The GdNA (German: Oberkommando des Heeres/General der Nachrichtenaufklärung) was the signals intelligence agency of the Wehrmacht, before and during World War II. It was the successor to the former cipher bureau known as Inspectorate 7/VI in operation between 1940 and 1942, when it was further reorganised into the Headquarters for Signal Intelligence (German: Leitstelle der Nachrichtenaufklärung) (abbr.