I mentioned the issue of network partition in another post (How good is SAFE Network really for anonymity? - #5 by dirvine) and people kindly replied to me on how Safe could address it (was glad to see people welcoming new questions!). Unfortunately I was not completely convinced at the time (need more reading); and now seeing some relevant discussion here it has come back to my mind that network partition combined with some other techniques could still stand a fair chance to subvert the network.
First of all partitioning-based attack has been explored in the past for bitcoin (https://news.ycombinator.com/item?id=14594172), and I haven’t seen convincing proposals on solutions. One possibility might be to sacrifice liveness in case of partition to avoid further damage (which indeed was suggested in my other post); however someone raised a good point on this topic that ability to stall or refuse local chain is only viable if partition is not complete. That is to say a lot of what we try to rely on for security in a decentralized setting is having knowledge of the decentralized topology, and that knowledge itself is not localizable - in the sense that it requires exchange of information with the wider network where ‘the wider network’ needs to have a defined and consistent meaning across.
Say the attacker realizes it’s too expensive to control sections - what he can do instead is to build a walled garden with potential users inside such that he’ll have a partitioned network where he always has the main share, regardless of the resistance we build into the network by decentralization. He can do that by for example, using middleman rogue servers in front of the bootstrap servers controlling a few bootstrap servers and blocking others - so a new user by default is likely to enter his network, and of course he can also tweak his own network by making it corrupt as well. Only nodes which manage to exchange information with those outside the partition in the past can escape the fate of being walled - for new nodes any attempt of knowing the ‘true picture’ could be prevented by complete partitioning.