Luftnachrichten Abteilung 350: was the cipher bureau of the German Air Force, the Luftwaffe and part of the high command of the Luftwaffe. B-Dienst: (Observation Service) was a Department of the German Naval Intelligence Service (German: Marinenachrichtendienst, MND III) of the OKM, that dealt with the interception and recording, decoding and analysis of the enemy, in particular British radio communications. Abwehr: Military intelligence gathering and cipher bureau from 1941 to 1944.