Erik, thanks for the link. So referring to https://en.bitcoin.it/wiki/Proof_of_burn, I do not really understand how this is supposed to be that much better over many proof of stake proposals. If there is more research on PoB, please note I'm not commenting on that as I only read this wiki article and my comments are purely related to this only.
I hope we can agree that the idea with manual insertion of entropy every week can be discarded, but at the same time I don't think it is a crucial point of the whole idea. So we can just focus on the rest of it. Then the whole idea seems just like certain proof of stake implementations with just small differences, which I try to summarize: - in PoB, in order to use the coin for block production, you burn it in the past and wait some time -- in the certain PoS I'm talking about, in order to use the coin, you do not move the coin for some time - so in both there is the same idea - you somehow make the coin eligible for the block creation process by first doing some action followed by some inaction for some time; the difference here is that if later you use such coin in PoS, then after waiting more time, you can use the coin again (for whatever purpose), while in PoB the coin is gone forever (it is burned); this does not seem to be fundamentally different - in PoB, the author suggests there is an exponential decay of the power of the coin to create a block; in some PoS schemas, there historically was an era of so called CoinAge mechanism, which was somewhat inverse to this exponential decay, it was that the coin gets more power the older it is untouched, some implementations were for linear increase in the power, some exponential. Usually there was a certain limit - i.e. a maximum power the coin may have reached. It turned out quite quickly that such property is making attacks easier. PoB reverses the idea, but I don't think that helps that much. In any case, there seems to be an optimal period of time for each used coin, in both PoS and PoB, where the coin is most suitable for block production. I admit PoB version is better, but the crucial property here is that some coins are more powerful than other. - in both PoB and PoS it seems there is linear increase of the ability of the coin to produce blocks with the size of the coin (more BTC you burn/stake, the better your chance) This characteristic of PoB does not suggest that it would have that much different properties than PoS. So it should suffer from same problems as PoS. Namely, the problems I see now, with the given proposal from wiki, are: - there seems to be lack of definition of the heaviest chain and difficulty adjustment - this seems crucial, but likely solvable, I'm just saying it is importantly missing in the description - there seems to be a problem with nothing at stake (nothing at burn maybe?) - How that can be? Again, it seems that every burned coin can be used for free checks at any time after the initial waiting period. These free checks are indeed free and are the core of the nothing at stake problem in PoS. You seem to make those checks for free and you seem to be able to use those burned coins to create arbitrary number of forks build on any parent blocks of your choice, not just the last block of the heaviest chain. I can't see at the moment how is this different from PoS nothing at stake problem. Maybe you can explain? - it seems to me that there is a trivial attack against the scheme by a wealthy attacker. Suppose a common size of the burn is 1 BTC per block, suppose you define the heaviest chain rule somehow in relation to total number of burned coins or the cumulative "strength" of the "lowest" hashes, then you can just burn 20 UTXOs, each being 10 BTC in value, so you spent 200 BTC on this attack, but you are in very strong position because after you wait the needed time, you should be able to do pretty nasty reorg. Suppose that the main chain is A-B-C-D-E-F, so what you do at that point is that you just "try for free" all your 20 UTXOs, whether or not they can build on top of block A (which has 5 confs on top, F is the tip of the main chain). Since you have big UTXOs, your chances should be good, of course you can always try many times because you have a "lottery ticket" for every timestampt t. So with this you should be able, with good chance, to find such B' and then you have 19 UTXOs remaining to try to build on B' in the same way. I can't see what prevents this attack in the described scheme. - the ability to retroactively try all different kids of timestamp t seems devastating - you again get super easy and somewhat cheap attack (due to nothing at burn problem) that allows you to rewrite even long chains at will. Could you explain what am I missing here, because this actually does not seem better, but rather worse than some PoS schemes? Sent with ProtonMail Secure Email. ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On Friday, May 28, 2021 9:06 PM, Erik Aronesty <e...@q32.com> wrote: > best writeup i know of is here: > > https://en.bitcoin.it/wiki/Proof_of_burn > > no formal proposals or proofs that i know of. > > On Fri, May 28, 2021 at 10:40 AM befreeandopen > befreeando...@protonmail.com wrote: > > > Erik, I am sorry, I have little knowledge about proof-of-burn, I never > > found it interesting up until now. Some of your recent claims seem quite > > strong to me and I'd like to read more. > > Forgive me if this has been mentioned recently, but is there a full > > specification of the concept you are referring to? I don't mean just the > > basic idea description (that much is clear to me), I mean a fully detailed > > proposal or technical documentation that would give me a precise > > information about what exactly it is that you are talking about. > > Sent with ProtonMail Secure Email. > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ > > On Wednesday, May 26, 2021 11:07 PM, Erik Aronesty e...@q32.com wrote: > > > > > note: the "nothing at stake" problem you propose is not broken for > > > proof-of-burn, because the attacker > > > a) has no idea which past transactions are burns > > > b) has no way to use his mining power, even 5%, to maliciously improve > > > his odds of being selected > > > On Wed, May 26, 2021 at 9:12 AM befreeandopen > > > befreeando...