CWI Cryptology Group

Abstract: The title of this talk is the title of Chapter 1 of the second volume of the now declassified 1946 US Army Security Agency book "European Axis Signal Intelligence", which starts off: German high-level cryptographic systems were insecure although brilliantly conceived. In this talk I discuss the reasons for this paradox based on the material in various TICOM documents. (TICOM was the "Target Intelligence Committee", a joint UK-US group at the end of WWII tasked with acquiring German signals intelligence assets - personnel, equipment, and intercepts.) Surprisingly, it turns out that the reasons for this meltdown in operational security on the German side are quite simple to understand, involving both deficiencies in organization and resistance to facing inconvenient truths. Even more surprisingly, many of the research cryptologists in both the Wehrmacht and Army were well aware of these problems, but their concerns were (fortunately) ignored.