Japanese  Cipher Machine (Green)

The Germans manufactured Enigma machines for the Japanese Government but they were never received. "Officially" they were lost when the German submarine tasked with the delivery was sunk. Japanese experts, having a very basic shared knowledge of the Enigma, created their own device.

Only two surviving examples of the Japanese Green machine are known to exist.

The machine has four rotors, each with 25 positions, a keyboard with
25 character keys, two shift keys and a lamp-board with 25 lights.
With only 25 characters on the rotor disks, this machine can't use a UKM since it cannot join characters in reciprocal pairs unless one character is left unencrypted.
It is believed that operating the shift keys somehow switches between the two sets of 25 displayed lights.
This unit is on display at the National Cryptologic Museum. The literal translation of the nameplate is  as follows:

                3 way word-substituting machine
                Number 150
                Year of Showa 18, August (Showa 18 would equal to 1943)
                Institute of Navy Technology

Jerry McCarthy provides a more refined description of the first line in the nameplate:   " Type 3 character substituting machine" or better yet "Type 3 katakana substituting machine".

All photos in this table by Ralph Simpson.

Contributors and Credits:

1)  Ralph Simpson <ralphenator(at)gmail.com>
2) Jerry McCarthy  <jerry_mccarthy_uk(at)yahoo.co.uk>

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April 2/18