The American Black Chamber

Indianapolis: Bobbs-Merrill. Very Good. (1931). First Edition. Hardcover. 375 pages; Contents clean and unmarked, secure in original black cloth binding with red lettering; mild fading at spine. Herbert Osborn Yardley (1889 – 1958) was an American cryptologist. He founded and led the cryptographic organization the Black Chamber. Under Yardley, the cryptanalysts of The American Black Chamber broke Japanese diplomatic codes and were able to furnish American negotiators with significant information during the Washington Naval Conference of 1921–1922. Recipient of the Distinguished Service Medal. He wrote The American Black Chamber (1931) about his experiences there. He later helped the Nationalists in China (1938–1940) to break Japanese codes. Following his work in China, Yardley worked briefly for the Canadian government, helping it set up a cryptological section (Examination Unit) of the National Research Council of Canada from June to December 1941. Yardley was reportedly let go due to pressure either from the Secretary of War Henry L. Stimson or from the British. Yardley proved to be a very good administrator and during the war the people of MI-8 performed well even if they did not have any spectacular successes. After the war, the American Army and the State department decided to jointly fund MI-8 and Yardley continued as head of the "Cipher Bureau". They located their operations in New York City for legal reasons. Cracking Japanese codes was a priority. After almost a year, Yardley and his staff finally managed to break the Japanese codes and were still reading Japanese diplomatic traffic when Washington hosted the Washington Naval Conference in 1921. The information the Cipher Bureau provided the American delegation regarding the Japanese government's absolute minimum acceptable battleship requirements was instrumental in getting the Japanese side to agree to a 5:3 ratio instead of the 10:7 ratio the Japanese Navy really wanted. This allowed Japan only 18 battleships to 30 for the U.S. and 30 for Great Britain instead of the 21 battleships Japan desired. This was the height of Yardley's cryptanalytic career. MI-8 closed its doors for good on October 31, 1929, just two days after the stock market crashed. With Yardley's esoteric skills in very low demand, and no government pension due to his secretly funded work, he took up writing about his experiences in codebreaking to support his family. His memoirs, The American Black Chamber, were published by Bobbs-Merrill in 1931. The book outlined the history of the first U.S. Signals Intelligence (SIGINT) organization, described the activities of MI-8 during World War I and the American Black Chamber in the 1920s, and illustrated the basic principles of signals security. This work was instantly popular. Its critics at the time concluded that it was "the most sensational contribution to the secret history of the war, as well as the immediate post-war period, which has yet been written by an American. Its deliberate indiscretions exceed any to be found in the recent memoirs of European secret agents." In the U.S., 17,931 copies were sold, with 5,480 more sold in the U.K. It was translated into French, Swedish, Japanese, and Chinese. The Japanese version sold an unprecedented 33,119 copies. This book was an embarrassment to the U.S. government and compromised some of the sources Yardley and his associates used. Through this work an estimated 19 nations were alerted that their codes were broken. Much of the post-World War I codebreaking was done by obtaining copies of enciphered telegrams sent over Western Union by foreign diplomats, as was the custom before countries had technology for specialized communications devices. William F. Friedman, considered the father of modern American signals intelligence (SIGINT) gathering, was incensed by the book and the publicity it generated in part because sources and methods were compromised. .