Cryptography

The History and Mathematics of Codes and Code Breaking

Author: Junhao

The Complex Interplay Between Privacy and Publicity

“There’s a big difference between being in public and being public.… At first blush, the desire to be in public and have privacy seems like a contradiction…. teens’ engagement with social media highlights the complex interplay between privacy and publicity in the networked world we all live in now.” (boyd 57)

In boyd’s book It’s Complicated, he discusses many theses related to privacy and publicity. To my surprise, “many journalists, parents and technologists seem to believe that a willingness to share in public… is incompatible with a desire for personal privacy” (boyd 56). While it is true that by posting photos on Facebook, teens give up the privacy, of these photos, it does not mean that teens forfeit all their privacy. Emerging social networks lead to teens’ increasing online engagement with not just their friends, but also the public. As a result, we post more and more texts and photos, but we also become more aware of what to post, and with whom we share. We actually care a lot about our privacy, since we usually post things that are insignificant to be publicized, and communicate information of much significance with our close friends via texting, the more private medium.

However, the social norms mentioned by boyd are indeed quite complex on social media. Most people follow these norms in real life; for instance, when two people sit next to each other, one does not stare at the other’s phone screen to see what he or she is texting. Nonetheless, there exist conflicts between social norms and the concept of public social media. We post things, giving everyone the permission to see them, yet on the other hand we may not expect strangers and other unwanted people to view parts of our life. What’s at stake is not whether someone can view but whether one should. The reconciliation of online social norms and the public nature of social media is a challenge in today’s networked world, and should be solved as social media becomes more widely used.

Podcast Episode Numbers Stations

I listened to this podcast episode and the most interesting part about it was the mysterious nature of those random numbers. Though there are many guesses about what are the numbers for and who receives the numbers, we do not know the truths. More interestingly, numbers stations’ podcasts are accessible for everyone who owns a shortwave radio, making people more curious about them. This podcast episode kept catching my attention with many examples of numbers stations’ broadcasts. They well illustrate the concept of numbers stations, and because people usually get bored with repetitive things, the podcast utilizes various stations' broadcasts in different languages as examples, thus captivating listeners all the time. Additionally, the podcast invited a savant in the studies of numbers stations, David Goren, to give his perspectives on them. The speech from such a professional clarifies the technical aspects of the material and makes them more understandable. I also found the script and pictures below the podcast very helpful. While the script provides the brief content and some links to more information, the pictures give listeners a glimpse at what numbers stations look like so that they can visualize what they hear. Having listened to this episode, I will try to include a variety of detailed examples for my topic; also, I want to complement my podcast with script and pictures for listeners to follow along.

The Allies’ Teamwork Against the Germans’ Human Error

While the Germans’ overconfidence in the strength of Enigma was a primary factor leading to their loss in the World War II, I believe how the Allies worked in a united and coherent way also significantly influenced the outcome of the battle of cryptography. The French Secret Service first obtained the documents that suggested the wirings of the military Enigma machine, and then handed them to the Poles so that the Biuro Szyfrów could try to crack the Enigma with such a starting point. Furthermore, after the Poles successfully broke the Enigma cipher for several years but were no longer able to decipher the Germans’ messages when more scramblers and plugboard cables were added, they offered their code-breaking techniques to the British and the French, letting them continue the decipherments. Therefore there came the stories at Bletchley Park and Alan Turing’s well-known accomplishments. If any one of France, Poland and Britain was unwilling to share its information and works with others, the Allies might not break the Enigma because no one would have enough resources indispensable to cracking the codes.

In comparison to the Allies’ teamwork, the Germans, interestingly, compromised their own cipher. Germans are always acknowledged as procedural and rigid; with these characteristics they sometimes yielded advantages in the war in which the order and decisive operations mattered. However, their adherence to rules also resulted in flaws in their encryption. The repetition of message keys, and the rigidly structured weather reports were exploited by the Allies to crack the Enigma. Without the human error on the German side, it would take the Allies more time to break the code and end the war.

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What Are the Differences Between Giving Privacy to the Government and to Our Campus?

