The man who can keep a secret may be wise, but he is not half as wise as the man with no secrets to keep. E. W. Howe
Whoever wishes to keep a secret must hide the fact that he possesses one. Johann Wolfgang von Goethe
He that has eyes to see and ears to hear may convince himself that no mortal can keep a secret. If his lips are silent, he chatters with his fingertips; betrayal oozes out of him at every pore. Sigmund Freud
Anyone who knows how difficult it is to keep a secret among three men - particularly if they are married - knows how absurd is the idea of a worldwide secret conspiracy consciously controlling all mankind by its financial power; in real, clear analysis. Oswald Mosley
The only way to keep a secret is to say nothing. French Proverb
So long as I can keep a secret it is my prisoner. Arabic Proverb