Walter Schellenberg. Memoirs (№ 377780)

Great importance to command the troops had the eavesdropping of radio communications of the enemy between armies, divisions and regiments. The great success we achieved when we were able to connect to the radio channels of the Central apparatus of Russian intelligence in Moscow. Here we were widely conceived of the radio game in order to deceive the enemy. In the end, Moscow had to change the code and the personnel of agents.