Remember the opening scenes of Raiders of the Lost Ark? Indiana Jones had to get past the spiders, the wall-of-spikes trap, the pit, the poison darts released by stepping on the wrong floors stones, and the self-destruct mechanism tied to moving the statue. This is defense in depth.Though Bruce Schneier's Secrets and Lies cites Raiders of the Lost Ark as an example of strength in depth in cryptography, its leitmotif seems to be steganography: the Well of Souls is hidden in Tanis, a city itself obscured by the desert sands. The ark is later filed and presumably forgotten in an archival warehouse, amongst zillions of other similarly marked crates... In contrast, The Last Crusade would seem to take cryptanalysis as its trope (Indy's interpretation of signs, symbols and quotes in his father's notebook). And the Temple of Doom is therefore, er, about eating monkey brains.