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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

#61

Post by lukebitts »

omarfarooq wrote: post #43
TTPrograms wrote: post #22

Why do unsophisticated, redundant, vitriolic takes like this get upvoted on HN so much? Is there some common ax to grind here? The strongest point here is the strawman presentation of the altered security model that PoS can be proven to form consensus under. Reading the source he cites is far more informative: https://blog.ethereum.org/2014/11/25/proof-stake-learned-lov... The majority of the article frames distribut…

One way of conquering FOMO is to totally write the thing off, and to stubbornly stick to that thesis.

Questioning people's motives is always a boring endeavor. You don't actually know that's the reason, why not respond to the arguments that were made?

Re: Proof of stake is incapable of producing a consensus

#62

Post by betwixthewires »

TTPrograms wrote: post #22

Why do unsophisticated, redundant, vitriolic takes like this get upvoted on HN so much? Is there some common ax to grind here? The strongest point here is the strawman presentation of the altered security model that PoS can be proven to form consensus under. Reading the source he cites is far more informative: https://blog.ethereum.org/2014/11/25/proof-stake-learned-lov... The majority of the article frames distribut…

Thanks for that link, it has been a few years since I've read it.

I spent a lot of time talking about this topic with people. The article does have a point, that the security model of proof of stake is fundamentally different and relies on a key assumption (from the article you linked):

> any new node coming onto the network with no knowledge except... the set of all blocks and other "important" messages that have been published...

This is referenced in the OP as a point of security failure. The assumption is that we can rely on social interactions between nodes and that that is good enough. The criticism is that a new node can have no way of definitively knowing that their copy of the chain is the widely used canonical chain. An eclipse attack can occur, or as the OP stated new nodes may need to rely on authoritative sources to get current state which puts centralized power centers in the security model.

It is not a deal breaker (IMO), remember, PoW relies on the security assumption that it is prohibitively difficult for more than half the network to collude. I'd argue these assumptions are equally tenuous. I think as long as disparate, non colluding sources of the canonical chain are available (arguable if this is foregone, seeing as we need PoW to ensure consensus and resistance to collusion, probably not, but all it takes is one person to not collude and contention exists) it wouldn't be a problem.

Another big sticking point is the fact that no external resources must be invested, and/or that there is no ongoing cost. I find this to be the big problem with PoS schemes, I've had quite a number of discussions focused on these two particular issues (stemming from the same fundamental difference, that an internal capital stake is made) and I see benefits of not having ongoing cost and benefits of having it, and also of having a fully self contained system as well as having a system grounded in the outside world. All in all I have come to the conclusion that these differences make neither better nor worse, but that they are simply two completely different game theoretical environments with different security and incentive properties.

Re: Proof of stake is incapable of producing a consensus

#63

Post by anonporridge »

josnyder wrote: post #8

PoW systems rely on the "phone a friend method" as well. When you download a Bitcoin client from a "friend", you are trusting them to honestly introduce you to the network. If you fall asleep for a period of years, you have to trust your friends to honestly inform you of all of the PoW forks and policy changes that have occurred over that interval. The only difference is that PoS blockchain clients must be bundled wi…

You really don't need to trust a "friend" while bootstrapping into the network with PoW, because the proof of work is irrevocably embedded within the blockchain, and the real world cost of creating those blocks can be pretty easily estimated.

So long as you have a general idea of how much hash power is being used currently for the network, or even just how efficient ASIC computing is in general at your point in history, you can work out how great the hashing difficulty should be. You can trivially verify that the block hash with a large number of preceding zeros, e.g. 0000000000000000000b98dd8e7504793c0644cb0c27eb98f06aab9ea93c4ec2, is the hash of block it's attached to, and that a hash value that small would require a huge amount of energy to find. And every block beneath it also required a huge amount of energy, creating a huge real world economic cost to produce. You can't fake that chain without equivalent sacrifice of energy and compute resources.

Anyone trying to deceive you with a false chain would have to expend approximately as much energy as the entire legitimate bitcoin network does, and then keep doing it for as long as they want to deceive you. Sure, that theoretically could happen, but the economic incentives to do it just aren't there.

