[bigdaddyrabbit]

> ...proof of stake will make this sort of attack 10k worse. With proof of stake there is essentially no resource cost.

This is not true. For a 51% style attack on a PoS chain, you need to acquire a majority of staked coins. Each coin you buy increases the cost of the next coin, (demand/supply and all that), and the price of the coin increases exponentially as an attacker accumulates 51% of the coins.

With PoW, cost of acquiring hashpower is linear (acquiring the last 1% costs the same as the first 1%), which is why PoW is easier to attack.

[amluto]

> For a 51% style attack on a PoS chain, you need to acquire a majority of staked coins.

Not really. All you need is a controlling vote for enough confirmations. At 51%, you’re very likely to have a controlling vote. Below 50%, it’s still possible.

[hndamien]

And that is why these are not decentralised solutions. Just maintain a controlling stake and you are good to go!