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Proofs of Useful Work [pdf]

eprint.iacr.org

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Re: Proofs of Useful Work [pdf]

#31

Post by bluesign »

Taek wrote: post #3

Useful work is not actually a good foundation for securing a decentralized cryptocurrency. The value of PoW in cryptocurrency is that I know for a fact that you have to burn $X million dollars if you want to double-spend my cryptocurrency. That has to be burned in electricity, and that burn can't be used for anything else. It's expensive for you to attack me. If suddenly we've got useful works, such that you can appl…

"if suddenly we've got useful works, such that you can apply that $X million in electricity to solve problems that are actually not wasteful, and worth perhaps $X million dollars in solutions"

first if we ignore the part "not everyone is going to have equal access to people who are willing to pay for solutions of useful work"

I think this can never happen.

----

People should think PoW as lottery.

Every X minutes there is a prize draw giving you Y coins.

But ticket price converges to market value of:

ticket price = (Y coins)/(total tickets sold)

So if you add a value to 'not winning ticket' by introducing 'useful work', you are changing ticket price to:

ticket price = (Y coins)/(total tickets sold)-'work value'

so you are just giving coins more value, means making 'new ticket' more expensive.

new ticket = old ticket + work value

In the end you will still 'waste' the same amount at equilibrium.

Re: Proofs of Useful Work [pdf]

#32

Post by Franciscouzo »

Retric wrote: post #29
SilasX wrote: post #21

Earlier quoted context omitted.

Right, I agree that a useful PoW is possible in theory[1], but the requirements imposed (by needing to work as PoW for a blockchain cryptocurrency) are burdensome: 1) The difficulty must be adjustable so that you can make it harder or easier as computational power joins or leaves the network -- so it can't be some generically hard problem with no free parameter that affects the hardness. 2) The difficulty must be pre…

Your list is missing verifiable. What makes hashing < vale is useful is you get a high probability that someone handing a solution actually did a lot of work. Someone getting lucky could find a solution within a second using a CPU miner today, they are not going to keep getting lucky for 100 blocks.

Nobody is going to get lucky and find a solution within one second on a CPU miner, it's a 1 in 750000000000 chance.

Re: Proofs of Useful Work [pdf]

#33

Post by homakov »

icebraining wrote: post #26
homakov wrote: post #24

Earlier quoted context omitted.

On a side note: it's proven PoW is centralized and does not in fact secure the coin. Only guarantees work, not security. Just not being used to double spend yet.

Can you elaborate? By whom and when was that proven?

Like every hashrate chart? https://medium.com/@homakov/stop-calling-bitcoin-decentraliz...

Re: Proofs of Useful Work [pdf]

#34

Post by [deleted] »

homakov wrote: post #24
Taek wrote: post #3

Useful work is not actually a good foundation for securing a decentralized cryptocurrency. The value of PoW in cryptocurrency is that I know for a fact that you have to burn $X million dollars if you want to double-spend my cryptocurrency. That has to be burned in electricity, and that burn can't be used for anything else. It's expensive for you to attack me. If suddenly we've got useful works, such that you can appl…

On a side note: it's proven PoW is centralized and does not in fact secure the coin. Only guarantees work, not security. Just not being used to double spend yet.

[deleted]

Re: Proofs of Useful Work [pdf]

#35

Post by tromp »

jcoffland wrote: post #28

An important consideration that is missing in section 7 A Blockchain Scheme is that the PoW must also be tied to the miner's receive address otherwise anyone could claim the reward as soon as the PoW was broadcast onto the network. A simple solution is to also hash the miner's receive address along with the previous block and transaction hash. This seems like a pretty major omission on the part of the authors and cas…

It's not so much missing, as it is implicit in the H(current block), since current block includes all transactions, includes the coinbase for the miner. (In reality, only the merkle root of the transaction tree is hashed, with similar effect).

Re: Proofs of Useful Work [pdf]

#36

Post by Retric »

Franciscouzo wrote: post #32
Retric wrote: post #29

Earlier quoted context omitted.

Your list is missing verifiable. What makes hashing < vale is useful is you get a high probability that someone handing a solution actually did a lot of work. Someone getting lucky could find a solution within a second using a CPU miner today, they are not going to keep getting lucky for 100 blocks.

Nobody is going to get lucky and find a solution within one second on a CPU miner, it's a 1 in 750000000000 chance.

Did you calculate that?

750000000000 chance every 10 minutes * say 1,000,000 CPU miners = 1 / 750000 per 10 minutes, and 1 in 14.27 per year. I don't think their are 1,000,000 CPU miners, but I suspect their are at least a few thousand of them for the lul's.

Re: Proofs of Useful Work [pdf]

#37

Post by wybiral »

Taek wrote: post #3

Useful work is not actually a good foundation for securing a decentralized cryptocurrency. The value of PoW in cryptocurrency is that I know for a fact that you have to burn $X million dollars if you want to double-spend my cryptocurrency. That has to be burned in electricity, and that burn can't be used for anything else. It's expensive for you to attack me. If suddenly we've got useful works, such that you can appl…

The thing being "spent" is no longer electricity but rather is the value of the work being completed.

That means the value would change if new ways to solve the problems arise. But currently the value changes based on your electricity bill (new tech could disrupt that too).

Re: Proofs of Useful Work [pdf]

#38

Post by tromp »

This work is theoretically very interesting, but nowhere does the paper explore what parameter choices would make its use in e.g. bitcoin practical. In particular, would n be close to a million? How large would the problems (f,x) be? How large are the solutions? Both of these would need to be included in the block header which is currently only 80 bytes long. Any sizes substantially larger than a few KB would make this rather impractical. What are the best known implementations for these sizes? How many seconds does it take to solve and how many to verify a solution?

Re: Proofs of Useful Work [pdf]

#39

Post by bsbechtel »

richdougherty wrote: post #7
bsbechtel wrote: post #5

Earlier quoted context omitted.

Like carbon sequestration?

That's an interesting idea, but is there a way to prove carbon sequestration, except by providing me with some physical carbon?

It was more of an off-handed comment, but I suppose you could rig some sort of carbon sensor that measures X amount of carbon pulled from the atmosphere. Of course any sort of sensor to the physical world can be rigged to produce a false signal.

Re: Proofs of Useful Work [pdf]

#40

Post by Boussac »

Taek wrote: post #3

Useful work is not actually a good foundation for securing a decentralized cryptocurrency. The value of PoW in cryptocurrency is that I know for a fact that you have to burn $X million dollars if you want to double-spend my cryptocurrency. That has to be burned in electricity, and that burn can't be used for anything else. It's expensive for you to attack me. If suddenly we've got useful works, such that you can appl…

Excellent reminder of why 'useful PoW' is a very bad idea. Furthermore, the value of 'useful' may vary over time to the point where it exceeds the value of mining. That is when a 'useful' corporation takes over mining and decides to kill the chain because 'useful inc.' is promoting its own corporate token (another bad idea: bad ideas generally lead to other bad ideas).
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