Cryptography

The History and Mathematics of Codes and Code Breaking

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Cryptohipster Beliefs

Whitfield Diffie is, in essence, a cryptohipster. Or, one might call him a cryptotarian (crypto libertarian). He graduated from MIT, and studied cryptography just for the thrill of it. In the early 70's, Diffie had the foresight to realize that one day, people would have their own computers. He believed that "if people then used their computers to exchange emails, they deserved the right to encrypt their messages in order to guarantee their privacy."

I do agree that private citizens have a right to have access to secure encryption technologies. Encryption technologies would be used to protect communication - the same communication that might take place face-to-face. Since in-person private conversation has never been a right that's been questioned, why should we give up our communication rights if it's simply a different medium of communication? Living in America, we have a right to privacy. This right shouldn't be infringed upon due to the development of the internet. If someone is able to develop their own encryption system, they should be able to use it at their will. There's a lot of work that goes into developing/utilizing such a system, including the logistical problems that come with key distribution. If people want to go through the trouble of exchanging keys, they should be able to communicate in private.

More Than Capable of Completing Men's Work

My copy of the book did not have any reading questions so I will do my best to interpret the first blog post question and answer it to the fullest extent. The roles that gender played in the codebreakers life and work World War II were significant. Women were subject to doubt, cut wages, and a lack of job security. After all, the main reason why women were searched for and employed by the government was because so many men from the top colleges had already enlisted in the Army. Among the population of women in the United States, very few were even qualified for the codebreaking positions. 

Many girls were often told not to attend college because of the small job market for educated women and there was a stigma that higher education did not guarantee a more fulfilling life. The girls who were recruited primarily studied science and mathematics, two subjects that women were often coerced to avoid because they were considered men’s work. Women cryptographers were also paid half the wages of their male counterparts to complete the same tasks. Despite the lower wages, these women still decided to serve their country the best way they knew how. Also, this job for the government was in no way a permanent position upon the conclusion of World War II. Once the men came back from Europe, there would be less demand for women these positions. However in other industries there was a demand for women workers which led the economy to boom.

Mean Girls (WWII Edition)

Arlington Hall, the epicenter of the American code breaking effort, was s densely populated pseudo-tenement housing for some of the brightest and most flexible minds the country had to offer. Of course, with such a high population of men and women living together in close quarters, gender played a significant role in both the code breaking efforts and daily lives of the residents of Arlington Hall.

The most prominent aspect of the gender dynamic in Arlington Hall was complaining. Most notably was the case of William Seaman, who consistently complained of being the target of a clique-y group of female coders who bullied and harassed him. Many other men in the facility voiced a similar complaint, especially of the college-educated women, a group of people who seemed to point their nose up and look down on a good portion of the civilians and other employees that populated the hall.

Further, gender also played a significant role in the jobs that men and women carried out on campus. Women were placed into every level of codebreaking on account of their skill in reading and interpreting languages and having a general understanding of mathematics. However, in addition to this, women also filled in many of the mundane and rudimentary jobs, such as sanitation or security. On the other hand, the men staffed at Arlington Hall all were involved in many of the higher level positions, as any who were of the physical capacity to go to war were sent away as such. This left behind many men who, despite lacking in the masculinity department, could contribute more than their fair share to the code breaking efforts. However, despite these differences, it would take the harmonious cooperation of men and women to thwart the Axis' cryptographic efforts and ultimately win the Second World War.

Women in Cryptanalysis - a Unique Circumstance

For many years, cryptanalysis was an occupation with neither fame nor prestige. It was largely unrecognized in the United States, despite being crucial in many parts of history. However, this lack of renown - the field had barely been established at all, much less established as a "mens field" - created a unique situation that allowed women to enter the field of cryptography easier than other professions.

As the war progressed, it became much less shocking and uncommon that a woman was doing what typically would've been seen as mens work. For example, one woman, on secret 8-day trip to Washington to obtain government material, wrote "at times I have to laugh. It is all so foreign to my training, to my family's old fashioned notions about what and where a woman's place is, etc... yet none of those things seem to shock the family now. I suppose it is the War." Whether it was from changing ideas about gender in the mid 1900's, or simply out of necessity (men couldn't possibly fill all the wartime jobs), attitudes about women definitely did shift during the War.

Despite progress, notions about gender still had a large effect on a women's life. For example, early in the war, Elizabeth Friedman wanted to work with the Navy (rather than a cryptanalysis firm) to have a greater impact on her country and the war. However, her male boss censored her mail and communications, keeping her from getting in touch with the Navy. And, later on, when Elizabeth and her husband (also a cryptanalyst) were both working for the Army, Elizabeth was paid exactly half the salary of her husband, even though they worked the same job. We still see this inequality persist today.