@protonmail.com wrote: > > > > > > > @befreeandopen I guess I misunderstood your selfish minting attack. Let > > > > me make sure I understand it. You're saying it would go as follows?: > > > > > > > > 1. The malicious actor comes across an opportunity to mint the next 3 > > > > blocks. But they hold off and don't release their blocks just yet. > > > > 2. They receive a new block minted by someone else. > > > > 3. The malicious actor then chooses to release their other 2 blocks on > > > > on the second from the top block if it gives them more blocks in the > > > > future than minting on the top block. And instead lets the top block > > > > proceed if it gives them more blocks in the future (also figuring in > > > > the 3 blocks they're missing out on minting). > > > > 4. Profit! > > > > > > > > The problem with this attack is that any self respecting PoS system > > > > wouldn't have the information available for minters to know how blocks > > > > will affect their future prospects of minting. Otherwise this would > > > > introduce the problem of stake grinding. This can be done using > > > > collaborative randomness (where numbers from many parties are combined > > > > to create a random number that no individual party could predict). In > > > > fact, that's what the Casper protocol does to decide quorums. In a non > > > > quorum case, you can do something like record a hash of a number in the > > > > block header, and then have a second step to release that number later. > > > > Rewards can be given can be used to ensure minters act honestly here by > > > > minting messages that release these numbers and not releasing their > > > > secret numbers too early. > > > > Yes, you misunderstood it. First, let me say that the above thoughts of > > > > yours are incorrect, at least for non-quorum case. Since the transition > > > > in the blockchain system from S1 to S2 is only by adding new block, and > > > > since stakers always need to be able to decide whether or not they can > > > > add the next block, it follows that if a staker creates a new block > > > > locally, she can decide whether the new state allows her to add another > > > > block on top. As you mentioned, this COULD introduce problem of > > > > staking, that you are incorrect in that it is a necessity. Usual > > > > prevention of the grinding problem in this case is that an "old enough" > > > > source of randomness applies for the current block production process. > > > > Of course this, as it is typical for PoS, introduces other problems, > > > > but let's discard those. > > > > I will try to explain in detail what you misunderstood before. You > > > > start with a chain ending with blocks A-B-C, C being the top, the > > > > common feature of PoS system (non-quorum), roughly speaking, is that if > > > > N is the total amount of coins that participate in the staking process > > > > to create a new block on top of C (let's call that D), then a > > > > participant having K*N amount of stake has chance K to be the one who > > > > will create the next stake. In other words, the power of stakers is > > > > supposed to be linear in the system - you own 10 coins gives you 10x > > > > the chance of finding block over someone who has 1 coin. > > > > What i was claiming is that using the technique I have described, this > > > > linearity is violated. Why? Well, it works for honest stakers among the > > > > competition of honest stakers - they really do have the chance of K to > > > > find the next block. However, the attacker, using nothing at stake, > > > > checks her ability to build block D (at some timestamp). If she is > > > > successful, she does not propagate D immediately, but instead she also > > > > checks whether she can build on top of B and on top of A. Since with > > > > every new timestamp, usually, there is a new chance to build the block, > > > > it is not uncommon that she finds she is indeed able to build such > > > > block C' on top of B. Here it is likely t(C') > t(C) as the attacker > > > > has relatively low stake. Note that in order to produce such C', she > > > > not only could have tried the current timestamp t(D), but also all > > > > previous timestamps up to t(B) (usually that's the consensus rule, but > > > > it may depend on a specific consensus). So her chance to produce such > > > > C' is greater than her previous chance of producing C (which chance was > > > > limited by other stakers in the system and the discovery of block C by > > > > one of them). Now suppose that she found such C' and now she continues > > > > by trying to prolong this chain by finding D'. And again here, it is > > > > quite likely that her chance to find such D' is greater than was her > > > > chance of finding D because again there are likely multiple timestamps > > > > she could try. This all was possible just because nothing at stake > > > > allows you to just try if you can produce a block in certain state of > > > > block chain or not. Now if she actually was able to find D', she > > > > discards D and only publishes chain A-B-C'-D', which can not be > > > > punished despite the fact that she indeed produced two different forks. > > > > She can not be punished because this production was local and only the > > > > final result of A-B-C'-D' was published, in which case she gained an > > > > extra block over the honest strategy which would only give her block D. > > > > Fun fact tho: there is an attack called the "selfish mining attack" for > > > > proof of work, and it reduces the security of PoW by at least 1/3rd. > > > > How is that relevant to our discussion? This is known research that has > > > > nothing to do with PoS except that it is often worse on PoS. > > > > > > > > > the problem is not as hard as you think > > > > > > > > I don't claim to know just how hard finding the IP address associated > > > > with a bitcoin address is. However, the DOS risk can be solved more > > > > completely by only allowing the owner of coins themselves to know > > > > whether they can mint a block. Eg by determining whether someone can > > > > mint a block based on their public key hidden behind hashes (as normal > > > > in addresses). Only when someone does in fact mint a block do they > > > > reveal their hidden public key in order to prove they are allowed to > > > > mint the block. > > > > This is true, but you are mixing quorum and non-quorum systems. My > > > > objection here was towards such system where I specifically said that > > > > the list of producers for next epoch is known up front and you > > > > confirmed that this is what you meant with "quorum" system. So in such > > > > system, I claimed, the known producer is the only target at any given > > > > point of time. This of course does not apply to any other type of > > > > system where future producers are not known. No need to dispute, again, > > > > something that was not claimed. > > > > > > > > > I agree that introduction of punishment itself does not imply > > > > > introducing a problem elsewhere (which I did not claim if you reread > > > > > my previous message) > > > > > > > > I'm glad we agree there. Perhaps I misunderstood what you meant by "you > > > > should not omit to mention that by doing so, typically, you have > > > > introduced another problem elsewhere." > > > > Perhaps you should quote the full sentence and not just a part of it: > > > > "Of course you can always change the rules in a way that a certain > > > > specific attack is not doable, but you should not omit to mention that > > > > by doing so, typically, you have introduced another problem elsewhere, > > > > or you have not solved it completely." > > > > You can parse this as: (CREATE PROBLEM ELSEWHERE) OR (NOT SOLVE IT > > > > COMPLETELY) > > > > In case of the punishment it was meant to be the not solve it > > > > completely part. > > > > Also "typically" does not imply always. > > > > But this parsing of English sentences for you seems very off topic > > > > here. My point is, in context of Bitcoin, reject such unsupported > > > > claims that PoS is a reasonable alternative to PoW, let's stick to that. > > > > > > > > > As long as the staker makes sure (which is not that hard) that she > > > > > does not miss a chance to create a block, her significance in the > > > > > system will