What is frightening? That you misunderstand? Lets give you the benefit of the doubt, and blame me for not explaining well enough.
For miners to build on top of a block then nodes would have to have propagated it to them, i'm sorry that I didn't explain this. I should not have assumed implicit knowledge.
So to be doubly clear, if the majority hash rate is ming >1MB blocks and the nodes are propagating >1MB blocks then that is the longest chain and by definition it is valid. So I say again 'valid' is redundant.
For miners to build on top of a block then nodes would have to have propagated it to them, i'm sorry that I didn't explain this. I should not have assumed implicit knowledge.
So to be doubly clear, if the majority hash rate is ming >1MB blocks and the nodes are propagating >1MB blocks then that is the longest chain and by definition it is valid. So I say again 'valid' is redundant.
I am sorry if I am coming accross as anal retentive but unless you clearly state the differences unfamiliar users will be dangerously misled. This doesn't involve having to write a 500 page lecture and you can simply state something like - "ultimately the economic majority of nodes define what is valid"
We have to be clear with our language as not to confuse others unfamiliar with how consensus is formed. This isn't being nitpicky, but a very important principle which needs to be stressed as new users will be confused and mislead into believing that the miners control the network and define what is valid when this isn't necessarily true. We need to be clear with our language that it is the nodes and more specifically the economic majority of nodes that define what is valid and what is not.
Not understanding this distinction can lead to some very large errors in judging the security of the network and understanding how consensus is formed.
This means that -
1) Not all nodes are created equal. Nodes without economic actors on the other side can slightly degrade the network security. Spinning up 1k nodes on amazon ec2 will not create a successful coup. This is why it is important to stress that the economic majority of nodes decides on valid transactions.
2) In a hardfork scenario implementations will typically use an indirect means of approximating the will of the economic majority
of nodes by either using 750 of the last 1k mined blocks or 950 of the last 1k blocks. It is important to reflect that this doesn't necessarily indicate that the majority of the economic consensus aligns themselves with the miners and there could be a disastrous(or wonderful - depending on perspective) split where the economic majority of nodes(merchants/wallets/processors/large bagholders/exchanges) fall on the otherside of the miners. This is why many individuals stress that we need a much higher threshhold of 95% to approximate general consensus.
3) While the majority of nodes have an incentive to follow the most hashing power on the longest chain during a hardfork it can become very unclear as to which implementation will have the most hashing power or economic majority. For this reason individuals should safeguard their bitcoins in cold storage(remove from banks and exchanges) under contentious hardforks(and any fork that needs such a low threshold as 75% mined blocks to activate certainly is contentious )
During a hardfork scenario there are several different options the chain with the perceived less hashing power can do -
- 1) Quickly move over to the longest chain with the most hashing power out of security fears
- 2) Stay on their chain with less hashing power and hope the other chain doesn't become hostile and conduct a 51% attack. Notice there are now two chains , each with equal length , and each following the same principle of the logest valid PoW chain. One simply has more hashing power over the other, which can quickly and dynamically adjust as miners move back and forth between chains or one group ramps up ASICs that use their consensus code.
- 3) Nodes can choose to give up the PoW algo altogether and fork off with one of many PoS / or hybrid algos.
- 4) Nodes can choose another PoW algo and make the existing miners irrelevant to themselves.(There is already code in place ready for this if needed).
What I mean is all the nodes might be happy with bigger blocks but if the majority of miners refuse to build on them then they will just get orphaned off, so although the nodes have the power of veto, its the miners that instigate the change in consensus.
More specifically it is the developers of the implementation who instigate the change that allow the miners to chose.... and this is only for technical limitations of the difficulty in approximating the economic consensus of nodes vote. This may change in the future and it is important to stress that allowing the miners to vote is a clumsy and rough approximation that doesn't necessarily reflect the will of the economic majority.
