Title: The American Black Chamber
Author: Herbert O. Yardley
Yardley, Herbert O. (2004). The American Black Chamber. Annapolis, MD: US Naval Institute Press (reprint of 1931 edition)
- United States. War Department. Military Intelligence Division. Section No. 8–History.
- World War, 1914-1918–Secret service–United States.
- World War, 1914-1918–Military intelligence.
Date Updated: June 14, 2016
I’m a cipher freak, and am fascinated with how they are created and, even more, broken. It still amazes me that until World War II the United States, via Henry Lewis Stimson, Herbert Hoover’s secretary of state, still held that “Gentlemen do not read other people’s mail.” Yardley’s Black Chamber operation got him fired owing to Stimson’s view.
High-risk covert operations, usually of an unavowable nature, are termed “black operations.” The most common circumstances in which such operations are mounted concern the burglary of diplomatic premises. The term implies a degree of illegality that, if discovered, would be difficult to conceal or could result in an incident with political ramifications.
It’s great to see this classic book back in print. Yardley was, as they say, accustomed to luxury, and when fired in 1929 wrote this book on the breaking of foreign codes by the United States. In March 1929 the newly appointed United States secretary of state, Henry Stimson, reportedly remarked that “gentlemen do not read each other’s mail” when he closed down the State Department’s cryptographic unit. He had been shown Japanese intercepts and had been shocked to learn how they had been acquired. At that time the Black Chamber consisted of the veteran code breaker Herbert Yardley and a staff of five. Appalled by Stimson’s behavior, Yardley published his book, The American Black Chamber, in 1931 and revealed that his code breakers had for years read Japanese diplomatic telegrams. The Japanese Foreign Ministry promptly changed its cipher systems.
Yardley had found a loophole in the law so that he couldn’t be prosecuted, but boy did it annoy the Government. The book was a best seller, and started him or a career as an author. He wrote another four or five books on codes and another best seller called The Education of a Poker Player (originally published in 1957).
In the eighteenth century, a number of countries operated Black Chambers, but the most famous was the Geheime Kabinets-Kanslei of Vienna. Every morning the bags of mail to be delivered to embassies were brought to the chamber, where their seals were melted, the letters opened, and important sections copies, come by reading out loud and using shorthand for the copy. After copying, the letters were resealed with forged seals and were sent on their way within two or three hours. Regular mail was also examined, as was all the outgoing mail from the embassies. Anything in code was especially noted, and codebreakers received bonuses for cracking a new code.
The book is fascinating, well written and filled with stories of stealing code books, beautiful female spies. It has excellent descriptions of how to break ciphers, one of the best in books on the history of code breaking. That may be since the codes in the 1920’s were simpler minded than later Enigma machines.
Reviewed by George C. Constantinides
In his own book on cryptology, The Codebreakers, Kahn gave his opinion that Yardley’s book was “the most famous book on cryptology ever published” and that Yardley himself was “the most famous cryptologist in history.” Kahn felt that Yardley owed his fame to his sensational book rather than to what he actually did but that his book, despite any faults and errors, captured public imagination and inspired interest in cryptology. Yardley described his experiences as head of MI8 during World War I and of the famous Black Chamber until 1929 when it was abolished by order of the secretary of state. The book caused a sensation, especially in Japan because of what it said of U.S. work against Japanese and other systems. One of its many consequences was the passage of the law in 1933 known popularly as the Yardley Law protecting cryptologic matters. See Kahn’s discussion of the aftermath and the political and other fallouts from this book.
As Yardley’s name faded from public awareness, so has the book’s reputation for reliability, accuracy, and innovation. Galland in An Historical and Analytical Bibliography of the Literature of Cryptology in 1945 called Yardley’s work “romantically exaggerated, somewhat inaccurate.” Kahn regarded it as having not only faults but falsehoods as well. Shulman in An Annotated Bibliography of Cryptography opined that from a cryptanalytical point of view the book contributed nothing new and that the account of Yves Gylden of ciphers before and during World War I was more accurate and thorough. The U.S. Army Security Agency’s The History of Codes and Ciphers in the United States During World War I spells out in some detail where Yardley was considered to be incorrect, unreliable, or exaggerated. This latter work, for example, called Yardley’s three chapters on secret inks “untrustworthy” because the author was in no position to write on this matter from first-hand experience. There are aspects of Yardley’s life and work yet to be explained adequately. The failure to continue the employment of this talented and experienced cryptologist after the Black Chamber was closed needs further inquiry. Faragos allegations in The Broken Seal of Yardley’s later relations with the Japanese have been attacked by such experts as Shulman. Kahn felt Farago must be read “with extreme caution”; both views, however, should not close the subject to further research. If Farago were proven right, it would then be the case that the Japanese did not first learn of U.S. cryptanalytic successes from this book. Ballantine Books in 1981 issued a paperback edition with a short introduction by Kahn.
This is a review by the Defense Intelligence School.
Yardley, originally a cipher clerk in the State Department, became the officer in charge of the code and cipher section in Military Intelligence in the U.S. Army in World War I. After the war, with State and War Department funds, Yardley established what came to be known as the American Black Chamber. His career there came to an end in 1929 when Secretary of State Stinson closed the Black Chamber. This book sets forth Yardley’s cryptologic work.
Reviewed by Paul W. Blackstock and Frank L. Schaf
A history of the first modem organization for cryptanalysis in the United States by its originator and director during the period of World War I through the 1920s.
 See West, Nigel (2006). Historical Dictionary of International Intelligence. Lanham, MD: Scarecrow Press, p. 30
 West, Nigel (2006). Historical Dictionary of International Intelligence. Lanham, MD: Scarecrow Press, pp. 29-30
 Constantinides, George C. (1983). Intelligence and Espionage: An Analytical Bibliography. Boulder, CO: Westview Press, pp. 504-505
 Galland, Joseph Stanislaus (1945, 1970). An Historical And Analytical Bibliography of The Literature of Cryptology. New York: AMS Press
 Barker, Wayne G. (1979), ed. The History of Codes And Ciphers in The United States During World War I. Laguna Beach, CA: Aegean Park Press
 Farago, Ladislas (1969). The Broken Seal: the Story of Operation Magic and the Secret Road to Pearl Harbor. London: Mayflower
 Defense Intelligence School (1981). Bibliography of Intelligence Literature: A Critical And Annotated Bibliography of Open-Source Literature (7th ed, rev.). Washington, DC: Defense Intelligence School, p. 76
 Blackstock, Paul W. (1978) and Frank L. Schaf, Jr. Intelligence, Espionage, Counterespionage, And Covert Operations: A Guide to Information Sources. Detroit: Gale Research Co., p. 127