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Here is a list of past presentations at ICCH. The most recent presentation is at the top. Click on each listing to reveal more information below, including the speaker, presentation description and to access recordings.
Note: Effort has been made to ensure that the information on each presentation is accurate and up-to-date. To suggest a correction please contact the ICCH webmaster Patrick Hayes at .
In the 1920s, Japan as well as other countries explored the use of cipher machines. Based on what they learned from European manufacturers, during the 1930s, Japan produced two families of cipher machines for their diplomats and their Navy. The 1931 series of cipher machines were based on the Damm half-rotor. Three types of machines were designed and produced: RED (a machine for diplomatic use that enciphered Roman letters), ORANGE (a machine for use by large naval stations that enciphered kana characters), and M-2 (a machine for use by naval attachés that enciphered Roman letters). These machines were later replaced by the 1937 series of machines that were based on Strowger switches (telephone exchange switches). The three replacements machines were: PURPLE (which replaced RED), JADE (which replaced ORANGE), and CORAL (which replaced the M-2). This presentation will briefly discuss the cryptography and the history of these two families of Japanese cipher machines.
February 21, 2021
Here is a list of past presentations at ICCH. The most recent presentation is at the top. Click on each listing to reveal more information below, including the speaker, as well as the presentation date and description. Presentation recordings are available separately, in the ICCH Portal.
To view upcoming ICCH presentations, click here.
Note: Effort has been made to ensure that the information on each presentation is accurate and up-to-date. To suggest a correction please contact the ICCH webmaster Patrick Hayes at info@cryptologichistory.org.
In the 1920s, Japan as well as other countries explored the use of cipher machines. Based on what they learned from European manufacturers, during the 1930s, Japan produced two families of cipher machines for their diplomats and their Navy. The 1931 series of cipher machines were based on the Damm half-rotor. Three types of machines were designed and produced: RED (a machine for diplomatic use that enciphered Roman letters), ORANGE (a machine for use by large naval stations that enciphered kana characters), and M-2 (a machine for use by naval attachés that enciphered Roman letters). These machines were later replaced by the 1937 series of machines that were based on Strowger switches (telephone exchange switches). The three replacements machines were: PURPLE (which replaced RED), JADE (which replaced ORANGE), and CORAL (which replaced the M-2). This presentation will briefly discuss the cryptography and the history of these two families of Japanese cipher machines.
February 21, 2021
