Codebreaking

Reading two books more than a decade ago (Kahn's Siezing the Enigma, and Lewin's Ultra Goes to War--see below ) introduced me to the fascinating story of places like Bletchley Park in Britain and Arlington Hall right here in Washington, and their cracking of the German "Enigma" and "Fish" and Japanese "JN-25" and "Purple" codes of World War II. While I will never understand the math involved, the implications and impact of what was accomplished (including the creation of early analog computers to reduce the number of code variations, thus making codebreaking possible) are amazing. Here are but a handful of the many sites and books now available.

The non-descript abandoned buildings above (as photographed in the fall of 1997) are some of the famous wooden "huts" at Bletchley Park (northwest of London) in which some of the codebreakers were housed during the war. Hut 6 (to the right) evaluated deciphered German Wermacht and Luftwaffe signals (see Welchman's book cited below). The low brick wall is all that remains of higher barriers built to protect against possible air attacks that thankfully never came.

Websites

Codes and Ciphers in the Second World War Tony Sale knows more about this than nearly anyone else. His site is chock-full of information, some way over my head, and includes data about his rebuild of the pioneering Colossus computer at Bletchley Park.

Cryptologic History and NSA Codebreaking still goes on, of course, and here is some of what's been declassified from the past, as well as the NSA museum which is well worth seeing, and the now declassified VENONA project.

Station X: Bletchley Park The site is a mite hokey, but the place is amazing and has to be seen to be really understood. This is the official site for Britain's World War II codebreaking effort.

Suggested Reading

Bamford, James. Body of Secrets: Anatomy of the Ultra-Secret National Security Agency. New York: Doubleday, 2001. Best public account (and very readable) of the major American codebreaking entity, following on the author's earlier The Puzzle Palace (1982).

Budiansky, Stephen. Battle of Wits: The Complete Story of Codebreaking in World War II. New York: Free Press, 2000. Certainly one of the better recent accounts that tries to place codebreaking results in context.

Clark, Ronald. The Man Who Broke Purple: The Life of Col. William F. Friedman, Who Deciphered the Japanese Code in World War II. Boston: Little, Brown, 1977. Only biography of perhaps the key figure in developing American codebreaking abilities.

Copeland, B. Jack, et al. Colossus: The Secrets of Bletchley Park's Codebreaking Computers. New York: Oxford University Press, 2006. Ignore the title--the computer didn't "break" the codes, but helped to reduce the number of choices the codebreakers had to deal with. The Colossus was the world's first digital computer--not the ENIAC which came two years later. Colossus was secret for decades--but now a rebuilt replica operates at Bletchley.

Haynes, John Earl, and Harvey Klehr. Venona: Decoding Soviet Espionage in America. New Haven: Yale University Press, 1999. Of the several books on the now declassified "Venona" project to break Soviet codes (1944-1960s), this is the best.

Hinsley, F. H., and Alan Stripp, eds. Codebreakers: The Inside Story of Bletchley Park. New York: Oxford University Press, 1993. Anthology of articles written by veterans of the British codebreaking center on how it all worked.

Kahn, David. The Codebreakers. New York: Macmillan, 1967. The standard book and by far the best---though dauntingly long for newcomers. A revised edition in the late (Scribners, 1997) merely added one chapter--stick with the original which is easily found. The doyen of code historians, Kahn has written several other related books, including the next one listed.

(Ibid). Seizing the Enigma: The Race to Break the German U-Boat Codes, 1939-1943.. Boston: Houghton-Mifflin, 1991. Excellent updating of the book above, and one of the better accounts of one of the key codebreaking efforts of the war.

Lewin, Ronald. Ultra Goes to War. New York: McGraw-Hill, 1978. Still among the best studies of how breaking the World War II German codes impacted the direction of fighting in Europe.

(Ibid). The American Magic: Codes, Ciphers and the Defeat of Japan. New York: Farrar, Straus & Giroux, 1982. The American effort against the Japanese "Purple" and other codes--and its impact.

Newston, David E. Encyclopedia of Cryptology. Santa Barbara, CA: ABC-CLIO, 1997. Aimed at those with no background, with brief entries on a wide variety of topics, historical and current.

Sexton, Donal J. Jr. Signals Intelligence in World War II: A Research Guide. Westport, CT: Greenwood, 1996. Annotated guide to a large and still-growing literature.

Smith, Michael and Ralph Erskine, eds. Action This Day. London: Bantam Books, 2001. Excellent anthology of papers, many by those who were at Bletchely during the war, about how the place worked and the processes used.

Welchman, Gordon. The Hut Six Story: Breaking the Enigma Codes. New York: McGraw-Hill, 1982. One of the key figures at Bletchley Park reveals how it was all done (originally in the building pictured above)---a classuc account that got its author into trouble with British authorities over half-century old secrets.

West, Nigel. The Sigint Secrets: The Signals Intelligence War, 1900 to Today. New York: William Morrow, 1986, 1988. Useful overall survey of the British scene by an authoritative writer of books on intelligence.

Wrixton, Fred B. Codes, Ciphers & Other Cryptic and Clandestine Communication: Making and Breaking Secret Messages from Hieroglyphs to the Internet. New York: Black Dog & Leventhal, 1998. Semi-encyclopedia approach on how it all works, a good deal of history, and famous codebreakers.

Yardley, Herbert O. The American Black Chamber. Indianapolis: Bobbs-Merrill, 1931. The classic account of World War I and post-war codebreaking efforts by the man who led them. (For the first biography of this seminal figure, see David Kahn, The Reader of Gentlemen's Mail: Herbert O. Yardley and the Birth of American Codebreaking, Yale University Press, 2004.)