always increase in time. It will increase relative to all > > > > > normal users who do not stake > > > > > > > > Well, if you're in the closed system of the cryptocurrency, sure. But > > > > we don't live in that closed system. Minters will earn some ROI from > > > > minting just like any other financial activity. Others may find more > > > > success spending their time doing things other than figuring out how to > > > > mint coins. In that case, they'll be able to earn more coin that they > > > > could later decide to use to mint blocks if they decide to. > > > > This only supports the point I was making. Since the optimal scenario > > > > with all existing coins participating is just theoretical, the > > > > attacker's position will ever so improve. It seems we are in agreement > > > > here, great. > > > > > > > > > Just because of the above we must reject PoS as being critically > > > > > insecure > > > > > > > > I think the only thing we can conclude from this is that you have come > > > > up with an insecure proof of stake protocol. I don't see how anything > > > > you've brought up amounts to substantial evidence that all possible PoS > > > > protocols are insecure. > > > > I have not come up with anything. I'm afraid you've not realized the > > > > burden of proof is on your side if you vouch for a design that is not > > > > believed and trusted to be secure. It is up to you to show that you > > > > know how to solve every problem that people throw at you. So far we > > > > have just demonstrated that your claim that nothing at stake is solved > > > > was unjustified. You have not described a system that would solve it > > > > (and not introduce critical DDOS attack vector as it is in quorum based > > > > systems - per the prior definition of such systems). > > > > Of course the list of problems of PoS systems do not end with just > > > > nothing at stake, but it is good enough example that by itself prevents > > > > its adoption in decentralized consensus. No need to go to other hard > > > > problems without solving nothing at stake. > > > > On Tue, May 25, 2021 at 11:10 AM befreeandopen > > > > befreeando...@protonmail.com wrote: > > > > > > > > > @befreeandopen " An attacker can calculate whether or not she can > > > > > prolong this chain or not and if so with what timestamp." > > > > > The scenario you describe would only be likely to happen at all if > > > > > the malicious actor has a very large fraction of the stake - probably > > > > > quite close to 50%. At that point, you're talking about a 51% attack, > > > > > not the nothing at stake problem. The nothing at stake problem is the > > > > > problem where anyone will mint on any chain. Its clear that if > > > > > there's a substantial punishment for minting on chains other than the > > > > > one that eventually wins, every minter without a significant fraction > > > > > of the stake will be honest and not attempt to mint on old blocks or > > > > > support someone else's attempt to mint on old blocks (until and if it > > > > > becomes the heaviest chain). Because the attacker would need probably > > > > > >45% of the active stake (take a look at the reasoning here for a > > > > > deeper analysis of that statement), I don't agree that punishment is > > > > > not a sufficient mitigation of the nothing at stake problem. To > > > > > exploit the nothing at stake problem, you basically need to 51% > > > > > attack, at which point you've exceeded the operating conditions of > > > > > the system, so of course its gonna have problems, just like a 51% > > > > > attack would cause with PoW. > > > > > This is not at all the case. The attacker benefits using the > > > > > described technique at any size of the stake and significantly so > > > > > with just 5% of the stake. By significantly, I do not mean that the > > > > > attacker is able to completely take control the network (in short > > > > > term), but rather that the attacker has significant advantage in the > > > > > number of blocks she creates compared to what she "should be able to > > > > > create". This means the attacker's stake increases significantly > > > > > faster than of the honest nodes, which in long term is very serious > > > > > in PoS system. If you believe close to 50% is needed for that, you > > > > > need to redo your math. So no, you are wrong stating that "to exploit > > > > > nothing at stake problem you basically need to 51% attack". It is > > > > > rather the opposite - eventually, nothing at stake attack leads to > > > > > ability to perform 51% attack. > > > > > > > > > > > I am not sure if this is what you call quorum-based PoS > > > > > > > > > > Yes, pre-selected minters is exactly what I mean by that. > > > > > > > > > > > it allows the attacker to know who to attack at which point with > > > > > > powerful DDOS in order to hurt liveness of such system > > > > > > > > > > Just like in bitcoin, associating keys with IP addresses isn't > > > > > generally an easy thing to do on the fly like that. If you know > > > > > someone's IP address, you can target them. But if you only know their > > > > > address or public key, the reverse isn't as easy. With a quorum-based > > > > > PoS system, you can see their public key and address, but finding out > > > > > their IP to DOS would be a huge challenge I think. > > > > > I do not dispute that the problem is not trivial, but the problem is > > > > > not as hard as you think. The network graph analysis is a known > > > > > technique and it is not trivial, but not very hard either. > > > > > Introducing a large number of nodes to the system to achieve very > > > > > good success rate of analysis of area of origin of blocks is doable > > > > > and has been done in past. So again, I very much disagree with your > > > > > conclusion that this is somehow secure. It is absolutely insecure. > > > > > Note, tho, that quorum-based PoS generally also have punishments as > > > > > part of the protocol. The introduction of punishments do indeed > > > > > handily solve the nothing at stake problem. And you didn't mention a > > > > > single problem that the punishments introduce that weren't already > > > > > there before punishments. There are tradeoffs with introducing > > > > > punishments (eg in some cases you might punish honest actors), but > > > > > they are minor in comparison to solving the nothing at stake problem. > > > > > While I agree that introduction of punishment itself does not imply > > > > > introducing a problem elsewhere (which I did not claim if you reread > > > > > my previous message), it does introduce additional complexity which > > > > > may introduce problem, but more importantly, while it slightly > > > > > improves resistance against the nothing at stake attack, it solves > > > > > absolutely nothing. Your claim is based on wrong claim of needed > > > > > close to 50% stake, but that could not be farther from the truth. It > > > > > is not true even in optimal conditions when all participants of the > > > > > network stake or delegate their stake. These optimal conditions > > > > > rarely, if ever, occur. And that's another thing that we have not > > > > > mention in our debate, so please allow me to introduce another > > > > > problem to PoS. > > > > > Consider what is needed for such