Coupling dynamic block sizes (and times?) to Nakamoto consensus.
Notes from MRL to clean up later:
Hmm this is an interesting thought experiment. Our economic security model has some quirks, if you think about it.
Normally, users (txn volum) set block size. If users set it too high, protocol intervenes. If protocol drifts too high, miners intervene.
(e.g. picture a few years in the future, when cryptokitties accepts XMR. Users are generating 4 GB txns per 2 minutes, and protocol limits block size to 3 GB txns per 2 minutes, but the network can only handle 2 GB txns per 2 minutes)
The usual response is “well, if miners can only handle 2 GB blocks, they’ll self-limit to 2 GB”. In other words, we fallback to miners vetoing the difference between the protocol limit and practical limit.
So I perceive the block size chain of command to be [Users] < [Protocol] < [Miners]
(with the obvious caveat that miners can only veto the protocol limit when mining smaller blocks, and cannot arbitrarily exceed the protocol limit)
So, operating on that last-ditch assumption that the majority of miners will act in the best interest of the network, maybe we want to approach it from this angle from the start!
After all, Nakmoto consensus is very well defined and studied, so we can think through it somewhat formally. Likewise for privacy-preserving voting systems. Considering that framework:
Each miner casts one [encrypted] vote per block on whether or not to increase the block size. Value of 1
is a vote in favor of increasing block size, and a value of 0
is a vote against increasing.
Every 100 blocks a new voting window begins. At the end of the window, the encrypted votes are tallied. If >=51 of 100 miners voted in favor of the increase, it passes. Otherwise, block size does not increase.
Thus we’ve reduced the matter to Nakamoto consensus, which is both 1) the practical fallback anyways, and 2) the main security requirement and guarantee for Monero anyways.
So framed this way, if the voting system is “gamed” then it implies a violation of the assumption that 51% of miners are acting in the best interest of Monero.
Anyways, I’m rambling. You could consider variations like voting on block time as well, or having an option to vote for a decrease as well, etc etc.
Also, I’ve only thought this halfway through, lots of edge cases and whatnot. Again, not proposing that we do this now.