 In June 1918, Captain Georges Painvin, a DB cryptoanalyst, was able to crack part of the Germans' ADFGVX cipher.These intercepts allowed an effective response to the movements of the German Army's 15 division-strong advances under Ludendorff at Montdidier and Compiègne, about 50 miles north of Paris.Prior to World War II, a Deuxième Bureau agent codenamed 'Rex' made contact with Hans-Thilo Schmidt, a German cipher clerk, in the Grand Hotel of the Belgian town of Verviers.