optimal conditions to occur - all > > > > > coins are always part of the stake, which means that they need to > > > > > somehow automatically part of the staking process even when they are > > > > > moved. But in many PoS systems you usually require some age (in terms > > > > > of confirmations) of the coin before you allow it to be used for > > > > > participation in staking process and that is for a good reason - to > > > > > prevent various grinding attacks. In some systems the coin must be > > > > > specifically registered before it can be staked, in others, simply > > > > > waiting for enough confirmations enables you to stake with the coin. > > > > > I am not sure if there is a system which does not have this cooling > > > > > period for a coin that has been moved. Maybe it is possible though, > > > > > but AFAIK it is not common and not battle tested feature. > > > > > Then if we admit that achieving the optimal condition is rather > > > > > theoretical. Then if we do not have the optimal condition, it means > > > > > that a staker with K% of the total available supply increases it's > > > > > percentage over time to some amounts >K%. As long as the staker makes > > > > > sure (which is not that hard) that she does not miss a chance to > > > > > create a block, her significance in the system will always increase > > > > > in time. It will increase relative to all normal users who do not > > > > > stake (if there are any) and relative to all other stakers who make > > > > > mistakes or who are not wealthy enough to afford not selling any > > > > > position ever. But powerful attacker is exactly in such position and > > > > > thus she will gain significance in such a system. The technique I > > > > > have described, and that you mistakenly think is viable only with > > > > > huge amounts of stake, only puts the attacker to even greater > > > > > advantage. But even without the described attack (which exploits > > > > > nothing at stake), the PoS system converges to a system more and more > > > > > controlled by powerful entity, which we can assume is the attacker. > > > > > So I don't think it is at all misleading to claim that "nothing at > > > > > stake" is a solved problem. I do in fact mean that the solutions to > > > > > that problem don't introduce any other problems with anywhere near > > > > > the same level of significance. > > > > > It still stands as truly misleading claim. I disagree that > > > > > introducing DDOS opportunity with medium level of difficulty for the > > > > > attacker to implement it, in case of "quorum-based PoS" is not a > > > > > problem anywhere near the same level of significance. Such an attack > > > > > vector allows you to turn off the network if you spend some time and > > > > > money. That is hardly acceptable. > > > > > Just because of the above we must reject PoS as being critically > > > > > insecure until someone invents and demonstrates an actual way of > > > > > solving these issues. > > > > > On Tue, May 25, 2021 at 3:00 AM Erik Aronesty e...@q32.com wrote: > > > > > > > > > > > > > you burn them to be used at a future particular block height > > > > > > > > > > > > > This sounds exploitable. It seems like an attacker could simply > > > > > > > focus all their burns on a particular set of 6 blocks to double > > > > > > > spend, minimizing their cost of attack. > > > > > > > > > > > > could be right. the original idea was to have burns decay over time, > > > > > > like ASIC's. > > > > > > anyway the point was not that "i had a magic formula" > > > > > > the point was that proof of burn is almost always better than proof > > > > > > of > > > > > > stake - simply because the "proof" is on-chain, not sitting on a > > > > > > node > > > > > > somewhere waiting to be stolen. > > > > > > On Mon, May 24, 2021 at 9:53 PM Billy Tetrud billy.tet...@gmail.com > > > > > > wrote: > > > > > > > > > > > > > Is this the kind of proof of burn you're talking about? > > > > > > > > > > > > > > > if i have a choice between two chains, one longer and one > > > > > > > > shorter, i can only choose one... deterministically > > > > > > > > > > > > > > What prevents you from attempting to mine block 553 on both > > > > > > > chains? > > > > > > > > > > > > > > > miners have a very strong, long-term, investment in the > > > > > > > > stability of the chain. > > > > > > > > > > > > > > Yes, but the same can be said of any coin, even ones that do have > > > > > > > the nothing at stake problem. This isn't sufficient tho because > > > > > > > the chain is a common good, and the tragedy of the commons holds > > > > > > > for it. > > > > > > > > > > > > > > > you burn them to be used at a future particular block height > > > > > > > > > > > > > > This sounds exploitable. It seems like an attacker could simply > > > > > > > focus all their burns on a particular set of 6 blocks to double > > > > > > > spend, minimizing their cost of attack. > > > > > > > > > > > > > > > i can imagine scenarios where large stakeholders can collude to > > > > > > > > punish smaller stakeholders simply to drive them out of > > > > > > > > business, for example > > > > > > > > > > > > > > Are you talking about a 51% attack? This is possible in any > > > > > > > decentralized cryptocurrency. > > > > > > > On Mon, May 24, 2021 at 11:49 AM Erik Aronesty e...@q32.com wrote: > > > > > > > > > > > > > > > > > your burn investment is always "at stake", any redaction > > > > > > > > > > can result in a loss-of-burn, because burns can be tied, > > > > > > > > > > precisely, to block-heights > > > > > > > > > > I'm fuzzy on how proof of burn works. > > > > > > > > > > > > > > > > when you burn coins, you burn them to be used at a future > > > > > > > > particular > > > > > > > > block height: so if i'm burning for block 553, i can only use > > > > > > > > them to > > > > > > > > mine block 553. if i have a choice between two chains, one > > > > > > > > longer > > > > > > > > and one shorter, i can only choose one... deterministically, > > > > > > > > for that > > > > > > > > burn: the chain with the height 553. if we fix the "lead time" > > > > > > > > for > > > > > > > > burned coins to be weeks or even months in advance, miners have > > > > > > > > a very > > > > > > > > strong, long-term, investment in the stability of the chain. > > > > > > > > therefore there is no "nothing at stake" problem. it's > > > > > > > > deterministic, so miners have no choice. they can only choose > > > > > > > > the > > > > > > > > transactions that go into the block. they cannot choose which > > > > > > > > chain > > > > > > > > to mine, and it's time-locked, so rollbacks and instability > > > > > > > > always > > > > > > > > hurt miners the most. > > > > > > > > the "punishment" systems of PoS are "weird at best", certainly > > > > > > > > unproven. i can imagine scenarios where large stakeholders can > > > > > > > > collude to punish smaller stakeholders simply to drive them out > > > > > > > > of > > > > > > > > business, for example. and then you have to put checks in place > > > > > > > > to > > > > > > > > prevent that, and more checks for those prevention system... > > > > > > > > in PoB, there is no complexity. simpler systems like this are > > > > > > > > typically more secure. > > > > > > > > PoB also solves problems caused by "energy dependence", which > > > > > > > > could > > > > > > > > lead to state monopolies on mining (like the new Bitcoin Mining > > > > > > > > Council). these consortiums, if state sanctioned, could become a > > > > > > > > source of censorship, for example. Since PoB doesn't require > > > > > > > > you to > > > > > > > > have a live, well-connected node, it's harder to censor & > > > > > > > > harder to > > > > > > > > trace. > > > > > > > > Eliminating this weakness seems to be in the best interests of > > > > > > > > existing stakeholders > > > > > > > > On Mon, May 24, 2021 at 4:44 PM Billy Tetrud > > > > > > > > billy.tet...