naval-enigma-decryption

The chapter chronicles the critical advancements in breaking the German naval Enigma from 1940 to mid-1941, focusing on Alan Turing's development of a mathematical theory based on Bayesian inference and weight of evidence, which was practically implemented through the Bombe machine. Key captures of cipher materials, including those from weather ships and the complex officer-only signals, significantly enhanced Hut 8's decryption capabilities, enabling near real-time intelligence that disrupted U-boat operations. Despite these successes, the chapter also highlights organizational challenges within the Admiralty and the risks posed by German misattribution of British codebreaking achievements.

This chapter discusses operational challenges faced by the Hollerith section under Mr. Freeborn in breaking Naval Enigma codes, specifically the halt of night shifts due to staff shortages which delays naval key findings by at least twelve hours daily. It highlights the urgent need for additional untrained female clerks to resume night work and the looming threat posed by the potential conscription of skilled male staff previously exempt from military service.