Archive for April 11th, 2008

Enigma, Bletchley, and ordinary heroes

April 11, 2008

In early April BBC Radio 4 carried a radio programme – part of the series “The Reunion” – that anyone who uses computers or calculators, or who has any interest in codes and ciphers, really should have listened to. (Unfortunately it is no longer up on the BBC’s Listen Again site – if it is lurking somewhere else on the web, esp. as an MP3, I would be grateful for info on where).

Bletchley Park

The programme re-united several people who had taken part, in their early 20s, in perhaps the greatest ever piece of “Signals Intelligence” work, and certainly the greatest feat of sustained codebreaking, ever. This was the top secret work at Bletchley_Park, outside London, during WW2. In total secrecy, a core of mathematicians, boffins, military codebreakers and bright young Oxbridge types, and a much larger staff of mostly female assistants, cracked the codes the Germans used for all top secret communications. These codes were mostly based on the fearsome Enigma cipher machine, which the Germans regarded as uncrackable. It remains questionable whether the Allies would have been able to defeat Nazi Germany without the information derived from the Enigma decrypts, and the work is widely viewed as having shortened the war by two to four years. The computation machines built to attack the Enigma ciphers, including the Colossus, were among the key forerunners of modern computers.

With typically British-ness, after the war the British government mandated the “sanitizing” of anything at BP that would tell people what had gone on there, right down to dismantling all the equipment down to individual components. The site became a training college for telephone engineers. As all the people who had worked at Bletchley had signed the Official Secrets Act, it took nearly 30 years – until 1974 – for the first hints of the Bletchley codebreaking story to emerge, and even longer until accurate accounts appeared. Luckily many of the buildings were saved from the bulldozers (just) in 1992 and are now preserved as a museum. The piece de resistance is a reconstructed, and fully working, Colossus computer.

Bletchley Park and its work is now more widely known through fictionalized portrayals, such as Robert Harris’ novel Enigma and the 2001 film derived from it. The book is a good starting point for the Bletchley story. The list_of_people that worked at, or for, the real Bletchley Park includes a remarkable gemisch of British mathematicians, academics, (not just scientists), a couple of chess champions, and even a future Chancellor of the Exchequer.

The computing machines built at Bletchley used pre-transistor valve technology. When I visited the Bletchley Museum a decade or so back I remember being struck by this since my father, who I went with, was a teenage radio geek in his time and a whizz with valves (he subsequently studied physics). One of my abiding childhood memories of my dad is of him with his head buried in some old radio, or TV set, or other electronic thingummy, which he would be trying to mend. If not there he would be under the car, or washing machine, trying to fix that.

Anyway, walking round Bletchley I was struck by how people not that many years older than my father was then, and with the same sort of skills (radio, and electromechanical tinkering, and physics know-how) had built the machines from scratch. Although the electrical engineers like Tommy_Flowers never got quite the recognition of the mathematicians and codebreakers like Alan Turing, they were indispensable too. Perhaps this is a reminder that while in science you need geniuses and visionaries, you also need people who can turn the visionary ideas into real experiments, or techniques, or machines.

When my dad and I visited BP in the 90s some of the volunteer helpers were people who had actually worked there during the war, while electronics enthusiasts of similar vintage were busy reconstructing the Colossus. The word I would use to describe these people, then in at least their mid 70s and now well into their 80s, is “formidable”. Or even better, “indomitable”. I had the same feeling again listening to the Radio 4 show. Anyway, a tremendous piece of living history, and a fitting testament to peoples’ ingenuity and ability to meet challenges.