@gmail.com wrote: > > > > > > > > > > > > > > > > > > proof of burn clearly solves this, since nothing is held > > > > > > > > > > online > > > > > > > > > > > > > > > > > > Well.. the coins to be burned need to be online when they're > > > > > > > > > burned. But yes, only a small fraction of the total coins > > > > > > > > > need to be online. > > > > > > > > > > > > > > > > > > > your burn investment is always "at stake", any redaction > > > > > > > > > > can result in a loss-of-burn, because burns can be tied, > > > > > > > > > > precisely, to block-heights > > > > > > > > > > > > > > > > > > So you're saying that if say someone tries to mine a block on > > > > > > > > > a shorter chain, that requires them to send a transaction > > > > > > > > > burning their coins, and that transaction could also be spent > > > > > > > > > on the longest chain, which means their coins are burned even > > > > > > > > > if the chain they tried to mine on doesn't win? I'm fuzzy on > > > > > > > > > how proof of burn works. > > > > > > > > > > > > > > > > > > > proof of burn can be more secure than proof-of-stake > > > > > > > > > > > > > > > > > > FYI, proof of stake can be done without the "nothing at > > > > > > > > > stake" problem. You can simply punish people who mint on > > > > > > > > > shorter chains (by rewarding people who publish proofs of > > > > > > > > > this happening on the main chain). In quorum-based PoS, you > > > > > > > > > can punish people in the quorum that propose or sign multiple > > > > > > > > > blocks for the same height. The "nothing at stake" problem is > > > > > > > > > a solved problem at this point for PoS. > > > > > > > > > On Mon, May 24, 2021 at 3:47 AM Erik Aronesty e...@q32.com > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > I don't see a way to get around the conflicting > > > > > > > > > > > requirement that the keys for large amounts of coins > > > > > > > > > > > should be kept offline but those are exactly the coins we > > > > > > > > > > > need online to make the scheme secure. > > > > > > > > > > > > > > > > > > > > proof of burn clearly solves this, since nothing is held > > > > > > > > > > online > > > > > > > > > > > > > > > > > > > > > how does proof of burn solve the "nothing at stake" > > > > > > > > > > > problem in your view? > > > > > > > > > > > > > > > > > > > > definition of nothing at stake: in the event of a fork, > > > > > > > > > > whether the > > > > > > > > > > fork is accidental or a malicious, the optimal strategy for > > > > > > > > > > any miner > > > > > > > > > > is to mine on every chain, so that the miner gets their > > > > > > > > > > reward no > > > > > > > > > > matter which fork wins. indeed in proof-of-stake, the > > > > > > > > > > proofs are > > > > > > > > > > published on the very chains mines, so the incentive is > > > > > > > > > > magnified. > > > > > > > > > > in proof-of-burn, your burn investment is always "at > > > > > > > > > > stake", any > > > > > > > > > > redaction can result in a loss-of-burn, because burns can > > > > > > > > > > be tied, > > > > > > > > > > precisely, to block-heights > > > > > > > > > > as a result, miners no longer have an incentive to mine all > > > > > > > > > > chains > > > > > > > > > > in this way proof of burn can be more secure than > > > > > > > > > > proof-of-stake, and > > > > > > > > > > even more secure than proof of work > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Sun, May 23, 2021 at 3:52 AM Lloyd Fournier via > > > > > > > > > > bitcoin-dev > > > > > > > > > > bitcoin-dev@lists.linuxfoundation.org wrote: > > > > > > > > > > > > > > > > > > > > > Hi Billy, > > > > > > > > > > > I was going to write a post which started by dismissing > > > > > > > > > > > many of the weak arguments that are made against PoS made > > > > > > > > > > > in this thread and elsewhere. > > > > > > > > > > > Although I don't agree with all your points you have done > > > > > > > > > > > a decent job here so I'll focus on the second part: why I > > > > > > > > > > > think Proof-of-Stake is inappropriate for a Bitcoin-like > > > > > > > > > > > system. > > > > > > > > > > > Proof of stake is not fit for purpose for a global > > > > > > > > > > > settlement layer in a pure digital asset (i.e. "digital > > > > > > > > > > > gold") which is what Bitcoin is trying to be. > > > > > > > > > > > PoS necessarily gives responsibilities to the holders of > > > > > > > > > > > coins that they do not want and cannot handle. > > > > > > > > > > > In Bitcoin, large unsophisticated coin holders can put > > > > > > > > > > > their coins in cold storage without a second thought > > > > > > > > > > > given to the health of the underlying ledger. > > > > > > > > > > > As much as hardcore Bitcoiners try to convince them to > > > > > > > > > > > run their own node, most don't, and that's perfectly > > > > > > > > > > > acceptable. > > > > > > > > > > > At no point do their personal decisions affect the > > > > > > > > > > > underlying consensus -- it only affects their personal > > > > > > > > > > > security assurance (not that of the system itself). > > > > > > > > > > > In PoS systems this clean separation of responsibilities > > > > > > > > > > > does not exist. > > > > > > > > > > > I think that the more rigorously studied PoS protocols > > > > > > > > > > > will work fine within the security claims made in their > > > > > > > > > > > papers. > > > > > > > > > > > People who believe that these protocols are destined for > > > > > > > > > > > catastrophic consensus failure are certainly in for a > > > > > > > > > > > surprise. > > > > > > > > > > > But the devil is in the detail. > > > > > > > > > > > Let's look at what the implications of using the leading > > > > > > > > > > > proof of stake protocols would have on Bitcoin: > > > > > > > > > > > > > > > > > > > > > > ### Proof of SquareSpace (Cardano, Polkdadot) > > > > > > > > > > > > > > > > > > > > > > Cardano is a UTXO based PoS coin based on Ouroboros > > > > > > > > > > > Praos3 with an inbuilt on-chain delegation system5. > > > > > > > > > > > In these protocols, coin holders who do not want to run > > > > > > > > > > > their node with their hot keys in it delegate it to a > > > > > > > > > > > "Stake Pool". > > > > > > > > > > > I call the resulting system Proof-of-SquareSpace since > > > > > > > > > > > most will choose a pool by looking around for one with a > > > > > > > > > > > nice website and offering the largest share of the block > > > > > > > > > > > reward. > > > > > > > > > > > On the surface this might sound no different than someone > > > > > > > > > > > with an mining rig