In any case, if you would plan any of that, I would guess that it would most probably leak out through entirely nontechnological channel - e.g. by somebody overhearing in person, or even by a co-conspirator defecting for their own gain.

Cloak-and-dagger games are very similar to building your own crypto: likely to be broken at a fundamental level, never mind the amount of magic security glitter that you pile on top.