[2] He later started work as part of a group of five mathematicians, recruited by Wilhelm Fenner, and which included Ernst Witt, Georg Aumann, Alexander Aigner, Oswald Teichmueller and Johann Friedrich Schultze, and led by Wolfgang Franz, to form the backbone of the new mathematical research department in the late 1930s, which would eventually be called: Section IVc of Cipher Department of the High Command of the Wehrmacht (abbr.
in Göttingen with Emmy Noether, (who was described by Pavel Alexandrov, Albert Einstein, Jean Dieudonné, Hermann Weyl, and Norbert Wiener as the most important woman in the history of mathematics), with a dissertation titled: Ideal theoretical interpretation of the representability of any natural numbers by square forms, (German: Idealtheoretische Deutung der Darstellbarkeit beliebiger natürlicher Zahlen durch quadratische Formen)[5] Noether had not been authorized to supervise dissertations on her own.
He left a detailed manuscript (written down before 1940) about his discussion with Hasse,[10] which serves as an important source for the events at that time in Göttingen.
[11][12] In November 1933, he signed the Vow of allegiance of the Professors of the German Universities and High-Schools to Adolf Hitler and the National Socialistic State.
Weber was involved in the removal of the Jewish mathematician Edmund Landau on 2 November 1933 from the mathematics faculty at the University of Göttingen.
Several days later Weber recommended, as the best mathematician, the algebraist Helmut Hasse, then working at the University of Marburg, and Udo Wegner as his second choice.
Udo Wegner was a strong candidate, but the probability theorist Erhard Tornier and ardent Nazi, eventually gained the second chair.
[18] During World War II, he worked with Oswald Teichmüller in the Cipher Department of the High Command of the Wehrmacht in section IVc under Wolfgang Franz which was scientific decoding of enemy crypts, the development of code-breaking methods and working on re-cyphering systems not solved by practical decoding.