A German World War II-era Enigma machine, used by the Nazis to encrypt their military transmissions during the war, will go up for auction in London next week.

According to a report in the Guardian, the encoding machine — surviving models of which are rare — will be up for offer at Sotheby’s in Mayfair, West London, where it is expected to sell for around £70,000 ($108,000).

The Sotheby’s website described the item as “a rare and exceptionally well-preserved example of the famous German cipher machine.”

The Enigma machine was invented at the end of World War I and used by the German military from the 1930s onward to encrypt messages. With trillions of possible combinations, its codes were considered impregnable.

Benedict Cumberbatch in 'The Imitation Game' as Alan Turing, the man chiefly responsible for cracking the vaunted Enigma code used by the Germans in World War II. (courtesy)

Benedict Cumberbatch in ‘The Imitation Game’ as Alan Turing, the man chiefly responsible for cracking the vaunted Enigma code used by the Germans in World War II. (courtesy)

However, following on earlier breakthroughs by Polish intelligence services, in 1939 a British team led by Alan Turing at Bletchley Hall finally managed to break the Enigma machine codes, giving the allies an inestimable advantage over the Nazis.

It is widely believed that cracking the Enigma shortened the war by several years and saved millions of lives.

British mathematician Alan Turing. (screen capture: Youtube/The Telegraph)

British mathematician Alan Turing. (screen capture: Youtube/The Telegraph)

The success was one of the most closely guarded secrets of the war and afterwards, as Britain encouraged former colonies that had gained their independence to use the enigma machines for their own military secrets.

Turing and his work were brought to increased public awareness by the 2014 film “The Imitation Game,” which starred Benedict Cumberbatch as the eccentric genius.