There is a reasonable fix for this though, just set a reorg limit say 100 blocks, and prompt for manual intervention from the user. Given a prolonged network partition situation, there would be either a central or democratic procedure to determine the winning branch, via a checkpoint. This assumes that network partition does not happen too often for longer than a day in practice.
Actually this might be the approach ppcoin eventually adopts.
that means that anyone who can create 100 blocks can shut the network down 'forever' if that'll never happen, why secure against it? If you have some consensus method that can easily resolve the shutdown why not use that for your consensus system instead of a PoX hashchain? ::meh:: It might actually be a prudent sort of thing to do, but I'm skeptical.
It doesn't shut it down. It just refuses the reorg and log the event and tell user about it, and the network is still chugging along. User should be notified so if there was a legitimate network partition event going on, people can notice and start discussion about it.
Of course the concensus mechanism to deal with these partition event would be quite a bit centralized and costly, that's why there needs to be assumption that it rarely happens.