The cryptanalytic method Alan Turing devised for the Lorenz cipher was called Turingery.
Turing developed the method in July 1942 while working at Bletchley Park, Britain’s wartime codebreaking centre. The target was the German Lorenz teleprinter cipher, which British cryptanalysts codenamed Tunny. Unlike the better-known Enigma machine, Lorenz traffic was produced by a complex machine with twelve rotating wheels.
Turingery was a manual “wheel-breaking” procedure. It helped analysts use recovered stretches of key, especially messages sent with the same key, to infer the cam patterns controlling the cipher wheels. The method also introduced differencing: comparing successive characters with XOR to expose statistical patterns hidden in the key stream.
The name is sometimes described as “Turing’s method”; colleagues also jokingly called it “Turingismus.” It should not be confused with Colossus, the electronic computer later built to automate parts of Lorenz analysis, or Banburismus, a separate statistical technique mainly associated with Enigma work. Turingery was an important early step in the successful attack on Tunny.