Brain teaser time... prove you aren't a brainlett

If it doesn't matter, then let the secret be me thinking of a number, and you finding out the number. To escape discovery, I don't think of it until I'm beyond the event horizon of a black hole. As long as you don't count blindly guessing correctly as knowing the secret, I'm good.

you tell everyone the secret, it can't be leaked if everyone already knows.

get outsmarted brainlet

destroy the secret and everyone who knows it.

destroy everyone who is able to comprehend the secret (right now or in future).

dropping the secret into a black hole,
the information is lost forever