But if there are too few non-mining full nodes then it would be easier for the miners to "Sybilize" their way to change the rules, is it not?
Sybil attacks can not change the program code on my node therefore they can not change the rules of the network.IE: They can't change hard coded things like block size or block speed or anything that my node program code will reject.
I reply to this one first.
Ok. But what if the Bitcoin network has
very few mining or non-mining nodes. Would it not be an open opportunity for some group to do a UAHF Sybil set up to force the decentralized part of the network to hard fork to the rules the group wants?
Nope,
Sybil attacks can not change the program code on my node therefore they can not change the rules of the network.# of nodes is irrelevant. You are confusing a hard fork with a sybil attack. My previous post explained what a sybil attack could do:
https://bitcointalk.org/index.php?topic=4554671.msg43399300#msg43399300https://www.investopedia.com/terms/h/hard-fork.aspA hard fork as it relates to blockchain technology, is a radical change to the protocol that makes previously invalid blocks/transactions valid (or vice-versa).
This requires all nodes or users to upgrade to the latest version of the protocol software.
*Any attempts to change the protocol with less than full consensus of all of the miners does nothing more than create an ALT coin for the splinter group.*