The History and Mathematics of Codes and Code Breaking

Page 2 of 47

Exam Corrections

Given how the math exam went down, I've decided to give you the opportunity to earn a few points back by doing corrections.  For each problem where you missed points, you can write up a complete (and hopefully correct) solution to the problem (with explanation, in the cases where there's no work to show) to earn up to 1/3 of your points back.  So, for instance, if you made a 70, you can pull that up to an 80.

These are due at the beginning of class on Wednesday, December 2nd.  Please turn in your original exam along with your corrections on separate paper.  Very important: You are not allowed to work with each other (or anyone else outside our class) on these corrections.  If you need help, come talk to me.  Collaborating with others will be considered a violation of the Honor Code.  Very few of you took advantage of my office hours earlier in the semester, so let's see if some one-on-one assistance will help clarify some of the mathematics we've covered in this course.

Paper #3 - Practical Crypto

In this paper, you will identify and describe one way that cryptography is (or could be) relevant to the digital life of a college student in 2015. You might address one of the ways that cryptography is embedded in the computer systems we already use (e.g. how credit card information is encrypted by websites) or explain how to better protect one’s online privacy by adopting new practices (e.g. sending and receiving encrypted emails).

Your paper will have an expository component, in which you explain cryptographic and/or mathematical processes in ways a fellow student can understand, and an argumentative component, in which you make the case for why a fellow student should care about the topic you’ve chosen. The best papers will be posted to the course blog and shared with the Vanderbilt student community.

Your paper will be graded on the strength and clarity of your arguments as well as the effectiveness of your technical explanations. See the Paper #3 rubric for details. Some of the better papers from the 2014 offering of this class are available on the course blog. (Note that the word count was much higher for the 2014 version of this assignment.)

For topic ideas, see this summary of a 2014 class discussion. See also our Diigo group. For help on identifying reputable and scholarly sources, see this 2014 blog post about sources.


Your paper should be between 1,500 and 2,000 words in length, and it should use American Psychological Association (APA) formatting for citations and references. Citations appear within the text of your paper, references at the end. Both should be properly formatted. See Purdue University’s Online Writing Lab, for a useful guide to APA formatting.


A topic and outline is due at the start of class on Friday, November 20th. We’ll workshop your papers in class that day.

Your final paper is due at the start of class on Friday, December 4th, submitted through Blackboard. I’m not planning a revision cycle for this paper, so make sure this version is solid.


Please familiarize yourself with Vanderbilt’s Honor System. I’m encouraging a lot of sharing and collaboration in this course, but your work on your paper assignments should be your own. Please be careful not to plagiarize. The Writing Studio has a great set of resources on working with sources in academic writing. We’ll spend some class time exploring plagiarism and academic integrity more generally.

If your life is falling apart and you are tempted to plagiarize to save time or get a good grade, please see me instead. I would rather grant you an extension than send you before the Honor Council.


Bookmark Assignment #4

Interesting PinFor your next bookmarking assignment, you should bookmark a resource of potential use to the "practical crypto" paper assignment. You might bookmark something that discusses how cryptography is embedded in the computer systems we already use (e.g. how credit card information is encrypted by websites) or one that explains how to better protect one's online privacy (e.g. controlling how GPS data is shared on social media).  Leave a comment indicating why you thought the resource you bookmarked is important or interesting.

Your bookmark is due by 9:00 a.m. on Monday, November 16. Be sure to give your bookmark at least two useful tags.

What Do I Have to Hide?

By focusing on what to keep private rather than what to publicize, teens often inadvertently play into another common rhetorical crutch - the notion that privacy is only necessary for those who have something to hide (boyd, 63).

When social media first began to crop up in my household, my parents weren't sure how to react. With crude interfaces such as Myspace, my parents banned their use completely (thought this was a much more relevant issue to my older sister than it was for me). However with the upswing of social media sights such as Facebook and LinkedIn, sights my parents could use and were therefore inherently more comfortable with, our family had to have our first conversations about internet safety.

As a kid my parents were very aware of not only everything I posted but also everything my friends were posting. I distinctly remember one post my friend made about being home alone that had my mother rushing to phone her parents. While I was little, this level of online privacy made sense to me. My parents were obviously worried about my safety, and I was not yet rebellious enough to want to defy them just for the sake of being defiant. As I aged, however, my opinions began to deviate from my parents.

There came a point in my online life when I began to believe that my security didn't matter too much: nothing I did was really all that interesting anyways, if someone wanted to read the FanFiction in my internet history they could be my guest. As Facebook privacy updated, I didn't keep up with my account privacy settings, and my wall became increasingly public. I definitely adhered to the ideology that boyd was describing. For the most part, my views have changed again, but to an extent, I still do agree with it.

