Part Five: The Basics of Programming & Software
By Shreyas K. Rising 8th Grader
This is part five out of a multi-part section of a series. (That’s definitely not confusing…). Unlike the previous section, this series will be teaching you programming and software. We’ll mainly cover the basics and some advanced programming concepts. Enjoy and keep on the lookout for more parts!
Introduction:
Computers. Smartphones. TVs. Gaming Consoles. These are all different types of technology, and we previously examined how they were built and how the hardware functions. But what about the software? When I say software, I specifically mean the programming behind the computer. Computer programming is the method of creating and building an executable computer program to perform a specific computing event. Basically you’re, in a way, “talking” to the computer in a language that it understands. In this section of the series, we WILL be going over programming languages, software, and many other things. And, yes! we are going to be learning to program. Enjoy!
Part Five: The Man Himself, Alan Turing
Hey everyone! Today we’re doing something a little different. We are going to taking a step back from the world of programming and software and discuss the person who formulated many of the theoretical concepts that underlie modern computation — the father of computer science himself: Alan Turing.
Alan Turing was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical computer science, providing a formalization of the concepts of algorithm and computation with the Turing Machine, which can be considered a model of a general-purpose computer. Turing is widely considered to be the father of theoretical computer science and artificial intelligence.
Now that you know who he is, let’s go more in-depth about his contributions to our world.
Alan Mathison Turing was born in 1912 and showed an incredible aptitude for math and science throughout his childhood. A few decades later, during the Second World War, Turing was a leading participant in the breaking of German ciphers at Bletchley Park. From September 1938, Turing worked part-time with the Government Code and Cypher School, the British codebreaking organization. He concentrated on cryptanalysis of the Enigma cipher machine used by Nazi Germany, together with Dilly Knox, a senior GC&CS codebreaker. Soon after the July 1939 Warsaw meeting at which the Polish Cipher Bureau gave the British and French details of the wiring of Enigma machine’s rotors and their method of decrypting Enigma machine’s messages, Turing and Knox developed a broader solution.
By using statistical techniques to optimize the trial of different possibilities in the code-breaking process, Turing made an innovative contribution to the subject. He wrote two papers discussing mathematical approaches, titled The Applications of Probability to Cryptography and Paper on Statistics of Repetitions, which were of such value to GC&CS and its successor GCHQ that they were not released to the UK National Archives until April 2012, shortly before the centenary of his birth. A GCHQ mathematician, “who identified himself only as Richard,” said at the time that the fact that the contents had been restricted for some 70 years demonstrated their importance and their relevance to post-war cryptanalysis. Turing had a reputation for eccentricity at Bletchley Park.
Within weeks of arriving at Bletchley Park, Turing had specified an electromechanical machine called the bombe, which could break Enigma more effectively than the Polish bomba kryptologiczna, from which its name was derived. The bombe, with an enhancement suggested by mathematician Gordon Welchman, became one of the primary tools, and the major automated one, used to attack Enigma-enciphered messages. A complete and working replica of a bombe now at The National Museum of Computing on Bletchley Park The bombe searched for possible correct settings used for an Enigma message (i.e., rotor order, rotor settings, and plugboard settings) using a suitable crib: a fragment of probable plaintext. For each possible setting of the rotors (which had on the order of 1019 states, or 1022 states for the four-rotor U-boat variant), the bombe performed a chain of logical deductions based on the crib, implemented electromechanically.[citation needed.
The bombe detected when a contradiction had occurred and ruled out that setting, moving on to the next. Most of the possible settings would cause contradictions and be discarded, leaving only a few to be investigated in detail. A contradiction would occur when an enciphered letter would be turned back into the same plaintext letter, which was impossible with the Enigma. The first bombe was installed on 18 March 1940. By late 1941, Turing and his fellow cryptanalysts Gordon Welchman, Hugh Alexander, and Stuart Milner-Barry were frustrated. Building on the work of the Poles, they had set up a good working system for decrypting Enigma signals, but their limited staff and bombes meant they could not translate all the signals. In the summer, they had considerable success, and shipping losses had fallen to under 100,000 tons a month; however, they badly needed more resources to keep abreast of German adjustments. They had tried to get more people and fund more bombes through the proper channels but had failed. On 28 October they wrote directly to Winston Churchill explaining their difficulties, with Turing as the first-named.
They emphasized how small their need was compared with the vast expenditure of men and money by the forces and compared with the level of assistance they could offer to the forces. As Andrew Hodges, biographer of Turing, later wrote, “This letter had an electric effect.” Churchill wrote a memo to General Ismay, which read: “ACTION THIS DAY. Make sure they have all they want on extreme priority and report to me that this has been done.” On 18 November, the chief of the secret service reported that every possible measure was being taken. The cryptographers at Bletchley Park did not know of the Prime Minister’s response, but as Milner-Barry recalled, “All that we did notice was that almost from that day the rough ways began miraculously to be made smooth.” More than two hundred bombes were in operation by the end of the war.
The next part of this section will be out soon.