem, the full nodes are centralized towards the miners? They can change the rules without community consensus?

You don't need a zillion of full nodes to beware of frauds, illegal inflation, ... one full node suffices: It could publish a proof for any malfunction in the press and everybody would be informed! It is game theory, its basic "rational behavior" assumption, that is saving bitcoin right now.

It is fragile and weak, I do agree, but it is how one could explain the price not being high enough and the lose of stem we experience.

[DooMAD]

You don't need a zillion of full nodes to beware of frauds, illegal inflation, ... one full node suffices: It could publish a proof for any malfunction in the press and everybody would be informed! It is game theory, its basic "rational behavior" assumption, that is saving bitcoin right now.

One full node may be sufficient for one person, but if each user wants certainty that all the information they have is valid, they will each require a full node.  Anything short of that introduces a requirement to trust a third party.

[aliashraf]

You don't need a zillion of full nodes to beware of frauds, illegal inflation, ... one full node suffices: It could publish a proof for any malfunction in the press and everybody would be informed! It is game theory, its basic "rational behavior" assumption, that is saving bitcoin right now.

One full node may be sufficient for one person, but if each user wants certainty that all the information they have is valid, they will each require a full node.  Anything short of that introduces a requirement to trust a third party.

Nope. We don't live in the Middle Ages, once there is proof that some entity is playing dirty, it is doomed, forever. We have the press, social media, etc. we don't need to do the test on our own behalf. It is how the real world works.

My point: A full node keeps its own user from being defrauded (and become the example of a victim for the press) not bitcoin as a whole. Pools are not afraid of full nodes, they are afraid of losing funds because of the obvious social penalties like price falling near zero as a consequence of any misdemeanor.

[DooMAD]

Nope. We don't live in the Middle Ages, once there is proof that some entity is playing dirty, it is doomed, forever. We have the press, social media, etc. we don't need to do the test on our own behalf. It is how the real world works.

Trust the press?  In this day and age?  When the number of page impressions are clearly prioritised over maintaining even the slightest semblance of journalistic integrity and the articles generally appear to give the impression that the given publication is merely a mouthpiece for the vested interests of whichever billionaire owns it?  It's likely that very few people become genuinely informed of anything by absorbing modern media content, aside from perhaps what the 1% would prefer the herd to think.  As such, I think I'll stick to form and say that this is yet another one of your ideas I won't be lending my support to.  

My point: A full node keeps its own user from being defrauded (and become the example of a victim for the press) not bitcoin as a whole. Pools are not afraid of full nodes, they are afraid of losing funds because of the obvious social penalties like price falling near zero as a consequence of any misdemeanour.

Pools don't have to be "afraid" of nodes, they just have to know unquestioningly that should they choose to build a chain upon a block which the full nodes won't validate, they'll be forked off the network and mining a worthless chain.  Blocks are either valid or invalid.  Binary outcome.  That's what full nodes keep in check, which prevents certain types of misdemeanour.  Not hashrate attacks, though.  For the purposes of the OP, I'd say it's likely you are correct in the assertion that it's mainly game theory keeping that part in check.  But that shouldn't in any way be interpreted to mean we don't still need a healthy node-count.

[aliashraf]

Trust the press?  In this day and age?  When the number of page impressions are clearly prioritised over maintaining even the slightest semblance of journalistic integrity and the articles generally appear to give the impression that the given publication is merely a mouthpiece for the vested interests of whichever billionaire owns it?  It's likely that very few people become genuinely informed of anything by absorbing modern media content, aside from perhaps what the 1% would prefer the herd to think.

Sure there are limitations to the extents and the aspects but we don't live in absolute darkness, do we? For deciding to go short on a digital asset, sometimes even rumors are enough.
Actually, it is part of the sectarianism, I'm not comfortable with. We don't live in such a terrible world in which you just can't be informed that people are getting defrauded by a bunch of stupid collided pools, it is just absurd, having such a presumption as serious design criteria for any real-world system.

Believe it or not, there is no, zero, long-range reorg threat to bitcoin in foreseeable future and it has nothing to do with the cardinalit of full nodes.

As such, I think I'll stick to form and say that this is yet another one of your ideas I won't be lending my support to.  

you should reconsider, because it is the right thing to do, seriously.

