Cryptography

The History and Mathematics of Codes and Code Breaking

Author: patelhg1

Protection of Privacy

Citizen Four opened my eyes to the many different ways the government invades privacy in order to protect its citizens. The government uses many devices to spy on its citizens, including location tracking and following people online with tracking cookies. This invasion of privacy can easily be avoided by any citizen. This is the topic of my paper. Now that I have watched citizen four, I plan on taking a slightly different approach to my paper. One can avoid tracking cookies to prevent themselves from being tracked by businesses and even the government itself.

Businesses today can use search history information in order to price discriminate online. Many companies, most famously airlines, but also amazon and other online shopping companies can use your history in order to charge you a higher price. This is the original take on my paper. However, after watching citizen four, I realized that the government can use the exact same type of procedure to spy on you directly. For example, if you commonly search the word “bomb,” you are very likely to be targeted by the government as a potential terrorist simply because of your search history. Simple tracking cookies can result in big accusations from the government.

Simply put, Edward Snowden revealed a lot about the way the government tracks its citizens. This tracking can also be easily avoided by simply deleting one’s cookies. In this form and fashion high school students can both avoid price discrimination and having their privacy invaded by the government of the United States.

9/11 Changed Everything

At the time Singh wrote the novel, there was no blatant reason for the government to use surveillance for the interest of national security. Then September 11, 2001 happened. This day completely changed the interests of both the American citizens and the government. After this terrorist attack, people were willing to give up their privacy in order to achieve more security. I am not saying that the government should have complete control over all communications all the time. What I am saying is that the government should have substantial surveillance over communications in order to prevent other significant threats to the citizens of the United States.

In times of fear, people are willing to give up some of their privacy in order to feel safer. The thing is, cryptography should not disappear. Cryptography will only keep improving, and there is little to nothing that the government can do to slow it down. What the government, mainly the NSA, can do is keep its cryptanalysis above and better than the cryptography present at the time. Then the government can use its cryptanalysis in order to analyze and read encrypted messages. The government used wiretapping in the 1920s, but its new weapon is code breaking. Of course, citizens will always want their information to be private, but with the new information age, the government can use data mining and break through encryptions in order to evaluate certain suspects without any normal computer user ever noticing. The government can give people the illusion of privacy while also providing them with the reality of security.

It’s not so much whether the government can have wide latitude but what it can do with its wide latitude. For all we as normal citizens of the nation know, the government can read any and all of our messages. The government has the technology to break into almost any kind of encryption with its super computers, so as long as the government stays within its boundaries of security and does not blatantly invade its citizens’ privacy, it can continue to successfully use its array of electronic surveillance.

Photo Credit: "tower1-2"  by Damlan Korman via flickr CC.

Photo Credit: "tower1-2" by Damlan Korman via flickr CC.

 

Espionage is the Key

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Photo Credit: Tim Gage via flickr

One of the main reasons the Allied code breakers were able to crack the German Enigma cipher was espionage. Both stealing code books and obtaining documents from Schmidt gave the Allies the edge they needed to crack the Enigma machine several times. The Allies would be very far set back if they did not have access to the Enigma machine. Rejewski would never have made such quick progress on the Enigma machine if he did not have access to the documents explaining how the key was enciphered and a model Enigma machine. If Rejewski had not made such quick progress, the Allies would probably never had the break through that he achieved because Germany would have invaded Poland before the Polish could give the notes to the Allied nations. Espionage was also helpful for the guys in Bletchley Park. Stealing code books from German U boats was critical in deciphering the Enigma later on by using cribs that are established through the location of the U boats.

What is also important to note is that the Germans made the Enigma machine more complicated throughout the war without knowledge of the fact that the Allies had cracked it. This means that saying the Allies would have eventually cracked the code is not entirely accurate. Speed was actually pretty critical in attempting to crack the Enigma. Every time the Allies cracked a form of the Enigma, the Germans would make it more complicated later, so the Allies would have to reevaluate their attempts and use a slightly different method. What is important to note is that the Allies did not necessarily have to start completely over; they could just reevaluate and use their old notes since they had already cracked one form of the Enigma before. Without the espionage involved in stealing important documents and books, who knows if the Enigma would even have been cracked before World War II ended?

The Failure of Trust Itself

As I was reading Little Brother, I was intrigued by the points that Cory Doctorow made. Some of his arguments were interesting since Marcus was purely intent that the DHS was terrible. It seemed that the US would turn into chaos from the inside out because of another terrorist attack. We do not actually see the adult side. Without Marcus, the tactics the DHS was using to track down terrorists would have definitely been more efficient. The jailing teenagers’ part was a little extreme, but the other tactics such as following unusual routes could prove to be useful in tracking drug deals and even potential terrorist attacks.

