Nothing at stake is discussed in Ethereum casper official FAQ:
https://eth.wiki/en/concepts/proof-of-stake-faqs
Ethereum already thought about all those common and most discussed problems.
The real problems will be the ones nobody antecipated.
https://eth.wiki/en/concepts/proof-of-stake-faqs
Quote
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.
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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:
...
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
