Proof of Stake or Proof of Work, What's the Difference?(dapp.com)
dapp.com
Proof of Stake or Proof of Work, What's the Difference?
https://www.dapp.com/article/proof-of-stake-or-proof-of-work-whats-the-difference
90 comments
> One issue that proof of stake proponents often ignore is that proof of stake has its own costs that are roughly equivalent to the dollar cost of PoW.
> Also, if the PoS staking rewards are too low, you are vulnerable to the exact same 51% attacks as PoW.
"We all theoretically agree that I could have burned the most oil today (and in so doing, I will not be able to do something I could otherwise have done as my funds are locked up, which feels like a waste)" is a way way way way better scenario than "I guess we will all have to burn a bunch of oil to make sure I'm right (and in so doing we destroy our habitat, which more than feels like a waste)"... it really doesn't matter if it provides a better result than proof-of-work as long as it doesn't provide a worse one and has fewer externalities (if nothing else, as the people willing to play this game at all will have a selection bias for people who don't think the environment is important; we are already at the point where 1% of humanity's CO2 impact is from cryptocurrency mining, which is insane: "the economy is moving 1% slower as we are locking up capital in silly ways" is roughly harmless in comparison).
> Also, if the PoS staking rewards are too low, you are vulnerable to the exact same 51% attacks as PoW.
"We all theoretically agree that I could have burned the most oil today (and in so doing, I will not be able to do something I could otherwise have done as my funds are locked up, which feels like a waste)" is a way way way way better scenario than "I guess we will all have to burn a bunch of oil to make sure I'm right (and in so doing we destroy our habitat, which more than feels like a waste)"... it really doesn't matter if it provides a better result than proof-of-work as long as it doesn't provide a worse one and has fewer externalities (if nothing else, as the people willing to play this game at all will have a selection bias for people who don't think the environment is important; we are already at the point where 1% of humanity's CO2 impact is from cryptocurrency mining, which is insane: "the economy is moving 1% slower as we are locking up capital in silly ways" is roughly harmless in comparison).
> 1% of humanity's CO2 impact is from cryptocurrency mining
(I misremembered this by a factor of 10: it is actually 0.1%. But I still find that ludicrously high.)
(I misremembered this by a factor of 10: it is actually 0.1%. But I still find that ludicrously high.)
First of all you do realize that nobody is burning oil to mine bitcoin? And if you do but still represent it as such - why are you being manipulative?
Second, “let’s all agree I can be in charge of selecting which transactions to process because I have most money, which means I could have spent most energy” is circular system where security of money is paid for using same money.
Third, CO2 impact of cryptocurrencies is orders of magnitude lower than CO2 impact of fiat money and military structures required to assert their worth. Things don’t exist in a vacuum and you have to make the right comparisons.
Second, “let’s all agree I can be in charge of selecting which transactions to process because I have most money, which means I could have spent most energy” is circular system where security of money is paid for using same money.
Third, CO2 impact of cryptocurrencies is orders of magnitude lower than CO2 impact of fiat money and military structures required to assert their worth. Things don’t exist in a vacuum and you have to make the right comparisons.
> Third, CO2 impact of cryptocurrencies is orders of magnitude lower than CO2 impact of fiat money and military structures required to assert their worth.
And how many orders of magnitude are cryptocurrencies smaller than fiat money?
And how many orders of magnitude are cryptocurrencies smaller than fiat money?
it’s probably the right amount of orders of magnitude, it’s free market after all, everybody is free to long and short accordingly to their beliefs.
>"We all theoretically agree that I could have burned the most oil today [...]" is a way way way way better scenario than "I guess we will all have to burn a bunch of oil to make sure I'm right [...]"
note this argument only works if the costs of burning oil (habitat destruction) is being externalized. thus, this is more of a problem with externalization than a pos vs pow issue.
note this argument only works if the costs of burning oil (habitat destruction) is being externalized. thus, this is more of a problem with externalization than a pos vs pow issue.
The realization of that sort of idealism is so far fetched it doesn't change the argument. Sure, you could possibly get the USA to create laws to stop externalizing the costs of co2 production, but everyone, everywhere? Including the most corrupt, war torn, and penniless places in the world? And what about the deep state? They once sold cocaine to us citizens in order to raise money for black ops. Would they think twice about mining PoW?
> Sure, you could possibly get the USA to create laws to stop externalizing the costs of co2 production, but everyone, everywhere?
If you got 2 out of (USA,EU,PRC) to do it, and those countries all put big import tariffs and other sanctions on other countries that didn't, that would switch over the world economy to lowering CO2 emissions.
> Including the most corrupt, war torn, and penniless places in the world?
Corrupt and war-torn places still interact with the global economy. Penniless places aren't going to have enough of an economy to emit much CO2.
> And what about the deep state? [...] Would they think twice about mining PoW?
If there is a worldwide effort to shut down PoW cryptocurrencies, they will become useless and the deep state won't be able to achieve anything with them that it couldn't do more easily by other means.
If you got 2 out of (USA,EU,PRC) to do it, and those countries all put big import tariffs and other sanctions on other countries that didn't, that would switch over the world economy to lowering CO2 emissions.
> Including the most corrupt, war torn, and penniless places in the world?
Corrupt and war-torn places still interact with the global economy. Penniless places aren't going to have enough of an economy to emit much CO2.
> And what about the deep state? [...] Would they think twice about mining PoW?
If there is a worldwide effort to shut down PoW cryptocurrencies, they will become useless and the deep state won't be able to achieve anything with them that it couldn't do more easily by other means.
I can see your argument up to this point:
> If there is a worldwide effort to shut down PoW cryptocurrencies, they will become useless and the deep state won't be able to achieve anything with them that it couldn't do more easily by other means.
The whole discussion is about whether PoS is equivalent to PoW in terms of environmental harm, and I'm arguing that PoW is more costly. I don't understand what your general point is. Do you think PoW is more harmful than PoS or not? The parent was saying that it's an externalization problem. I don't think it's realistic to think that the damage to the environment could be charged back to the miner in every case, therefore PoW would always be more dirty than PoS. Could you clarify what your main point is in light of this?
> If there is a worldwide effort to shut down PoW cryptocurrencies, they will become useless and the deep state won't be able to achieve anything with them that it couldn't do more easily by other means.
