We’ll never have good Sybil resistance if we make being Sybil extremely profitable, or give the impression of it being profitable, ala governance. It’s too easy to pay people.
At this point, quadratic voting people say “yay basic income”, but once they’ve incentivized this payment infrastructure, then they’ve lost Sybil resistance. Aka quadratic voting wrecks Sybil resistance in exchange for a “small basic income for the criminally minded”.
We want the Sybil resistance elsewhere where incentives look much lower for typical users, but which improve security and performance, or in future maybe in privacy ala mixnets.
Example 1. We’ve some minimal number n of validators per relay chain, which we determine by the on-chain randomness quality, the number of relay chains, the honesty assumption ala 80% or 85% or whatever, and optionally who we imagine colluding. We improve this last part if we spread validators evenly across the relay chain. Now n being larger makes sharding secure, but gossip is O(n^2) so n being smaller saves resources, so this should impact the number of parachains per relay chain.
Example 2. Approval checkers tranche zero assignments could be adjusted so that individual operators rarely duplicated their own work, not unlike Example 1. It’s possible this permits fewer approval checkers, which makes polkadot slightly more efficient.
Example 3. A mixnet depends upon users choosing one honest node, out of five to three random choices. If an operator honestly declares its multiple nodes, ala MyFamily in Tor, then users can chose only one, which ups their chances in theory.
Example 4. A referendum passes or looks likely to, but people complain about how Wally the Whale pushes it. This could prompt less involved whales to take action, but they might not do so if Wally set up Sybils beforehand.
All of 1-3 have some small cost for large operators, although only after they make dangerous code modifications. And nominators matter here too, even if they do not incur costs. We could compensate this cost by paying larger operators or nominators very slightly more, or giving them slightly more say in governance.