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Proof of stake is incapable of producing a consensus

yanmaani.github.io

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Re: Proof of stake is incapable of producing a consensus

#341
post #323

Earlier quoted context omitted.

No one is talking about governance. The term "consensus" refers to the decision about which transactions to append to the ledger, and the decision is to go with whatever set of transactions the miner that has spent the most money has chosen. It has nothing to do with governance issues.

then if you're not talking about governance, you're still wrong. there's no voting, only if you insist on re-defining what words mean, at which point i won't be interested in continuing the discussion.

Of course there is voting. Who do you think decides which transactions go in the chain, and in what order? The miner who wins leader election during this round (in Bitcoin anyway) does, and the rest of the nodes decide whether to accept its vote. The other nodes can also choose to reject this vote for a while, as long as after seeing it they don't accept a chain with less hashpower, and still follow the protocol (more or less).

The leader can even opt to put no transactions in the current block, something that has actually happened on many occasions: https://www.theblockcrypto.com/post/67928/bitcoin-miners-are.... Obviously, the leader was making a decision here, there were not actually zero transactions to process :)

Re: Proof of stake is incapable of producing a consensus

#342

Earlier quoted context omitted.

Smelting metals actually produces something, proof of work just burns electricity for the random chance of winning a lottery

PoW produces something intangible. You're probably basing on an assumption that tangible products are more worthy or justifiable of resources consumed than intangibles. If you work with software development - which you probably do - I'd suggest checking what you do for a living, how much energy it consumes and how much physical product it generates.

That argument could even be somehow valid if it were only possible to demonstrate that these intangibles improve life for people, like contributing to food, housing, education or even only entertainment. They do not. We do not have to care for those who are affluent enough to burn electricity just in order to gamble. Those people have the resources to gamble in less harmful ways without raising electricity prices and polluting the air the way they do. Those people could even do something helpful and productive if they chose to. Cryptomining is wasting energy for the sake of wasting energy. You may argue we (the 99.999% who do not cryptomine) are too stupid to see the value of your imaginary intangibles but that's not true. We are the ones who want no part in a pyramid scheme, who do not want to succumb to gambling, and whose time and money are too scarce and too precious to be put on the line. Sure, all activity has its price, its waste, and sure, there are other occupations whose overall usefulness is doubtful and askew with the accompanying resource consumption. Doesn't mean you have too excuse bad behavior just because there are other guys doing no good.

Just as an aside, when you move a newspaper or a magazine from print to only existing as a web page, you certainly have 'dematerialized' it to a degree. However you still need hardware to keep and display the data and energy to move it around and light up the screens. In so far it does not stop being physical. The 'intangible' is somewhat of a red herring. Yes, it is less haptic, but it's still physics, physical all the way down. Other than that, currencies, freedom, equality, education, entertainment—we've been having intangibles all the time, at least from the dawn of human culture onward. Cryptomining does not bring anything genuinely new to the table in this respect. It's not even new in being a fraudulent, volatile scheme that betrays traits of a cult, one that benefits a few and hurts the many.

Re: Proof of stake is incapable of producing a consensus

#343

Earlier quoted context omitted.

Smelting metals actually produces something, proof of work just burns electricity for the random chance of winning a lottery

When I write code for my work does it not exist? I'm in essence minting new programs using my time as proof of work.

No, I'm quite sure the proof of work is a program which works.

Re: Proof of stake is incapable of producing a consensus

#344
An intentionally dishonest article.

The actual truth is that PoS is infinitely safer than PoW in the short to medium term, while theoretically weaker in the long term. A long-term attack would require first buying obsolete signing keys, which would stop nodes that sync starting from the pre-fork point from syncing - ie. a denial of service attack. Which is in a very weak threat, as online nodes wouldn't even notice it. A short to medium term attack would stop finalization for a while at an enormous cost of slashing. It's a denial of service attack because nodes would be able to see contradictory signing from the same keys - so while without out of band data they won't be able to decide which one is the commonly accepted chain, it's enough information to recognize than an attack is happening.

PoW is very weak in the short term to medium term because runtime cost of attack is equal to mining rewards + epsilon, which is negligible, meaning it's just a question of hardware. Contrary to PoS, mining hardware is an external resource - it's always possible to get enough of it, given enough money (single digit billions for bitcoin). Getting 2/3 stake of a long-running PoS system is impossible - it's a scarce internal resource and there isn't enough for sale.

Reverting years of blocks is indeed infeasible - but interestingly in practice it would also amount to a DoS attack, as everyone would notice it and pause all payments. Contrary to PoS, where it would only work on newly syncing nodes, it would stop everyone. However, while theoretically more expensive, it's still only a matter of money - while a long-run DoS attack against newly syncing nodes in PoS would require buying obsolete keys, which is very likely to be impossible in practice.

Is this even an advantage? I don't think so, but it's arguable. However, for this singular arguable point PoW pays with a 4 orders of magnitude higher cost and a much, much weaker short and medium term security.

Empirically, lower security of PoW is confirmed: multiple 51% attacks happened (most famously ETC), while even a much weaker DPoS coins never had a successful double spend attempt.

In terms of public trust, not many people are able or even interested in technical arguments - they just observe if something works. In reality, consensus-level attacks are very rare as it's currently very hard to profit from them regardless of the consensus method, and the biggest danger is from software bugs in nodes, most likely unrelated to consensus.

If any PoW blockchain became a foundation of global commerce, attacking it would become very profitable, or even a military target - but that's never going to happen. So I don't expect bitcoin to get 51% attacked in any near future - at best years in the future when value of block rewards is so low one person with lots of old mining hardware can attack it just for fun.