The whole discussion is about whether PoS is equivalent to PoW in terms of environmental harm, and I'm arguing that PoW is more costly. I don't understand what your general point is. Do you think PoW is more harmful than PoS or not? The parent was saying that it's an externalization problem. I don't think it's realistic to think that the damage to the environment could be charged back to the miner in every case, therefore PoW would always be more dirty than PoS. Could you clarify what your main point is in light of this?
> The whole discussion is about whether PoS is equivalent to PoW in terms of environmental harm
it's wrong question anyway because it implies PoW necessarily causes environmental harm. PoW is consumption of energy, just like vast majority of other human activities. consumption of energy is not what harms the environment, at least not as directly as production of energy. the two are only closely related because of unwillingness of political elites to punish harmful producers, because those producers are the political elites or are closely related to them.
it's wrong question anyway because it implies PoW necessarily causes environmental harm. PoW is consumption of energy, just like vast majority of other human activities. consumption of energy is not what harms the environment, at least not as directly as production of energy. the two are only closely related because of unwillingness of political elites to punish harmful producers, because those producers are the political elites or are closely related to them.
This is not strictly true.
That’s like saying that in the US where factory farms are the norm, a new game causing people to buy as much veal as they can and throw it in the garbage has absolutely no responsibility for how many calves are raised in terrible conditions, because they COULD have been raised in good conditions, regardless of how many there are.
The fact is that human production capacity for energy is finite. The more pressure you put on this production capacity, the more it will cause companies to pop up and produce more energy. AS LONG AS the proportion of FOSSIL FUEL sources among these new companies will be high, you are indirectly contributing, via induced demand, towards more CO2 pollution. Yes if the world had moved to 99% sustainable energy then Bitcoin and Ethereum would not be contributing to the CO2 pollution problem in a meaningful way. But the current disitribution of energy production is relevant in assigning responsibility.
Just as if we all moved to fake lab grown veal, then maybe the game of throwing veal in the trash would not be harming animals in any meaningful way.
That’s like saying that in the US where factory farms are the norm, a new game causing people to buy as much veal as they can and throw it in the garbage has absolutely no responsibility for how many calves are raised in terrible conditions, because they COULD have been raised in good conditions, regardless of how many there are.
The fact is that human production capacity for energy is finite. The more pressure you put on this production capacity, the more it will cause companies to pop up and produce more energy. AS LONG AS the proportion of FOSSIL FUEL sources among these new companies will be high, you are indirectly contributing, via induced demand, towards more CO2 pollution. Yes if the world had moved to 99% sustainable energy then Bitcoin and Ethereum would not be contributing to the CO2 pollution problem in a meaningful way. But the current disitribution of energy production is relevant in assigning responsibility.
Just as if we all moved to fake lab grown veal, then maybe the game of throwing veal in the trash would not be harming animals in any meaningful way.
Nothing is strictly true except truisms, but I still disagree. Unless bitcoin consensus rules necessitated energy source that is harmful for environment, it is not fair to blame energy consumer for environment impact. Energy producer is the villain and spineless politicians that won’t enforce punishment for harmful energy sources.
I disagree, just as in the food example. Consumers are also to blame. If you know that your induced demand will be filled in the same way that current demand is being filled, then creating more demand is irresponsible, if it can be avoided. What benefit does wasting so much energy have? At least Siberian homes using mining to heat their house in the winter have a good side effect.
> If you know that your induced demand will be filled in the same way that current demand is being filled, then creating more demand is irresponsible, if it can be avoided. What benefit does wasting so much energy have?
I think you misunderstand PoW. Energy is not wasted, energy is spent to provide the security level that is demanded by the market. Nobody will spend a joule mining bitcoin unless it is profitable.
> At least Siberian homes using mining to heat their house in the winter have a good side effect
This is actually a bad thing, because it means mining is inefficient. Primary purpose of mining is to convert energy into PoW, if you get heat doing that - you’re not getting as much PoW as you could’ve got.
I think you misunderstand PoW. Energy is not wasted, energy is spent to provide the security level that is demanded by the market. Nobody will spend a joule mining bitcoin unless it is profitable.
> At least Siberian homes using mining to heat their house in the winter have a good side effect
This is actually a bad thing, because it means mining is inefficient. Primary purpose of mining is to convert energy into PoW, if you get heat doing that - you’re not getting as much PoW as you could’ve got.
You always create heat. That’s where the energy goes. Google “reversible computing” for theoretical approaches for computations that release zero heat.
Look, I can come up with a terrible sorting algorithm and get everyone using it as a requirement to participate a network protocol that will never change and then say look, it’s useful, it’s sorting stuff.
People have long invented far better things than PoW to secure distributed BFT systems. The transcations they can handle even scale with the number of machines, which is the case with the vast majority of applications on the Internet. If there was no alternative then MAYBE it wouldn’t be a waste (I think it would still be a bad trade-off). But you can literally just have a coin on another protocol which doesn’t use PoW arms race.
Look, I can come up with a terrible sorting algorithm and get everyone using it as a requirement to participate a network protocol that will never change and then say look, it’s useful, it’s sorting stuff.
People have long invented far better things than PoW to secure distributed BFT systems. The transcations they can handle even scale with the number of machines, which is the case with the vast majority of applications on the Internet. If there was no alternative then MAYBE it wouldn’t be a waste (I think it would still be a bad trade-off). But you can literally just have a coin on another protocol which doesn’t use PoW arms race.
> Do you think PoW is more harmful than PoS or not?
I've no idea.
My point was that if enough big states decided that PoW cryptocurrencies were undesirable, they would not find it enormously difficult to prevent much electricity being used on PoW mining, worldwide.
I've no idea.
My point was that if enough big states decided that PoW cryptocurrencies were undesirable, they would not find it enormously difficult to prevent much electricity being used on PoW mining, worldwide.
> The issue is that you need to lock up money for PoS in order to mine it. That has a cost as you are forgoing interest on lending that money to an actually productive enterprise that is creating value.
You do realize that stakers in PoS earn interest (paid for through inflation) on their locked collateral?
You do realize that stakers in PoS earn interest (paid for through inflation) on their locked collateral?
As I understand it, they earn a larger share of the money supply, as interest. But not actual economic profit stemming from some productive wealth-creating investment. Except insofar as their support of the coin itself enables ecomonic activity.
> productive wealth-creating investment
like hashing blocks?
If you believe this is a critique of PoS then it must also be a critique of PoW
like hashing blocks?