My point: A full node keeps its own user from being defrauded (and become the example of a victim for the press) not bitcoin as a whole. Pools are not afraid of full nodes, they are afraid of losing funds because of the obvious social penalties like price falling near zero as a consequence of any misdemeanor.

Pools don't have to be "afraid" of nodes, they just have to know unquestioningly that should they choose to build a chain upon a block which the full nodes won't validate, they'll be forked off the network and mining a worthless chain.

And should be afraid of being forked-off, yes? NO!

[Wind_FURY]

{snip}
I never said that they were not a threat. I said, the entities that actually secure Bitcoin are the full nodes.

In your imagined Bitcoin ecosystem, the full nodes are centralized towards the miners? They can change the rules without community consensus?

You don't need a zillion of full nodes to beware of frauds, illegal inflation, ... one full node suffices: It could publish a proof for any malfunction in the press and everybody would be informed! It is game theory, its basic "rational behavior" assumption, that is saving bitcoin right now.

BUT, that isn't a reason to discourage the community from running a full node in a permissionless system. If they want to run a full node for themselves, then they should a full node.

PLUS, your opinion is debatable. There's rational behavior BECAUSE of full nodes securing the network.

It is fragile and weak, I do agree, but it is how one could explain the price not being high enough and the lose of stem we experience.

It's not weak, it's centralized, and it's not secure FOR the community. More full nodes = more security, and it's better to overshoot security.

[figmentofmyass]

Nope. We don't live in the Middle Ages, once there is proof that some entity is playing dirty, it is doomed, forever. We have the press, social media, etc. we don't need to do the test on our own behalf. It is how the real world works.

My point: A full node keeps its own user from being defrauded (and become the example of a victim for the press) not bitcoin as a whole. Pools are not afraid of full nodes, they are afraid of losing funds because of the obvious social penalties like price falling near zero as a consequence of any misdemeanor.

in your scenario, it's easy to attack the network. users would have to coordinate out-of-band and fork the network every time that happens.

with a robust network of full nodes, such attackers would just be ignored.

how could your scenario possibly be preferable for bitcoin users? even if you are right about the game theory, why give miners that opportunity?

[aliashraf]

even if you are right about the game theory, why give miners that opportunity?

Fair question. Before proceeding to it let's have a comparison between the role of game theory and full nodes (supposedly millions of them) in securing bitcoin:

Full nodes have no power to mitigate the real attacks a hypothetical 51% collided pools can carry out, no matter how many of them are present:

- Short-range chain rewrite attacks are not detectable by full nodes, they just bend the knee to the more difficult chain, forget about resisting against such attacks.

- Long-range attacks are the same as it is just a relative concept.

- Full nodes can't resist censorship/blacklisting attacks against peoples/institutions/nations.

- Full nodes can resist against protocol breach and most importantly double-spending/illegal-inflation attempts very well.

Game-theory addresses all those problems vigorously with the exception of censorship attacks: There is a hole.
It is possible for an aggressive coalition of governments to push for blacklisting groups of people by pools/big-miners and convince other people not to care as long as they feel somewhat/somehow safe (wrongfully). Pools/miners might conclude the negative impact as being tolerable compared to the legal penalties they have to bear otherwise.

The last point tells us why we should take care of the centralized situation we are in with pools and ASICs as well as centralized exchanges they are all part of compromise threat to bitcoin resistance agenda against tyranny and greed.

Back to your question:

why give miners that opportunity?

Answer: To use their power for implementing excellent features and solving crucial problems where it is needed.

Right now, bitcoin needs mobile secure wallets, doesn't it? A simple UTXO commitment enhancement could provide the opportunity for having elegant full nodes to be set up in a few minutes on an ordinary low-end mobile. The argument, if it deserves to be called an argument at all, is the vulnerability of this proposal to stupid miners who are susceptible to run a 500 blocks rewrite attack on bitcoin!

[DooMAD]

And should be afraid of being forked-off, yes? NO!

Fear has nothing to do with it.  I'm not sure I understand your insistence to introduce an emotion to such a simple equation.  Either miners build on blocks that conform to consensus rules or they cannot continue to contribute to securing the network.

If there is a legitimate argument to counter my assertion that a healthy nodecount prevents certain attack vectors, I certainly haven't heard it yet.