 Number 196 - September 1999 |
| Computers in 1937? Britain's Best Kept Secret | ||
| by Lynn L. Kauer, Saginaw Valley PCUG | ||
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This past October when
Crystal and I shared some vacation time in Florida, with her sister
(Yvonne) and husband (Brian) from Oxford, England. We met with them, and
their friends (John and Janet) who were also traveling with them.
During the week we spent with them I learned that John was involved with
a British Historical organization on the task of rebuilding a computer.
While I didn't understand too much about what he was doing I did learn that one problem he had encountered was obtaining the proper screws with which to rebuild the machine. To make a long story short, via e-mail I was able to obtain a list of the screws he needed (15,000 of them) so I could take them with us to England when we went on vacation this past month. During our stay in England I had the opportunity to tour the site where the machine was being rebuilt. As always, the story behind the story I will be sharing is the more fascinating. It begins in 1935. Poland began to intercept radio transmitted messages being sent from Germany to other countries. It occurred to them that Germany might be up to something so they began to monitor the messages. After a short time, the messages began to be transmitted in an encoded fashion. A couple of their mathematicians learned how to interpret the code, translated the messages and learned of Hitler's plans for invasion of neighboring countries. During 1936 Hitler's forces began to encode their messages with a machine called the "Enigma." It wasn't a top-secret machine because someone had attempted to market it for encoding banking transactions years earlier. At the time, there were over 1,000 of the devices on the market but the banks were not interested. However, Hitler was! The machine looks a bit like a manual typewriter. The encoding feature was accomplished via three wheels with five positive and negative positions to determine the characters the machine would type. It worked as follows: If the user set the first wheel to the 'positive 5' position, the second wheel to the 'minus 3' position, the third wheel to the 'positive 2' position and typed the word "and" it result would result in the word "ekf." [Should be +4 -3 +2 for "ekf" or else "fkf" by my count, but I quibble. -rjt] What happened is that when the "a" key was entered the letter five characters beyond (positive) would be used. The next key would select the second letter to the left of its preset position and so forth. This three-wheel combination was considered to be so secure as it offered tens of thousands of possibilities. Each night at midnight, Hitler's forces changed the wheel combinations, which resulted in a new encoding procedure. Mathematical probability dictated that it would take 1,000 people working independently nine lifetimes to break the code. As the code was being changed on a daily basis, and sometimes twice in the same day, the encoding procedure was considered to be very secure. A Computer is Born One night three of the Polish mathematicians were eating ice cream and trying to figure out a way to automate a decoding process. After a while one of them did, they made a simple mockup of the decoding machine and were thrilled that it worked. They code named the device "Bomba" because it was the new flavor of ice cream they had been eating the night they developed the idea for the machine. Fighting On An Allied Front In 1937 these scientists invited British and French security specialists to a secret conference to inform them of what Hitler was up to. At first they didn't believe them. When the Polish scientists showed them the broken encoded messages they asked them how they had broken the code. They answered their question by simply handing over to them the simple machine they had developed. They knew Poland would soon be invaded and a captive of Germany. Their intent was to give a tool to someone who could work to free them in the future. The other problem was, a fourth wheel was added to the Enigma encoding machine, making the decoding process far more complex. The machine was taken to England and the British Government "assumed ownership" of a private residence of a large landowner near London at a site known as Bletchley Park. It became the headquarters, and location, for 12,000 men and women working on code breaking that ended WWII two years early saving thousands of lives. |
The Bombe is Developed
Using the principles passed along from the Poles, a new machine was quickly developed. From a recovered photo, the machine is about eight feet in length and about six feet high. There are three banks of cylinders each three high with a combination of 12 and 13 cylinders in a row. On the ends of each cylinder are ten notches, five for positive positions and five for negative positions. When a newly encoded message is captured, it is coded into the machine. Once entered the cylinders are turned notch by notch via a series of hydraulic pumps and lines. As soon as a message can be read (in German) it means the position code of the Enigma encoding machine for the three wheels is broken. Once the start positions are known, they were set in a captured Enigma encoder, the encoded message entered, and the decoded message was translated by the Enigma. (Submarine Enigma's used four wheels.) What amazed me was that British intelligence would capture an encoded message, transmitted by radio, enter it into the Bombe and three to five hours later have the information to be able to read Hitler's messages for the rest of the day. (The U.S. also had a similar machine with four vertical banks of cylinders. There was a photo of it at the park.) Tour Notes On the day I visited the site there was a tour open to the public. I learned that the code-breaking site was kept secret until twenty years ago. Obviously, the persons conducting the tours were quite proud of the accomplishments achieved at the site. One story was the occasion when a message being sent to Rommel in Africa was broken at 3:00am, translated and sent to Montgomery by 3:30am. Rommel got the same message at 6:30am, three hours after Montgomery had received it. Submarine locations were found by interpreting messages sent to wolf packs. In order to maintain a veil of secrecy, a group of 20 to 40 spotter planes would be sent in random flight patterns. (Hitler had his spies in England also. If it became obvious that the plane would fly directly to the submarine, the cat would be out of the bag.) Only one of the planes was sent in the direction to find the sub--a decision that was unknown to the pilots of the planes. The pilots never understood why the military wanted the subs to see them to know that they were spotted. Now it's obvious that in the interest of keeping Hitler from learning that all of his top-secret messages were being broken, the game was played to the fullest. On other occasions, flights of bombers were sent (and most shot down) to bomb factories that were known to be vacated by the Germans. Colossus is Born In 1939, the world's first large electronic valve computer was developed that further speeded up the process of breaking and interpreting Hitler's messages to his Generals. It's about thirty feet in length, has hundreds of vacuum tubes (the English call them "valves" - ed), and a streaming paper tape punched with a series of holes that has a beam of light passing through them. It accomplishes the similar task of turning the cylinders of the Bombe computer. Reflections After the tour, I was somewhat in awe of the effectiveness of simple technology. Until now, I was under the understanding that computers were developed in the 50's. How many of us know that the breakthrough came as a result of some Polish mathematicians eating ice cream in 1937? I also couldn't help but wonder if the "bragging" of Symantec toward how secure their encryption software is. Maybe we haven't progressed as far as we might like to think. From the "Blue Chip News" a publication of the Saginaw Valley Computer Association, PO Box 5827, Saginaw, MI 48603-0827 (517)496-2440 day (517)792-6874 nite (517)496-2465 fax
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Number 196 - September 1999 |
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