Cryptography

The History and Mathematics of Codes and Code Breaking

Month: September 2017 (Page 1 of 6)

Essential Liberty vs. Temporary Privacy

The first quote I noticed on the board was the Ben Franklin quote stating "Those who would give up essential liberty, to purchase a little temporary safety, deserve neither liberty nor safety." This seems like a perfect and very compelling quote for the pro-privacy argument, especially since it was said by an important figure in United State's history. But in actuality it is used largely out of context; after some further investigation, I came across an NPR article about the actual context of the quote. Robert Siegel points out that this quotes is more of a "pro-taxation" and "pro-defense spending" quote since is was in response to the legislature trying to tax the Penn family for property. While this quote has lost its context in the 21st century debate, I think it still serve a good purpose in putting many people's thoughts into words . It portrays the idea that being willing to trade some freedom for some confinement feels inherently un-American and goes against everything the nation was built upon. I personally still have mixed feelings towards the pro-privacy, pro-security debate. I think that Little Brother showed the absolute extreme of invasion of privacy that could occur. Since it was so extreme, it seemed unrealistic to me and has left me on the fence regarding pro-privacy. While I would rather not have people reading my personal text messages, I can understand being pro-security and being willing to give up "as much (privacy) as necessary to feel safe."

This is the NPR article:

http://www.npr.org/2015/03/02/390245038/ben-franklins-famous-liberty-safety-quote-lost-its-context-in-21st-century

The Need to Establish a Common Ground

When the 9/11 attacks occurred on American soil, the government had to respond in a certain manner to ensure the safety of its people. Based off of an argument brought up by Cory Doctorow in his novel Little Brother, I agree that the government first has to protect the safety of all citizens above anything else. Therefore, the government's action to look into previous phone calls and other similar information I believe is justified. While I also advocate for privacy rights, technology has such an affect on globalization that the government would not be able to ensure these terrorists were brought to justice if they did not search through these messages.

However, my concern is: when does this investigation stop? The government can be justified for looking to catch the terrorists and their accomplices, but how do we know that once they are found the government will stop peering on our personal data. The answer is that we don't. It is this sole reason that causes me to deter the allowance of the government to have access to this technological data. At times our rights have to be compromised to ensure our safety, but when will we be certain that we will ever be fully safe again. It is arguments like this that continually give the government justification to continue their investigations through people's private matters.

Therefore, I would grant access to the government for these investigations if I could be assured there would be a set termination to the investigations. For example, if the information could not be found after a few months, then it would be halted. I believe this serves to establish the perfect medium between ensuring privacy rights while also ensuring the safety of the citizens of the United States.

Blog Assignment #6

For your next blog assignment, read and comment on a blog post written by a student in a previous offering of this course, one that dealt with topics from Singh Chapter 3. Your response should be between 200 and 400 words, and it should expand upon, add nuance to, or debate assertions made in the original post. To find a post to respond to, I recommend you use the tags listed in the righthand column of the blog. Those are the most popular tags. You can also view all tags.

Leave your response as a comment on the original post. You'll need to click through to the post itself to see the comment field. Be sure to login before leaving your comment.  Your comment is due by 9:00 a.m. on Monday, October 2nd.

Bookmark #3

I maintain a list of Twitter users who provide information, resources, opinions, and occasionally humor about cryptography, encryption, surveillance, and privacy. Here are the members of my "Crypto" Twitter list, and here are their most recent tweets.

For your third bookmarking assignment, find and bookmark a Twitter user who should be added to my "Crypto" Twitter list. Look for scholars, researchers, journalists, or others who are active on Twitter and regularly provide useful perspectives on encryption and its role in our society today. When evaluating a potential addition, know that humor is fine, but crazy is not.

The goal here is to build a list of sources that will provide good material for your "practical crypto" and "security vs. privacy" papers later in the semester.

Your bookmark is due by 9 a.m. on Friday, September 29th. Please bookmark the Twitter user's account. The URL should have the form http://twitter.com/username or something similar.

Online Participation Grade

A few of you have asked how the online participation portion of your grade will be computed. I address this briefly in class, but I thought I would go ahead and put it in writing here on the blog.

Your online participation in this course contributes 10% of your final course grade. At the end of the semester, I'll ask you to review your online participation in this course, compare your participation to that of your peers, and assess your contributions to the learning community. I'll ask you to give yourself an online participation score between 0 and 10 points, and email it to me with a justification (not more than a paragraph). If I think your score is reasonable, given your justification, I'll use that as your online participation grade.

To assess your online participation, focus on blog posts and bookmarks on Diigo, as well as other forms of online participation to come. In each of these areas, I usually ask you for specific contributions -- posts that responded to particular questions, or bookmarks about specific topics, or tags and comments that fit certain parameters. As you look over your contributions to the course, keep these requests in mind. Also consider how your online participation contributed to the learning of your peers in the course.

