Fatima seems a little... mysterious.
The Church has secrets: every sacramental confession is secret, no matter how long ago it took place. The prelates have their privacy. There are bank accounts, the diplomatic pouch, -- like in any organization. There is no secret teaching though, like for example the Gnostics claimed to have.
Jesus answered him: I have spoken openly to the world: I have always taught in the synagogue, and in the temple, whither all the Jews resort; and in secret I have spoken nothing (John 18:20)