Re: Proof of stake is incapable of producing a consensus

#64

Post by Eelongate »

xiphias2 wrote: post #36
barbegal wrote: post #5

Proof of work has always had an economic flaw that you could theoretically temporarily rent enough mining power to perform double spends of more value than the cost of renting those devices. But this attack has never been performed because the reality of all these cryptocurrencies is that the security depends only relatively weakly on proof of work. Instead it relies on trust between the main stakeholders: miners, bi…

Renting out equipment for miners is dangerous, as an attack on the network can wipe out all their sunk costs. Bitcoin miner farms are very strongly incentivized to be aligned with the long term health of the system, so they try to play nice close to the ethos of Bitcoin (they learned enough from the blocksize wars that they can get burned if they go against Bitcoin)

An attack on bitcoin might have other motivations. For instance, a powerful government might attack bitcoin specifically to undermine bitcoin's credibility and utility.

Re: Proof of stake is incapable of producing a consensus

#65

Post by justusw »

5350-uiop-1130 wrote: post #11

PoS is a flawed system that enriches the project founders primarily. Just look at Charles Hoskinson or Gavin Wood. PoW is apparently bad for the environment. So it leaves us in an interesting situation. The Ethereum project has shown that the concept of decentralization only applies when it's on their terms. It's not a true principle.

How were Charles Hoskinson and Gavin Wood enriched? Is this about Cardano and Polkadot?

Re: Proof of stake is incapable of producing a consensus

#66

Post by G3rn0ti »

CraftingLinks wrote: post #19

Can't wait for the day all PoW mining activities are declared illegal. To be honest, I don't understand why it hasn't been banned already. Sweden has recently called for a EU wide ban because it identified PoW mining as a threat to transition their economy to renewable energy. https://www.fi.se/en/published/presentations/2021/crypto-ass...

Energy consumption of anything is irrelevant. The carbon footprint is the interesting marker of a technology and this will depend on the source of energy used.

Re: Proof of stake is incapable of producing a consensus

#67

Post by suikadayo »

sp332 wrote: post #26
rhincodon wrote: post #17

If POS is really as bad as claimed, then why is Ethereum 2.0 going to be using POS?

Well, how many times has it been delayed? Clearly it's not all sunshine and rainbows.

What’s delayed? Beacon chain has been running on mainnet since last December-ish. http://beaconcha.in

Re: Proof of stake is incapable of producing a consensus

#68

Post by xg15 »

barbegal wrote: post #5

Proof of work has always had an economic flaw that you could theoretically temporarily rent enough mining power to perform double spends of more value than the cost of renting those devices. But this attack has never been performed because the reality of all these cryptocurrencies is that the security depends only relatively weakly on proof of work. Instead it relies on trust between the main stakeholders: miners, bi…

> Instead it relies on trust between the main stakeholders: miners, big nodes and developers.

In other words, it relies not on one central authority but on a small clique of central authorities.

Re: Proof of stake is incapable of producing a consensus

#69

Post by EGreg »

This is like two homeless people arguing who is richer.

Yes both PoW, PoS solve the double-spend problem, but in a brute-force way. And they never really get rid of the ambiguity of which chain is the one to go by. They just aggregate all the little ambiguities into one or another consistent version of history (a chain) and let them duke it out by massive electricity or stake or whatever. But at any moment, someone could have been mining a chain in “secret” and will emerge to thwart the rest of the network for a while.

There is a better way. Blockchains are actually quite centralized since to make any progress every N seconds you need to send all transactions in the entire world to one miner, and the block is limited in size. Actually it’s worse than that in Proof of Work — because you don’t know who will solve the silly problem, you have to gossip every transaction to every miner!

Oh yeah, and if you store UTXOs then you have to store the history of everything. And even if you didn’t, you have to store the current state of everything. Oh how nice and decentralized! LMAO

Re: Proof of stake is incapable of producing a consensus

#70

Post by Eelongate »

SturgeonsLaw wrote: post #13
jimbob45 wrote: post #4

Earlier quoted context omitted.

It’s already fixed to some extent. On Reddit, you make a new subreddit of your own. On GitHub, you fork. The problem is that some projects are too big to effectively fork (or forking would over leverage the community) or people are lazy and don’t want to do the forking themselves despite accurately identifying the presence of a problem.

So you can sit around in your new subreddit with enough subscribers that you can count them on your fingers, posting freely, while /r/politics (or wherever) has a subscriber base measured in millions. Reminds me a bit of the "free speech zones". It's a poor facsimile of true freedom of speech. Seeing as the new public squares are, by and large, digital spaces controlled by megacorps, we need to expand the first amend…

> So you can sit around in your new subreddit with enough subscribers that you can count them on your fingers, posting freely, while /r/politics (or wherever) has a subscriber base measured in millions.

And if by some chance your subreddit manages to become popular, the admins and power mods will conspire to take it from you. Reddit sucks.

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