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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

#721

Post by meribold »

rufusroflpunch wrote: post #658
meribold wrote: post #553

Earlier quoted context omitted.

I imagine the idea of a hard fork of Bitcoin may become more popular as the supply limit is approached and transaction fees go up. The current transaction fee is only a few dollars but the cost is over a hundred. Eventually the fee will have to cover the full cost and a hard fork may start to look more interesting. If this happens I can technically stay on the original protocol, but that would be rather pointless if…

I wouldn’t worry about it. Bitcoin incentivizes energy development. As the world moves to a Bitcoin standard, we will unlock new types of energy that were previously unproductive. It’s likely that energy will more cheap and plentiful under a Bitcoin standard, leading to downward pressure on transaction prices as mining is more economical. Also, more transactions are likely to move off chain to Lightning Network and s…

I don't see how cheaper energy would help. Bitcoin needs a certain amount of power in units of cost to be tied up mining to secure the network. If the cost of energy goes down ten times then the same PoW requires ten times the energy.

Re: Proof of stake is incapable of producing a consensus

#722

Post by PeterisP »

comex wrote: post #713
mattalex wrote: post #703

Earlier quoted context omitted.

> It's not 66% of the stake that has to be good, it's 66% of anyone who has ever staked. In PoW, I only need to trust the miners of today to tell me the truth about what happened today. I don't quite get that. As far as I understand it the "nothing at stake" problem works by a malicious party inducing a fork, one of which they double-spend in. Since it's in the best interest for everyone else to mine both forks, you…

> If it is recognised that you mine on more than one fork at a time, you lose the security deposit you gave before the fork. Yes, modern proof-of-stake algorithms work this way. The caveat is that at some point (on the order of months later) the security deposit is refunded, and at that point you can lie about the past without consequence. But this is a limited attack: you can only successfully lie to someone who has…

The original article asserts that this does not work according to their requirements since there's no way to independently verify which is the "real successor chain" - they just have to trust someone's word that chain A is true and chain B is not, and a convincing liar could provide them with opposite data. In schemes like Bitcoin, there's objective validation of the "longest chain" with the most work invested; in your example where would that "record of the real successor chain" come from, and how can it be validated/verified in a decentralized manner in a way that a major ex-staker can't satisfy?

Like, this is trivially solved with a central authority (e.g. have some trusted core developer every day publish a signed message saying "this is the real successor chain"), but it does enable that central authority to arbitrarily bless a fake ex-staker's fork.

Re: Proof of stake is incapable of producing a consensus

#723

Post by meribold »

javert wrote: post #621
meribold wrote: post #553

Earlier quoted context omitted.

I imagine the idea of a hard fork of Bitcoin may become more popular as the supply limit is approached and transaction fees go up. The current transaction fee is only a few dollars but the cost is over a hundred. Eventually the fee will have to cover the full cost and a hard fork may start to look more interesting. If this happens I can technically stay on the original protocol, but that would be rather pointless if…

The natural scenario is that as the mining reward goes down, hash rate will dwindle until mining is profitable again. The only real problem with that is that with a small hash rate, bitcoin can be attacked more easily. If bitcoin is the monetary backbone for many nations, they will subsidize miners to maintain the balance of power. That is the actual scenario that I'm optimistically predicting. If bitcoin isn't the m…

I don't see why many nations would jump at the opportunity to make Bitcoin their monetary backbone. For example because an immutable monetary policy won't be seen as a feature.

Re: Proof of stake is incapable of producing a consensus

#724

Post by PeterisP »

rocqua wrote: post #300
supermatt wrote: post #94

Earlier quoted context omitted.

> For PoW, you'd have to know the hash of the start of the chain (the "genesis block") in advance to verify you downloaded the correct chain. Nope. You could fork the chain at a period of low difficulty and it would still stem from the genesis block. It would either be a short chain, or have clearly low difficulty though, so it wouldnt fool anyone knowledgeable. Im not sure how you would leverage that chain for fraud…

A while ago bitcoin clients changed from facoring the 'longest' chain to favoring the chain with the most work done on it. (To prevent long chains with low difficulty)

The client can choose properly, but it needs to "call a friend" in order to get the options - if the client doesn't receive the proper chain but only fake ones, it will chose the fake one with the most work done on it.

Re: Proof of stake is incapable of producing a consensus

#725

Post by hackernews777 »

comex wrote: post #60
ricardolopes wrote: post #49

Earlier quoted context omitted.

The Bitcoin Core client includes a hardcoded list of DNS servers that point to thousands of nodes. These lists get updated frequently by different people. Other clients may use other lists. What is the threat model you're suggesting here, exactly? Do you know any other way to bootstrap a peer to peer network without centralised authorities? All network participants are forced to verify the full chain from genesis. So…

> Do you know any other way to bootstrap a peer to peer network without centralised authorities? I’m not the parent, but – no, I don’t. But that’s exactly the point. The need to bootstrap from centralized authorities is what’s supposedly so bad about weak subjectivity in proof-of-stake. Yet in practice, it’s needed with proof-of-work as well.

It's not actually needed, its simply a convenience for users who just want it to work out of the box. You can hand configure the bootstrapping process with -connect and -addnode if you wish.

