Bitcoin Client Majority Protocol Attack?

[LanYu]

Hi,

I was wondering if somebody could explain to me why this isn't a plausible attack:

A majority of clients have an alternative target determination mechanism, i.e. always deciding to raise the target.

[socrates1024]

The difficulty for the next block is fixed by the protocol, as a deterministic function of the previous blocks. There is no choice involved in setting the difficulty.

[LanYu]

The difficulty for the next block is fixed by the protocol, as a deterministic function of the previous blocks. There is no choice involved in setting the difficulty.

Thanks for the answer. So, if a certain portion of the network decided to alter this function, they would no longer conform with the protocol. So then, when the target changes, it is verified by every full node?

[theymos]

So then, when the target changes, it is verified by every full node?

Yes.

Bitcoin is not a democracy. Except in a few cases where it can't be avoided, full nodes will follow their rules regardless of what everyone else does.