Enigma Machine Enthusiasts' Manual 1915 to 1945 (Enigma 1) * The famous encryption machine used by the German military in the Second World War, how it was constructed, how it was used, why the code was considered 'unbreakable', and how the Enigma code was

In the Second World War the German military used a small coding machine called Enigma to encode and send secret messages. They believed the Enigma was invincible and its codes unbreakable. What they didn’t know was that Britain’s code-breaker’s at top secret Bletchley Park had cracked the cypher early on in the war and were reading Enigma’s coded messages for much of the conflict.

This insider information gave the Allies access to everything from top secret high-level conversations between Hitler and his commanders to routine signals exchanges between one army unit and another.
 
Throughout the war Germany remained unaware that Britain's code-breakers were eavesdropping on every conversation sent by Enigma.The vital intelligence gleaned by the Allies from the Enigma decrypts was so sensitive it was given the highest security classification possible of ‘Ultra Secret’.

There is no doubt that having this information helped shorten the war by several years and it saved many thousands of lives.

Read about how the Enigma machine was developed, how it was used by the German Wehrmacht (military), how it works mechanically, why the number of possible codes is so high, and how encoded messages sent between German locations were deciphered by British code-breakers at Bletchley Park.

The authors have been granted special access to actual Enigma machines during the course of their research.