Fruit

Chris Christensen (from the Dept of Mathematics, Northern Kentucky Univ.) spoke on Aug 28, 2012, for about 30 minutes on WWII ciphers attacked by cryptographers in the US Navy. Here is a more detailed summary of the talk: JN-25, the primary Japanese naval cipher of World War II, used additives. British and American codebreakers tried to separate the additives from the transmitted messages first by hand and then by machine. One of the machines used to attack JN-25 was built at National Cash Register in Dayton, Ohio. Because of its appearance, the British called the machine "Fruit.'' We will consider how Fruit operated and how it was used to attack JN-25. Video and editing in FCPX by me.