Correct me if I'm wrong but this only solves the problem if the miners aren't purposefully coordinating the take over of the system. It is merely that a pool of otherwise benign miners can't be used by the pool operator to rewrite the transaction history.
This doesn't stop an organized attack of someone who has rented lets say half of amazon's cloud infrastructure for a 10 minute attack to take over the transaction history. Something that becomes more and more profitable with the reduction of bitcoin income from mining and increase of the total number and price of bitcoins.
This doesn't stop an organized attack of someone who has rented lets say half of amazon's cloud infrastructure for a 10 minute attack to take over the transaction history. Something that becomes more and more profitable with the reduction of bitcoin income from mining and increase of the total number and price of bitcoins.