If you believe this is a critique of PoS then it must also be a critique of PoW
right, that's the main point. Why switch to POS at all? Suppose for a second ETH POS solution works as advertised. really fast and scalable. Then, there will be economic activity as a result of that speed and scalability, that would not have happened otherwise. At least that's the idea - may not ultimately work out.
So you’re saying it’s the same but better for environment and faster, with the same dollar cost?
>The issue is that you need to lock up money for PoS in order to mine it.
Not really fiat money. You have to stake the coin in question but presumably you'd be holding that anyway. I don't see any real world costs that compare to the spend on electricity and GPUs you get with proof of work.
Not really fiat money. You have to stake the coin in question but presumably you'd be holding that anyway. I don't see any real world costs that compare to the spend on electricity and GPUs you get with proof of work.
By the way (as someone who thinks PoS has serious problems) even if Proof of Stake had the same dollar cost, it wouldn’t have the same energy cost. That matters significantly, now.
Not everyone wants to lend their money (I say this as someone who runs a crowdfunding loan site). Most cryptocurrency today is just being hodl'd by folks, not put into active investments. There are also not a lot of good, trustworthy investments available to those who want to lend directly in crypto, though I'm sure we'll get more and more as time goes on.
> read http://www.truthcoin.info/blog/pow-cheapest/.
Modern PoS protocols prevent stake grinding with per-verifier VRFs and multi-round verification procedures.
Modern PoS protocols prevent stake grinding with per-verifier VRFs and multi-round verification procedures.
The complexity involved in making PoS “work” just increases the attack surface and enables political games around which workaround to implement next. And political games are decided by money, which is exactly what brings MR=MC, just like in PoW.
So why bother and not use simplest possible system that guarantees security using the ultimate currency - energy?
So why bother and not use simplest possible system that guarantees security using the ultimate currency - energy?
Why bother with baroque consensus algorithms at all, and not just use USD? Because new systems with new properties will enable new capabilities.
PoS is closer to fiat than PoW. PoS is more complex and relies on trust. There is nothing “baroque” about PoW, it’s simplest, cheapest and most reliable of them all.
"The issue is that you need to lock up money for PoS in order to mine it. That has a cost as you are forgoing interest on lending that money to an actually productive enterprise that is creating value. The net result is that funding and investment becomes more scarce because private investment is "crowded out" by people simply staking their Ethereum. This is the same harm caused by too much government debt "crowding out" private investment"
This is zero sum thinking. Yes, people will lock up money, which could have been invested elsewhere.
But you have to take into account the activity that happens on the chain as a result of POS, which itself will be productive presumably.
Thus the capital locked up in POS will be invested productively - because the activities enabled by POS themselves will be productive.
Of course, if there is nothing new that you can do as a result of POS - meaning, without POS you can already do all those things, then indeed there is no reason for POS. But the idea here ( which could be right or wrong ) is that POS will enable decentralized computation that would not happen otherwise.
EDIT: to downvoter: you can't say that locking up coins detracts from productive investment without evaluating what the chain ends up doing as a result of switching to POS. I mean, if you think that nothing useful will happen on a POS chain, that's a valid argument, but that's a different argument than simply worrying about locked up coins
This is zero sum thinking. Yes, people will lock up money, which could have been invested elsewhere.
But you have to take into account the activity that happens on the chain as a result of POS, which itself will be productive presumably.
Thus the capital locked up in POS will be invested productively - because the activities enabled by POS themselves will be productive.
Of course, if there is nothing new that you can do as a result of POS - meaning, without POS you can already do all those things, then indeed there is no reason for POS. But the idea here ( which could be right or wrong ) is that POS will enable decentralized computation that would not happen otherwise.
EDIT: to downvoter: you can't say that locking up coins detracts from productive investment without evaluating what the chain ends up doing as a result of switching to POS. I mean, if you think that nothing useful will happen on a POS chain, that's a valid argument, but that's a different argument than simply worrying about locked up coins
curious, what the downvoters are disagreeing with specifically in this comment.
An interesting idea I've been pondering is PoS' effect on wealth distribution and inequality. Its clear that this system exhibits the phenomenon of "wealth begetting wealth," which isn't that different from our current society. However, the real kicker here is that the more wealth you have on a PoS network the more control you have over the network. This is baked into the system by construction, whereas in our current framework of wealth this is merely a correlation which can be controlled via legislation.
PoW has economies of scale that reward existing wealth too.
Not just economies of scale. PoW IS a proof of capital.
"I can buy one million dollars worth of mining hardware and wait a year to earn my money back" is a proof of capital.
While it's true that the barriers to entry are quite similar in both (Eth 2.0 PoS depost is approx the same as 1 good bitcoin ASIC).
However, the dynamics wrt capital are different in PoW, and it's probably more accurate to say that it represents proof of captial _burned_ (miner depreciation & electricity costs).
However, the dynamics wrt capital are different in PoW, and it's probably more accurate to say that it represents proof of captial _burned_ (miner depreciation & electricity costs).
Not capital burned, because it's reimbursed by the network via fees.
With PoW all you get back are block rewards and fees; your hardware and energy are burned. With PoS you get block rewards and fees and you get your original stake back. Of course at equilibrium this means the rate of return from staking can be much lower.
It also means that a network based on PoS is much cheaper to maintain if we assume equal RoI between PoS and PoW. This is great and should give PoS a competitive advantage.
moreover the problem with PoW is that you can move your investment between different coins.
wealth is a correlate for control over legislation
Surprisingly, that isn't true [1]. I and others (link in the article) have shown that inequality actually (although quite slowly) decreases in PoS systems. [1] https://hackernoon.com/introducing-reputation-weighted-proof...
>Surprisingly, that isn't true
the linked article is light on details, but the source given in that article makes the following conclusion
>The Matthew Effect, where the rich get richer, is not much of a concern for Ethereum on a Proof of Stake issuance schedule, since the platform more or less in a steady state of relatively extreme wealth inequality
the linked article is light on details, but the source given in that article makes the following conclusion
>The Matthew Effect, where the rich get richer, is not much of a concern for Ethereum on a Proof of Stake issuance schedule, since the platform more or less in a steady state of relatively extreme wealth inequality
> energy consumption won't get any better unless some incredible technological achievements are made in processing capabilities or clean energy production.
How would power consumption decrease if there's a technological advancement on processing capabilities? They'll just put more money to increase their hardware and not everyone will somehow feel easy on earth to never expand their hardware.
> the fact that the 51% mark is becoming achievable is at best unsettling
Seeing 51% should be treated as a given. The point is the system should not give incentive for them to act as such.
