William Friedman’s Bletchley Park Diary: A New Source for the History of Anglo-American Intelligence Cooperation by Colin MacKinnon This is an Author's Accepted Manuscript of an article published in Intelligence and National Security, December 2005, copyright Taylor & Francis, available online at: http://www.tandfonline.com/doi/full/10.1080/02684520500426602. 1 William Friedman’s Bletchley Park Diary: A New Source for the History of Anglo-American Intelligence Cooperation On the afternoon of Friday, 23 April 1943, the great American cryptologist William F. Friedman1 boarded a government C-54 at National Airport in Washington and flew in secrecy to Great Britain. Friedman, a civilian employee of the U.S. Army’s Signal Security Service2, was one of a three-man clandestine American mission to the U.K. – the other two were Col. Alfred McCormack and Lt. Col. Telford Taylor,3 both of the Special Branch of Military My thanks to Ms. Rowena Lausch Clough, libarian at the National Cryptological Museum, Fort Meade, Maryland, for bringing the Diary to my attention. I am tremendously grateful to the late John E. Taylor of the National Archives at College Park, Maryland, who gave invaluable help and advice to a novice at archival research. Thanks, too, to Barry Zerby, of the National Archives, and to Ms. Joanne D. Hartog, archivist at the George C. Marshall Research Library, Lexington, Virginia, for their assistance. Finally I thank the anonymous reviewers of Intelligence and National Security for their useful suggestions. 1 Friedman was born in Kishinev, Russia 4 September 1891 and died in Washington, D.C. 2 November 1969; his wife Elizebeth was born in Huntington, Indiana 26 August 1892 and died 31 October 1980 in Plainfield, New Jersey. For Friedman’s life with much material on Elizebeth, see Ronald Clark, The Man Who Broke Purple: The Life of William F. Friedman, Who Deciphered the Japanese Code in World War II (NY: Little, Brown 1977). For a short but more up-to-date account see James R. Chiles ‘Breaking codes was this couple’s lifetime career’, Smithsonian, June 1987, pp. 128-143. 2 What began as the Signal Intelligence Service in 1930 had by early 1943 become the Signal Security Service (SSS). Later that same year it was renamed the Signal Security Agency (SSA). See Robert Louis Benson, A History of U.S. Communications Intelligence during World War II: Policy and Administration (Ft. Meade, MD: Center for Cryptologic History: National Security Agency, written between 1975 and 1976, but classified until publication in 1997), p. 40. At just what point in 1943 the SSS morphed into the SSA is not clear, but by 12 August of that year, when Friedman submitted his Report on E Operations (see below, fn. 37), he addressed it to ‘Commanding Officer, Signal Security Agency’. 3 At the time of the attack on Pearl Harbor McCormack was a partner in the upscale New York law firm Cravath, de Gersdorf, Swaine and Wood. Shortly after the attack, he was appointed special assistant to Secretary of War Henry L. Stimson, then inducted into Army Intelligence as a full colonel. McCormack was made deputy chief of the Special Branch under Col. Carter Weldon Clarke, a career army officer, and was serving in that 2 Intelligence – sent to observe British wartime cryptanalytical operations against the Axis powers. Evidently unknown to scholars until now, Friedman kept a meticulous, day-to- day, sometimes hour-to-hour diary of his activities on the mission, noting in it virtually everything he saw and did. Thanks to his Diary,4 which runs to almost 26,000 words, we now know whom Friedman met among British cryptologists and when he met them, what British facilities he visited and when, and what the British were willing to show him and in what sequence. We also know in a general way what the Americans in the U.K. and their British hosts were saying to each other: Friedman almost invariably noted in his Diary the subjects under discussion. It must be said, however, that Friedman gives us few of the details of these discussions. He was a highly circumspect intelligence officer who was close-mouthed about his trade and jotted down only what he thought was safe to record in an informal document. Nevertheless, historians of intelligence should find the Diary useful for a number of reasons. For example, read carefully and in conjunction with other documents, the Diary sheds new light on how the agreement between the U.S. Army and GC&CS5 (widely but erroneously referred to as BRUSA – see below) was negotiated and on Friedman’s role in the negotiations. It also gives us an on-the-spot view of Bletchley Park and its denizens as seen by the premier American cryptologist of the period as well as his assessment of the British wartime decrypting effort. The Diary is remarkable as well because it is a hitherto unknown, lengthy piece of prose written by Friedman and it gives us a picture of the man himself as none of his other writings do. What follows is an account of Friedman’s Diary and its contents. II Friedman had begun work in cryptology at Riverbank Laboratories near Chicago, where he had been hired as a geneticist in 1915. Riverbank was owned and operated by capacity when he traveled to the U.K. in the spring of 1943. Taylor, like McCormack, had been a lawyer when war broke out (he was special counsel to the Federal Communications Commission). He joined army intelligence in 1942 with the rank of major and was assigned to Special Branch. 