:For the Polish organization see Biuro Szyfrów, for the U.S. intelligence agency see Black Chamber.
Lt. Col. Jan Kowalewski (23 October 1892 – 31 October 1965) was a Polish cryptologist, intelligence officer, engineer, journalist, military commander, and creator and first head of the Polish Cipher Bureau.
Federal Bureau of Investigation | Shanghai Railway Bureau | Bureau of Land Management | Central Bureau of Investigation | Bureau of Alcohol, Tobacco, Firearms and Explosives | Bureau of Indian Affairs | United States Census Bureau | United States Bureau of Reclamation | Bureau of Meteorology | Citizens Advice Bureau | Better Business Bureau | Wuhan Railway Bureau | Federal Bureau of Prisons | Bureau of Engraving and Printing | National Guard Bureau | Bureau of Internal Revenue | Bureau of Plant Industry | The Adjustment Bureau | Japan Credit Bureau | cipher | Bureau of Meteorology (Australia) | Bureau of Labor Statistics | Bureau of American Ethnology | American Farm Bureau Federation | National Bureau of Economic Research | Lorenz cipher | Elias Sports Bureau | United States Bureau of Mines | Oklahoma State Bureau of Investigation | Bureau of Western Hemisphere Affairs |
Beginning in 1929, the modest shop, ten minutes' walk from the General Staff building, which housed the Cipher Bureau, was transformed into AVA.
Before World War II, Pyry was also the seat of the Polish General Staff's Cipher Bureau, the agency that before the war was the only one in the world to break the German Enigma cipher (beginning in December 1932).
Biuro Szyfrów 4, the German section of the Polish Cipher Bureau
When Henry L. Stimson, Secretary of State under President Herbert Hoover, found out about Yardley and the Cipher Bureau, he was furious and withdrew funding, summing up his argument with "Gentlemen do not read each other's mail".
A month before the outbreak of World War II, in late July 1939, Rejewski and his Cipher Bureau colleagues and superiors, at an official Warsaw conference, initiated French and British military cryptologists into their techniques and technology and gave each of their western allies a German Enigma machine that they had reconstructed.