When Cryptographers Die

There were many strong ciphers that seemed impossible to decipher, but only one has the name "Great Cipher." The Great Cipher stood undecipherable for 200 years. Created by Antoine and Bonaventure Rossignol, it was used by King Louis XIV as a way to keep his secrets hidden, "protect details of his plans, plots, and political schemes." He was impressed by the cipher and the Rossignols' so much he gave the father-son duo offices near his apartments.

What made the Great Cipher so great was the combination of its use of syllables as cipher text in the form of numbers, and the death of both Antoine and Bonaventure. The Great Cipher was secure because it turned basic french syllables into cipher text into numbers, specifically 587 of them. As mentioned before, 200 years went by before it was deciphered. Many people tried their hand at the cipher and ultimately failed, died, or gave up before they could solve it. Along with the death of the Rossignols, there was no one to read the messages. This lead to messages being unreadable for years, thus securing the cipher for years until Etienne Bazeries deciphered the Great Cipher. This still took him a total of 3 years of work of using various techniques. Some of these techniques led to gibberish and complete restarts of his journey. He finally considered the numbers could be syllables, then he found a single word, "les ennemis," from a cluster of numbers that appeared several times. From here he could examine the other parts of cipher texts and decipher them.

The Great Cipher is remembered as one of the most secure ciphers in all of history. The techniques used to decipher it are still used in other deciphering techniques, and it is one of the "forefathers" of today's unsolved ciphers.

Resources on Plagiarism and Academic Integrity

Some resources relevant to our discussion of plagiarism and academic integrity...

The Greatest Cipher

Louis XIV's Great Cipher was unique in its complexity, far far beyond the other ciphers used during the time period. Indeed at the time, by far the most popular type of cipher was the mono alphabetic substitution cipher, yet that is easily deciphered by a good cryptanalyst through the use of frequency analysis.  The Great Cipher was much more than a simple mono alphabetic substitution cipher in that it utilized numbers to represent letters, but on top of this, the numbers didn't just stand for letters they also stood for syallables. Since there was not a 1 to 1 relationship between letters and the cipher alphabet, it was nearly impossible to perform traditional frequency analysis on the cipher text. Furthermore, the cipher was brilliantly created with cipher text indicating to ignore the previous syllable or letter, making it tricky for any decoder to figure out what was part of the cipher and what was simply nonsense.

Perhaps the deciphering of the Great Cipher is even more impressive than the creation of such a complex cipher. The amazing creativity and brilliant thinking that Bazeries had to even consider looking at syllables has to be commended. Furthermore, for him to harp on a repeated phrase and be able to figure out what it meant is incredibly impressive. This also illustrates how amazing the cipher was in that it took Bazeries over three ears to crack it even with his uncanny ability to recognize that it is comprised of syllables.

Blog Assignment #5

This summer, I visited the Newseum in Washington, DC, with my kids. The Newseum is a museum focused on the five liberties of the First Amendment to the US Constitution: religion, speech, press, assembly, and petition. One of their current exhibits looks at the FBI's role in fighting crime and terrorism. As my daughters and I were walking through the exhibit, I noticed this display:

For your fifth blog assignment, respond to this display in a post between 200 and 400 words. I'm really curious to know what you make of it, given the discussions we've had in the course about privacy and security.

Please (1) give your post a descriptive title, (2) assign it to the "Student Posts" category, and (3) give it at least three useful tags. Also, (4) try embedding the above photograph in your post. (Click on "Add Media" when you're composing your post to do so.)

Your post is due by 9:00 a.m. on Wednesday, September 27th.

I Don't Really Think There Was Difference

What was the difference?

There was none! The environment that Mary Queen of Scots experienced is quite the same compared to the environment leading up to the development of the Vigenère cipher. In fact, it even states in the book that Vigenère’s publication of Traicté des chiffres happened “ironically… [in] the same year that Thomas Phelippes was breaking the cipher of Mary Queen of Scots.”

Even Mary herself was aware of how insecure the code was. It was just that (1) she could not come up with a better method of encryption and (2) she never questioned if her beloved messenger was a double-agent for Thomas Phelippes which he in fact was.

All of this just goes to show how much of an edge the cryptanalyst had over the cryptographers. No matter how much variation the cryptographers tried to invest into their monoalphabetic, the cryptanalyst could break them easily with one tool — frequency analysis.

However, this was only until Vigenère took the works of three other men to create a cipher that gave the edge back to cryptographers. With it, cryptanalyst would be left to sit hunch-back over their desk for years. It is only a shame however that his amazing cipher would not be appreciated until another two hundred years.

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