After the 9/11 attacks, counterterrorism became the FBI’s primary mission. But in order to catch terrorists and thus increase national security, the FBI expanded its intrusion into our personal lives. Therefore it again comes the argument over privacy versus security, which seems quite similar to the campus data-mining case we discussed before. Interestingly, while I refused to give up any privacy last time, I believe the government’s access to some of our privacy is justified as long as it will not compromise our rights of freedom and the pursuit of happiness.

Ensuring nation’s security is extremely hard, because the government has to beware all aspects on its lands that may have security loopholes. Only with the data-mining and digital surveillance, the technologies that can span the country to watch on people’s moves, the government is able to prevent bad things from happening, and take immediate action in case of terror attacks. The campus security, however, is relatively easier to be maintained. Since the campus is merely a small community, rather than infringing students’ privacy, the university can instead increase the number of its security guards, thereby achieving nearly the same safety purpose.

Additionally, giving our privacy to the government’s security departments is much safer than to non-governmental institutions. In other words, the FBI is more reliable than others because it is one of the US leading security agencies in which almost all its officers are selectively recruited and rigorously trained so that they are well capable of keeping our personal data safe after examining it. However, when it comes to non-governmental institutions, it is reasonable to be paranoid that our data may be leaked; criminals may easily hack into the database of a university, but few of them can invade the FBI’s security systems. The FBI can actually protect us from terror attacks with the control over some of our private data against criminals, and thus we should make a concession to exchange some privacy for the nation’s security.

The Great Cipher: An Unbreakable Cipher for 2 Centuries

The father-and-son team of Antoine and Bonaventure Rossignol invented the Great Cipher for the French king Louis XIV to encrypt the empire’s most secret messages, protecting details of his plans, plots and political schemings. While the nature of the Great Cipher was simply an enhanced monoalphabetic cipher with homophones, it seemed implausible that it remained unbreakable for two centuries. However, there were two main factors that led to such a secure cipher.

The most significant one was considered to be the Rossignol’s ingenuity and resourcefulness. Including 587 different numbers, the Great Cipher was obviously not a straightforward substitution cipher. But when Étienne Bazeries, a distinguished cryptanalyst tried to crack it as a homophonic cipher, he failed. He then came up with the idea that each number might represent a digraph, or a pair of letters. Although his efforts to this deciphering approach again yielded nothing, it enlightened him on the possibility that some numbers corresponded to syllables. After a few attempts, he made a breakthrough, with the discovery of “les-en-ne-mi-s” represented by a cluster of numbers (124-22-125-46-345), and thus his idea eventually proved to be right. During that time when cryptography was mainly about encrypting plain alphabets with cipher alphabets, it was creative of the Rossignol to use syllables for the complexity of homophones. More importantly, they had also laid traps for codebreakers, adding numbers which deviously deleted previous numbers instead of representing any meaningful letters or syllables. All their creative encipherment contributed to the strength of its encryption, making it confusing and harder to decipher.

Additionally, after the death of both father and son, the Great Cipher fell into disuse and many details about it were lost; therefore, for those who wanted to break the codes had to start from scratch. Due to its difficulty, only the most prominent cryptanalysts were capable of deciphering it with consistent dedication and patience. As a result, it was no surprise that the Great Cipher was known as one of the strongest ciphers in the history of cryptography.

Private ≠ Illegal

“The truth is that I had everything to hide, and nothing.” (Doctorow 56)

Doctorow provides us with many interesting ideas in his novel; the one caught my attention the most is Marcus’s comparison between living without privacy and using the toilet in a glass room perched in the middle of Times Square, where people can see you naked for a while. While everyone goes to a bathroom, almost no one wants to share his or her nudity with others, simply because it is something private, something only belonging to our own life. Living under close surveillance is just as creepy as joining naked shows in public.

In a debate of privacy vs. security, perhaps one objection to keeping privacy from data mining is that if people have nothing to hide, nothing needs to be hidden. However, such a thesis is untenable and thus fallacious. Many people have long hold a misunderstanding of privacy, that what people are trying to hide is shameful, or even the proof that they are guilty since it looks stealthy, just as the severe haircut lady says, “honest people don’t have anything to hide” (Doctorow 49).  But the truth is, something private doesn’t mean it’s illegal; or we should never write down our secrets and goofy thoughts in diaries because by doing this, we break the law. That’s also why Marcus is reluctant to unlock his phone for the DHS agents though he has nothing to do with the terrorist attack.

