Naval Warfare Movies

Decoding Nazi Secrets

Producer: Nova

Published: 1999
Country: USA
Length: 120 min.
Keywords: Enigma, Recommended

This is the VHS release (see more).


This documentary takes a detailed look at how the German Enigma cipher machine worked, and how Polish and British codebreakers were able to monitor German radio traffic in all branches of the German armed forces (Kriegsmarine, Luftwaffe, and Heer), consequently gaining the intelligence information that led to German defeats and which is said to have shortened World War II by two years.


Interviewees include former codebreakers at Bletchley Park, who recall the excitement and urgency of their task; and Erwin Rommel's son, who relates that his father never knew that the North African campaign was lost due to surveillance of his radio traffic (instead, he always suspected spies and informers among the Italians). In one of the most interesting segments, Georg Högel, radio officer on U-110, recounts the circumstances that led to the officers and crew abandoning the U-boat without first disposing of the confidential books; but admits that he returned one last time to the abandoned boat in order to retrieve a book of love poems he had written for his girlfriend.

The theme of human error recurs frequently in the narration, as cipher experts and Bletchley Park veterans note that it was the German conviction that the code was unbreakable that led to carelessness in transmissions and in changing rotor settings. The codebreakers' recollections of how they became intimately familiar with the habits of specific German radio operators and with general transmission practices lends an insight into the human aspect of the war which is often overlooked in discussions of Morse code, rotors, and calculating machines.

Also told is the story of the most vivid character among the codebreakers, the shy and eccentric mathematical genius Alan Turing. Another interesting note is that the first programmable computer, Colossus, was developed as part of the code-breaking effort, preceding its more famous postwar cousin ENIAC by several years. Due to the intense secrecy with which the British veiled their codebreaking operations for decades after the war's end, the existence of Colossus and many other devices and capabilities were unknown until recently.

The best part of this documentary had to be the close look at the inner workings of the Enigma machine. It really makes you wish you had one of your own.

Two U-boat related errors were noted: U-110 is incorrectly listed as the boat that sank the Athenia (really U-30), and wolfpacks were described as huge concentrations of 30 or more U-boats (in reality the number ranged from 3 to 20).

Overall this is an excellent documentary.