Update 2026

This year I’ve added a new essay on the Compromise of Polish codes in WWII. This is a summary of the work done on Polish codes and ciphers (diplomatic, intelligence service, resistance movement) by the codebreakers of Germany, the United States and Britain. I uploaded the file TICOM report D-3 ‘The Polish Cyphers for Diplomatic and Consular Traffic’ by Scherschmidt (1943) I’ve also added information and rewritten parts of the essay Intercepted conversations - Bell Labs A-3 Speech scrambler and German codebreakers. Specifically, I added a new section on the transoceanic radiotelephone service operated by AT&T from 1927 up to the 1950’s.