On Tue, Nov 5, 2013 at 6:43 PM, Ittay <ittay.eyal@cornell.edu> wrote:

> The attack can be easily hidden. And be sure that before today, today,
> and after today, very smart people are at their computer planning attacks
> on Bitcoin. Exploits must be published and fixed FAST.
>

I think it would be helpful if you actually implemented and pulled off this
attack, by becoming the dominant miner capable of reversing spends at will.
Then we'd know how quickly it can be done.