Proof of stake to elect a leader that mines using a verifiable delay function seems viable. Proof of stake ensures majority support. And only a single person needs to max out their cpu computing the vfd.
You can rewrite the chain easier than with PoW, but it is plenty hard - requires a majority to precommit to a secret fork. Safe enough for many purposes at a fraction of the cost.
You don't need a secret fork. You just need the community to split over some sort of doctrinal issue, such as already happened with the ETH/ETC split.
Only with PoS, there's no way to judge which fork is the "right" one. In PoW, miners vote with their finite hashpower. There's no practical limit to how many hard forks a PoS system can sustain because they don't rely on anything that's actually scarce.
Because a fork approximately divides the value of the currency between the two parts.
Imagine the USD was suddenly split into two incompatible and free-floating currencies, with the US House of Representatives saying one currency is the official one and the US Senate claiming the other. It would be chaos.
Please expand. Frankly if POS isn't viable I don't see a future for POW either; especially when carbon costs are priced in.
As things stand POW chains have traded massive inefficiency for decentralization. I doubt this can stand long term if we wish to address climate change. Crypto already has a higher energy use than many countries.
> [...] especially when carbon costs are priced in.
You misunderstand the economics of proof-of-work. Perhaps we should call it 'proof-of-waste'. Basically, in something like bitcoin proof-of-work functions a bit like an auction: the total amount of resources wasted on mining tends to equal the total amount of mining rewards.
For simplicity, assume mining rewards are fixed.
If hashing becomes cheaper, (eg first because of GPU miners, later because of ASICs), the hash rate will go up, but the total amount of resources wasted on mining will stay the same.
If hashing becomes more expensive (eg because of a universal carbon tax), the hash rate will go down, but the total amount miners spend on mining stays the same.
Arguably, that's exactly how a carbon tax is supposed to work in the best case.
Of course, there will be plenty of incentives to avoid the carbon tax. Both by mining with clean power (good!) and by mining in places that don't implement the carbon tax (less good!).
half agree with that. PoW is the most efficient method of converting raw energy into a digitally secure token. It would be much better if the work done was actually useful beyond that.
Some attempts have been done in the past, but with low success (Riecoin IIRC uses cpus to find sequences of primes, GridCoin used BOINC for the PoW, proof-of-boinc in that case).
There is still work to be done on EVM chains. Contract calls need to be processed and verified by every (full) node
> half agree with that. PoW is the most efficient method of converting raw energy into a digitally secure token. It would be much better if the work done was actually useful beyond that.
I'd say PoW is not the most efficient method. It's a terrible waste by design.
The kind of 'work' that works in PoW has some rather strict requirements, that's why it's almost impossible to shoehorn useful work into a PoW scheme.
Wikipedia tells me that eg GridCoin uses proof-of-stake to prevent double-spending attacks; its rewarding people for BOINC work is a totally separate gimmick.
Proof of waste is an interesting way of putting it. I don't disagree. Maybe it would be interesting for power companies and govt to pair up and provide coins that are deflationary, and are only mined by putting power back into the grid. Make those coins useful to pay for car registration, taxes, or whatever. At least some deflationary value could be put to work there.
> Maybe it would be interesting for power companies and govt to pair up and provide coins that [...] are only mined by putting power back into the grid.
That idea sounds good, but would only be a solution for a problem that doesn't exist.
Bitcoin's design solves two problems:
(1) only someone who owns a coin should be able to spend it
(2) they should only be able to spend it once
The first problem had been solved for ages: use digital signatures to authenticate messages of essentially the form "I, Alice, hereby send 3 bitcoins to Bob." Given some initial coin assignment to specific private/public key pairs, you can follow along these messages, keep a tally in a ledger, and know how much everyone has.
Solving the second problem is where bitcoin innovates. Without a trusted third party coordinating things, Alice could just show a message to Bob and Charles each 'sending' them the same 3 bitcoins. Bitcoin uses proof-of-work to pick (at most) one of these messages to be part of the consensus reality.
The scheme you are suggesting requires some trust in the partnership of government and power companies. But as soon as you have very minimal amounts of trust, you can just solve the double-spending problem directly.
And that direct solution involves much less trust than what is required for accepting any statements about the power grid.
If you want, I can sketch out a minimum trust system for the direct solution I mentioned.
PoS, to my knowledge isn't a viable alternative to PoW. There are too many similarities to the traditional financial system. That's partly (mostly?) why PoW was invented.
PoST (Proof of Space and Time) is PoW 2.0 essentially. It addresses the energy consumption of PoW using the same Nakomoto Consensus mechanism that provides true decentralization and the security that comes with it. It does this by doing the work ONCE up-front and saving it to space (generating plot files) rather than doing the work for every block. Lookups are incredibly energy efficient (farming plots). The Time component ensures that a certain amount of time passes between blocks, and is responsible for moving the chain forward.
There is also the added benefit of utilizing datacenter drives destined to be scrapped // still perfectly usable for storing plot files.
PoST is a step in the wrong direction. It doesn't address anything, because energy use is not a problem. PoST consumes natural resources and produces e-waste, which is way worse than just consuming clean energy and producing heat, which is what PoW does.
PoST (Chia specifically) produces 20,000 times less e-waste than Bitcoin. Chia also has 20x the nodes as Bitcoin. A comparison of network security would probably be the best way to compare the scales of each.
In the long run, hard drives used for crypto lookups in PoST (farming) have very low load and can last for a decade.
Whereas Bitcoin ASIC miners become obsolete much faster and can't be reused for general purpose computing afterwards.
> Consensus in both of them is based on unforgeable costliness, to make it economically unviable to create alternative histories.
> In both systems, total cost of mining approaches the block reward. For example, if block rewards are $10 million a day, then $10 million worth of energy is used in PoW. PoST burns through $10 million worth of hard drives.
Consensus in both of them is based on unforgeable costliness, to make it economically unviable to create alternative histories. In PoW, the costliness is based on production and consumption of energy. In PoST, the costliness is based on production and consumption of hard drives. Hard drive production needs both energy and natural resources.
In both systems, total cost of mining approaches the block reward. For example, if block rewards are $10 million a day, then $10 million worth of energy is used in PoW. PoST burns through $10 million worth of hard drives.
The cost of PoST is based on scarcity in hard drives, which incentivizes production of hard drives. The cost of PoW is based on scarcity in energy, which incentivizes production of cheap and clean energy.
If PoW's costliness is based on production and consumption of energy, it requires a certain amount of energy and natural resources to produce the hardware required to consume the energy, correct?
I'm failing to follow how PoW is fundamentally different than PoST in terms of hardware (and the resources to produce it) necessary to validate blocks.
It seems that the point of PoST is that we get a similar potential of decentralization that we get with PoW with significantly less energy usage.
I somewhat understand the argument of PoW incentivizing production of cheap and clean energy and I hope this is realized ... specifically clean energy, specifically advanced nuclear as its utilization isn't geographically restricted.
You can rewrite the chain easier than with PoW, but it is plenty hard - requires a majority to precommit to a secret fork. Safe enough for many purposes at a fraction of the cost.