I got this theory while reading an article about selfish mining, but for selfish mining to work you'll need to have something around 25% hash rate? (can't remember the exact %)
Anyway, the idea was taken from selfish mining, but I added that attacker needs to have couple nodes under his control and he isolate them in order to massively reduce the target difficulty so he can generate blocks at ridiculous high speed to make up for the time he didn't generate blocks while isolated.
also I'm not sure if 10 nodes are enough? maybe he needs something like 1/3 of total number of nodes to make sure that his blockchain will be published to everyone?
That's all, if anyone can explain if it's possible or not or if you can provide links to articles that help me finding the answer I'll be really appreciated, hope I explained my theory in an easy way.
if you separated yourself from the main network at block h 322992. and started mining in your smal network. the difficulty will still initially be high. so if you only had some USB erupter miners. you probably wont even mine one block in the 2 weeks you have to wait.
once the 2 weeks are up and it time to change difficulty down because your small network is suppose to be at 2016 blocks further on. yet you have not solved a block due to complexity too high.. it will drop alot..
you have already by now lost the game before you even got a block, just by not keeping up with the real network block numbers.
so the problem is that even if you do not mess with the code to make a block you want to solve give you 5 trillian coins. even if you think you have solved a legitimate block. when you then connect to the main network. your blockchain will put you at 322993, yet everyone else's chain will be atleast 324000. meaning that block you hoped would net you 25legit coins or 5trillian reprogrammed coins.. would both be simply ignored and your personal block would be orphaned/binned/thrown out, 'shown the hand because the tcp aint listening'. simply because your block 322993 does not follow on from everyone elses.
thus its not worth it.