Mincemeat was a successful British disinformation plan during World War II.
As part of Operation Barclay, the widespread deception intended to cover the invasion of Italy from North Africa, Mincemeat helped to convince the German high command that the Allies planned to invade Greece and Sardinia in 1943 instead of Sicily, the actual objective.
This was accomplished by persuading the Germans that they had, by accident, intercepted "top secret" documents giving details of Allied war plans. The documents were attached to a corpse deliberately left to wash up on a beach in Punta Umbría in Spain. The operation started with the planting of false documents on the corpse but the use of the Enigma machine by the Germans helped double agents work for the Allies. In addition to technology, the use of double agents like Garbo was integral to Allied success in World War II.
The story was used as the plot in Duff Cooper's 1950 novel Operation Heartbreak, but revealed as a true story in the 1953 book The Man Who Never Was. A film of the same name was made in 1956. BBC. online article These videos tell the story of the grave of the man who never was
In part, this was possible due to the intervention of a Mathematician and a group of data researchers and linguists working for the British Intelligence. This story has been told in a film called The Imitation Game
How an Enigma machine works
Enigma allowed an operator to type in a message, then scramble it by means of three to five notched wheels, which displayed different letters of the alphabet. The receiver needed to know the exact settings of these rotors in order to reconstitute the coded text.
The Germans were convinced that Enigma output could not be broken, so they used it for all sorts of communications - on the battlefield, at sea, in the sky and, significantly, within its secret services.