As I have become more aware of the information that is being sent out online, or rather the information behind the information (such as location services we don't even realize we are posting), I have become increasingly more cautious about what I post and how I post it. Even if I have nothing illegal or secretive to hide, I would still like to keep the location of my house private to the internet. However, instead of changing my online visibility, I simply edited what I post in the first place. I still don't have very strong Facebook security settings, but I make sure that the posts themselves are not revealing any threatening information. The only things I have to hide are those things which affect my safety.

Protection, or Paranoia?

"Some teens see privacy as a right, but many more see privacy as a matter of trust. Thus, when their parents choose to snoop or lurk or read their online posts, these teens see it as a signal of distrust." In this quote from her book It's Complicated, danah boyd points out the potential effects of strict parental control of computers. She discusses specific examples of teenagers who have a variety of opinions on this parenting policy.

In my experience, strict parental restrictions on computers and media are often ineffective parenting methods. While my parents were entirely trusting and never even checked my grades, let alone my computer history, my best friend's were not. Neither of us was ever doing anything we needed to hide, but it was clear to me the effect of our parents' different styles. For example, I was perfectly willing to give my parents my passwords, and we had talked about how I should be willing, but they had never asked for them--my friend's passwords were taped to the refrigerator. As we grew up, going through high school, I began to recognize the great disparity between our experiences. My parents trusted me to be responsible on my laptop, to come to them with problems or questions, and to monitor my own media. When I got a Twitter, for example, I let them know. My friend's parents, however, generally trusted her as long as they could verify that their trust was well-placed. Their restrictions diminished as we got older, but they were still present--and still a topic of conversation for us.

While my friend's parents meant well, they restricted their daughter's freedom to explore. She never really rebelled, but we would have lengthy conversations about what tv shows she would watch when we went to college, and why we thought the rules were unfair. The idea of privacy was a well-covered topic in our discussions. Looking back, her parents' rules caused my friend to wish she could hide at least something, while my parents' made me to feel free to come to them with anything. From my perspective, my friend never developed the kind of trust I have in my parents, because hers never gave her the chance. boyd's statement on this topic fits this observation. My friend never saw privacy as a right, but more as a signal of trust that she never received.

I've Heard it Both Ways

It’s easy to think of privacy and publicity as opposing concepts, and a lot of technology is built on the assumption that you have to choose to be private or public. Yet in practice, both privacy and publicity are blurred.     (danah 76)

As with many of the issues surrounding cryptography, privacy versus publicity is often viewed as a false dichotomy. Both privacy and publicity are relative terms, though. Without a public realm of information with which to compare it, privacy would not exist. The problem with sharing information publicly, though, arises when we must decide what information we wish to keep private. As discussed in this chapter, the fact that teens wish to keep information private does not indicate that they have something to hide; rather, it is an example of them choosing which parts of their lives to keep to themselves.

In a way, making aspects of our lives public can actually increase our privacy relatively. It is possible for teens to hide behind a screen and only post what they want other people to see, not the whole truth. By choosing which aspects of our lives to keep private, we are realizing that just about everything else can be accessed by the general public. It is a trade-off that many choose to make, but in reality is just a consequence of trying to find a balance between privacy and publicity. In an era where private information is becoming increasingly public, we must work to find a happy medium where we can easily communicate with others while still respecting individual decisions on which parts of life they wish to keep private.

Taking a structuralist tactic, legal scholar Alan Westin argues that privacy is “the claim of individuals, groups, or institutions to determine for themselves when, how, and to what extent information about them is communicated to others," (boyd, 59).

With all of the definitions and specifics of privacy that dana boyd gives in Chapter Two of her book It's Complicated, I think Alan Westin's is the most sound. Many argue that privacy is the right to be left alone or the right for someone to keep personal information to themselves, but I think a better definition is that privacy is the ability to control how and how much personal information is made public, which is exactly how Alan Westin defines it. This definition is the best one because when teens post personal information on social media websites, they are not depriving themselves of privacy as some parents think; they are still in control of when, how, and to what extent their personal information is posted on these sites.

The reason many teens dislike when their parents look at their texts without permission or go onto their Facebook accounts is because they have no control over what their parents might see, which is a complete invasion of privacy by the parents. On the other hand, teens should not be bothered by their parents viewing their social media pages from their own social media accounts. Teens should assume that whatever pictures get put on the Internet are there permanently and almost anyone can access them. Teens have the ability to control what they put on public social media sites, so they cannot be annoyed by their parents viewing and commenting on their Facebook picture if they choose to be friends with their parents on Facebook. Teens are in control of what information they post on public social media sites, so they have no one to blame but themselves if they are bothered by how much information their parents can see on their Facebook, Twitter, or Instagram page.