shopping around for a good mining pool > > > > > > > > > > > but there are crucial differences: > > > > > > > > > > > > > > > > > > > > > > 1. The person making the decision is forced into it just > > > > > > > > > > > because they own the currency -- someone with a mining > > > > > > > > > > > rig has purchased it with the intent to make profit by > > > > > > > > > > > participating in consensus. > > > > > > > > > > > > > > > > > > > > > > 2. When you join a mining pool your systems are very > > > > > > > > > > > much still online. You are just partaking in a pool to > > > > > > > > > > > reduce your profit variance. You still see every block > > > > > > > > > > > that you help create and you never help create a block > > > > > > > > > > > without seeing it first. > > > > > > > > > > > > > > > > > > > > > > 3. If by SquareSpace sybil attack you gain a dishonest > > > > > > > > > > > majority and start censoring transactions how are the > > > > > > > > > > > users meant to redelegate their stake to honest pools? > > > > > > > > > > > I guess they can just send a transaction delegating > > > > > > > > > > > to another pool...oh wait I guess that might be censored > > > > > > > > > > > too! This seems really really bad. > > > > > > > > > > > In Bitcoin, miners can just join a different pool at > > > > > > > > > > > a whim. There is nothing the attacker can do to stop > > > > > > > > > > > them. A temporary dishonest majority heals relatively > > > > > > > > > > > well. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > There is another severe disadvantage to this on-chain > > > > > > > > > > > delegation system: every UTXO must indicate which staking > > > > > > > > > > > account this UTXO belongs to so the appropriate share of > > > > > > > > > > > block rewards can be transferred there. > > > > > > > > > > > Being able to associate every UTXO to an account ruins > > > > > > > > > > > one of the main privacy advantages of the UTXO model. > > > > > > > > > > > It also grows the size of the blockchain significantly. > > > > > > > > > > > > > > > > > > > > > > ### "Pure" proof of stake (Algorand) > > > > > > > > > > > > > > > > > > > > > > Algorand's4 approach is to only allow online stake to > > > > > > > > > > > participate in the protocol. > > > > > > > > > > > Theoretically, This means that keys holding funds have to > > > > > > > > > > > be online in order for them to author blocks when they > > > > > > > > > > > are chosen. > > > > > > > > > > > Of course in reality no one wants to keep their coin > > > > > > > > > > > holding keys online so in Alogorand you can authorize a > > > > > > > > > > > set of "participation keys"1 that will be used to create > > > > > > > > > > > blocks on your coin holding key's behalf. > > > > > > > > > > > Hopefully you've spotted the problem. > > > > > > > > > > > You can send your participation keys to any malicious > > > > > > > > > > > party with a nice website (see random example 2) offering > > > > > > > > > > > you a good return. > > > > > > > > > > > Damn it's still Proof-of-SquareSpace! > > > > > > > > > > > The minor advantage is that at least the participation > > > > > > > > > > > keys expire after a certain amount of time so eventually > > > > > > > > > > > the SquareSpace attacker will lose their hold on > > > > > > > > > > > consensus. > > > > > > > > > > > Importantly there is also less junk on the blockchain > > > > > > > > > > > because the participation keys are delegated off-chain > > > > > > > > > > > and so are not making as much of a mess. > > > > > > > > > > > > > > > > > > > > > > ### Conclusion > > > > > > > > > > > > > > > > > > > > > > I don't see a way to get around the conflicting > > > > > > > > > > > requirement that the keys for large amounts of coins > > > > > > > > > > > should be kept offline but those are exactly the coins we > > > > > > > > > > > need online to make the scheme secure. > > > > > > > > > > > If we allow delegation then we open up a new social > > > > > > > > > > > attack surface and it degenerates to Proof-of-SquareSpace. > > > > > > > > > > > For a "digital gold" like system like Bitcoin we optimize > > > > > > > > > > > for simplicity and desperately want to avoid extraneous > > > > > > > > > > > responsibilities for the holder of the coin. > > > > > > > > > > > After all, gold is an inert element on the periodic table > > > > > > > > > > > that doesn't confer responsibilities on the holder to > > > > > > > > > > > maintain the quality of all the other bars of gold out > > > > > > > > > > > there. > > > > > > > > > > > Bitcoin feels like this too and in many ways is more > > > > > > > > > > > inert and beautifully boring than gold. > > > > > > > > > > > For Bitcoin to succeed I think we need to keep it that > > > > > > > > > > > way and Proof-of-Stake makes everything a bit too > > > > > > > > > > > exciting. > > > > > > > > > > > I suppose in the end the market will decide what is real > > > > > > > > > > > digital gold and whether these bad technical trade offs > > > > > > > > > > > are worth being able to say it uses less electricity. It > > > > > > > > > > > goes without saying that making bad technical decisions > > > > > > > > > > > to appease the current political climate is an anathema > > > > > > > > > > > to Bitcoin. > > > > > > > > > > > Would be interested to know if you or others think > > > > > > > > > > > differently on these points. > > > > > > > > > > > Cheers, > > > > > > > > > > > LL > > > > > > > > > > > On Fri, 21 May 2021 at 19:21, Billy Tetrud via > > > > > > > > > > > bitcoin-dev bitcoin-dev@lists.linuxfoundation.org wrote: > > > > > > > > > > > > > > > > > > > > > > > I think there is a lot of misinformation and bias > > > > > > > > > > > > against Proof of Stake. Yes there have been lots of > > > > > > > > > > > > shady coins that use insecure PoS mechanisms. Yes there > > > > > > > > > > > > have been massive issues with distribution of PoS coins > > > > > > > > > > > > (of course there have also been massive issues with PoW > > > > > > > > > > > > coins as well). However, I want to remind everyone that > > > > > > > > > > > > there is a difference between "proved to be impossible" > > > > > > > > > > > > and "have not achieved recognized success yet". Most of > > > > > > > > > > > > the arguments levied against PoS are out of date or > > > > > > > > > > > > rely on unproven assumptions or extrapolation from the > > > > > > > > > > > > analysis of a particular PoS system. I certainly don't > > > > > > > > > > > > think we should experiment with bitcoin by switching to > > > > > > > > > > > > PoS, but from my research, it seems very likely that > > > > > > > > > > > > there is a proof of stake consensus protocol we could > > > > > > > > > > > > build that has substantially higher security (cost / > > > > > > > > > > > > capital required to execute an attack) while at the > > > > > > > > > > > > same time costing far less resources (which do > > > > > > > > > > > > translate to fees on the network) without compromising > > > > > > > > > > > > any of the critical security properties bitcoin relies > > > > > > > > > > > > on. I think the critical piece of this is the > > > > > > > > > > > > disagreements around hardcoded checkpoints, which is a > > > > > > > > > > > > critical