Are you feeling unsettling to know U.S, Russia and Chinese army can combine their forces one day to take over the world?
How would power consumption decrease if there's a technological advancement on processing capabilities? They'll just put more money to increase their hardware and not everyone will somehow feel easy on earth to never expand their hardware.
> the fact that the 51% mark is becoming achievable is at best unsettling
Seeing 51% should be treated as a given. The point is the system should not give incentive for them to act as such.
Are you feeling unsettling to know U.S, Russia and Chinese army can combine their forces one day to take over the world?
The difference is that there exists no proof that PoS is even possible.
It exists purely as a rhetorical tool, used to attack the energy consumption of PoW.
It exists purely as a rhetorical tool, used to attack the energy consumption of PoW.
I'm still unconvinced about proof of stake. I've never seen a satisfactory answer to what happens if the chosen stakeholders are unwilling or unable to forge the next block in a timely manner.
I'll do some more research, but this problem still nags at me.
I'll do some more research, but this problem still nags at me.
There's a similar attack in PoW: a 51% attacker can just make empty blocks.
Either way, if your attacker is persistent and too dominant to beat, you can fix it with a hard fork. In PoW you change hash functions; you can generally do this only once for each hash implemented in ASICs and then you're down to general-purpose hardware and new functions don't help you.
In PoS, you can make a fork that simply eliminates the attacker's stake. You can continue this as many times as necessary.
This is, of course, the last-ditch remedy, applicable to any PoS protocol. Researchers do aim for "liveness," and can prove how dominant an attacker has to be to break it.
Either way, if your attacker is persistent and too dominant to beat, you can fix it with a hard fork. In PoW you change hash functions; you can generally do this only once for each hash implemented in ASICs and then you're down to general-purpose hardware and new functions don't help you.
In PoS, you can make a fork that simply eliminates the attacker's stake. You can continue this as many times as necessary.
This is, of course, the last-ditch remedy, applicable to any PoS protocol. Researchers do aim for "liveness," and can prove how dominant an attacker has to be to break it.
What do you mean no proof? I'm not saying any of these are worth much in global economy, but they definitely exist as a proof PoS works: https://www.poslist.org/
Actually there are formal proofs for the properties of various PoS designs, both in the Ethereum research community and outside it with academic projects. It's a fairly active area of research.
There are 500+ coins implementing some variation of PoS. Some are just copies, so the actual number is lower. Some are really innovative ideas that enable a whole new class of functionality that could not be accomplished with just PoW.
IOHK (Cardano) has proven that PoS is just as safe as PoW with actual mathematical proofs that are peer reviewed by actual cryptography professors. This is actually a big step forward as we now have trust that there's a system that acts the exact same way as PoW but in a vastly more energy efficient way in PoS. This almost relegates PoW to a legacy technology as there's no reason to use it anymore.
https://twitter.com/IOHK_Charles/status/989540452322836480
https://twitter.com/IOHK_Charles/status/989540452322836480
I think that Ouroboros paper [1] is a bit overhyped. A common criticism of proof of stake is that an attacker could acquire private keys to old accounts whose coins have already been spent, then use those to build a long fork. It has been shown [2] that these attacks are not wholly preventable if we assume that posterior corruption will happen:
> We shall formally prove that absent additional trust assumptions, it is impossible to achieve consensus in the presence of posterior corruptions when nodes can join or rejoin late.
The only tool we have to defend against posterior corruption attacks is checkpointing. If we treat blocks beyond a certain age T as irreversible checkpoints, and posterior corruption requires going back farther than T (because of staker withdrawal delays), then continuously running nodes won't be fooled by posterior corruption forks. New nodes, or nodes which went offline for a long period, could still be fooled, but they can always "ask a friend" for a recent checkpoint. This approach is what Vitalik [3] and others call weak subjectivity.
Charles et al. like to imply that they've solved this problem without resorting to weak subjectivity, but their "solution" to posterior corruption attacks is to mandate that honest parties delete private keys after using them:
> in order to achieve adaptive security the blocks are signed using a key-evolving signature scheme F_KES instead of a standard signature, and honest parties are mandated to update their private key in each slot.
It isn't much of a solution, since users have no incentive to delete their old private keys.
[1] https://eprint.iacr.org/2018/378
[2] https://eprint.iacr.org/2016/919
[3] https://blog.ethereum.org/2014/11/25/proof-stake-learned-lov...
> We shall formally prove that absent additional trust assumptions, it is impossible to achieve consensus in the presence of posterior corruptions when nodes can join or rejoin late.
The only tool we have to defend against posterior corruption attacks is checkpointing. If we treat blocks beyond a certain age T as irreversible checkpoints, and posterior corruption requires going back farther than T (because of staker withdrawal delays), then continuously running nodes won't be fooled by posterior corruption forks. New nodes, or nodes which went offline for a long period, could still be fooled, but they can always "ask a friend" for a recent checkpoint. This approach is what Vitalik [3] and others call weak subjectivity.
Charles et al. like to imply that they've solved this problem without resorting to weak subjectivity, but their "solution" to posterior corruption attacks is to mandate that honest parties delete private keys after using them:
> in order to achieve adaptive security the blocks are signed using a key-evolving signature scheme F_KES instead of a standard signature, and honest parties are mandated to update their private key in each slot.
It isn't much of a solution, since users have no incentive to delete their old private keys.
[1] https://eprint.iacr.org/2018/378
[2] https://eprint.iacr.org/2016/919
[3] https://blog.ethereum.org/2014/11/25/proof-stake-learned-lov...
CAN CRYPTOCURRENCY HELP SAVE THE WORLD?
I have an idea. What about a cryptocurrency that is generated by proving you planted a tree, or other type of carbon sink? Maybe some viral MLM scheme?
I originally wanted to make a cryptocurrency that encourages good, a “pay it forward” cryptocurrency. But I have come to realize that ultimately the priority is undoing the pollution and deforestation and desertification.
If we can harness the power of viral mechanics and of greed but make a system that rewards only REDUCING the CO2 and other pollution, then this system would actually make a very significant impact motivating large groups of people, including those organized into corporations and other organizations, to take action.
Maybe put carbon credits on a blockchain, for a start. But I would want reforestation, curbing other types of pollution, etc. to generate currency too.
https://u.today/ibm-launches-carbon-credit-cryptocurrency-on...
