Gavin Andresen - 2012-09-07 02:20:19

First: I think it is extremely unlikely that somebody would spend a million dollars on an attack that takes months to pull off, doesn't benefit the attacker at all, is easy to fix, and that would be easy for the network to recover from.

Quote from: Sergio_Demian_Lerner on September 06, 2012, 09:51:42 PM
The only way to recover from these attacks is by downloading a new version of the client with a new checkpoint with a much higher block difficulty. I can't think of any other possible patch. Maybe the interval between new releases
during the transition from GPUs to ASICs could be decreased.
Good idea, and easy to do.

I've got a half-finished "user-defined checkpoint" patch in my personal git tree, so users, merchants, and big mining pools can decide for themselves to add checkpoints on-the-fly (via an 'addcheckpoint' RPC command) to protect against this type of attack.