Bletchley Park: Overcoming Prejudice to Solve the Enigma

Wilson Hibbs

Historical Paper

Junior Division

Paper Length: 2,464 words

Process Paper Length: 491 words

Process Paper

How I Chose My Topic and How it Relates to the Theme

I chose this topic because though I am interested in History, I am also interested in Math and Science. The story of , , and the Enigma is obviously heavily impacted by these two subjects. It’s also about a massive breakthrough in communication, the Enigma

Machine. The topic fits the theme and contains information on subjects I am interested in, which is why I chose it.

How I Conducted My Research and Created My Project

I love writing, and a paper I wrote last year made it to Nationals, so it was easy to choose the paper category. I created my project by reviewing sources and taking notes, then putting those notes together into a paper. I was careful to cite where each note came from so that citations were easy once I got into the actual writing of the paper.

The first source I found was a book titled Alan Turing: The Enigma, which was about Alan

Turing’s life. I managed to find many other secondary sources, but finding primary sources was a challenge because much of the work that occurred at was kept secret. However, I did manage to find two papers written by Turing about discoveries he made that were unrelated to his work at Bletchley, along with the pamphlet including the law that got him arrested.

Alan Turing: The Enigma goes into a lot of detail about every aspect of Turing’s life. I didn’t take notes on the whole thing, only his most important discoveries and his time at Bletchley

Park. I had to filter out a lot of interesting information.

1 With my book on Joan Clarke, Joan Clarke: The Biography of a Bletchley Park Enigma, I had the opposite problem. Because of sexism, this was the only book on Clarke I was able to find and a lot of it was more about the general work going on at Bletchley Park, not her specifically.

However, I did manage to find enough information to conduct effective research.

My Historical Argument

My argument in this paper is about the important role that people like Clarke and Turing played in World War II. Without them, the war would have lasted much longer and millions more people could have been killed. A lot of people don’t recognize the significance of what happened at Bletchley Park, and most people don’t even know who Joan Clarke was. I want to prove that

Alan Turing and Joan Clarke are two of the most important, and least recognized, people in history.

Significance in History

As I said before, this topic has incredible significance in history. Without Turing and

Clarke, WWII would likely have lasted at least two years longer and caused millions of deaths that could have been avoided. Additionally, the could have been used in future wars. The people at Bletchley Park saved millions of lives, and most of them aren’t fully recognized. This story also shows how laws can be unjust and destroy lives. Turing’s story has inspired many people, including me.

2 Alan Turing stared at the apple.

He’d done a lot in his short life. He’d invented the concept of artificial intelligence. He’d solved a seemingly impossible mathematical problem. He’d even broken the Enigma Cipher, helping Britain to win World War II. He’d done so much, but none of it mattered to the government.

All that mattered was that he was gay.

The apple had been dipped in cyanide, ready to kill whoever ate it.

Was he really going to do it?

He hadn’t been himself for a while. When the British government had found out his secret, they’d forced him to take drugs to get “cured.” It didn’t work. All it did was make him miserable.

Turing took a bite from the apple.

Introduction

Alan Turing and Joan Clarke are two of the most important, and least recognized, people in history. Alongside many other brilliant scientists and mathematicians, the two worked at Bletchley

Park to solve the Enigma Code.

The was one of the greatest communication breakthroughs in history, but greater still was the feat of cracking its code. The machine was capable of encrypting a message so completely that most people deemed it unsolvable. However, people like Turing and Clarke were not easily defeated. Through the grit, determination, and intelligence of people like them, the code was eventually broken.

1 However, Turing was gay and Clarke was a woman. Both of them faced prejudice throughout their lives. Turing took his own life after undergoing gruesome government treatment.

Clarke wasn’t paid nearly as much as she deserved.

Solving the Enigma Code was one of the most important communication breakthroughs in history, but many people who helped with it are not fully credited. This is the story of how two of them, Alan Turing and Joan Clarke, overcame prejudice to make one of the greatest communication breakthroughs in history.