We have markets for crypto to trade vs fiat. The problem is, who will really prove that you did the good, and why can’t they just collude to issue more money? They would need something bigger to lose...
If you have some desire to do this, please contact me at greg and the domain is qbix.com
I have an idea. What about a cryptocurrency that is generated by proving you planted a tree, or other type of carbon sink? Maybe some viral MLM scheme?
I originally wanted to make a cryptocurrency that encourages good, a “pay it forward” cryptocurrency. But I have come to realize that ultimately the priority is undoing the pollution and deforestation and desertification.
If we can harness the power of viral mechanics and of greed but make a system that rewards only REDUCING the CO2 and other pollution, then this system would actually make a very significant impact motivating large groups of people, including those organized into corporations and other organizations, to take action.
Maybe put carbon credits on a blockchain, for a start. But I would want reforestation, curbing other types of pollution, etc. to generate currency too.
https://u.today/ibm-launches-carbon-credit-cryptocurrency-on...
We have markets for crypto to trade vs fiat. The problem is, who will really prove that you did the good, and why can’t they just collude to issue more money? They would need something bigger to lose...
If you have some desire to do this, please contact me at greg and the domain is qbix.com
PoW is a proven method to reach Byzantine-fault-tolerant consensus.
PoS is a deceptive marketing ploy that the Ethereum "Foundation" has been using since 2014[1] to dupe people into buying ethereum believing that PoS will replace Proof-of-Work.
[1] https://blog.ethereum.org/2014/01/15/slasher-a-punitive-proo...
PoS is a deceptive marketing ploy that the Ethereum "Foundation" has been using since 2014[1] to dupe people into buying ethereum believing that PoS will replace Proof-of-Work.
[1] https://blog.ethereum.org/2014/01/15/slasher-a-punitive-proo...
There are other coins that already use PoS.
How is it a ploy?
How is it a ploy?
>There are other coins that already use PoS.
There are some coins that use PoS as a voting mechanism not a consensus mechanisms. If you so desired, you could do the same in any PoW chain.
>How is it a ploy?
Broadly small-game fallacy[1]. If PoS would work at scale ethereum developers would have already deployed it. It doesn't work. Why?
An physical analogy for why PoS can never achieve BFT is: Assume 1) A cryptographic hash function is not broken 2) you live in a cave and you cannot talk the outside world
You are given a letter with a series of nested hash pointers that could have only been produced if they expended resources to created. There is no way this could have been faked, even though you live in a cave, you can trust the message. PoW is a stable BFT solution.
Another version of you in PoS land is also in a cave. You receive a message. It has a list of Arcade tickets that are signed by other Arcade tickets. In order to trust the veracity of this message you have to hope that someone else outside of your cave also saw this message to you because if they haven't, you could be being eclipse attacked, consequently defrauded. You cannot trust that this message hasn't been forged without contacting other people or hoping that other people have see this message. It's not stable it's not a solution to BFT. It's why after 4 years and counting Ethereum still hasn't implemented it.
[1] https://unenumerated.blogspot.com/2015/05/small-game-fallaci...
There are some coins that use PoS as a voting mechanism not a consensus mechanisms. If you so desired, you could do the same in any PoW chain.
>How is it a ploy?
Broadly small-game fallacy[1]. If PoS would work at scale ethereum developers would have already deployed it. It doesn't work. Why?
An physical analogy for why PoS can never achieve BFT is: Assume 1) A cryptographic hash function is not broken 2) you live in a cave and you cannot talk the outside world
You are given a letter with a series of nested hash pointers that could have only been produced if they expended resources to created. There is no way this could have been faked, even though you live in a cave, you can trust the message. PoW is a stable BFT solution.
Another version of you in PoS land is also in a cave. You receive a message. It has a list of Arcade tickets that are signed by other Arcade tickets. In order to trust the veracity of this message you have to hope that someone else outside of your cave also saw this message to you because if they haven't, you could be being eclipse attacked, consequently defrauded. You cannot trust that this message hasn't been forged without contacting other people or hoping that other people have see this message. It's not stable it's not a solution to BFT. It's why after 4 years and counting Ethereum still hasn't implemented it.
[1] https://unenumerated.blogspot.com/2015/05/small-game-fallaci...
Why? Easy, people kept figuring out attacks so they kept working on better designs. Figuring out a solid PoS protocol is nontrivial.
A few days ago Vitalik went through the history of Ethereum's proof of stake research at the annual Devcon, if anyone's interested: https://www.youtube.com/watch?v=Km9BaxRm1wA
At this point they're pretty happy with the protocol, the spec is mostly written, and eight teams are working on clients. The new design includes blockchain sharding for about 1000X better scaling.
Regarding your analogy, regardless of protocol you have a certain amount of "weak subjectivity," in that you at least have to know what client software to run. Otherwise you might be accepting invalid blocks.
The attacks you mention can be handled by requiring stake to be locked up for several months, and slightly broadening the subjectivity you accept to include a periodic known blockhash. You have to use off-chain social means to find out the correct recent hash, but you have to do the same to find out the correct software to run. https://blog.ethereum.org/2014/11/25/proof-stake-learned-lov...
A few days ago Vitalik went through the history of Ethereum's proof of stake research at the annual Devcon, if anyone's interested: https://www.youtube.com/watch?v=Km9BaxRm1wA
At this point they're pretty happy with the protocol, the spec is mostly written, and eight teams are working on clients. The new design includes blockchain sharding for about 1000X better scaling.
Regarding your analogy, regardless of protocol you have a certain amount of "weak subjectivity," in that you at least have to know what client software to run. Otherwise you might be accepting invalid blocks.
The attacks you mention can be handled by requiring stake to be locked up for several months, and slightly broadening the subjectivity you accept to include a periodic known blockhash. You have to use off-chain social means to find out the correct recent hash, but you have to do the same to find out the correct software to run. https://blog.ethereum.org/2014/11/25/proof-stake-learned-lov...
>you at least have to know what client software to run
The beauty of PoW is that you don't. By examining a PoW blockchain one can determine the relative amount of work expended. That provides trust with little to no external information. (All you need to know is the relative difficulty of hash functions and what info is hashed to form a block, both independently verifiable).
With PoS there is no analog. You must get your 'trust' externally, through deciding which codebase/client you want to use. Without external information / sidechannels, you have no way of determining which client nor which history to trust.
The beauty of PoW is that you don't. By examining a PoW blockchain one can determine the relative amount of work expended. That provides trust with little to no external information. (All you need to know is the relative difficulty of hash functions and what info is hashed to form a block, both independently verifiable).
