3.11

The finite fields are kind of neat in this chapter since you can divide by any of the numbers from [1,(p-1)] mod p. I really didn't understand what they were going over in the book. Maybe it was just a little too long winded, or maybe it was just confusing. I kind of got lost after the first few things about the properties of a vield and the X polynomial.

3.3-3.4

The interesting part of this was the chinese remainder theorem. It seemed kinda cool how they found the number based on the congruences. It was also somewhat difficult to understand since the book wasn't quite clear enough for me.

3.1-3.2

The most intersting part of this section was the pi function. I didn't know that there were x/ln(x) primes from 1 to x. I thought it was interesting since it's not obvious that the distribution acts like it does. The extended Euclidian algorithm isn't exactly explained completely in why it works. I could probably use a better explanation of this.

2.8-2.11

I found the one time pad as the most interesting part of this section. It's interesting how the one time pad is impossible to break. This appeals to me since it's pretty cool to see something that is concrete like this in it's security. The only downside that they indicated was that the pad can only be used once, so generating them can be prohibitive. One part I didn't get completely was the linear feedback shift register. I'm not quite sure how it works and what the matrices that were int he book were used for.

2.5-2.8

One thing that I thought was somewhat vague was how to decrypt the ADFGX cipher. It left it up in the air how to deterministically figure out the boundaries for each column in the example listed in the book since one column has one more letter than the rest. I thought the matrix based block cipher was really interesting since it can be expanded to multiple letters easily and has many possibilities, but it also fails so easily once one plaintext is discovered.

2.1-2.4

One of the interesting things from the reading was the vigenere cipher which shifts a variable amount since it is a clever modification of the shift cipher. The first method for attacking the cipher is interesting since finding the key length seems somewhat incredible since it just involves counting coincidences. Finding the key was expected since it just analyzed letter frequencies. One thing that was not quite explained was how a combination of several ciphers could be solved. For example if a vigenere cipher was applied to a random substition cipher or the other way around, would it need new methods for an attack?

Name? Year? Major?
Brian Kennedy
Fifth Year
Computer Science Major

What courses have you taken post-calculus (please include course names and not numbers)?
Math 115 (Linear Algebra)
Math 151A (Applied Numerical Methods)

Why are you taking this course?
I need to take one more math course to satisfy my major's "Pick three upper division courses from some other department" requirement, and this class looked interesting.

Tell me about the math professor/teacher you've had whose been most effective. Tell me what s/he did that worked so well.
It was the professor for applied numerical methods. He posted his notes online, and when he would go over the material, he was always excited about what he was teaching. He would also have small 'quizzes' during class where now and then. Just after he had introduced something new, he would have us take out a piece of paper and work on one or two problems and then switch papers, grade and go over the answers. If I remember correctly, the quizzes didn't count against you, and it could help improve your grade by participating. It seemed to help us know whether or not we really got what he was teaching us.

Tell me about the math professor/teacher you've had whose been least effective. Tell me what s/he did that worked so poorly.
It was the professor for math 115A. This was the first math class where I had to prove things for homework and the exams. He never went through the different methods of mathematical proofs and just guessed that we knew how without asking. He would also go through the proofs for various things during class, but not really give us any idea for the rationale behind them. He also called us all stupid after the midterm since everyone except for one person scored less than 50%.

You wouldn't know it by looking at me, but ...
I like to play racquetball.