Will ETH solve the "Nothing at Stake" problem?

[Abiky]

As times passes by, we're becoming one step closer towards experiencing PoS on the Ethereum blockchain. Some say that it'll be here by 2020, while others say it'll be next year (2021). What's important is not when will ETH switch to PoS, but rather how robust the consensus algorithm will be. After all, PoS is long known to have its issues such as the "Nothing at Stake" problem. It'll be quite a challenging task to try to solve it, but not impossible. It's said that ETH will penalize validators who behave maliciously on the Blockchain. It could very well prevent the "Nothing at Stake" problem, but it brings other issues along the way. What if a validator mistakenly supports a fork, leading to the loss of his/her funds? It makes me wonder how ETH's PoS consensus will work out in the long run. If successful, I'd expect other cryptocurrency projects to adopt ETH's model. Otherwise, the majority will adopt PoW all the way through the ETC blockchain.

What are your thoughts? Do you think ETH will be able to successfully solve the "Nothing at Stake" problem? If no, why?

[btc_angela]

What are your thoughts? Do you think ETH will be able to successfully solve the "Nothing at Stake" problem? If no, why?

Hard to say, "Nothing at Stake" is based on assumptions, I would compare this to the so called 51% attack on bitcoin. Theoretically, it is possible, but why no miners are attempting to used this attack vector and incentivize themselves? So we can't really tell at this point, and to somewhat reduced the odds of ETH validators performing it, penalising them will keep this theory away.

[Tomohisa]

Yeah, I also want to see how ETH fare in PoS as from my history with crypto that has PoS, MM, there is a lot of time shit happens (spit chain, dud coin, nothing at stake,...). I do believe that ETH could develop something new to tackle those problems eventually tho.

[bitmover]

Nothing at stake is discussed in Ethereum casper official FAQ:

https://eth.wiki/en/concepts/proof-of-stake-faqs

This can be solved via two strategies. The first, described in broad terms under the name “Slasher” here and developed further by Iddo Bentov here, involves penalizing validators if they simultaneously create blocks on multiple chains, by means of including proof of misbehavior (ie. two conflicting signed block headers) into the blockchain as a later point in time at which point the malfeasant validator’s deposit is deducted appropriately.
...

The second strategy is to simply punish validators for creating blocks on the wrong chain. That is, if there are two competing chains, A and B, then if a validator creates a block on B, they get a reward of +R on B, but the block header can be included into A (in Casper this is called a “dunkle”) and on A the validator suffers a penalty of -F (possibly F = R). This changes the economic calculation thus:

Ethereum already thought about all those common  and most discussed problems.
The real problems will be the ones nobody antecipated.

[Abiky]

Nothing at stake is discussed in Ethereum casper official FAQ:

https://eth.wiki/en/concepts/proof-of-stake-faqs

This can be solved via two strategies. The first, described in broad terms under the name “Slasher” here and developed further by Iddo Bentov here, involves penalizing validators if they simultaneously create blocks on multiple chains, by means of including proof of misbehavior (ie. two conflicting signed block headers) into the blockchain as a later point in time at which point the malfeasant validator’s deposit is deducted appropriately.
...

The second strategy is to simply punish validators for creating blocks on the wrong chain. That is, if there are two competing chains, A and B, then if a validator creates a block on B, they get a reward of +R on B, but the block header can be included into A (in Casper this is called a “dunkle”) and on A the validator suffers a penalty of -F (possibly F = R). This changes the economic calculation thus:

Ethereum already thought about all those common  and most discussed problems.
The real problems will be the ones nobody antecipated.

I wasn't aware about that. Thanks for sharing. Day after day, the ETH team impresses me with their outstanding development in the crypto/Blockchain space. I wouldn't worry if PoS takes a long time before launch, as long as it's implemented in the safest way possible. Security/reliability is what matters here. As with anything, new issues might arise after making the transition from PoW to PoS. We have to keep in mind that nothing is perfect no matter how its proponents claim it to be. For once, Blockchain technology was thought to be "unhackable" only to be found that chains with low hashrate were susceptible to 51% attacks. Something similar might happen with ETH where flaws will be discovered as time goes by. With a dedicated development team by the project's side, nothing can go wrong.

I think that once ETH successfully adopts a new model of PoS, older PoS blockchain networks might follow ETH's "footsteps". Peercoin, Blackcoin, and other PoS-based cryptocurrencies could adopt ETH's model in order to prevent the "Nothing at Stake" problem. For sure, the level of security within PoS will be lesser than PoW. But this should make ETH much faster, eco-friendly, and extremely convenient for the masses. Let's hope for a successful launch of the most anticipated PoS upgrade in the world's second-largest cryptocurrency by market cap. Just my opinion