Hans Pietsch

Hans Karl Georg Heinrich Pietsch (22 November 1907 – 14 October 1967) was a German mathematician who was most notable for being a director of the Mathematical Referat of the Wehrmacht signals intelligence agency, the General der Nachrichtenaufklärung during World War II.

Life In 1938, Pietsch was promoted to Dr Phil with a doctoral dissertation titled: Areas that have a bundle of closed geodesic or a pair of conjugated counterparts (German:Über Flächen, die ein Bündel geschlossener Geodätischer oder ein Paar konjugierter Gegenpunkte besitzen), achieving a rerum naturalium at Humboldt University of Berlin. This included the mathematicians Herbert von Denffer, Friedrich Böhm and Hans-Peter Luzius. When he left the internment camp, Pietsch returned to work as an editor, gaining employment at the Jahrbuch über die Fortschritte der Mathematik and the East German Academy of Sciences in East Germany, and he maintained these positions until he died in 1967. and rested upon the discovery of a solved Enigma message that had been discovered in the Cryptanalytic Bureau Wicher organisation in Warsaw, Poland in 1939. This was an Enigma message that had been transmitted from a German cruiser in Spanish waters during the Spanish Civil War and had been transmitted using the officers cipher. Pietsch along with Bohm and Steinberg played an important role in conducting security studies into the Enigma that resulted from Case Wicher in the years that followed the discovery of the solved message. Two specific instances of studies leading to action were demonstrated. The first was the discovery that double encipherment of the indicator was a serious insecurity in the use of the Enigma. As a result, on 1 May 1940, nine days before the beginning of the western campaign, in army and air force, the key procedure was radically changed for the Army and Luftwaffe Enigma machines. The second in 1944 was when Pietsch recommended that the Enigma daily use should be set below 20000 letters of use a day.