Turing’s Childhood

Alan Mathison Turing was born on June 23rd, 1912, to a fairly rich family in London. 1 At the age of ten, he got a book titled Natural Wonders Every Child Should Know. 2 This book described several different wonders of science, and Turing found it fascinating.3

As many of the boys at Turing’s school reached puberty, they started becoming more attracted to girls. Turing himself, though, made a startling discovery. He was attracted to other boys. 4

In 1927, Turing met Christopher Morcom. 5 Neither of them really understood what homosexuality was, or that they were both gay, they just knew that they liked each other. They became close friends, and stayed that way for the next few years.

1 , Alan Turing: The Enigma (Princeton University Press, 1982), 8 2 Hodges E nigma 16 3 Hodges E nigma 19 4 Hodges, E nigma 45 5 Hodes, Enigma 46

2 In 1930, Morcom suddenly died of tuberculosis. 6 The two had never made steps towards a closer relationship, and now they never would.

After Morcom’s death, Turing formed a close bond with Morcom’s parents. With their help, he got a scholarship to Cambridge in 1931. 7 It was there that he would make his first major discovery.

Clarke’s Childhood

Alan Turing’s childhood had contained one major loss, but Joan Clarke’s would contain several. Joan Elisabeth Lowther Clarke was the youngest of five children, born in 1917. Their parents were William and Dorothy Clarke. 8

In 1920, Clarke’s grandmother Alice died. The entire family moved to Lymington the next year. 9 Over the next five years, four different people in Clarke’s family died of various causes. 10

One of these people was Clarke’s brother, Stephen.

Through it all, Clarke simply stayed in school. She displayed an incredible talent for mathematics, and her family had the money to send her to college later if she wanted. Most girls didn’t go to school past the age of 14.

Meanwhile, unrest was growing in Germany. Britain had only just prevailed in the first world war, and it looked like a second one was coming. This one would depend more on math and science. The German Navy had even begun building a machine that could encode any message, giving them a huge advantage. 11 This war would require people like Joan Clarke to be won.

6 Hodges, E nigma 59 7 Hodges, E nigma 77 8 Anthony J. Randall, Joan Clarke: The Biography of a Bletchley Park Enigma (Cloister House Press, 2019), 4 9 Randall, Bletchley 6 10 Randall, Bletchley 34 11 Randall, Bletchley 29

3 Turing and Clarke “both had a facility for mathematics; Turing had a vision, while Joan had the determination to solve the problem; Turing to find a solution; Joan to see it through to the result.” 12

The Turing Machine After learning about mathematics and science at Cambridge for four years, Turing decided to take on the Entscheidungsproblem .

The Entscheidungsproblem , proposed by German mathematician David Hilbert, asked if there was “an algorithm that takes, as an input, a statement written in formal logic, and produces a

‘yes’ or ‘no’ answer that is always accurate?” 13 In 1935, an American named Alonzo Church used lambda calculus to prove that the answer was no. 14

Turing, however, decided to take it a step further than the mathematics. He started work on a hypothetical machine to answer the Entscheidungsproblem called a Turing Machine.

The Turing Machine had two main parts: a read- write head and a memory tape. The memory tape was infinitely long and could display symbols. The read- write head could read those symbols, erase them, write new ones, and move left or right along the tape. There was also a set of rules and a “state” variable to define those rules. 15

The value of the state variable was determined by the symbol that the head scanned, while the rules were determined by the state. The rules would tell the read- write head what to do, which could change the state, thereby changing the rules.

For example, if the machine needed to turn this:

12 Randall, Bletchley 29-30 13 Crash Course, A lan Turing: Crash Course Computer Science #15 (YouTube) 14 Alan Turing C rash Course 15 An Turing Crash Course

4

1 1 1 1 1 1 1 1 1 into this:

1 1 1 1 1 1 1 1 1 it would follow these rules: State Rules Blank 1

Config. 1 Move right; config. 1 Move right; config. 2

Config. 2 Write “1;” move right; config. Move right; config. 2 3

Config. 3 Move left; config. 4 Move right; config. 3

Config. 4 No move; config. 4 Erase; no move; config 4

16

To test his theoretical machine, Turing set it to a problem of his own devising which asked,

“Is there an algorithm that can determine, given a description of a Turing Machine and the input from its tape, whether the machine will run forever or halt?” 17

Turing eventually discovered that a device as simple as a Turing Machine could not solve the problem. 18 Since the original challenge was to create a machine that could solve any problem, this determined that computing could not solve everything.

