Josh Harr

        Cryptography

Frank B Rowlett

Frank Rowlett was one of the three original cryptanalysts in the Signal Intelligence Service, an Army Signal Corps' cytological organization during the second world war.  He was born on May 2, 1908 and received a BA in mathematics and chemistry from Emory and Henry College.   During his tenure in the Signal Intelligence Service, the task fell to him as well as his colleagues to not only intercept and decipher foreign code but to create their own codes and ciphers for the US Army.  Rowlett and his team are responsible for cracking two important Japanese codes: Red and Purple.  While Red was a worthy accomplishment, Purple was the decipher that took Rowlett's name to all corners of the US government.  Taking 18 months of effort to break, Purple was the highest level of Japanese cipher that was used for all of their diplomatic transmissions.  The machine used to decipher Purple, called "Magic", was shared with not only different departments in the US government but copies were also given to the Philippines and to the British.  Some wonder if the tragedy at Pearl Harbor could have been avoided after all, as Purple was deciphered well before the infamous attack on December 7th, 1941.  When asked what his main contribution was in creating the decipher for Purple, Rowlett simply replied, "I was the one who believed it could be done".

All of Rowlett's time was not spent deciphering the codes of foreign powers.  Rowlett is also responsible for creating the SIGABA, which is a cipher machine used during the war that was never broken by the Axis powers.  Based on the German Enigma encryption machine, this machine incorporated a series of repositional and reversible rotors that utilized a complicated stepping motion to encrypt the information.  While the stepping appeared to be at random, it was actually so complicated that it just gave the illusion of randomness.  Some 20 years after its completion, Rowlett was granted $100,000 from Congress as compensation for his classified invention.

As good of a manager as he was a cryptanalyst, Rowlett did very well in which ever of the organizations he was in.  In no time, he rose to the position of Chief of the General Cryptanalytic Branch and then to the chief of the Intelligence Division of the SIS.  In 1949 he joined the Office of Operations of the Armed Forces Security, which later became the NSA.  Not seeing eye to eye with the first director of the NSA, Rowlett transferred to the CIA in 1952 before coming back to the NSA in 1958 as the special assistant to the director.  In 1965 the National Cryptologic School was founded under Rowlett's supervision and he became its first commandant.  He retired a year later and then on June 19th, 1998 he passed away at the age of 90.

While most of Rowlett's work was classified at one point, he received much recognition for his actions.  Among some of the awards bestowed to him include the President's Award for Distinguished Federal Civilian Service for his work on the "Magic" machine, the National Security Medal, the Legion of Merit and the Order of the British Empire.  Emory and Henry College in Virginal bestowed on Rowlett an honorary Doctor of Science degree.  There is even an award named after him, which is the highest award that the Information Assurance organization gives.  In 1999 he was inducted into the NSA Hall of Fame for his many achievements in national security.  

'Big' Machine Exhibit. NSA. 10 Sept 2004. http://www.nsa.gov/museum/museu00002.cfm

Frank B Rowlett.  NSA.  10 Sept 2004. http://www.nsa.gov/honor/honor00002.cfm

Kovach, Karen.  Frank B Rowlett: The Man Who Made 'Magic”.  INSCOM Journal.  10 Sept 2004.  

http://www.fas.org/irp/agency/inscom/journal/98-oct-dec/article6.html