Cryptography

The History and Mathematics of Codes and Code Breaking

Author: peinrm

From the perspective of the losing side

I listened to Cipher, or Greenhow girls The Memory Palace episode 111 and I thought it was so interesting how they started first from older Rose's perspective and then transitioned to trying to empathize with little Rose after her mother passed. The chronological way the podcast was delivered made it very easy to follow and the music in the background helped set the mood of the story. Similarly, the narrator's intonation and speech patterns created a sense of intrigue and suspense which fell perfectly in line with the content of the podcast. I really liked this podcast because in school we had to read a fictional book from the perspective of Rose's servant, a Union sympathizer, so I liked hearing how Rose and her daughter experienced the same event but with a completely different view. The podcast gave Rose a complete persona, rather than just labeling her as a spy or confederate, which makes her a more interesting character to study because she has all these personalities such as mother, spy, southern belle, cryptographer, etc. Something interesting to note was that even though during the time of the Civil war when women were not offered equal opportunities to men, Rose was still able to concoct such a complicated spy circle and successfully aid her side in the war effort, her code being something I'm sure many men to break. The main things I will take away from this podcast to help me with my own is that music is extremely helpful when it comes to creating a mood for the piece, and that telling your ideas in the form of a story makes it more interesting than just listing facts in a textbook fashion.

Human intellect vs. Machine power

The deciphering of Enigma remains as one of the most significant cryptanalyst achievements of all time. One of the main reasons the Allies were successful in cracking the code was due to their ability to look beyond the microcosm of the daily messages they received and focus on tackling the code at the highest level. Alan Turing's idea to create a machine that could handle Enigma was the exact creativity needed to win the war. Since the origins of cryptography, the battle between cryptanalysts and cryptographers was typically of human brainpower, and whoever had better linguistic or cryptographic knowledge would be the winner. However, in the Second World War, the use of a machine to encipher messages practically renders all human brainpower useless, as no human can match the speed and efficiency at which a machine can work. For this reason, it was of the utmost importance for Turing to design a machine to defeat Enigma, as the progress made by humans was simply not enough.

 

What is most interesting about Turing's process was that it did not use a machine to generate a key first and then possible plaintext. Instead, he looked for links between ciphertext and plaintext called cribs, and used those to generate the possible key. This way is considerably more accurate because it both decreases the risk of creating a different plaintext than intended and can be used repeatedly. Finally, allowing a machine to perform this method increased the speed at which keys could be generated and eliminated possible human error. I have no doubt that the cryptanalysts at Bletchley Park could have made errors due to the amount of stress and pressure they faced. Therefore, the Allied success can really be attributed to Turing's exceptional engineering of code-cracking machines.

Timelessness of personal liberty

The display demonstrated that most people would settle for a balance of privacy and safety, which is understandable as I feel most people lie somewhere in the middle of the spectrum. However, the Ben Franklin quote really caught my eye because he would not have lived in a time of data-mining, internet surveillance, etc. so the fact that he would argue that can assign the privacy vs. security debate to almost a higher moral level. What type of surveillance was there in his day? What was he worried about people finding out? What were the risks of giving up privacy? I feel that it goes to show that no matter the type of information, or method of communication, people will always perceive their information to be sensitive. I guess humans have a timeless tendency to think of themselves and their lives as the most important type of information!

 

Additionally, most people wrote on the board that they would give up a "some" privacy for security. As if they have a choice! In all seriousness, one cannot pick and choose the security they receive, nor the privacy they relinquish. I feel as though a better question would not be "what" would you give up, but maybe "would you rather" be safe or have privacy?

 

Finally, a few posts on the board were about cell phones, which I think constitute the majority of security v privacy debates. With a phone you can track location, pictures, social media apps, etc. So in a way giving up security means to an extent giving up social media and maybe even your phone.  With my generation, I think this will be the question we will have to deal with.

The Great Cipher: Coding in a primitive form

Great Cipher used by Louis XIV was such a successful cipher because it incorporated many types of cryptography, but also "foolproofed" itself by creating almost a ciphertext keyboard. For example, certain numbers created sounds, similar to how computer code can prompt a computer to emit audio. Similarly, certain groups of numbers deleted the previous letter/cluster, like the backspace key of a computer, and how a computer is coded to understand that deleting is the function of the key. I would argue that the Great Cipher was a form of computer code before its time, with the Rossignols being the coders and Louis XIV or any recipient being the computer. Before the Great Cipher, many cryptanalysts were accustomed to assigning one letter with a singular symbol, or group of numbers, but this cipher was so successful because it prompted the reader to emit a syllable, as computer code prompts a computer to perform a very specific behavior rather than reword the code given. It is remarkable to imagine that such a complicated form of cryptography was developed so long ago, because we in some ways still utilize it today. Again, this method connects back to the argument of monarchs controlling the most developed forms of cryptography because of their resources and the content of their messages (Louis XIV could afford to house the Rossingnols). If records were kept, it would be interesting to research whether Antoine and Bonaventure were the first people to develop such a code, and how it relates to modern day technology programming.

