Guests leave their coats in the small, sunless foyer - you can imagine taking a cloakroom ticket and paying someone a cover charge, then uttering a secret password.

The location was emailed to me a day beforehand, plus a secret password to say on the door.

Eight stages are present in the game; with a secret password responsible for hiding a secret ninth level.

Cheat codes are usually activated by typing secret passwords or entering pressing controller buttons in a certain sequence.

Key derivation functions are also used to derive keys from secret passwords or passphrases.