Additionally, Friedman was faced with sexist condescension as her reputation grew. Many suspected that her husband was secretly doing her work, or accredited her successes to her husband's status. Though, there were others on the opposite side - many newspapers liked to create the story that Elizabeth had trained her husband. This time period consisted of many conflicting ideas about gender and identity.

Ted Cr- I Mean, The Zodiac Killer

The podcast on the Zodiac Killer was well made and well produced.  From a technical standpoint, the intonation, projection, and fluency of the speaker made it very enjoyable to listen to the podcast. Often times, even when simply reading from a script, people can falter, trip over words and phrases, and stutter, all of which detract from the listening experience of the podcast. In addition, these kinds of mistakes also decrease the ethos of the speaker, making them seem unprepared or nervous. These issues, however, were not present in the Zodiac Killer podcast. as the speaker delivered her message with clear intonation and projection and few, if any, stutters or mistakes. In addition her speaking style, the incorporation of background music made the podcast that much more enjoyable, as rather than it simply being one person droning on about a subject matter, the background music helps to supplant the voice of the speaker. Altogether, I hope to incorporate these two aspects of this particular podcast into my own, as they seemed to help enhance the efficacy of the podcast and overall make it more engaging.

Beyond merely technical details, the content of this podcast also piqued my interest. Having seen many documentaries and movies about serial killers - even the ones about the titular killer - it was interesting to learn even more about one of the most notorious killers in American history. It was even more fascinating to learn about the killer's extensive use of cryptography in hiding his killings and communicating with the police and those who would have liked to have stopped him. Altogether, the communication of relevant information in an easy-to-listen-to manner made this podcast interesting and enjoyable, as well as giving me ideas on how to create my own.

Podcast Critiques

To start, I'm writing this blog post now for the second time. For the second week in a row. To my fellow FYWS Cryptographers, write this in Word, Google Docs, or somewhere that's not here. Because this website likes to play cruel tricks and delete your post right when you click publish.

Anyway, I listened to The VIC Cipher, One-Time Pod Episode 14. Overall, I enjoyed the podcast, but there were definitely aspects that could've been improved. Here's a "pros and cons" list that I created while listening.

Pros:

  • Introduction with a narrative style. The opening piece was engaging, and the story-telling style made it easy and fun to listen to.
  • The music seemed mysterious, helping to set the mood from the beginning.
  • The pacing was very appropriate - the podcast moved quickly, but not too quick that the listener couldn't follow along.

Cons

  • After the 3 minutes of story-telling in the beginning of the podcast, it became a lot more informational and dry. It was definitely harder to listen to for the last 10 minutes.
  • Sound effects sometimes seemed out of place and louder than the voice of the narrator.
  • At one point, the podcast took ~30 seconds to allow the listener to get out a pen and pencil. I think it could've been more effective to say something along the lines of  "at this point, feel free to pause the podcast and take out a pen and pencil" rather than stopping the whole podcast.
  • Definitely could've used some more humor/personality. The middle section was especially dry.

In my podcast, I would love to use the narrative, story-telling style that is used in the opening of this podcast. Additionally, I want to find music and sound effects that help set the mood and engage the listener, drawing them into the story that the podcast is creating. I definitely want to avoid losing the listener, which I hope to do by using a more excited tone, sometimes incorporating humor and more informal aspects.

 

Ethics vs. Strategy

The Zimmerman Telegram was a telegram from Germany to Mexico containing crucial war information about The Great War. It included the Germans' plans for unrestricted submarine warfare, as well as a proposal asking Mexico to ally with the Germans and invade the US. The Germans had hoped to attack the US on three fronts: Mexico from the South, Japan from the West, and Germany from the East.

However, this telegram was intercepted and decrypted by the British, led by Admiral Sir William Hall. Upon reading the telegram, rather than warning the Americans about the U-Boat warfare that was about to ensue, he decided to keep the telegram a secret. He did this because he knew that if America publicly condemned Germany's acts of aggression, the Germans would know that their encryption system had been compromised, and strengthen it. Admiral Hall was thinking long-term; he knew that the Germans could not win the war.

While Admiral Hall's decision may not have been completely ethical, I do believe it was the right decision to make. Yes, American lives were compromised due to the unrestricted submarine warfare, but if the Germans had changed their encryption the Allies may not have won the war. In wartime, it's imperative that the most strategic decisions are made. In eventually using the stolen telegram from Mexico to convince America to enter the war, I believe Hall found a happy medium between handing over the telegram and keeping it a secret. Many times, secrets are necessary if kept for the greater good.