Absolution of the Constitution

On page 208 of Little Brother, Marcus gets into a heated argument with his replacement social studies teacher and Charles. The teacher and Charles are arguing that rights provided to the people in the Constitution/Bill of Rights can be suspended under certain circumstances. Marcus is arguing that the rights are absolute, and that the teacher's way of thinking leads to the idea that the government can perform any action they deem necessary to "keep citizens safe". While I completely understand this opinion, I don't know if I agree with Marcus entirely about this conflict. The Bill of Rights, while an incredibly important document of American history, at the end of the day are just reflections of the perspectives of men who lived in an entirely different era. I feel honored and protected by this document, yet I do not believe it is absolute. In my opinion, certain laws/rights are outdated, and to argue that a rule should stay as it was written because "it's my constitutional right" is simply not a valid argument. Times change, and with it, so should governing structures. The men who wrote the Constitution were never under the constant danger we experience today, danger of identity theft, bombings, terrorism, hackers, etc. Why do we continue to take their word as law? Granted, the extent to which the government invaded privacy in Little Brother was certainly extreme, and I don't condone that, but I do believe the government should be allowed to access certain information about people if it can help prevent terrorism or violence. In Judaism, there is this idea of pikuach nefesh, which is that saving even one life overrules any other religious obligation. If it can be proven that government surveillance saves even a handful of lives, then I believe that we as citizens should understand that.

At the mercy of campus surveillance

In “Mining Student Data Could Save Lives” by Michael Morris, the main argument is that if campuses use data mining to detect possible violence, it will be beneficial to the safety of the students. While I agree that this tactic may be very effective, it does make me wonder about the extent to which universities will use this technology. For example, they may develop algorithms that can track the search for certain illegal activities, and use that information to seek out students who may not intend to be violent, but are intending to violate certain campus policies. Certainly, there is a fine line between conducting surveillance to ensure the safety of the students and surveillance to find out more personal details of a student's life, but there is always that underlying notion that everything you publish or send via the University's network can be accessed at any time. In some ways, I believe this puts the student at an unfair disadvantage. If they got in trouble for doing something their senior year, should evidence from something they did as a freshman be allowed to convict them? I am in favor of using technology and statistical data to take extra precaution against possible violent or mentally unhinged students, but I know there is no way to simply sort out the people who should be under surveillance. It's either everyone has to relinquish a part of their privacy, or nobody does. It's not the matter of being guilty, it's more the knowledge that what I do or say over the network will be monitored despite  the content of my post. In that sense, I do agree that data mining will be an effective crime-management strategy for universities, but the implications of that in terms of my own internet privacy are something I would have to consider further.

Duty of the Government to divulge sensitive information

In response to question 3, I believe that examples of cryptography noted in Singh chapter 1 were mainly of monarchs and leaders because the information they trade is far more dangerous and powerful than information traded by those who weren't involved in the politics of the world. For example, when the Greeks defended themselves against the Persians using the wax tablets from Demaratus, the lives of all the people of Ancient Greece would have been affected by the Persian naval attack, and hypothetical subsequent takeover. In fact, that could have rewritten history! However, Leonidas was a leader of Ancient Greece, which is why they were encountering such sensitive information and therefore were more motivated to develop more effective methods of stenography. (Kahn) In contrast, I can think of an example where perhaps two peasants wanted to communicate with each other, yet had to do so in secret because of a family feud, inappropriate relationship, etc. Since they are communicating on a much smaller scale, their cryptographic practices may not appear as developed as the Greeks or Mary's because the consequences of the message being intercepted would not be as far-reaching. I don't believe this has changed over time because as of now, we have even more sensitive information to deal with, such as nuclear weapons and troop deployment. This provides the government an even greater incentive to create difficult ciphers and keep certain knowledge a secret. Yet, in the textbook the Greek victory was won over the Persians because the people of Greece had received notice about these secret messages. In our society, we do not have unlimited access to the messages our government intercepts. Is it the duty of the government to share the messages they decipher to us as citizens? With the technology we possess today there would almost definitely be word sent to a possible enemy that their code has been broken, which may lead to even more advanced ciphers which the government would be unable to break, and left rendered unable to defend us as citizens. Clearly, there is a difference in the types of cryptography and stenography used in the times of Ancient Greece and Medieval England, but the governments still remain the most sophisticated of cryptanalytics due to the content of the messages they receive.

 

Citations: Kahn D. (1996) The history of steganography. In: Anderson R. (eds) Information Hiding. IH 1996. Lecture Notes in Computer Science, vol 1174. Springer, Berlin, Heidelberg

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