piece solving attacks that could be levied on > > > > > > > > > > > > a PoS chain, and how that does (or doesn't) affect the > > > > > > > > > > > > security model. > > > > > > > > > > > > @Eric Your proof of stake fallacy seems to be saying > > > > > > > > > > > > that PoS is worse when a 51% attack happens. While I > > > > > > > > > > > > agree, I think that line of thinking omits important > > > > > > > > > > > > facts: > > > > > > > > > > > > > > > > > > > > > > > > - The capital required to 51% attack a PoS chain can > > > > > > > > > > > > be made substantially greater than on a PoS chain. > > > > > > > > > > > > - The capital the attacker stands to lose can be > > > > > > > > > > > > substantially greater as well if the attack is > > > > > > > > > > > > successful. > > > > > > > > > > > > - The effectiveness of paying miners to raise the > > > > > > > > > > > > honest fraction of miners above 50% may be quite bad. > > > > > > > > > > > > - Allowing a 51% attack is already unacceptable. It > > > > > > > > > > > > should be considered whether what happens in the case > > > > > > > > > > > > of a 51% may not be significantly different. The > > > > > > > > > > > > currency would likely be critically damaged in a 51% > > > > > > > > > > > > attack regardless of consensus mechanism. > > > > > > > > > > > > > > > > > > > > > > > > > Proof-of-stake tends towards oligopolistic control > > > > > > > > > > > > > > > > > > > > > > > > People repeat this often, but the facts support this. > > > > > > > > > > > > There is no centralization pressure in any proof of > > > > > > > > > > > > stake mechanism that I'm aware of. IE if you have 10 > > > > > > > > > > > > times as much coin that you use to mint blocks, you > > > > > > > > > > > > should expect to earn 10x as much minting revenue - not > > > > > > > > > > > > more than 10x. By contrast, proof of work does in fact > > > > > > > > > > > > have clear centralization pressure - this is not > > > > > > > > > > > > disputed. Our goal in relation to that is to ensure > > > > > > > > > > > > that the centralization pressure remains insignifiant. > > > > > > > > > > > > Proof of work also clearly has a lot more barriers to > > > > > > > > > > > > entry than any proof of stake system does. Both of > > > > > > > > > > > > these mean the tendency towards oligopolistic control > > > > > > > > > > > > is worse for PoW. > > > > > > > > > > > > > > > > > > > > > > > > > Energy usage, in-and-of-itself, is nothing to be > > > > > > > > > > > > > ashamed of!! > > > > > > > > > > > > > > > > > > > > > > > > I certainly agree. Bitcoin's energy usage at the moment > > > > > > > > > > > > is I think quite warranted. However, the question is: > > > > > > > > > > > > can we do substantially better. I think if we can, we > > > > > > > > > > > > probably should... eventually. > > > > > > > > > > > > > > > > > > > > > > > > > Proof of Stake is only resilient to ⅓ of the network > > > > > > > > > > > > > demonstrating a Byzantine Fault, whilst Proof of Work > > > > > > > > > > > > > is resilient up to the ½ threshold > > > > > > > > > > > > > > > > > > > > > > > > I see no mention of this in the pos.pdf you linked to. > > > > > > > > > > > > I'm not aware of any proof that all PoS systems have a > > > > > > > > > > > > failure threshold of 1/3. I know that staking systems > > > > > > > > > > > > like Casper do in fact have that 1/3 requirement. > > > > > > > > > > > > However there are PoS designs that should exceed that > > > > > > > > > > > > up to nearly 50% as far as I'm aware. Proof of work is > > > > > > > > > > > > not in fact resilient up to the 1/2 threshold in the > > > > > > > > > > > > way you would think. IE, if 100% of miners are > > > > > > > > > > > > currently honest and have a collective 100 exahashes/s > > > > > > > > > > > > hashpower, an attacker does not need to obtain 100 > > > > > > > > > > > > exahashes/s, but actually only needs to accumulate 50 > > > > > > > > > > > > exahashes/s. This is because as the attacker > > > > > > > > > > > > accumulates hashpower, it drives honest miners out of > > > > > > > > > > > > the market as the difficulty increases to beyond what > > > > > > > > > > > > is economically sustainable. Also, its been shown that > > > > > > > > > > > > the best proof of work can do is require an attacker to > > > > > > > > > > > > obtain 33% of the hashpower because of the selfish > > > > > > > > > > > > mining attack discussed in depth in this paper: > > > > > > > > > > > > https://arxiv.org/abs/1311.0243. Together, both of > > > > > > > > > > > > these things reduce PoW's security by a factor of about > > > > > > > > > > > > 83% (1 - 50%*33%). > > > > > > > > > > > > > > > > > > > > > > > > > Proof of Stake requires other trade-offs which are > > > > > > > > > > > > > incompatible with Bitcoin's objective (to be a > > > > > > > > > > > > > trustless digital cash) — specifically the famous > > > > > > > > > > > > > "security vs. liveness" guarantee > > > > > > > > > > > > > > > > > > > > > > > > Do you have a good source that talks about why you > > > > > > > > > > > > think proof of stake cannot be used for a trustless > > > > > > > > > > > > digital cash? > > > > > > > > > > > > > > > > > > > > > > > > > You cannot gain tokens without someone choosing to > > > > > > > > > > > > > give up those coins - a form of permission. > > > > > > > > > > > > > > > > > > > > > > > > This is not a practical constraint. Just like in > > > > > > > > > > > > mining, some nodes may reject you, but there will > > > > > > > > > > > > likely be more that will accept you, some sellers may > > > > > > > > > > > > reject you, but most would accept your money as payment > > > > > > > > > > > > for bitcoins. I don't think requiring the "permission" > > > > > > > > > > > > of one of millions of people in the market can be > > > > > > > > > > > > reasonably considered a "permissioned currency". > > > > > > > > > > > > > > > > > > > > > > > > > 2. Proof of stake must have a trusted means of > > > > > > > > > > > > > timestamping to regulate overproduction of blocks > > > > > > > > > > > > > > > > > > > > > > > > Both PoW and PoS could mine/mint blocks twice as fast > > > > > > > > > > > > if everyone agreed to double their clock speeds. Both > > > > > > > > > > > > systems rely on an honest majority sticking to standard > > > > > > > > > > > > time. > > > > > > > > > > > > On Wed, May 19, 2021 at 5:32 AM Michael Dubrovsky via > > > > > > > > > > > > bitcoin-dev bitcoin-dev@lists.linuxfoundation.org wrote: > > > > > > > > > > > > > > > > > > > > > > > > > Ah sorry, I didn't realize this was, in fact, a > > > > > > > > > > > > > different thread! :) > > > > > > > > > > > > > On Wed, May 19, 2021 at 10:07 AM Michael Dubrovsky > > > > > > > > > > > > > m...