Sworn to secrecy

Cryptologia, Apr 2000 by Kruh, Louis

Sworn to Secrecy: Breaking the Japanese Codes: Secrets of War. The History Channel, 235 E. 45th St., New York NY 10017 USA. 1 hour. www.secretsofwar.com.

Secrets of War is a 52-hour television documentary event narrated by Charlton Heston. Each episode appears on the History Channel every Sunday at 9 p. m. ET/10 p. m. PT, with repeats airing the following Saturday.

"Breaking the Japanese Codes" uses still film and live action footage to provide an exciting history of code breaking by the United States, events leading to the Japanese attack on Pearl Harbor, and how breaking Japanese codes insured victory. Highlights include: the formation of the Army's first cipher bureau, MI8, headed by Herbert O. Yardley; Secretary of State Stimson closed the bureau and Yardley wrote his famous (or infamous) book, The American Black Chamber, exposing its secrets, which caused Japan to strengthen its codes; William F. Friedman and Elizebeth Smith (later Mrs. Friedman) work for George Fabyan at his Riverbank estate; Friedman writes his renown Riverbank papers, leaves Fabyan to work as a cryptanalyst for the Army and hires Rowlett, Sinkov, and Kullback; use of IBM calculating machines for cryptanalysis; they solve Japan's Red code and later, its Purple machine; describe the arrival of the 14th part of Japan's message, and the bombing of Pearl Harbor.

At this point, the story shifts to the history of Navy code breaking, starting with the formation of Op-20-G and the On The Roof Gang, the first group of enlisted men training as radio intercept operators. Navy cryptanalysts spent much time on the difficult Japanese JN-25 ciphers before finally solving them. This paid off at the Battle of the Coral Sea, Midway, and the shooting down of Admiral Isoroku Yamamoto, who had planned the attack on Pearl Harbor.

Expert commentary during the film is provided by David Hatch, head of NSA's Center for Cryptologic History, Jack Ingram, Curator, National Cryptologic Museum, and, for scenes featuring his parents, John Friedman. Phil Jacobsen, WW II veteran, who did the commentary on the Navy sections, spent 27 years with the Naval Security Group and its predecessor organizations. It is an excellent and enjoyable film. Contact the History Channel to find out when this episode may be repeated or if a videotape is available.