[nootropicat]

>The PoW used in Bitcoin has demonstrated resiliency against attacks

Multiple PoW coins have been successfully attacked, like ETC. Because they are already on GPUs there's no fix - just hope it doesn't repeat. Those successful attacks prove that any attack on PoW is only a question of external resources (sha256 ASICs for btc).

It's also surprisingly hard to profit from a 51% attack on pure speculation coins like btc or etc because next to zero actual economic activity is happening on them, which is why such attacks were rare and small in scope. The best you can actually do is to try to double spend an exchange. If they were actually used for real commerce profit becomes much easier. It could also become a military goal - if Iran relied on a PoW-coin for its economy, blocking their coins would destroy their economy.

This is one of the reasons why ethereum absolutely must switch to PoS - PoW is extremely insecure for smart contracts because there are many more ways to profit from an attack, like censoring price updates for defi.

[swensel]

I'm aware of the ETC attacks. I don't think ETC can really be compared to BTC though. The ETC network is composed of the idealistic (or maybe stubborn) folks who didn't want to switch over to the new ETH chain after the DAO hack. I'm not saying ETC has no merit, but it didn't have the same network resilience due to the split.

Seems like you know a lot about PoS, would you be willing to check out my other comments on this post (https://news.ycombinator.com/threads?id=swensel)? I've covered some concerns / questions that I have about PoS that maybe you can answer in more detail.