Re: Proof of stake is incapable of producing a consensus

#345

Earlier quoted context omitted.

There is a difference between each of those uses of electricity and PoW. PoW is throwing away electricity for the sake of it, and resists getting more efficient. If the goal is for the bitcoin network to cost $1M to do a single double spend, then PoW has to use $1M worth of electricity every 10 minutes. Let's say we live in a future where we suddenly have 10x as much electricity. Due to supply and demand, electricity…

bitcoin incentivizes the search for cheaper energy, and allows for the instant monetization of once wasted energy. That's a LOT. this whole argument of energy use... i bet most of these people would have fallen for the same energy propaganda when the internet was just getting started... "what's email?? why would you waste electricity to send an electronic mail??"

> bitcoin incentivizes the search for cheaper energy, and allows for the instant monetization of once wasted energy.

This is just like saying: let's burn as much coal and oil as fast as we can, so we can accelerate the need to develop alternative fuel sources.

Re: Proof of stake is incapable of producing a consensus

#346

Earlier quoted context omitted.

then if you're not talking about governance, you're still wrong. there's no voting, only if you insist on re-defining what words mean, at which point i won't be interested in continuing the discussion.

Of course there is voting. Who do you think decides which transactions go in the chain, and in what order? The miner who wins leader election during this round (in Bitcoin anyway) does, and the rest of the nodes decide whether to accept its vote. The other nodes can also choose to reject this vote for a while, as long as after seeing it they don't accept a chain with less hashpower, and still follow the protocol (mor…

You have zero clue how bitcoin works.

No, there is no voting and there is no leader election. Miners construct blocks with transactions and if they manage to find a signature - that block is appended to the chain. If somebody does it faster - they append their block.

Please at least get the basics before you start arguing with people.

Re: Proof of stake is incapable of producing a consensus

#347

Earlier quoted context omitted.

If there’s a million tickets and you know one of them is a winner, then yes. If you have an effectively infinite stream of tickets and each have a 1 in X probability of winning, you will indeed go through X on average.

Yeah, I think that's right. The hypothesis was that on average , one in a million cards is a hit. That implies that if you scratch a million cards, you have a 50:50 chance of a hit. That the author got this basic thing wrong doesn't inspire much confidence in the rest of his reasoning.

Well, I guess in real life blockchains it’s like the latter case. You have a block and look for a nonce. There is an effectively infinite stream of nonces (“lottery tickets”). You have no guarantee that even one works, other than statistical hope. So then if probability of a match is 1 in X, you expect to have to do X attempts.

I have other issues with the article but this bit seems ok.

Re: Proof of stake is incapable of producing a consensus

#348
post #199

He lost me at the part where he thinks you can sign messages after withdrawing your stake. The whole point of proof of stake is that you can only sign blocks or messages while you have something staked. When you withdraw you are no longer allowed to sign anything. He also didnt need to spend 1000 words going on about the history of bitcoin and proof of work. This is literally just a filler piece with a provocative cl…

The argument he's making is, you could stake for blocks 10000-10005 and get your money back. And then produce a big fake chain from 10,002 (in the middle of the time you were staking) -> 10,000,000 later, with an alternate history in which you didn't stop staking. I don't think this attack is particularly realistic for a lot of reasons, but PoW does have some small amounts of additional strength against these scenari…

it's not realistic on POW because you have to mine the block and spend the resources. on pow you dont have to. Thats the whole problem.

Re: Proof of stake is incapable of producing a consensus

#349
post #131

> Proof of stake is a scam. When I say that, I mean that proof of stake is (1) claimed to be a consensus system, and (2) constitutionally incapable of actually producing a consensus. Ok. Go break one of the many existing systems that operates using proof of stake then. If you've done this, you should be leading your article with it. If you haven't, you shouldn't be speaking. Proof of stake is not some theoretical thi…

you didn't read the article to the end, did you? about 40% in: "Because of all the arguments above, we can safely conclude that this threat of an attacker building up a fork from arbitrarily long range is unfortunately fundamental, and in all non-degenerate implementations the issue is fatal to a proof of stake algorithm’s success in the proof of work security model. However, we can get around this fundamental barrie…

Observing what everyone else is using isn't 'trusting the rich'.

Re: Proof of stake is incapable of producing a consensus

#350

Earlier quoted context omitted.

Of course there is voting. Who do you think decides which transactions go in the chain, and in what order? The miner who wins leader election during this round (in Bitcoin anyway) does, and the rest of the nodes decide whether to accept its vote. The other nodes can also choose to reject this vote for a while, as long as after seeing it they don't accept a chain with less hashpower, and still follow the protocol (mor…

You have zero clue how bitcoin works. No, there is no voting and there is no leader election. Miners construct blocks with transactions and if they manage to find a signature - that block is appended to the chain. If somebody does it faster - they append their block. Please at least get the basics before you start arguing with people.

What, exactly, do you think the purpose of computing a SHA prefix is? It's to perform distributed, decentralized leader election. The leader who wins has the privilege of proposing the next block. "If somebody does it faster" is the voting aspect--nodes vote on who they think did it faster, and it is quite possible that they disagree (which can only be resolved by another round of leader election, since the next leader can choose which block to continue from). In the event that there's a longest chain, of course, nodes will go with the longest chain as a tiebreaker scenario.

I know far more about Bitcoin than I ever wanted to, believe me. You really should not be making these kinds of ad hominem arguments when you don't understand terms like "consensus" or "leader election."

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