With this exponential growth in difficulty lately I was wondering: Because the difficulty is adjusted each 2016 blocks and not some other measure of time, if there were a substantial decrease in network capacity wouldn't the blockchain get "stuck"? For example, say things keeps growing nicely and then the next reward split rolls around and half the miners decide to shut down their operations overnight because it's not profitable. It might go from 10 minutes to find a new block to 2 hours or more. Then it could take 168 days to reach 2016 blocks and have the difficulty readjust.
Is this a real danger, or an I missing something in the specification?
Thanks,
-Jay
If half the miners shut down the average time per block would rise to 20 min nominal and it would take 4 weeks not 2 weeks for difficulty to adjust and when it does difficulty would be cut in half doubling the reward for the remaining miners. If 99.9% of miners all stopped on the same day yes that would be bad but miners tend to act independently and shutdown at different times.