Cipher Bureau

After World War I, an Army cryptological unit colloquially known as The American Black Chamber was eliminated by Secretary of State Henry L. Stimson in 1929. The unit, headed by Herbert O. Yardley, gained worldwide fame when Yardley wrote his bestselling _The American Black Chamber_, detailing the operations of the group.

This film seems to have been patterned on equivalent activities. The basic story is one of those involving a double agent, and the parallel activities the Cipher Bureau is doing in cracking secret messages.

While the story elements have been used before and will be used in the future, what sets this film apart is its cryptological elements. In many films involving secret communications, only a nod is made toward the actual solving encrypted messages. A significant amount of the footage illustrates different means of encrypting and decrypting messages, some of them fairly serious. The only other film I can think of that tries to bring some sense of understanding to the world of cryptology is the 2002 film, Enigma.

To be sure, modern codebreaking uses computer analysis to break ciphers, or at least try to. But the techniques of basic cryptanalysis are shown, and are a foundation for more advanced work. Viewing the film will not turn the viewer into a cryptanalyst, but it will "lift the curtain" a bit, and may bring a bit of appreciation to an art that is rather arcane.