The History of the Enigma Machine and its Role in World War II

At the beginning of the 20th century, secure communication channels were a pressing need for the military. In World War I, armies mainly used code books and simple substitution or transposition methods to encrypt secret messages. These methods usually involved replacing letters in the plaintext with other characters or letter combinations.

Over time, skills in the field of cryptanalysis advanced: increasingly complex methods were employed, yet human-to-human error remained high. The technological development was not advanced enough for broad machine use.

The weaknesses of those early methods later led to the desire for powerful, automated cipher machines such as the Enigma.

Scherbius patented the Enigma machine in 1918 and founded the company "Chiffriermaschinen Aktiengesellschaft." The first commercial success remained elusive, but the military soon recognized its enormous potential.

Scherbius' invention was based on the principle of rotating rotors, which encrypted text multiple times and in complex ways. This design was notable for its flexibility and the vast number of possible keys, making deciphering very difficult.

After World War I, the Enigma evolved from a civilian machine into a military tool. The German Reichswehr adopted and modified the original Enigma in the early 1920s. Features such as the plugboard (Steckerbrett) greatly increased the complexity of the cipher and the number of possible settings.

In the 1930s, the Enigma became the standard machine for different branches of the German armed forces. These changes made the encryption seemingly unbreakable for outsiders.

The great breakthrough for the Enigma came in World War II, when it became the most important encryption device of the German
Wehrmacht and navy. Nearly every military message was encoded with it, from simple orders to strategic plans.

Cracking the Enigma is widely regarded as a decisive factor in the outcome of the war.

Today's armed forces use highly advanced digital encryption technologies to protect their communications. The days of rotating rotors are gone; instead, strong mathematical algorithms like AES (Advanced Encryption Standard) or RSA are used.

These algorithms rely on complex calculations, long keys, and the use of crypto devices that may be software or hardware based. A key advantage is the possibility of end-to-end encryption even over unsecured networks. Military communication devices also feature strict access controls and regular key changes.

Constant progress in cryptography makes it nearly impossible for enemy interceptors to decrypt secret messages in useful time.

An engineer from Stuttgart is probably the only person worldwide who can faithfully and fully functionally reconstruct the infamous encryption machine of the Nazis, the so-called Enigma, today. This SWR program shows the craftsmanship and technical challenges involved in the reconstruction, as well as how deeply the engineer has understood the principles of Enigma.

The program provides insights into the workings of the historic machine, its special role in World War II, and the fascinating interplay of technical history, precision work, and passion for cryptography.