> This is just a balance between how much you win, and how much it costs you. If I double my earnings for sub 1% chance of being caught, then you need to have a very expensive reputation build-up to compensate for that, and this is going to put a big burden on legit providers who want to enter the system, making it even easier to cheat.
But there is also no need to make the chance of being caught so low, because a single digit percentage of overhead is completely reasonable while still providing a significant chance of being caught.
And you could scale the verification rate with reputation, so a 1% verification rate is possible but takes a very long time, whereas a 10% verification rate is more than ten times easier to get despite still not being a prohibitively high amount of overhead.
> Same as above: the higher the stacking is to fend of cheaters, the less attractive it is to legit players.
For things like GPU computation, you're going to do a unit of computation over a matter of minutes with verification taking the same amount of time or being done in parallel, and so you do many units of computation a day.
It's not that unreasonable to ask someone to put a month's earnings at stake at any given time, which is about what you get with a 24 hour verification window and a 7% verification rate.
> Also, with your scheme the “verification window” doesn't matter, since you're not going to catch me after the fact: you're going to catch me iif my adversarial transaction is being checked.
You're not the one who chooses whether to verify it. If other people are verifying 10% of your work but then someone catches you cheating, they can prove to the others that you cheated and then everyone goes back and verifies 100% of your work which is still in the verification window -- at your expense -- and you lose even more if you cheated more than once.
> Not if me cheating allows me to make even just 223% of the legit payment.
The thing this is preventing is you claiming to do some work but actually not, e.g. someone wants to use your GPU for AI but you don't even have a GPU and just return random numbers. To know if your result is right they would have to do the same computation again so they can compare them, which doubles the cost, or more if they want higher assurances against collusion. And then they're not willing to pay you as much because some of their money has to go to that.
Also, it's 223% plus the cost of provably damaging your reputation.
> I just realized that your scheme would be even more penalizing to legit node than I thought: with one random bit flip, the node would lose all their stacking and all their reputation. Talk about an expensive cosmic ray!
You can set the penalty to whatever is necessary to deter cheating at that level of verification. It doesn't have to be that high, but it can be that high if you need it to be without imposing an unrealistic amount of overhead.
And providers who don't want to be penalized for doing the calculation wrong should operate reliable hardware with functioning error correction. This is not a bad thing to incentivize.
You might also weight the reputational harm. If you get caught once, your reputation will be harmed and lots of people will be rechecking your recent results to see if you tried to screw them too, but if it's an isolated incident you only take a small hit. Whereas if you get caught repeatedly, well, you might as well just start over.
> Or an attacker could even voluntarily send rowhammer workload to legit node in order to destroy their reputation and stacking, reducing supply and hence increasing their own margin
At which point the node is at least as likely to crash as sign an invalid result, which is already a denial of service attack you have to mitigate. For example by using ECC memory and terminating workloads that induce detectable ECC errors instead of continuing them until they induce an undetectable one and crash the machine or cause it to sign a corrupted result.
(Also, rowhammer is a huge problem and almost nobody is actually mitigating it effectively for anything. Someone needs to come up with a generic solution for it before someone else starts using it for widespread exploitation or we're going to have a bad time regardless of what kind of reputation systems are in use.)
> Not if you've spend the said 2 years stressing the drive in a PoST scheme. There's a reason why these schemes break the manufacturer's warranty ...
Do you have some data to back up this claim? Drives are routinely used for heavy database workloads and reliable drive models still last for multiple years.
It seems evident that they're at least reliable enough to continue operating under that workload since that's what they have done instead of failing en masse and causing the storage capacity of the network to decline, given the assumption that the price is too low to justify anyone replacing them.
> You'll be able to sell them. You'll take a haircut (likely less than the 70% you're talking about when reselling old hard drives), but you'll sell them in the same day anyway.
You can sell the hard drives the same day too if you're willing to provide a sufficient discount from the market price. But there is rarely a good reason to do this, because the discount you'd have to provide is more than the time value of money in spreading the sales over somewhat more time.
> Good luck selling worn-out hardware to a data center!
Data centers run hardware until the resource consumption in power and space exceeds the cost of newer hardware, or until it dies. Reliability is just a number in an equation that tells you how much redundancy you have to operate with.
> Hodl to the moon (AKA sunk cost fallacy)
Those are two different things. If they want to hold the coin they'd have more of it to hold if they sell their hardware and use the money to buy the coin.
More likely they're expecting that others will quit and lower the supply to fall in line with demand (or more optimistically that demand will increase) so they can go back to making a profit, but since they all have that incentive they hodl until somebody blinks first, and lose if nobody does.
In the meantime their possibly irrational optimism provides for cheap storage.