Re: Proof of stake is incapable of producing a consensus

#726

Post by specialist »

drclau wrote: post #299
wcoenen wrote: post #268

Whether PoS will work, I don't know. But the author didn't realize that PoW is certainly doomed. PoW miners tend to spend more and more resources on finding blocks, until the cost approaches the rewards. But the rewards go up as the cryptocurrency becomes more popular, because the price and transaction fees go up. Therefore, a PoW cryptocurrency tends to "eat the world" as it becomes bigger. That's why Bitcoin is alr…

> Bitcoin is already approaching 1% of global electricity consumption, if it hasn't passed that point already And this is the reason why I cannot take any climate change conversation seriously unless it includes the topic of cryptocurrencies. Whatever the promises of cryptocurrencies were, now most (all?) degenerated into a mechanism for speculation, and effectively into a self-sustaining and self-promoting mechanism…

What percentage do you think merits serious consideration?

Re: Proof of stake is incapable of producing a consensus

#727

Post by zocoi »

cs702 wrote: post #693
teawrecks wrote: post #674

Earlier quoted context omitted.

IMO people listing things that discourage an attack (people will hate him, his credit cards won't work, etc) are just people trying to comfort themselves. It's like saying, "No one would break into my home because they might hurt themselves breaking in, or I might hurt them up, or they might get caught by the police and go to jail. It's just too risky." At the end of the day, Dr. Evil will gladly spend 10s of billion…

That's not what I said. Please don't attack a straw man. My main point was, and is, that the same attack-logic applies to ANY transaction network. The example with Doctor Evil was about other transaction networks. Why would Doctor Evil attack a block chain network when he could attack global/national/regional credit card/wire transfer/ACH networks, many of which are built upon ancient pre-Internet technology, are ful…

You didn’t answer the parent post. Your point was, in game theory, there’s no benefit in attacking the network or the loss is huge that it doesn’t worth the the attack. The parent post gave the counter point that there could be a benefit which we haven’t thought. If Dr Evil is heavily invested in 2 network, he might destroy one to focus on the remaining. The chance of the attack is low but it is not zero

Re: Proof of stake is incapable of producing a consensus

#728

Post by wmf »

cinquemb wrote: post #718
wmf wrote: post #575

Earlier quoted context omitted.

You can fork decentralized over (crypto) collateralized stablecoins In practice the value of the forked collateral is likely to be low, leaving the stablecoins insolvent.

If you are forking the chain state and not just the vm, that could be the case. However, if you are only forking the vm and allowing for people de deploy other protocols (or forks of other protocols), this is not the case (they just start off at lower total supply relative to the native collateral available on that network from a lower demand base).

I don't consider it a fork unless it includes the state. For example, ZCash is based on Bitcoin code but nobody considers it a fork of Bitcoin and there are various chains like Avalanche that support EVM but they aren't forks of Ethereum.

Re: Proof of stake is incapable of producing a consensus

#729

Post by cinquemb »

wmf wrote: post #728
cinquemb wrote: post #718

Earlier quoted context omitted.

If you are forking the chain state and not just the vm, that could be the case. However, if you are only forking the vm and allowing for people de deploy other protocols (or forks of other protocols), this is not the case (they just start off at lower total supply relative to the native collateral available on that network from a lower demand base).

I don't consider it a fork unless it includes the state. For example, ZCash is based on Bitcoin code but nobody considers it a fork of Bitcoin and there are various chains like Avalanche that support EVM but they aren't forks of Ethereum.

> I don't consider it a fork unless it includes the state.

I think id agree for things like ZCash/Dash etc compared to BTC, but I'm not sure I'd agree when it comes to the all contracts deployed on all EVM networks and none of this has anything to do with decentralized stablecoins.

For example, you can mint MIM (a decentralized stablecoin) on both avalanche c-chain and ethereum (as well as polygon, fantom, bsc and arbitrum), and they are both worth $1, but have different collateral backing it on both networks. If users wanted to leave one or the other, they could just redeem their mim for the underlying, sell it and buy the collateral on another network and mint it on the other network. The collateral might trade lower on one network based on market factors (like if the narrative shifted to that the chain became too centralized or w/e, and this assumes that even the price movement of the underlying overwhelms the over collateralization ratio, it might not) but it would just mean that there would be more or less mim on that particular network as assets are liquidated and not that the MIM itself would be worth less.

Re: Proof of stake is incapable of producing a consensus

#730

Post by dlubarov »

Kranar wrote: post #669
tromp wrote: post #229

Earlier quoted context omitted.

> You can literally validate the entire chain with a simple python script. I challenge you to present a "simple python script" that implements the exact bitcoin consensus rules (as codified in bitcoin core). Bitcoin is not all that simple and there's a nontrivial amount of complexity in bitcoin script alone [1]. > The chain is validated in its entirety upon first sync. 100% from genesis to tip. The default behavior i…

You're misunderstanding the default behavior which is fine becaue it's commonly misunderstood and discussed. At any rate signature verification is not skipped by default, what assumevalid skips is script verification. Everything else including UXTO, proof of work, the transactions themselves, are validated.

That seems a bit pedantic; the client itself prints

> Assuming ancestors of block %s have valid signatures.

when using -assumevalid. I agree it's imprecise, but it's not exactly wrong, since skipping scripts implies skipping signatures.

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