I always feel like somebody's watching me

"Like many of his peers, Christopher believes that there is a significant difference between having the ability to violate privacy and making the choice to do so." (Its Complicated, 74)

I love my mom. She is a great mother; however, her views on privacy line up pretty closely to that of the "intensive" parenting style described in the chapter which caused some tension growing up. Before my junior year of high school, it was not unordinary for her to read through my texts, track my location, or even search through my social media outlets, and this was not because of anything that I had done to warrant this, it was just her philosophy of what a loving parent should do.

I believe that, as a parent, it is important to have knowledge of your child's whereabouts when his safety is not ensured and general knowledge of what is going on his life. Because of this, parents should have access to this information of their child (e.g. location services and "friends" on social media); however, as the quote points out, there is a big difference between access to violating privacy and actually doing so. I think that parents too frequently make trust and privacy complementary properties, where the increase of one causes a decrease of the other, which I think misses the mark of what trust means completely.

There are plenty of ties that can be made to the security vs. privacy argument, but one obvious difference is the scale of operation. On the national scale, the government is far outnumbered by the people, while in the family, the child is typically outnumbered by other family members. A smaller scale makes bad behavior much more difficult to sneak by the involved parent. This makes invasions of privacy cause, usually, just negative feelings and no protection of the child. This being said there are plenty of examples in which this is not the case, including an ignorant child who does not know how to properly act online or a child who actually has had made poor decisions in the past.


What is Privacy?

"the failure to reach consensus on a definition of privacy may be frustrating to some, legal scholar Daniel Solove argues that each approach to privacy reveals insight into how we manage privacy in everyday life" (boyd, 59).

The above quote highlights an issue that we have peripherally mentioned since the beginning of this course. We have focused on privacy versus surveillance, or privacy versus security. We have alternated using surveillance and security because it is hard to pinpoint exactly which of them to which we are referring. However, although a slight majority of the class is on the side of privacy, we have not debated the use of the word privacy. We also haven't reached a clear consensus on privacy as a class, which is interesting to me. How can we be so sure privacy is the word we want to use if we don't have an actual definition of the word in the context we wish to use it.

boyd lists three different definitions of privacy, and although they are all similar in some ways, they are all definitely different definitions. I am also interested that the three definitions she list are all presented by people in law. I do not wholeheartedly agree with any of the definitions, and I'm sure that there each member of our class has their own personal definition of privacy. Technology experts would have different definitions, and I suspect that each privacy-oriented career would have individuals with their own definitions.

How can we continue to debate privacy versus surveillance or security when we do not have one clear definition of privacy for this debate? I do not believe that this debate will ever be settled, but I also think that it will be even harder to be settled without clear definitions for both sides of the issue. The definition of privacy was not something that I had previously considered before reading this work by boyd, but now I am extremely interested in its definition.

Privacy = Trust

Some teens see privacy as a right, but many more see privacy as a matter of trust. Thus, when parents choose to snoop or lurk or read their online posts, these teens see it as a signal of distrust.
-danah boyd
(It's Complicated, page 73)

I can remember in 8th grade when my friends' parents starting joining Facebook, not because they wanted to snoop on us, but because they saw Facebook as an opportunity to reconnect with old high school and college friends. However, some people did see this invasion into the "teen world" as their parents mistrust of them. Until recently, my parents have not had any desire to join social media (now my dad has a Twitter that he uses as a newsfeed for short, quick headlines). But more so than social media, my parents' surveillance of me in other ways has given me the same sense of distrust that the teens interviewed in It's Complicated expressed.

Until I turned 18, my dad received a text message every time I used my debit card, including where and how much. They also have the ability to (and they do) use the location services on my phone to see where I am. In short, if I wanted to go somewhere and do something without my parents' knowledge, it wouldn't be easy. Sometimes, it would seem that they don't trust me to tell them where I actually am and what I'm actually doing, but I'm sure their intentions are to ensure my safety in case anything were to happen.

In high school, I gave up some privacy to appease my parents and follow their rules. But now that I'm at college, our understanding is that unless I go off campus anywhere further than walking distance, I must let them know where I'm going. In other words, they trust me and give me the privacy to go and do what I please around and just off campus, and I expect that they won't betray that privacy by checking my exact location all the time. I think that in all aspects of life, the balance of privacy and trust versus safety and protection is an integral piece of the relationship between a teen and his/her parents. Even if we have nothing to hide, we associate having some privacy with the extent to which our parents trust us.

Page 2 of 47

Powered by WordPress & Theme by Anders Norén