@powx.org wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > Folks, I suggest we keep the discussion to PoW, > > > > > > > > > > > > > > oPoW, and the BIP itself. PoS, VDFs, and so on are > > > > > > > > > > > > > > interesting but I guess there are other threads > > > > > > > > > > > > > > going on these topics already where they would be > > > > > > > > > > > > > > relevant. > > > > > > > > > > > > > > Also, it's important to distinguish between oPoW > > > > > > > > > > > > > > and these other "alternatives" to Hashcash. oPoW is > > > > > > > > > > > > > > a true Proof of Work that doesn't alter the core > > > > > > > > > > > > > > game theory or security assumptions of Hashcash and > > > > > > > > > > > > > > actually contains SHA (can be SHA3, SHA256, etc > > > > > > > > > > > > > > hash is interchangeable). > > > > > > > > > > > > > > Cheers, > > > > > > > > > > > > > > Mike > > > > > > > > > > > > > > On Tue, May 18, 2021 at 4:55 PM Erik Aronesty via > > > > > > > > > > > > > > bitcoin-dev bitcoin-dev@lists.linuxfoundation.org > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 1. i never suggested vdf's to replace pow. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 2. my suggestion was specifically in the context > > > > > > > > > > > > > > > of a working > > > > > > > > > > > > > > > proof-of-burn protocol > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - vdfs used only for timing (not block height) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - blind-burned coins of a specific age used to > > > > > > > > > > > > > > > replace proof of work > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - the required "work" per block would simply be > > > > > > > > > > > > > > > a competition to > > > > > > > > > > > > > > > acquire rewards, and so miners would have to > > > > > > > > > > > > > > > burn coins, well in > > > > > > > > > > > > > > > advance, and hope that their burned coins got > > > > > > > > > > > > > > > rewarded in some far > > > > > > > > > > > > > > > future > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - the point of burned coins is to mimic, in > > > > > > > > > > > > > > > every meaningful way, the > > > > > > > > > > > > > > > value gained from proof of work... without > > > > > > > > > > > > > > > some of the security > > > > > > > > > > > > > > > drawbacks > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - the miner risks losing all of his burned > > > > > > > > > > > > > > > coins (like all miners risk > > > > > > > > > > > > > > > losing their work in each block) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - new burns can't be used > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - old burns age out (like ASICs do) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > - other requirements on burns might be needed > > > > > > > > > > > > > > > to properly mirror the > > > > > > > > > > > > > > > properties of PoW and the incentives Bitcoin > > > > > > > > > > > > > > > uses to mine honestly. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 3. i do believe it is possible that a "burned > > > > > > > > > > > > > > > coin + vdf system" > > > > > > > > > > > > > > > might be more secure in the long run, and > > > > > > > > > > > > > > > that if the entire space > > > > > > > > > > > > > > > agreed that such an endeavor was worthwhile, > > > > > > > > > > > > > > > a test net could be spun > > > > > > > > > > > > > > > up, and a hard-fork could be initiated. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 4. i would never suggest such a thing unless i > > > > > > > > > > > > > > > believed it was > > > > > > > > > > > > > > > possible that consensus was possible. so no, > > > > > > > > > > > > > > > this is not an "alt > > > > > > > > > > > > > > > coin" > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Tue, May 18, 2021 at 10:02 AM Zac Greenwood > > > > > > > > > > > > > > > zach...@gmail.com wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi ZmnSCPxj, > > > > > > > > > > > > > > > > Please note that I am not suggesting VDFs as a > > > > > > > > > > > > > > > > means to save energy, but solely as a means to > > > > > > > > > > > > > > > > make the time between blocks more constant. > > > > > > > > > > > > > > > > Zac > > > > > > > > > > > > > > > > On Tue, 18 May 2021 at 12:42, ZmnSCPxj > > > > > > > > > > > > > > > > zmnsc...@protonmail.com wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Good morning Zac, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > VDFs might enable more constant block > > > > > > > > > > > > > > > > > > times, for instance by having a two-step > > > > > > > > > > > > > > > > > > PoW: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 1. Use a VDF that takes say 9 minutes to > > > > > > > > > > > > > > > > > > resolve (VDF being subject to difficulty > > > > > > > > > > > > > > > > > > adjustments similar to the as-is). As per > > > > > > > > > > > > > > > > > > the property of VDFs, miners are able show > > > > > > > > > > > > > > > > > > proof of work. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 2. Use current PoW mechanism with lower > > > > > > > > > > > > > > > > > > difficulty so finding a block takes 1 > > > > > > > > > > > > > > > > > > minute on average, again subject to as-is > > > > > > > > > > > > > > > > > > difficulty adjustments. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > As a result, variation in block times will > > > > > > > > > > > > > > > > > > be greatly reduced. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > As I understand it, another weakness of VDFs > > > > > > > > > > > > > > > > > is that they are not inherently progress-free > > > > > > > > > > > > > > > > > (their sequential nature prevents that; they > > > > > > > > > > > > > > > > > are inherently progress-requiring). > > > > > > > > > > > > > > > > > Thus, a miner which focuses on improving the > > > > > > > > > > > > > > > > > amount of energy that it can pump into the > > > > > > > > > > > > > > > > > VDF circuitry (by overclocking and freezing > > > > > > > > > > > > > > > > > the circuitry), could potentially get into a > > > > > > > > > > > > > > > > > winner-takes-all situation, possibly leading > > > > > > > > > > > > > > > > > to even worse competition and even more > > > > > > > > > > > > > > > > > energy consumption. > > > > > > > > > > > > > > > > > After all, if you can start mining 0.1s > > > > > > > > > > > > > > > > > faster than the competition, that is a 0.1s > > > > > > > > > > > > > > > > > advantage where only you can mine in the > > > > > > > > > > > > > > > > > entire world. > > > > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > > > > ZmnSCPxj > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > bitcoin-dev mailing list > > > > > > > > > > > > > > > bitcoin-dev@lists.linuxfoundation.org > > > > > > > > > > > > > > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > > > > Michael Dubrovsky > > > > > > > > > > > > > > Founder; PoWx > > > > > > > > > > > > > > www.PoWx.org > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > > > Michael Dubrovsky > > > > > > > > > > > > > Founder; PoWx > > > > > > > > > > > > > www.PoWx.org > > > > > > > > > > > > > bitcoin-dev mailing list > > > > > > > > > > > > > bitcoin-dev@lists.linuxfoundation.org > > > > > > > > > > > > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > > > > > > > > > > > > > > > > > > > > > > bitcoin-dev mailing list > > > > > > > > > > > > bitcoin-dev@lists.linuxfoundation.org > > > > > > > > > > > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > > > > > > > > > > > > > > > > > > > > bitcoin-dev mailing list > > > > > > > > > > > bitcoin-dev@lists.linuxfoundation.org > > > > > > > > > > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
