https://en.wikipedia.org/wiki/Proof_of_stake
Start here.
“The threat of a 51% attack still exists on proof-of-stake as it does on proof-of-work, but it's even riskier for the attackers. A attacker would need 51% of the staked ETH (about $15,000,000,000 USD).”
The rest is game theory. Dishonest validators win the game being dishonest if they are over 2/3 of the validator set. Then they can enforce their bad blocks into everyone else. Otherwise they get slashed or suffer other kind of penalties (inactivity leak if they manage to prevent the network from reaching consensus for a while).
So if you manage to bribe or buy 2/3 of the staked ETH then you can attack the network. There is of course a very significant economic cost to it. More interestingly at that point you are strongly aligned with the network itself as you represent a huge % of its value so you would be attacking yourself in a way. This is a notable difference with PoW where miners are not necessarily aligned in economic incentives with token-holders or users.
The network which was just shown to be 51% malicious actors? And how is it evaluated? What if the slasher is dishonest? What if it sends trillions of fake requests?
What happens if you try to send trillions of invalid transactions in any sensible chain?
The thing here is that the validators don't need to be honest when responding to a slasher report.
Also, how can there be a fee to trying to send an invalid transaction? Such a fee would have to be sent as part of a transaction, yes? Isn’t it just that someone spamming the network gets dropped from the gossip protocol stuff?
There’s no one gate keeping your ability to become a slasher as long as you run a validator, and there’s no centralized entity deciding whether or not to slash someone’s stake.
Hmmm. It seems dangerous to rely on altruistic enforcement in a network built around economic incentives. What if the altruistic slashers are simply paid money to turn off their nodes?
This model assumes that 1/n is honest. This is almost as safe as it gets.
[1] https://docs.prylabs.network/docs/prysm-usage/slasher
> However, home stakers are advised not to run a slasher on personal hardware, as it is a tremendously resource-hungry process. Slasher is very heavy on database access and disk usage, and the slasher.db will quickly grow to 1TB or more when running on mainnet.
I’m pretty sure hardware costs will always be a rounding error compared to the $50k that “home stakers” need if they want to run their own validator.
The difference is that proof of work automatically tends to centralisation due to its economy of scale: it's cheaper to add one more miner to your pool if you already have a big mining operation, but staking 1 eth is always staking 1 eth.
Both PoS and PoW have the problem where you can buy out the majority if you have the power to do so.
If I have 100 GPUs and I buy one more can't I turn around and say "But buying one more GPU is just buying one more GPU"? Even if your point is that electricity bills are lower per additional GPU, surely humans discount the value of incremental money after some point so for those with lots of eth incremental eth isn't worth as much?
It’s the same price to add 1 eth when you own 100 eth as when you own 1 eth
Perversely, since double-validation happens rarely, since it is expensive, the actual interface for slashing on e.g. BSC is not well-documented or user-friendly.
To whom? Who gets to decide to slash the funds?
I caught you cheating and can prove it. You don't give a shit and control 51% of the network. How do you get punished?
It's no different from what would happen in PoW. Can you please stop with the concern trolling?
If that 67% is also true of the slasher voting protocol, then that means you just need 33% of the network to avoid being slashed. Is that wrong?
> Can you please stop with the concern trolling?
Can you please stop trying to claim a moral high ground for no reason?
Yes, it is wrong.
By the way, there is a bug bounty program. You can earn up to 1M USD per critical bug either in the protocol or its implementations.
If you were following the current events on Ethereum, this question has just arisen in the last weeks when the US sanctioned the privacy oriented Tornado Cash contract.
If you control 20% of the network, the other 80% is following the rules and colluding against you. (Even another 20% that are double-validating themselves are incentivized to slash you)
The whole cryptocurrency thing feels like a bit of a metastable equilibrium, but nobody's figured out anything better. Arguably even government-controlled fiat money is not much better - if >50% of the population doesn't like the rules, they will change them - we may be seeing the beginning of this right now, with a lot of people getting dissatisfied with half their income going to the black hole known as "landlords" who own the rights to take your income without producing any value whatsoever.
It might just lead to everyone abandoning your cryptocurrency and using a different one. Since you had to have >50% of the cryptocurrency in order to conduct the attack, you did lose a substantial amount of real-world value (billions or trillions of $) when everyone else stopped using your cryptocurrency.
It's pretty much analogous to if a majority of PoW miners decide to "go their own way" and make a chain where nobody else is invited. What happens then?
But what if most of the stakers collude to double spend tokens? My understanding is that there is an additional layer of validators that have the power to force them to give up their stake as a penalty. Hence "proof of stake". And that there are very few validators. And it's really just the ethereum foundation.