During World War 2, Japanese used many types of cipher machines one of which was known as the "Purple" machine. The machines used a series of telephone selector switches to encipher and decipher top secret messages. These messages were often intercepted by and decrypted by Allied Army and Naval Intelligence staff.
No complete "Purple" machine was ever captured during WW2. A fragment of one "Purple" machine was found in the courtyard of the Japanese Embassy in Berlin when the city was overrun by the Russians and Americans in 1945.
How the Purple Machine worked:
The Purple machine was a complicated piece of machinery not only in the 1930s, but even today.
The machine was made up of three major components.
One of them was an electric typewriter which was used for inputting information into the machine.
The second part was a “cryptographic assembly” which consisted of a plugboard, four electric coding rings, and numerous wires and switches that acted in unison with the other parts (Kahn 2).
The last part was an output unit that printed the encrypted message from the machine.
Instead of using rotors like the German Enigma machine did, the Purple machine used “electro-mechanical ‘stepping switches’” (Anon 1).
This in effect was similar to a second generation four rotor Enigma machine.
However, it was much heavier and bulkier than the Enigma machine and could not, therefore, be employed in the battlefield easily.
Further information on Purple Machine:
http://ovid.cs.depaul.edu/Classes/CS233-W04/Papers/PurpleMagic.pdf
Joe.
