Question, tell me please if there will be bitcoin split for example is the difficulty of the mining should be changed?
part of difficulty is based on how much hashrate is mining bitcoin or in other words how many miners.
if it splits and the splitted chain (BCC in this case) will obviously won't have enough miners on it.
the difficulty will stay the same at first but after reaching the difficulty adjustment block (which is every 2016 block) it will be readjusted) and comes down.
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BCC's difficulty will be adjusted quicker:
Forking rule:
“REQ-7 Difficulty adjustement in case of hashrate drop
In case the MTP of the tip of the chain is 12h or more after the MTP 6 block before the tip, the proof of work target is increased by a quarter, or 25%, which corresponds to a difficulty reduction of 20% .
RATIONALE: The hashrate supporting the chain is dependent on market price and hard to predict. In order to make sure the chain remains viable no matter what difficulty needs to adjust down in case of abrupt hashrate drop.”
There are 2 issues with this adjustment-algorithm:
First, it only compared the most recent block with the one 6 blocks before that. So if there's no BCC block mined yet, then the difficulty won't be adjusted. This means that if only a small fraction of the miners switch to BCC, then it will take a long time to find this first block (1% of mining power -> 16 hours on average).
Second, this algorithm doesn't adjust the difficulty further down once a rate of 6 blocks in 12 hours has been achieved. Neglecting variance, that means that when the average over the last 6 blocks hits 2 hours per block, the most recent block took about 1 hour. At that point this form of difficulty adjustment stops and the coin will be moving forward at 1 block per hour until the next difficulty adjustment, which will be somewhere between 1 and 2 months later.
This first issue is only relevant if mining support is very small, but the second issue is relevant in almost every realistic scenario. The chance is extremely high that under these adjustment rules, BCC blocks will be moving very slowly for a considerable amount of times. This will disincentivize miners and users from supporting the chain and it may ultimately doom it.