Nothing to Hide

Chapter one of Simon Singh’s The Code Book begins with two stories. The first one is about Mary Queen of Scots and the second one is about Demaratus, an exiled Greek who nevertheless worked to communicate secretly with his homeland. While both of their stories were told to establish a theme of secret writing, the two stories have very little else in common. 

Demaratus’s story is one of a brave and cunning man who, upon learning of a Persian plot against his homeland, found a way to conceal the existence of his message so it could reach its destination safely. His heroics allowed the Greeks to prepare a fleet to meet the advance of Xerxes’s fleet and defend themselves from an attack that would otherwise have caught them completely off guard. Demaratus’s successful use of steganography, the act of concealing the existence of a message, allowed him to save Greece from a major military defeat. 

The story of Mary Queen of Scots did not end as pleasantly for Mary as Demaratus’s did for the Greeks. Mary had concealed her message using cryptography rendering it unreadable to those who did not have the cipher, rather than by hiding its existence in the first place. The fate of her life hung, not on whether or not her message would be discovered, for it already had been, but rather on whether it could be deciphered. Her encrypted message was, unfortunately for her, in the hands of a man named Thomas Phelippes, one of the finest cryptanalysts of his day. He eventually succeeded in decrypting the message and laid bare a plot by Mary to assassinate Queen Elizabeth and take the English throne. She was relieved of her head shortly thereafter. 

There are several differences between these two stories. Obviously, one story sees the message successfully and discreetly transported to its intended audience, while the other one has the message discovered and decrypted. In addition, the British one is likely more factual, as it is based on historical data and physical records, rather than the legends and folklore that likely drive much of Heroditus’s account of Demaratus. Finally, the type of secret writing involved varies between the two. In the Ancient Greek story, Demaratus used steganography to conceal the existence of his message whereas Queen Mary of Scots relied on cryptography to keep the contents of her message a secret even once the message had been discovered.

The Theatricality of Cryptography

The first chapter of Singh's The Code Book is packed with historical examples of cryptography. The Greeks, Persians, Arabs, French, and English, to name a few, were just some of the infinite number of societies and civilizations of which cryptography was crucial to their development. However, most of the examples described did involve people in positions of power. Kings, queens, nobles, and military leaders of all types have had to use cryptography to defend or expand their nations; clearly, cryptography has been crucial to changing history.

Despite the importance of these examples, I do believe that there has been a need for cryptography since the dawn of written language. I can't imagine that cryptography was only used by well-resourced people; there has always been a need for encryption and secrecy, even if it's on the most rudimentary level. Perhaps these are the only examples that survived, or perhaps Singh chose to include them because of their dramatic nature - after all, he does need to entice the reader somehow. It would be foolish to say that cryptography requires exceptional resources.

Yes, the most theatrical and interesting stories usually include a plot, some characters, and a dramatic, dire consequence that will result if the code is decrypted. But we can't discount the more simple, day-to-day interactions that may have required people to encrypt their messages, like a potter who may have needed to protect his or her recipe for glaze, or a citizen who wanted to hide the contents of a letter from their government. I can't imagine that examples such as these, though less exciting, didn't exist before the stories of kings, queens, armies, and wars.

Breaking Codes Is Much More Difficult In Practice

In Chapter 3, Singh provides an example of breaking codes with keywords and makes everything seems quite easy. However, in practice, breaking such a code is definitely difficult and needs a lot of time and work.

Say you have a message which is enciphered by using a keyword as long as the plaintext. The first thing is that you can't use the Kasiski examination technique. The only way to start is to try some common words to find a clue about the keywords. In Singh's example, he assumes that the first word is "the". That is a reasonable strategy because "the" is one of the most frequent words in English. However, what if the first word is not "the" but one of the other common words? There is a problem that if the common word in the plaintext is a word with only one or two letters like "a" and "in", Singh's method described in the book will be useless that he couldn't find any corresponding key letters because there are too many possible combinations of two letters to check one by one. Also, Singh's deduction of the construction of the keyword is actually a special situation. Consider if you guess "CAN" and "YPT" in the keyword, it's actually hard to correspond them to "Canada" and "Egypt" and it must take a long time to try all the possible combinations. Finally, the work to find out the last four letters in the keyword is also a hard work which needs a lot of time even with the clue that it is a country name, let alone that in a usual time we don't have an explicit clue like the country name. Singh just assumes he is the most fortunate one that his every shot is perfect when breaking this code.

Besides all of these above, there is another thing we should know that probably we would face the problem of false positives in our breaking procedure. There are thousands of combinations with several certain letters and short words, how could we make sure that we get the right one? Each time we go on with an assumption means that we will spend a lot of time on this assumption and if we failed, everything needs to run again to check the next one.

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