The Green Network

Keys:

• February 21, 1940 traffic

Introduction

Greenshank (or Green as it was called in 1939 and 1940), was the network of the German Home Administration. Germany, even before the war, was divided into about 20 military districts (Wehrkreise), each with its HQ. Each district was responsible for the recruitment of a Corps, which in time of war would be reinforced from its home area, ans so the Wehrkreis administration was regarded as standing in place of the Corps. Hence the quality of nomenclature, whereby the home HQs were referred to as simply "Wehrkreiskommando I, II, etc.," or as "Stellvertredendes Generalkommando I, II etc,, Armeekorps".

Unlike the Air Force keys, the Green network was very secure and Hut 6 only broke this key very rarely. For example, there was almost no routine message (the basis for finding cribs). Also the re-encodings were not straightforward.