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PURPLE and The Life of William Friedman

PURPLE and The Life of William Friedman. Peter Smith Matt Salmon. PURPLE. A Japanese cryptographic machine used before and during WWII Similar to the German Enigma Broken by William Friedman MAGIC- information gained from decryptions (ULTRA in WWII).

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PURPLE and The Life of William Friedman

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  1. PURPLEandThe Life of William Friedman Peter Smith Matt Salmon

  2. PURPLE • A Japanese cryptographic machine used before and during WWII • Similar to the German Enigma • Broken by William Friedman • MAGIC- information gained from decryptions (ULTRA in WWII) Photo courtesy of: http://en.wikipedia.org/wiki/PURPLE

  3. How it Works • Used an electromechanical stepping-switch system • Plugboard and four coding wheels • Divided Alphabet: • “Twenties”- twenty consonants • “Sixes”- six vowels • Used a different algorithm to encipher the two groups • “Twenties” enciphered on three stepping switches • Fast, medium and slow • Repetition = 25x25x25 = 15,625 • “Sixes” enciphered on one six level, twenty-five position stepping switch • Repetition = 25

  4. Photo courtesy of: http://frode.home.cern.ch/frode/crypto/simula/purple/operation.html

  5. William Friedman • Born in 1891 in Kishinev Bessarabia • Childhood • Family • Education • Adult life and work in cryptology • Considered worlds greatest cryptologist Photo courtesy of: http://en.wikipedia.org/wiki/William_F._Friedman

  6. Early Life • Life at Riverbank • Influenced by Elizabeth Gallup’s work • George Fabyan • Accomplishments • Index of Coincidence • Joint success with wife • SIGABA Machine (with Rowlett) • American Black Chamber • Signals Intelligence Service (SIS)

  7. Friedman and PURPLE • Similar to breaking the ENIGMA • Cribs • Errors by senders • Friedman and Rowlett • Japanese abolished previous codes and methods • 1940: Construction of a “duplicate” of PURPLE • Francis A. Raven • Discovered key to keys Frank Rowlett Photo courtesy of: http://www.fas.org/irp/agency/inscom/journal/98-oct-dec/article6.html

  8. Friedman after PURPLE • Armed Forces Security Agency • National Security Agency (NSA) • Retirement: • The ShakespeareanCiphers Examined • Health problems • Military Intelligence Hall of Fame posthumously

  9. MAGIC • Information gained from PURPLE interceptions • Limited number of people eligible to see MAGIC • Fear of possible leak of information

  10. PURPLE’s Impact in WWII • Pearl Harbor • Warning signs • Intercepted messages • http://ibiblio.org/pha/timeline/411201e.html • http://ibiblio.org/pha/timeline/411202e.html • http://ibiblio.org/pha/timeline/411207b.html • http://ibiblio.org/pha/timeline/411206d.html

  11. Other Impacts • D-Day • Known location of German troops • Further confirmed trick worked • Japanese Evacuation • Executive Order No. 9066 • President Roosevelt • American advantage in WWII • Outcome • Questions?

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