Geniuses at War: Bletchley Park, Colossus, and the Dawn of the Digital Age
By David A. Price, Narrated by John Lee
Audiobook, 5 hours and 44 minutes
Published by Random House Audio
During the Second World War Germany used two major types of encryption for their messages. Enigma was used by the German military, each service had their own particular variations of the Enigma coding machine and operating procedures. It used a series of ten wheels to encode a message, each letter of the original could be represented by a different letter each time it occurred, resulting in millions of potential variations. Lorenz was an encryption used at the highest level of Nazi diplomatic and military communications. As complex as Enigma was, Lorenz was dozens of orders of magnitude more sophisticated.
British codebreaking efforts centered around an estate called Bletchley Park. Poland had broken the early version of the Enigma machine and shared the secrets with the British who continued the work as the machines were changed throughout the war. To deal with the ever-increasing complexity and volume of message traffic Bletchley Park eventually grew to employ 8,700 people, many of them WRENs and ATS women. The codebreakers worked in separate buildings, each building was assigned a specific problem and work proceeded in shifts twenty-four hours per day.
Alan Turing is today considered to be one of the fathers of modern computing, his “Turing Test” is still one method used to assess the sophistication of Artificial Intelligence. Turing invented an analog device dubbed “the Bombe” which was able to replicate the functions of the Enigma machine and reverse-engineer new cyphers, given time and the occasional lucky break. To crack Lorenz, Bletchely’s director hired a telephone engineer named Tommy Flowers. Given a team and a deadline to be done before June, 1944, Flowers designed a binary computing device built around hundreds of vacuum tubes named Colossus – the world’s first digital computer. He then went about producing improved models to speed up the work and allow more messages to be read.
After decades of state-imposed secrecy the stories of the codebreakers are finally being told. Such was the desire for secrecy that the Colossus machines were disassembled after the war, their records burned, and operators sworn to silence. One has to wonder what would have been the result if Colossus had been preserved, further improved, and mass produced – thereby beginning the Computer Age in 1946. This is an intriguing story, recommended.