wasn't a secret phrase; it was the way your shoulders slumped when you were tired, the jagged polygon formed by your fingers resting on a tabletop, or the "candid" tilt of your head when you heard a distant melody.
: This could also relate to more abstract concepts where geometric shapes or candid (open, honest) representations of shapes are used in cryptographic protocols. This might involve visual cryptography schemes where images or shapes are used to encode and decode messages. Candid Shapes Password