With PoS there is no analog. You must get your 'trust' externally, through deciding which codebase/client you want to use. Without external information / sidechannels, you have no way of determining which client nor which history to trust.
If a 51% attacker makes an invalid transaction, you actually don't want to accept it just because they have more hashpower; if you did then 51% attackers could arbitrarily steal funds. If you don't accept invalid transactions, then you're using external knowledge of current validation rules.
Also, if you really assume that only the chain with the most hashpower is the valid one, then you have to ignore all other blockchains. And even then, you're assuming you know the correct hash function; given ASICs it's not practical to know what hash function requires the most economic effort just by looking at it.
Also, if you really assume that only the chain with the most hashpower is the valid one, then you have to ignore all other blockchains. And even then, you're assuming you know the correct hash function; given ASICs it's not practical to know what hash function requires the most economic effort just by looking at it.
Knowledge of consensus rules is the knowledge you’re building consensus upon. It’s a given.
But you have to get that knowledge, and the specific software to implement it, from some source other than the blockchain. In practical terms, it barely changes the security model if the download for new users includes a known blockhash from several months back, instead of only the hash of block zero.
Barely but importantly. With bitcoin for every user it is still feasible even on raspberry pi to download and verify the whole chain for themselves. Not so for ethereum even with high end computers. I guess that is their way to phase in PoS scam, but it has nothing to do with “preserving the security model”.
Utxo commitment is definitely a shortcut that bitcoin will eventually implement, but it can only work reliably for long timeframes especially when you have “disturbances in the force” like what happened with BCH last year.
“Known” blockhash from several months back is something that can easily be faked unless you actually fetch all the history and verify.
Utxo commitment is definitely a shortcut that bitcoin will eventually implement, but it can only work reliably for long timeframes especially when you have “disturbances in the force” like what happened with BCH last year.
“Known” blockhash from several months back is something that can easily be faked unless you actually fetch all the history and verify.
Voting and consensus are the same thing.
Only when you can control who can vote (Paxos)
Not when systems can fail or lie (PoW/Nakamoto Consensus)
Voting is sybill vulnerable.
Voting is sybill vulnerable.
I agree with your general idea that PoW is still superior to, or at least more necessary than, PoS, but voting in a PoS system is not sybil vulnerable because you have to lock a resource. If you assume an attacker has enough resource to lock through a sybil attack then they would have the resource available to control a PoW system anyway.
The point is the resource has to be external (i.e. outside of the consensus system) in order to be invulnerable to sybil attacks. In PoW this external resource is computing power, while in PoS it is the resource of the system itself (which might be internal to the consensus system, but has to necessarily be gained externally).
The point is the resource has to be external (i.e. outside of the consensus system) in order to be invulnerable to sybil attacks. In PoW this external resource is computing power, while in PoS it is the resource of the system itself (which might be internal to the consensus system, but has to necessarily be gained externally).
the 'post 2017' bubble truth of the answer is this:
any successful network running proof of work will become a massive supercomputing cloud where only commercially centralized entities , including mining farms, and successful mining POOLS , are able to participate in a vast network which becomes dominated by a cartel of players who can bring the COST OF WORK DOWN AT SCALE. this doesn't necessarily mean the network dynamic leads to LESS decentralizatin over time, but it sort of means it does at the 'non-commercial' level of doing work. this is WORK WORK at the industrial scale.
proof of stake is everything else, where network participation doesn't require WORK as the core of ensuring a cryptophraphic signing system for a bunch of data.
in the modern sense, work is electricity or some proxy for electricity ( proof of compute cycles in the case of 'compute' coins like golem )
any successful network running proof of work will become a massive supercomputing cloud where only commercially centralized entities , including mining farms, and successful mining POOLS , are able to participate in a vast network which becomes dominated by a cartel of players who can bring the COST OF WORK DOWN AT SCALE. this doesn't necessarily mean the network dynamic leads to LESS decentralizatin over time, but it sort of means it does at the 'non-commercial' level of doing work. this is WORK WORK at the industrial scale.
proof of stake is everything else, where network participation doesn't require WORK as the core of ensuring a cryptophraphic signing system for a bunch of data.
in the modern sense, work is electricity or some proxy for electricity ( proof of compute cycles in the case of 'compute' coins like golem )
Can't believe after all this time, this is still up for debate... Proof-of-work is the only 'solution'. Proof-of-stake is a pipedream. You can't secure a system using itself, just ask Gödel.
Proof of stake is a solution to both the mining problem and scalability. Proof of stake, from a hardware perspective means professional machines being wholly dedicated to block production. This filters out smaller market participants who host nodes. This centralizes the network a bit, but not enough to make it not state power resistant. The trade off is enough scalability to fit current demand, and better and more efficient service as a global open computer. The bet of proof of stake vs work is really how much do we think states can influence the meme of blockchain’s uncheatable ledger, and if increases in performance is worth the risk. Either, due to the open properties of blockchain, we’ll likely see both situation play out in the open market.
So what amount is going to be roughly at stake for a single block? A lot? How much in %age if ether is going to be at stake? After X years, assuming better performance that is claimed by PoS?
Given that so many people are using cryptocurrency as a store of value we should expect a large fraction to be staked.
The problem with Proof of Work is that it is too inefficient and not that it consumes too much energy. If bitcoin could do 100k transactions per second globally, no one would be talking about Proof of Stake. We'd be talking about: how do we make mining green?
We don't. It will be bypassed.
Remember those happy times when you could mine crypto at home? We know how that story unfolded and ended.
Remember those happy times of a year ago when the greater fool game was being played out? We know how that story unfolded and ended.
The shape-shifting blockchain moved on.
There will be plenty of people that pursue their blockchain ideas with promises of revolution with people able to get kidney transplants extra betterly due to blockchain, promises of freeing people from the slavery of the 'fiat' printed money, promises of helping remote farmers in Africa have title to their land, promises of vegans able to buy their avocados with added blockchain goodness and so forth. There will be a lot of big words tantamount to pseudo science uttered complete with 'playground voices' (shouting louder if questioned) so these people will be able to get on with their save-the-world by blockchain things, in good faith, no arguments needed, picking up investors as needed. People like myself that ask the questions out of concern that folks involved don't get burned will learn to shut up.
This group of people that are ideologically invested in blockchain will be making promises for solving the problems of 'making it green', leave them to it and watch how the market for crypto investments shakes out. I think that the problem will get bypassed.
