I've skimmed over the paper.
I don't quite understand the
claims of reducing the effectiveness of grinding attacks .
To quote the paper:
The first step of the grinding attack is for the attacker to generate blocks in order to gain
in sequence over and eventually control the stake modifier. This step takes time and causes the
attacker to accumulate a signi cant lag behind the main chain. The process of gaining control of the
stake modifi er is very technical, dicult to express and dificult to follow.
But the details do not matter. The only important takeaway is that
the process takes a significant amount of time (at least hundreds of minutes).
Why does this process have to take "at least hundreds of minutes" when the block time
of this coin is 1 minute? The paper says its very technical and it doesn't matter
but I think it does matter since its at the heart of the matter here.
They should be able to explain in plain English and clear terms why
their design would necessitate a long lag in creating a false chain.
They seem to be saying that there is some kind of prohibition:
During the first 200 minutes (the first modifier interval) of the attack, the attacker
cannot grind through stake modifiers. He must use the stake modifier that was seeded
from blocks from the main chain over the preceding selection interval (1.6 day, or ∼ 2250
minutes).
But none of these time intervals happen in real time or matter to the attacker
in a PoS. They can all be spoofed...You can always broadcast a false chain
and that has always been the problem with PoS.
(Only PoW is resistant to time manipulations because it takes real time
to do the work.)
Can someone explain to me what is really new here?