Not necessarily. You could just have the members vote on whether to add or remove keys from a valid-key list. This basically amounts to putting the list of va

Not necessarily. You could just have the members vote on whether to add or remove keys from a valid-key list. This basically amounts to putting the list of valid keys on the blockchain itself. There's a chicken-egg problem there that requires a central arbiter to bootstrap, but the central arbiter then immediately becomes powerless.