Bletchley Park House.
FIRST THE BOMBE.
When I heard that Bletchley Park House was open to the public, I just could not wait to get there. To feast my eyes on Enigma machines, Bombes and Colossus had always been an ambition of mine. To visit the site of the development of the first electronic digital computers in the world, developed by people like Tommy Flowers and Alan Turing along with many others was going to be mind blowing. Machines so secret that they could not be known or talked about for many years after they were built. When I arrived at Bletchley Park House I was shown around by one of the guides, one who turned out to be a retired long time employee at Bletchley Park House. He had many tales to tell of the war time activities there, when close to 10,000 people worked in complete secrecy in this medium size country house and the group of nissen huts around it. The memorabilia and equipment on display were all explained in great detail. Some of the equipment is actually available for you to use. Bletchley was so secret during the war that any person who knew Bletchley existed was never allowed to travel out of the UK. Even after the war the secrecy was maintained at an intense level. What were they deciphering in these post-war years? You can be reasonably certain that attention was being given to information intercepts from the Soviet Union and its allies, however the feeling was that perhaps even the UK's own allies like France and USA could have been subject matter. When the British government decided to announce the closure of Bletchley, it also stated the site was to be sold and would be cleared ready for the erection of a superstore. They appeared to be determined that Bletchley was to be remove completely and the area sanitised. Was this an attempt bury those dark secrets? Fortunately a group of ex-employees challenged the destruction of this magnificent site and managed to get the government's plans overturned by highlighting the architecture of the main house and the uniqueness and rarity of some of the trees and shrubbery in the gardens. THEN CAME COLOSSUSThe first machine designed to break the Lorenz was built at the Post Office research department at Dollis Hill and called ‘Heath Robinson’ after the cartoonist designer of fantastic machines. Although Heath Robinson worked well enough to show that Max Newman’s concepts were correct, it was slow and unreliable. Max Newman called in the help of Tommy Flowers, a brilliant Post Office Electronics Engineer. Flowers went on to design and build ‘Colossus’, a much faster and more reliable machine that used 1,500 thermionic valves (vacuum tubes). The first Colossus machine arrived at Bletchley Park House in December 1943. This was the world’s first practical electronic digital information processing machine - a forerunner of today’s computers. Lorenz had to be cracked by carrying out compex statistical analyses on the intercepted messages. Colossus could read paper tape at 5,000 characters per second and the paper tape in its wheels travelled at 30 miles per hour. This meant that the huge amount of mathematical work that needed to be done could be carried out in hours, rather than weeks. Mark I Colossus was upgraded to a Mark II in June 1944, and was working in time for Eisenhower and Montgomery to be sure that Hitler had swallowed the deception campaigns prior to D-Day on June 6th 1944. There were eventually 10 working Colossus machines at Bletchley Park House.
ENIGMA MACHINE.
The Enigma cypher was the backbone of German military and intelligence communications. Invented in 1918, it was initially designed to secure banking communications, but achieved little success in that sphere. The German military, however, were quick to see its potential. They thought it to be unbreakable, and not without good reason. Enigma's complexity was bewildering. Typing in a letter of plain German into the machine sent electrical impulses through a series of rotating wheels, electrical contacts and wires to produce the encyphered letter, which lit up on a panel above the keyboard. By typing the resulting code into his own machine, the recipient saw the decyphered message light up letter by letter. The rotors and wires of the machine could be configured in many, many different ways. The odds against anyone who did not know the settings being able to break Enigma were a staggering 150 million million million to one. The Poles had broken Enigma in 1932, when the encoding machine was undergoing trials with the German Army. They even managing to reconstruct a machine. At that time, the cypher altered only once every few months. With the advent of war, it changed at least once a day, effectively locking the Poles out. But in July 1939, they had passed on their knowledge to the British and the French. This enabled the codebreakers at Bletchley Park House to make critical progress in working out the order in which the keys were attached to the electrical circuits, a task that had been impossible without an Enigma machine in front of them. Armed with this knowledge, the codebreakers Bletchley Park House were then able to exploit a chink in Enigma's armour. A fundamental design flaw meant that no letter could ever be encrypted as itself; an A in the original message, for example, could never appear as an A in the code. This gave the codebreakers a toehold. Errors in messages sent by tired, stressed or lazy German operators also gave clues. In January 1940 came the first break into Enigma. It was in Huts 3,6,4 and 8 that the highly effective Enigma decrypt teams worked. The huts operated in pairs and, for security reasons, were known only by their numbers. The codebreakers at Bletchley Park House concentrating on the Army and Air Force cyphers were based in Hut 6, supported by a team in the neighbouring Hut 3 who turned the decyphered messages into intelligence reports. Hut 8 decoded messages from the German Navy, with Hut 4 the associated naval intelligence hut. Their raw material came from the 'Y' Stations: a web of wireless intercept stations dotted around Britain and in a number of countries overseas. These stations listened in to the enemy's radio messages and sent them to Bletchley Park House to be decoded and analysed. To speed up the codebreaking process, the brilliant mathematician Alan Turing developed an idea originally proposed by Polish cryptanalysts. The result was the Bombe: an electro-mechanical machine that greatly reduced the odds, and thereby the time required, to break the daily-changing Enigma keys.
|