That is not what intrigued me the most. The most interesting part of the book for me came at the beginning of chapter 10. This is where I finally understood how public/private key encryption works. We mentioned it a few times in class, but the beginning of chapter 10 explains the logistics of it. Using only public key encryption is useless because it is not a secret. Anyone on the web will be able to read the messages you encrypt. However, using both a public and private key is a very secure means of communication. The message is encrypted twice, both with a public key and a private key. There is still a very sneaky way of bypassing this. Billy could trick Bob, who is trying to send a message to Jim, into thinking that Billy’s public key is actually Bob’s public key. In this way, Billy can intercept Jim’s messages and become a man in the middle. In order to actually maintain secrecy, one must establish a web of trusts. But even this web of trusts can be infiltrated, as evidenced by the events later in the novel. That is the inherent flaw in the private/public key encryption. It involves around human trust, which can be easily betrayed by anything from money to power. Human trust is what fails here in the situation provided in Cory Doctorow's novel.

Persistence is the "key"

New things can seem very challenging at first. For example, a question seems so much simpler when we already have an answer to it. However, the question without the answer can seem very daunting, making it seem too difficult to even attempt. This is very similar to how the pattern of ciphering worked. First there was the shift cipher. When people realized what it was, it was extremely simple to decipher. Then there was the substitution cipher. This took a while for people to decipher. Some gave up, but then the Arabs developed frequency analysis. Once people understood frequency analysis, it was relatively easy to break.

Then came the Vigenere cipher. People were baffled. They didn’t understand how to break it, so many gave up in the process. They understood the concept but did not understand how to cryptanalyze it. Because people did not have a known way of breaking into the cipher, they simply gave up. However, it took cunning and persistence from Babbage to finally crack it. Once the way to crack it became relatively well known, people could easily decipher Vigenere ciphers with a little bit of time.

The reason why people gave up so easily is not because they did not want to break it but because they did not know where to start. With a new cipher, the cryptographers have the advantage over the cryptanalysts. The cryptanalysts were so used to frequency analysis that when a new “unbreakable” cipher came out, they did not know how or where to tackle it from. This led to lots of confusion and most of them simply giving up rather than persistently experimenting with different techniques.

Is anything really secure?

There are several ways a college student can protect his or her online privacy. College students today accept terms of agreement without reading them and even save passwords onto their computer and phone without thinking about what would happen if they got stolen. Students not only don’t know how to protect their computers, they are also oblivious to the fact that their computers are being monitored on the web. Very few students know that photos will always stay on the web. A simple google search of someone can reveal several of their most “private” Facebook photos. In a prank video on YouTube, a person used the Instagram photo locator to find random people who had just posted Instagram photos in his general location. If a normal prankster can track a person that easily, who knows what a government agency could do?

One of the best ways to protect oneself from the number one threat of the five biggest privacy threats of 2013 is to simply download a browser add on. There are multiple browser add ons that one can choose from. Collusion or DoNotTrackMe can be used to either track which companies are following you or prevent companies from following your browsing in general. But even then, DoNotTrackMe only stops so many cookies from following your browsing. There is only so much you can do to keep your browsing private, but even then it is still not completely private. The safest thing you can do as a college student is be careful what information you put online, especially through social media. Think before posting because “deleting” something on the internet rarely actually means deleting it.

The Pattern of Cryptography

Cryptography is full of patterns. Patterns are evident in code-making, code-breaking, and even the history of cryptography itself. Code makers must use some sort of pattern when encrypting any message. Maybe the pattern is as simple as one in a rail fence transposition cipher or as complicated as one in the cipher in the Babington plot. Each encryption will always have some key (or pattern) that it must follow, or else the ciphered message will be as useless to the recipient as it would be to an anonymous third party trying to decipher the message.

Code breakers use similar patterns in order to decipher messages. For Caesar shift ciphers or even mono-alphabetic substitution ciphers, the pattern always begins with frequency analysis. From frequency analysis, all code breakers, whether amateurs or professionals, will attempt to form recognizable words or use clues such as double letter sequences in order to crack the code. Once a few common words, such as “and, the, of,” have been deciphered, the rest of the code can be deciphered with relative ease. Once parts of the code have been deciphered, a pattern tends to emerge in the key used to encipher the text. A key word or phrase may be used, or a pattern such as a shift may be used for the key. This simple pattern works with ciphers as complex as the one used in the Babington plot, as evidenced by the work of Philip Marnix.

The most intriguing pattern is the historical battle between cryptographers and crypt-analysts. Transposition ciphers, which came first, are useless because the text is just as hard to encipher by a crypt-analyst as it is for the intended receiver. Shift ciphers and mono-alphabetic substitutions were very secure until the rise of the Arab caliphate. Since they had so much time and knowledge, new advancements were made in frequency analysis in order to break these ciphers. Soon, nulls were added, and words would be spelled incorrectly in order to throw off potential crypt-analysts. This was largely unsuccessful because the most renowned crypt-analysts of the time could still crack the code with enough words and trying hard enough with frequency analysis. This historical pattern raises a few interesting questions. Will this historical battle ever end? If so, who will emerge the winner? And more importantly, how will important historical events shape this continuous conflict between cryptographer and crypt-analyst?

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