Constant surveillance is nothing new in today’s digital life, but before I read the novel, it never occurred to me that everything about us can be mined via different surveillance strategies. I felt even more unsettled when I thought of the likelihood that all those high-tech surveillance tools would become true and more widely used in the near future, and therefore it will be much easier for the government to keep an eye on each of our moves. While such development of technology is inevitable, I hope that the government still gives respect to our privacy, since it’s part of our own life that we don’t want others to see.

Sacrificing Individuals' Privacy for Overall Safety?

By writing “because campuses can be prime targets for large-scale acts of violence, …the use of data-mining technology to prevent violence should begin there”, Morris proposes to mine student data, and to allow universities’ surveillance on students for campus security; he also has some good comments on today’s digital life that makes the university easier to keep an eye on students’ behavior. However, his discussion does not take many consequences and potential moral arguments into consideration, and is therefore fallacious.

When Morris says “it is a form of behavioral surveillance, and it can be used to predict, with amazing accuracy, the propensity for a person's future behavior”, I believe he is overconfident about how precise the data analysis could be with today’s technology and social studies on human behavior. The case mentioned by Morris in which Amazon.com mines customers’ search histories so that it can better learn about their interests is untenable. I once heard that someone purchased a wreath for a funeral on Taobao, a Chinese shopping website similar to eBay, and then in the next couple of days he continuously got whole pages of recommendations on things related to funerals, which seemed really creepy; nevertheless, Taobao assumed that he was interested in them, according to its “amazingly accurate” data analysis. It turns out that algorithms designed for analyzing electronic data can’t even accurately tell people’s interests from what they occasionally look for, how could it be used to identify potential violence and predict crimes on campus?  What happens if the data analysis wrongly convicts students of potential violence? Perhaps, as Morris writes, the campus “will surely come much closer to the goal” of crime prevention, but flagging an innocent student as a criminal is undoubtedly a terrible outcome that will compromise one’s life.

Additionally, it comes to a more complex moral question of individual sacrifice and overall well-being. If we can sacrifice individuals’ privacy, or even a small group of people’s innocence to prevent something very bad from happening and thus increase the safety of a significantly larger group of people, should we do it? While the answer to this question is likely to vary from person to person, my response is no. Overall security matters, but personal interests matter too. There must be a reconciliation between them; giving up one’s privacy is not a solution to this.

Though Morris’s article is not convincing enough, but it does remind us that with the increasing cases of campus violence, we must find out a way to appropriately use the technology to keep campus safety, while our privacy are protected as well.

You Don’t Need to Be Trained to Be Professional

With sophisticated and detailed research on statistics, al-Kindī invented his system of cryptanalysis, later known as the frequency analysis. It’s not surprised that he was considered as the greatest scientist in the ninth century when many disciplines including mathematics, statistics and linguistics that are well developed today were still in their rudimentary stages; thus his research was undoubtedly remarkable. More importantly, the public, especially amateur cryptanalysts were not educated as well as those in today’s education system; few people were likely to have the opportunity to master, or even learn mathematics. Therefore those attempting to decipher encrypted messages had to depend merely on al-Kindī’s approach. However, things have changed.

Today’s schooling system guarantees the educational opportunity for almost everyone to learn basic mathematics and statistics, and to have personal perspectives on languages. As long as we comprehend the linguistic rules, do the math and then go through the process of trial and error, all of us can crack codes in our own ways.

The easy access to various resources and information should not be understated as well. Simply searching ‘cryptography’ on the Internet, even high school students are probably capable of decrypting substitution cipher. For those who want to dedicate more time and truly dive into code breaking, thousands of books will be available if they are willing to reach them. Learning new theories and grasping the nature of any discipline without instructions are no longer the missions impossible; in other words, self-study is relatively more feasible than ever before.

Generally, the simple truth is, we are getting more knowledgeable and everything is getting more accessible. Though code breaking is hard, the actual barrier for amateur cryptanalyst today may be their willingness to reach the resources and their persistence as well as patience when deciphering codes with complex encryption.

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