Enigma Cipher Machine

The Enigma Cipher Machine was an electro-mechanical rotor message coding device invented by the German engineer at the end of World War I to create secret coded messages.

Early models were used commercially from the 1920s and were adopted by military and government services of several countries.

Several different Enigma models were produced, but the German military models, having a plugboard, were the most complex and challenging to decipher and were used extensively by Nazi Germany before and during World War II.

In 1939, Poland shared with French and British military intelligence representatives their knowledge of German Enigma decryption techniques and equipment.

This information was a foundation for British cryptologists to start understanding how to decrypt messages enciphered on Enigma.

German procedural flaws, operator mistakes, and failure to systematically make changes in encipherment procedures provided clues to cracking the Enigma’s secrets.

Also, the Allied capture of critical German tables and hardware enabled the Allied cryptologists to break the Enigma codes successfully.

Bletchley Park was developed as a cryptanalytic facility. Alan Turing, a Cambridge University mathematician, provided much of the original thinking that led to the design of the cryptanalytical Bombe machines and the eventual breaking of Enigma.

The intelligence gleaned from this source, codenamed “Ultra” by the British, was a substantial aid to the Allied war effort.

An estimated 100,000 Enigma machines were constructed. After the end of World War II, the Allies sold captured Enigma machines, still widely considered secure, to developing countries.

The secret effort to break the Enigma was not disclosed until the 1970s. Since then, interest in the Enigma machine has grown. Today, Enigmas are on display in museums around the world.