4 Available on request at the library of the National Cryptologic Museum, Ft. Meade, Maryland. Friedman kept his Diary in a pocket-sized (6 3/8” by 3 ¾”) notebook of white, blue-lined pages with a red cover, on which he penned an elaborate capital ‘F’, two inches or so high. Except for a kind of title page which he printed, Friedman wrote the Diary in his distinctive cursive script, which is almost always legible. 5 Government Code and Cypher School, the British Comint service. 3 an eccentric millionaire named George Fabyan6, whose wide-ranging interests included acoustics, archaeology, bibliophily, and cryptology. Fabyan also entertained the theory that Francis Bacon was the real author of the plays and sonnets of William Shakespeare. Fabyan first had Friedman, and then another employee, Elizebeth Smith, hired on in 1916 (Friedman and Elizebeth would marry in 1917), begin researching what was then known of cryptology and try to use what they learned of that science to sift through the writings of Shakespeare and Bacon to prove the theory. Though the couple found no evidence that Bacon wrote Shakespeare7, the Friedmans did become experts at cryptology. William in particular became a master of the science, to which he made brilliant contributions during the next decades. (Elizebeth herself showed considerable talent in the field and had a long career working as cryptanalyst for various U.S. government agencies.) After the United States entered World War I, William was inducted into the U.S. Army as a first lieutenant and served in France in 1918 working on German codes and ciphers. In 1920, Friedman finished a groundbreaking theoretical contribution to cryptology, The Index of Coincidence and Its Applications in Cryptography8. Toward the end of that year Friedman happily left Fabyan’s enterprise and in 1921 went to work on a temporary contract for the War Department devising cryptosystems. He later became a civilian employee of the Department, where he continued to work on cryptosystems, taught cryptology, and made further theoretical contributions to the field. In 1930 he became chief of the U.S. Army Signal Corps’ Signal Intelligence Service, where he and his colleagues attacked the codes of foreign governments, particularly those of Japan. By late 1940 Friedman’s team at SIS had broken the main Japanese diplomatic code known as ‘Purple’ and had constructed a working model of the Japanese encrypting machine, Angooki Taipu A, an astonishing feat of analysis and of mechanical virtuosity. The emotional strain of the effort, however, seems to have broken Friedman’s always precarious mental health9 and shortly after Purple was solved he was admitted for treatment to the neuropsychiatric center of Walter Reed General Hospital in Washington. 6 For more on Riverbank and Fabyan, see Fred W. Kranz ‘Early History of Riverbank Acoustical Laboratories’, Journal of the Acoustical Society of America, Vol. 49, No. 2 – Part I (1971) pp. 381-384 (reprinted in Cryptologia, Vol. 9, No. 3 (1985) pp. 240-246). 7 Much later in their lives the Friedmans collaborated on a book exploding a number of such theories and in which they dealt harshly with Fabyan. See William F. and Elizebeth Friedman, The Shakespearean Ciphers Examined (NY: Cambridge University Press 1957). 8 Fabyan had the work published in France in 1922 as number 22 in the Riverbank Publications series. It has been reprinted as William F. Friedman, The Index of Coincidence and Its Applications in Cryptography (Walnut Hill, Calif.: Aegean Park Press, no date). The historian David Kahn calls Friedman’s Index ‘the most important single publication in cryptology’. See see Kahn, The Codebreakers. The Comprehensive History of Secret Communication from Ancient Times to the Internet (NY: Scribner 1996) p. 376. 9 Friedman’s life-long mental problems, particularly his depression, insomnia, and alcoholism, are summarized in a letter to his biographer, Ronald Clark, written by 4 When released in April 1941 Friedman returned to SIS, where he was put on short hours and confined mostly to performing administrative duties. He was given the title ‘Director of Communications Research’.