Not only had Turing answered a question that had been asked by mathematicians for decades, he had created an early computer.

16 Modified from an example in Hodges, E nigma pages 126 and 127 17 Alan Turing C rash Course 18 Alan Turing C rash Course

5 Solving the Enigma

As tensions rose between Britain and Germany, Clarke continued her education. She progressed through school, eventually entering Cambridge University. The threat of war loomed closer as Clarke studied geometry under mathematician .

Meanwhile, Turing traveled to America to continue his education. Upon returning, he “was invited to attend a course on cryptology at the Government Code and Cipher School.” 19 He agreed to help the government in solving the Enigma Code, a code used by the German Navy to communicate.

This code, created by the Enigma Machine, was discovered by Poland in 1938. The Polish government discovered a few things about how the Enigma worked.

The Enigma was essentially a typewriter with a few additions. Behind the letter keys was a

“lampboard” with each letter printed in a small window that would light up whenever a key was pressed to show the encoded version. 20

These letters were encoded using three rotors in the back of the machine and a plugboard.

The rotors turned according to a set algorithm that changed daily, setting part of the code.2 1 The plugboard displayed the alphabet, with an electrical socket under each letter. Letters were paired with each other by having a cord plugged between them, encrypting them further. Because the rotors and plugboard pairings were changed daily, the code changed daily as well.

The Polish did manage to find a flaw in the system. Sometimes, a letter would be encrypted as itself. 22 Analysts called this phenomenon, which occurred one in twenty five times, a “female.”

19 Randall, Bletchley 38 20 Alan Stripp, How the Enigma Works ( PBS Nova ) 21 Stripp, How the Enigma Works 22 Hodges, E nigma 219

6 “The very fact that the Enigma was a machine, made mechanical a possibility.” 23 The Polish invented the , a machine that would go through codes written on perforated sheets and find these females..

In December of 1938, disaster struck when Germany added two more rotors to the Enigma.

It only used three rotors at a time, but every day the combination of those three could be changed.

Females were now much too rare to be considered efficient, and Poland didn’t have the resources to design a new Bombe. Operations moved to Britain in 1939. 24

The British government chose Bletchley Park, a small neighborhood in Birmingham, as the codebreaking facility. Now all they had to do was hire some codebreakers.

Many people were brought in to solve the problem, organized into different “huts.” , which focused on the naval codes, contained some of the most important cryptanalysts in the facility. One of these people was Gordon Welchman. Another was Alan Turing.

Turing saw the merits of the Polish Bombe, and thought that he might be able to improve it.

He realized that an advanced Turing Machine might do the trick. Combining the best pieces of the

Polish bombe and the Turing Machine, Turing created the British Bombe. 25

This Bombe took advantage of the fact that a letter was never paired with itself. Two plugs couldn’t be plugged into the same socket. Turing’s Bombe would go through possibilities and discard any where a letter was paired with itself. 26 This process would work much better than the

Polish , but would still be slow.

Turing brought his ideas to Welchman, who then invented the “diagonal board.” This machine used electricity to figure out what happened to a letter as it went through the plugboard. 27

23 Hodges, E nigma 220 24 Hodges, E nigma 205 25 Hodges, E nigma 228 26 Alan Turing C rash Course 27 Hodges, E nigma 230

7 With the diagonal board attached to the Bombe, the possibilities for each day were reduced dramatically. However, that was all the machine could do: narrow down the possibilities. The rest had to be done by humans. That was where Joan Clarke came in.

Welchman sent Clarke a letter late in 1939. This letter “offered her ‘interesting’ work with the government ... in a field to which mathematicians were particularly adept.” 28 Clarke arrived at

Bletchley in 1940.

