diplomatic cipher, 1919 Until
World War I, the only codes and cypher organizations created by the
U.S. government were short-lived agencies of the
United States Armed Forces, such as the
U.S. Army's Military Intelligence (MI-8). The Cable and Telegraph Section or Cipher Bureau was established on April 28, 1917, three weeks after the
U.S. Congress declared war on the
German Empire and began
American involvement in World War I. It was headquartered in
Washington, D.C., operated under the executive branch without direct Congressional authorization, and was moved in the Army's organizational chart several times. On July 5, 1917,
Herbert O. Yardley was assigned to head the Cipher Bureau, which consisted of Yardley and two civilian clerks. It absorbed the
Navy's
cryptanalysis functions in July 1918. The Cipher Bureau moved to
New York City on May 20, 1919, where it continued intelligence activities as the Code Compilation Company, or the Black Chamber, under Yardley's command. Jointly funded by the Army and the
State Department, the Cipher Bureau was tasked with breaking the communications of other nations, primarily diplomatic communications, as occurred during the
Washington Naval Conference. According to intelligence historian
James Bamford, the Black Chamber secured the cooperation of American
telegraph companies such as
Western Union in illegally turning over the cable traffic of foreign embassies and consulates. Eventually, "almost the entire American cable industry" was part of this effort. However, these companies eventually withdrew their support, possibly due to the
Radio Act of 1927, which broadened criminal offenses related to breaching the confidentiality of telegraph messages. In 1929, the
State Department withdrew its share of the funding while the Army, undergoing unit reorganizations, transferred the Black Chamber to the
Signal Corps, which opted to rebuild the organization for their own purposes and dismissed Yardley and all of his employees. Stimson's ethical reservations about cryptanalysis focused on the targeting of diplomats from the U.S.'s close allies, not on spying in general. Once he became
Secretary of War during
World War II, he and the entire U.S. command structure relied heavily on decrypted enemy communications. == Legacy ==