Bitcoin futures did not take off, really this was a failure of marketing rather than a fundamental problem. Next time round you will be able to invest in a fund with your 'fiat' currency (or real money if you want to see it that way). The bank will invest your money in Bitcoin but they won't be trading in it or using it as a means of exchange. Other crypto-currencies including Ethereum will go by the wayside and the Bitcoin maximalists will kind of win.
In time this Bitcoin will be as originally promised - as good as gold. It will sit there in a bank and not in your wallet. It won't be vulnerable like a normal stock (even Apple isn't totally golden) or even property come the big crash. I am not saying that there will be a big crash in late stage, post 2008 capitalism, but what goes up must come down. Many perceived disadvantages of Bitcoin will become advantages. Not being able to do transactions quickly will become an advantage, it being too complicated for your grandma will become an advantage.
When the world was on the Gold Standard the gold just sat there in Fort Knox, none of it being transacted. Bitcoin will be just the same, it will just sit there, not having to have blockchain things actually happen to it. It is in this way that the PoW problem, the slow speed problem as well as the mining-green problem gets solved.
Already there are moves afoot for this new model of acceptance of how Bitcoin is going to be. Once Bitcoin is in the digital vaults of the financial institutions it will have a different store-of-value to today, people will be happy to invest in these products. It will work out fine and the people who are a tad zealous about saving-the-world-with-really-complicated-blockchain-ideas-and-no-domain-knowledge will just be heard from less and less.
I am not trying to be nasty or dismissive of blockchain out of any bitterness, this is just my assessment of how things actually are panning out.
Remember those happy times when you could mine crypto at home? We know how that story unfolded and ended.
Remember those happy times of a year ago when the greater fool game was being played out? We know how that story unfolded and ended.
The shape-shifting blockchain moved on.
There will be plenty of people that pursue their blockchain ideas with promises of revolution with people able to get kidney transplants extra betterly due to blockchain, promises of freeing people from the slavery of the 'fiat' printed money, promises of helping remote farmers in Africa have title to their land, promises of vegans able to buy their avocados with added blockchain goodness and so forth. There will be a lot of big words tantamount to pseudo science uttered complete with 'playground voices' (shouting louder if questioned) so these people will be able to get on with their save-the-world by blockchain things, in good faith, no arguments needed, picking up investors as needed. People like myself that ask the questions out of concern that folks involved don't get burned will learn to shut up.
This group of people that are ideologically invested in blockchain will be making promises for solving the problems of 'making it green', leave them to it and watch how the market for crypto investments shakes out. I think that the problem will get bypassed.
Bitcoin futures did not take off, really this was a failure of marketing rather than a fundamental problem. Next time round you will be able to invest in a fund with your 'fiat' currency (or real money if you want to see it that way). The bank will invest your money in Bitcoin but they won't be trading in it or using it as a means of exchange. Other crypto-currencies including Ethereum will go by the wayside and the Bitcoin maximalists will kind of win.
In time this Bitcoin will be as originally promised - as good as gold. It will sit there in a bank and not in your wallet. It won't be vulnerable like a normal stock (even Apple isn't totally golden) or even property come the big crash. I am not saying that there will be a big crash in late stage, post 2008 capitalism, but what goes up must come down. Many perceived disadvantages of Bitcoin will become advantages. Not being able to do transactions quickly will become an advantage, it being too complicated for your grandma will become an advantage.
When the world was on the Gold Standard the gold just sat there in Fort Knox, none of it being transacted. Bitcoin will be just the same, it will just sit there, not having to have blockchain things actually happen to it. It is in this way that the PoW problem, the slow speed problem as well as the mining-green problem gets solved.
Already there are moves afoot for this new model of acceptance of how Bitcoin is going to be. Once Bitcoin is in the digital vaults of the financial institutions it will have a different store-of-value to today, people will be happy to invest in these products. It will work out fine and the people who are a tad zealous about saving-the-world-with-really-complicated-blockchain-ideas-and-no-domain-knowledge will just be heard from less and less.
I am not trying to be nasty or dismissive of blockchain out of any bitterness, this is just my assessment of how things actually are panning out.
Why is this comment downvoted? It's a well reasoned opinion and guy has balls to make a solid prediction. You may not agree, ok fine. But he put it out there, it's not a stupid comment, not a "metoo" comment, it's a considered viewpoint and that's worth more than casual cheap dismissal. Slap it if you want to but this reactionary downvoting makes the site worth less.
Human psychology is far more interesting than Bitcoin. Time for an analogy.
In theory I could be getting a nice sweet pay-cheque for keeping a server room running like clockwork. This server room could be for a new startup paid for by the Danish Bacon Marketing Board and the product could be 'mySpace for pigs'. I could have my reservations about whether the target demographic ('pigs') might really be tech-savvy enough to post their squeals and grunts online.
Despite the reservations the pay-cheque might be very handy and I might also get to learn lots about 'sys-ops' along the way. For me the compromise might be worth it.
If a vegan Muslim friend disliked what I was working on, claiming that I was part of some evil plan to further enslave our animal friends, how would I respond? I could go ad-hominem on them, calling them a hypocrite for wearing blue suede shoes and skipping their prayers.
If a normal friend pointed out the doubts I already had then I could deny my reservations and quote some statistics about engagement claiming that it will only be a matter of time before the pigs will get with the programme. I could keep digging and cite how genetic modification will handle the lack of opposable thumbs. Or I could claim that the problems will be solved with new A.I. algorithms that will convert those squeaks into beautiful Unicode.
Alternatively I could explain the scam and why it works for me, i.e. that nice fat pay-cheque, my realistic chances of getting 'a proper job' and how that the client is absolutely loaded, that they need this project to work to show the government that they are doing their best for pig welfare and that they know that they know full to well that the project is bogus.
If I went with the latter option - being honest about my motives and the compromises I have made to pay the mortgage then I wouldn't need to put crazy arguments out there to defend myself. We could move on.
This analogy is not far off some of the projects I have worked on over the years, sometimes you take the money and experience gained knowing full too well that the business has a dubious future.
With Bitcoin and the wider cryptocurrency gig there are very few people who are able to express what they are doing with full appreciation for the contradictions given.
I have one friend who is honest about it and the irony is that his coins really are the proceeds of crime. He is up-front about playing the greater fool game and massaging income from the black economy into legitimate assets. He does not care about feeding the starving of Africa by Bitcoin and does not pretend to have any noble ambitions for making the world a better blockchain.