Using rotors recovered from various German submarines, Clarke helped figure out how the rotors spun. She then found out how to tell what position a rotor would likely be in based on the positions of the other rotors. 29

Another of Clarke’s jobs was to watch a “special-purpose machine named Baby ... the function of which was to continually encipher the four-letter German word EINS ... and look for that pattern at all positions for the machine with the day’s wheel-order and plugging.” 30 Both

Clarke and Turing were paid for their work, but Clarke was paid much less because of sexist laws. 31

Clarke and Turing were great friends, and Turing knew he should probably get married despite being gay. In 1940 he asked Clarke to marry him. After a one week vacation together,

Turing realized that this wasn’t what he wanted. “Being an honorable man, [Turing] could not, and would not, deceive Joan any further.” 32 They remained friends, but were no longer engaged.

Work at Hut 8 continued into 1942. In February, the German Navy changed the Enigma so that it used four rotors at once. 33 The Bombe suddenly became inefficient once again, unable to figure out the days’ settings in time.

28 Randall, Bletchley 41 29 Randall, Bletchley 56 30 Randall, Bletchley 56 31 Hodges, E nigma 245 32 Randall, Bletchley 107 33 Randall, Bletchley 72

8 Luckily, the British Navy managed to bring down U-559, a German submarine with important information on the Enigma. Clarke began working with this new information in

November, discovering that the fourth rotor’s position didn’t change with the rest. It remained the same, meaning that the possibilities had not increased nearly as much as originally thought. 34

Turing went on a trip to America to “resolve some of the tensions between the British and

American intelligence services.” 35 The U.S. helped produce more Bombes, returning their efficiency to normal. Turing returned to Bletchley in 1943.

Slowly but surely, pieces of the code were broken apart. The Bombe and the Baby decrypted messages as they came in, notifying the British of important German plans. Britain continued to fight the war in Europe, coming closer to victory every day. Hitler killed himself on

April 30th, 1945, and Germany offered their unconditional surrender on May 7th.3 6 The war officially ended on September 2nd with the surrender of Japan. 37 The hard work of the people at

Bletchley, along with everyone involved in the war, had paid off.

That didn’t mean there wasn’t more to come.

After the War

After the war, Alan Turing continued to make breakthroughs in his career. Alongside other distinguished mathematicians, he began work on “building a brain.” 38 He wanted to devise a machine that could think just like a human, and made several discoveries that eventually led to the artificial intelligence of today. 39

34 Randall, Bletchley 77 35 Randall, Bletchley 77 36 Christopher Klein, How Did World War II End? (History.com) 37 Klein World War II 38 Hodges, E nigma 395 39 Alan Mathison Turing, Computing Machinery and Intelligence (Mind), 1

9 Joan Clarke married Jock Murray and moved to Middlesex in 1952. 40 She continued working with the government into the Cold War, helping to break Soviet Codes. She would go on to live a long life, dying in 1996. 41 However, she would remain largely unrecognized for her work, mostly being known as the woman who was engaged to Turing.

In 1950, Turing met Arnold Murray. 42 They began seeing each other more and more often as the years went on, and things began getting more intimate.

In 1952, someone broke into Turing’s house. 43 Nothing very important was stolen, but

Turing still reported the crime to the police. The police identified Murray’s fingerprints and discovered Turing’s “crime.” Turing admitted to what he’d done and was convicted of “Gross

Indecency contrary to Section 11 of the Criminal Law Amendment Act 1885.” 44

Murray and Turing were both tried and convicted. They were given the choice between taking drugs to “cure” their homosexuality and imprisonment. Turing chose the drugs. 45

The months went by, and the drugs made everything worse. Turing began having wild emotional swings and suicidal thoughts.

In 1954, Turing poisoned an apple and ate it.

Postscript

It’s not entirely clear that Turing killed himself. Someone else could have dipped the apple in the cyanide, then forced him to eat it. Still, the evidence points to suicide. Both the apple and the cyanide were found in Turing’s house, along with his body.

40 Randall, Bletchley 113 41 Randall, Bletchley 156 42 Hodges, E nigma 566 43 Hodges, E nigma 572 44 Hodges, E nigma 576 45 Hodges, E nigma 581

10 Clarke and Turing both made major breakthroughs in communication, solving the Enigma code and helping Britain to win the second world war. However, prejudice fought them at every corner. Clarke was both underpaid and never fully credited for her work. Turing ended up dying because he was homosexual.

