Secret Target: The Enigma Code

Successful military operations have always depended on keeping communications secret from one’s enemy, and in every war there have been different methods employed to conceal messages about maneuvers through the employment of false leads, secret codes, and more. During World War II, much of Germany’s initial success in the European theatre was due to the nation’s development of a secret coding system that was nearly unbreakable. For years the Allies worked to break Germany’s code that was encrypted and read via a special device known as the Enigma Machine, but the complexity of the machine mean that deciphering the code would take countless sleepless nights and the fortuitous capturing of different Enigma Machines for the allied codebreakers to be able to finally read what the Germans were saying to one another.

Codebreaking and Secret Weapons in World War II

Cryptology and Its History

Espionage and Codebreaking

An Enigma Machine was extremely complex, which helps to account for the difficulty that codebreakers had in figuring out how they worked. In essence, the machine consisted of a lettered keypad that activating rotating wheels and circuits. Different circuits and wheel rotations would be activated every time a key was pressed, changing the code for each letter. Without the initial settings of the machine that were held by both the message creator and decipherer, it was almost impossible to figure out the code, which explains why German naval messages were undecipherable for four full years between 1937 and 1941.

The lack of initial success in the Allies attempt to read German military communiqués was not due to any lack of trying. British codebreakers based at Bletchley Park worked overtime to decipher the codes, employing mathematicians such as Alan Turing to work on the coding and the operation of the Enigma machines. Their efforts were helped immensely through the gift of an Enigma machine that had been reconstructed by Polish codebreakers in 1939, although those who worked at Bletchley made significant advancements that led to their being able to decipher messages encrypted with the later, more advanced German Enigmas. British scientists were ultimately able to construct several bombes, or machines that could be used to read Enigma-based codes. The intelligence that was recovered using these machines was deemed ULTRA, and when Allied maneuvers were undertaken on the basis of such intelligence, care was taken to fool the Germans into believing that information had been obtained in ways other than the breaking of the Enigma code.

One cannot underestimate the importance of breaking the Enigma code. Sir Harry Hinsley, a British historian, estimated that without the success of the efforts at Bletchley Park, World War II would have lasted somewhere between 2 and 4 years longer than it actually did, with greater damage and loss of life.

Bletchley Park National Codes Centre

Breaking Germany's Enigma Code

Daytona's Code Breakers

Enigma Machine Overview

Enigma and the Turing Bombe

Enigma Machine Simulator

How the Enigma Works

Influence of ULTRA in the Second World War

Origin of the ENIGMA/ULTRA Operation

Solving the Engima

Ultra and the Campaign Against the U-Boats in World War II

Following World War II, much of the process and tools used to decipher the Enigma code were kept secret, but Enigma Machine enthusiasts continued to work to build replicas of the machines and figure out how Bletchley Park scientists were so successful in their efforts. An exact replica of Turing’s first bombe was constructed in 2006, but many others have constructed similar machines. Collectors now look for old machines and their parts, and an entire industry has sprung up to help enthusiasts engage in their hobby.


Nifty Machines: Encryption and the Enigma Machine

Rebuilding the Enigma Code-Breaker

Paper Enigma Machine

Cryptography and codebreaking continues to be an important part of both successful wartime operations and computer security. Encryption allows for the secure transmission of banking information, national secrets, and much more. On a popular level, puzzles and games exploit the popularity of coding, and dozens of websites make information on codebreaking and encryption available to countless individuals.

Break the Enigma Code

Cipher Machines and Cryptology


Crypto Museum

Cryptography Game

Department of the Army: Basic Cryptanalysis

Overview of Computer Cryptography

Encryption and codebreaking are a vital part of world history, as the efforts involved with the Enigma Machine in World War II have revealed. There is no doubt that secret codes and figuring out how to read them will be important to many different areas of life in all of the years to come.