6 ms·
I really wonder if the authors of this paper actually understand how Proof of Work works. The game theory behind PoW requires it to be wasteful in order to crea
by lalaland1125 7y ago
I really wonder if the authors of this paper actually understand how Proof of Work works. The game theory behind PoW requires it to be wasteful in order to create strong incentives for constructing valid blocks. If the work is useful, then there is no incentive as there is no potential loss for attacking the network. The security of the network comes intrinsically from the waste.
- tzumby 7y agoI would argue against the PoW having to be wasteful. It has to be difficult (in terms of compute power and time) but not wasteful. I'm not affiliated in any way with this, but there is one project that uses PoW to search for large primes.
- garmaine 7y agoWhich only works because there those primes have no economic value. The issue is economic, not technical. If I can sell the “useful” side effect of mining, then I can subsidize any attack I perform. The actual security of the network is only the work that has non-reimburseable costs.
- tzumby 7y agoAgreed, the issue is economic. That's one of the things that I find fascinating about Byzantine Fault Tolerant state machine replication. You can view cryptocurrencies as a method of payment for the economic incentive of playing fair. I think the big story here is that we can have a BFT distributed consensus! Also, I think those large primes do have economic value (https://en.wikipedia.org/wiki/Largest_known_prime_number#Prizes https://en.wikipedia.org/wiki/Largest_known_prime_number#Pri...). I'm not sure if that's the purpose of PrimeCoin or who would get the prize, but they nonetheless have some economic value.
- Double_a_92 7y agoIt could work if you can't decide who the benefited person is. I.e. solving problems out of a random pool of them or so.
- garmaine 7y agoDo people pay for their problems to be solved in such a way? As long as I can translate PoW into cash, it stops providing benefit as PoW.
- drdeca 7y agoThe important things are that: a) it is economically rational to mine on the correct chain b) there are substantial economic net costs to mining on a wrong fork of the chain (and these are high enough that it is prohibitively expensive to mount an attack which would fool people as to what chain is correct) Right?
- koheripbal 7y agoIt doesnt matter. As long as the value is Equal for everyone, it doesn't benefit that specific miner more than everyone else who didnt mine, then it still works because everyone has the same incentive and same immediate benefit. Finding primes aren't a great example. ... but unfortunately, they are the best example we have so far.
- trevelyan 7y agoIt actually has to be costly, not difficult. And not wasteful. To see this, note that all POW and POS chains have "difficulty" functions that are actually just cost functions in external markets (hashpower or capital). What secures the difficulty of the attack in all casds is the supply curve of some block production factor in an external market.
- whatshisface 7y agoFor the network to be secure it has to be a waste of money, not philosophically wasteful.
- Kbelicius 7y agoNo it doesn't have to be wasteful. I do not follow crypto anymore but I remember gridcoin and primecoin as good examples of work not being wasteful.
- serverholic 7y agoThe gridcoin wiki states that it uses proof of stake instead of proof of work. The OP's comment is only relevant to proof of work.
- Kbelicius 7y agoIndeed, for some reason I tough that it is POW since it rewards work done on BOINC platform.
- gglon 7y agoI would argue that only some fraction x of the work should be wasteful. If the work would cost c on the market, it cost (1 + x)c on the network. Then if 51% attack total cost = (1 + x)c then only (x c) is wasted while c is recovered from the market. But just having (x c) is not enough to attack since you have to gain access to (loan) c which is an additional entry barrier.
- brighton36 7y agoThen that fraction would distort the incentive value of the work, in a way that compromised the Blockchain's security. (Proportionately).
- gglon 7y agoYes, but not proportionately since an access to capital would be an additional cost. Eg. Imagine 2 situations when you can earn $100 by investment: 1. Buy sth for $100 end sell for $200 2. Buy for $1mln end sell for $1 000 100 Option 1. seems much more accessible.
- lalaland1125 7y agoThis is equivalent to burning the cost of interest for that loan as wasted PoW. Any sophisticated attacker will have effectively unlimited capital at prevailing interest rates.
- gglon 7y agoThat would be the whole gain: set of attackers would be filtered down to sophisticated ones. That would be advantageous for the network since the more centralized potential attackers are, the easier it is to deal with them.
- krageon 7y ago> the more centralized potential attackers are, the easier it is to deal with them. The opposite of this is true, as you are talking about "centralised" in the context of "a smaller group of people" and not "a smaller cluster of attacking machines". The most sophisticated adversaries are the hardest to deal with.
- Scarblac 7y agoIt only needs to be wasteful for whoever is doing the computations. It can be useful for other people. Especially if it's not worth a lot of money.
- snarf21 7y agoBut that is the conundrum. If the "work" is not really worth anything to other people, then the work isn't useful. If it is useful, it makes attacking the blockchain free. The security is because the work can't be used for anything except securing the network.
- koheripbal 7y agoAs long as the work is as useful to everyone equally (regardless of who mines), then it still works. For example, if it were solving an incredibly complex mathematical or scientific problem that benefits all of mankind - then the incentive is equal for everyone.
- trophycase 7y agoAre you claiming that anything useful that requires thermodynamic work can be monetized? You may be right but that isn't obvious.
- jstanley 7y agoIt's a simpler claim than that. The claim is that anything useful can be monetised. If you come up with something useful, but noone is willing to buy it at any price, what's your basis for claiming that it's useful?
- 34679 7y agoThe security of the network depends on the work being widely distributed and having a lot of work to do. If there is a lot of work but one worker is performing over half the work, that worker can compromise the network. If there are a lot of workers but little work, a new worker who is more capable can compromise the network.
- ZhuanXia 7y agoIt strikes me that is can still be useful, it just has to produce a good whose value cannot be internalized. It would need to be a perfect public good. Can’t think of any examples though.
- trevelyan 7y agoJust as a heads up, Saito has a quantifiable cost of attack (for attackers) while still paying for a form of useful work (tx routing / fee collection) so waste and security are not intrinsically related. https://org.saito.tech/saito-economics https://org.saito.tech/saito-economics The approach works exactly because money is guaranteed to be pulled away from the block producer. Given that it always costs more money to produce blocks than attackers can earn from them, only honest nodes (who spend other people's money) have am incentive to do so. Cost of attack is the money attackers cannot get back if they spend their own money to censor the network. Check it out!
- msgilligan 7y agoIt doesn't have to be wasteful but the computation must be asymmetric. That is it must be much more difficult to compute than to verify. The SHA-256 nonce discovery computation used by Bitcoin has this property, but is not really useful. Others have given the example of PrimeCoin which is asymmetric, but somewhat useful as it discovers prime numbers. A great metaphor for this is a Sudoku puzzle. It is much harder to solve than it is to check the solution.
- CryptoPunk 7y agoThe work only needs to be wasteful from a personal compensation perspective. It can still generate a public good.