Signals intelligence agencies of World War II

interwar Polish-intelligence cryptology agency

The B-Dienst (, observation service), also called 'xB-Dienst, X-B-Dienst and χB-Dienst''''', was a Department of the German Naval Intelligence Service (, MND III) of the OKM that dealt with the interception and recording, decoding and analysis of the enemy. In particular, it focused on British radio communications before and during World War II. B-Dienst worked on cryptanalysis and deciphering (decrypting) of enemy and neutral states' message traffic and security control of Kriegsmarine key processes and machinery.

signals intelligence and cryptanalytic agency of the German Nazi Party

The Funkabwehr, "Radio Defence Corps," was a radio counterintelligence organisation created in 1940 by Hans Kopp of the Armed Forces High Command during World War II. It was the principal body for the monitoring of illicit broadcasts. Its formal name was Funkabwehr des Oberkommandos der Wehrmacht () (OKW/WNV/FU). Its most notable breakthrough occurred on 26 June 1941, when tracing teams at the Funkabwehr station at Zelenogradsk discovered the Rote Kapelle, an anti-Nazi resistance movement in Berlin, and two Soviet espionage rings operating in German-occupied Europe and Switzerland during World