Meanwhile I find others who have no history of actual crime are less than willing to admit that they might have ulterior motives for doing what they doing with cryptocurrency. I get the 'this problem will be solved' nonsense. They will get louder and louder in this not-so-constructive one-way discussion which is a waste of time. There is no need for them to go off into the post-truth world this way. It just makes me wonder if they have been drinking too much of the Koolaid and might be delusional.
I would prefer to move on to the more interesting discussion to be had on the real long term future of the blockchain and where real money can be made. And, as I understand it, the problems really can be solved by selling financial products that are backed by bitcoin and not any of the other cryptocurrencies. Bitcoin is a commodity, not centralised at all. The other coins have someone with a name and an address who might talk the decentralised talk but financial authorities aren't going to necessarily see it that way forever - someone controls the code or the website effectively meaning there is a central point of control. Bitcoin is the unicorn, with all of its flaws, the work around for financial products is as per my earlier post and there is evidence that is happening.
In theory I could be getting a nice sweet pay-cheque for keeping a server room running like clockwork. This server room could be for a new startup paid for by the Danish Bacon Marketing Board and the product could be 'mySpace for pigs'. I could have my reservations about whether the target demographic ('pigs') might really be tech-savvy enough to post their squeals and grunts online.
Despite the reservations the pay-cheque might be very handy and I might also get to learn lots about 'sys-ops' along the way. For me the compromise might be worth it.
If a vegan Muslim friend disliked what I was working on, claiming that I was part of some evil plan to further enslave our animal friends, how would I respond? I could go ad-hominem on them, calling them a hypocrite for wearing blue suede shoes and skipping their prayers.
If a normal friend pointed out the doubts I already had then I could deny my reservations and quote some statistics about engagement claiming that it will only be a matter of time before the pigs will get with the programme. I could keep digging and cite how genetic modification will handle the lack of opposable thumbs. Or I could claim that the problems will be solved with new A.I. algorithms that will convert those squeaks into beautiful Unicode.
Alternatively I could explain the scam and why it works for me, i.e. that nice fat pay-cheque, my realistic chances of getting 'a proper job' and how that the client is absolutely loaded, that they need this project to work to show the government that they are doing their best for pig welfare and that they know that they know full to well that the project is bogus.
If I went with the latter option - being honest about my motives and the compromises I have made to pay the mortgage then I wouldn't need to put crazy arguments out there to defend myself. We could move on.
This analogy is not far off some of the projects I have worked on over the years, sometimes you take the money and experience gained knowing full too well that the business has a dubious future.
With Bitcoin and the wider cryptocurrency gig there are very few people who are able to express what they are doing with full appreciation for the contradictions given.
I have one friend who is honest about it and the irony is that his coins really are the proceeds of crime. He is up-front about playing the greater fool game and massaging income from the black economy into legitimate assets. He does not care about feeding the starving of Africa by Bitcoin and does not pretend to have any noble ambitions for making the world a better blockchain.
Meanwhile I find others who have no history of actual crime are less than willing to admit that they might have ulterior motives for doing what they doing with cryptocurrency. I get the 'this problem will be solved' nonsense. They will get louder and louder in this not-so-constructive one-way discussion which is a waste of time. There is no need for them to go off into the post-truth world this way. It just makes me wonder if they have been drinking too much of the Koolaid and might be delusional.
I would prefer to move on to the more interesting discussion to be had on the real long term future of the blockchain and where real money can be made. And, as I understand it, the problems really can be solved by selling financial products that are backed by bitcoin and not any of the other cryptocurrencies. Bitcoin is a commodity, not centralised at all. The other coins have someone with a name and an address who might talk the decentralised talk but financial authorities aren't going to necessarily see it that way forever - someone controls the code or the website effectively meaning there is a central point of control. Bitcoin is the unicorn, with all of its flaws, the work around for financial products is as per my earlier post and there is evidence that is happening.
I think it unlikely that blockchains which can actually be used at scale will fall by the wayside, while bitcoins triumph over all just sitting in cold storage.
Regarding your new model of acceptance of how Bitcoin is going to be, that would make Bitcoin nothing less than a meme-coin. Which of course can work, just look a Dogecoin. However, it's kind of sad if that happens.
Even if PoW can scale, going from 0.5% of the world's electricity to zero would still be an advantage of PoS.
>The problem with Proof of Work is that it is too inefficient and not that it consumes too much energy. If bitcoin could do 100k transactions per second globally
The amount of energy mining consumes is not driven by the number of transactions. Decreasing the number of transactions 100% or increasing them 10X doesn't decrease the energy spend 100% nor 10X.
The amount of energy mining consumes is not driven by the number of transactions. Decreasing the number of transactions 100% or increasing them 10X doesn't decrease the energy spend 100% nor 10X.
If you decrease the number of transactions 100% there would be no need to mine blocks, resulting in an impressive energy savings. :)
Mind you that blocks are mined at regular intervals with or without transactions.
mining activity follows the price.
I went through a nice twitter exchange with Craig Wright of BCH about the math of Pow . It was an awesome learning experience . Craig explained Pow as a multi-leader-follower Stackelberg game. While POS degrades to an oligopoly
https://twitter.com/ProfFaustus/status/954320533654507520?s=...
https://twitter.com/ProfFaustus/status/954320533654507520?s=...
Just FYI, that guy is a fraud and a scammer, faked evidence that he is satoshi and has consolidated an absolute majority of cryptocurrency world in an opinion that he is the most toxic thing that happened to cryptocurrency world.
Craig is the guy who states himself as Satoshi, except he failed to provide any proof.
Even worse, he tried to fake a proof.
One issue that proof of stake proponents often ignore is that proof of stake has its own costs that are roughly equivalent to the dollar cost of PoW. The issue is that you need to lock up money for PoS in order to mine it. That has a cost as you are forgoing interest on lending that money to an actually productive enterprise that is creating value. The net result is that funding and investment becomes more scarce because private investment is "crowded out" by people simply staking their Ethereum. This is the same harm caused by too much government debt "crowding out" private investment.
Also, if the PoS staking rewards are too low, you are vulnerable to the exact same 51% attacks as PoW. So it's very unsure how this would significantly reduce fees unless you are also significantly increasing your vulnerability to attack. (Now, there are caveats about the fungibility and the ease of renting PoW miners vs renting PoS tokens, but many of the same principles apply).