Still, their accomplishments were amazing. Their breakthroughs in how the Nazis communicated helped Britain to win the war in Europe. That eventually led to the end of World

War II.

Prejudice didn’t stop Turing, Clarke, or anyone else at Bletchley from solving the Enigma.

11 Annotated Bibliography

Primary Sources

Burnie, Robert William. The Criminal Law Amendment Act 1885 . The British Library,

www.bl.uk/collection-items/the-criminal-law-amendment-act-1885. Accessed 18 Feb.

2021.

The Criminal Law Amendment Act of 1885 was the law that ended up getting Turing killed. Most

of it was unrelated to homosexuality, but section 11 condemned people like Alan Turing

and Oscar Wilde for "gross indecency."

Turing, Alan Mathison. "Computing Machinery and Intelligence." Mind ,

www.csee.umbc.edu/courses/471/papers/turing.pdf. Accessed 18 Feb. 2021.

This paper, written by Alan Turing, is about "," which is now called the Turing

Test. The Turing Test describes a sort of game in which a human holds a conversation with

both a machine and a human and tries to figure out which is which. This paper, which was

a milestone in engineering history, also described important qualities a machine would need

to have in order to be able to "think."

Turing, Alan Mathison. "On Computable Numbers, with an Application to the

Entscheidungsproblem." Proceedings of the London Mathematical Society , pp. 230-65,

www.cs.virginia.edu/~robins/Turing_Paper_1936.pdf. Accessed 14 Dec. 2020.

This article was written by Alan Turing himself, making it one of the most reliable sources that I

used. It is the paper Turing wrote to explain how the Turing Machine worked to the public,

and also explains a lot about the Entscheidungsproblem .

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Secondary Sources

"Alan Turing- Celebrating the Life of a Genius." Youtube , uploaded by Cambridge University, 21

June 2012, www.youtube.com/watch?v=gtRLmL70TH0&t=9s. Accessed 10 Dec. 2020.

This video, created by Cambridge University, discusses the life of Alan Turing. It talks about how

he invented the Turing Machine, helped solve the Enigma, and took his own life using a

poisoned apple. This is a very reliable source and one that helped me a lot on the history

side of things.

"Alan Turing: Crash Course Computer Science #15." YouTube , uploaded by Crash Course, 27

June 2017, www.youtube.com/watch?v=7TycxwFmdB0. Accessed 6 Nov. 2020.

This video, uploaded by Crash Course, gives a quick overview of Turing's life and scientific

achievements. It goes into great detail about how his inventions worked and provides a lot

of information on the engineering side of things. Crash Course is a YouTube channel that

uploads reliable videos on many different topics from history to computer science.

Hodges, Andrew. Alan Turing: The Enigma . Princeton University Press, 1983.

This book, written by mathematician Andrew Hodges, talks in great detail about Turing's life and

accomplishments. It explains how machines like the Enigma and Turing Machine worked,

and provides a lot of detail on Turing’s life in general. It includes information from a lot of

other reliable sources, including an account written by Turing’s mother.

13

Klein, Christopher. "How Did World War II End?" History.com,

www.history.com/news/world-war-ii-end-events. Accessed 8 Jan. 2021.

This website provided quick information on the ending of World War II. It taught me about a few

different battles fought to help end the war.

Randall, Anthony J. Joan Clarke- the Biography of a Bletchley Park Enigma . Cloister House

Press, 2019.

This book inspects the life of Joan Clarke, talking about her childhood and accomplishments,

including her time at Bletchley Park. It also provides a bit of information on Turing and the

codebreakers in general. This book was the main source that I used to learn about Joan

Clarke.

Stripp, Alan. "How the Enigma Works." Nova , 8 Nov. 1999,

www.pbs.org/wgbh/nova/article/how-enigma-works/.

This article, published by PBS Nova, explains how the Enigma machines worked and provides

information on their different functions. It didn't help me much with the history, but it did

help me learn about the math and science of what went on at Bletchley. This particular

article was written by Alan Stripp, a man who worked on Japanese ciphers in the United

States.

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