3.4 and 3.5, due Monday October 1st

1. Nothing difficult at all in this section:) I've seen it all before and done several assignments on these sections.

2. I love knowing how to use modular exponentiation. It makes life soo much easier! Also, I think it's neat how many things from 371 carry over to cryptography.

Blog due Friday September 28

Which topics and ideas do you think are the most important out of those we have studied?
Conceptually, I think the most important are DES, affine and vigenere ciphers, and possibly Hill ciphers

What kinds of questions do you expect to see on the exam?
Ones similar to those on the homework. I at least hope to have the formulas given for me for stuff like block ciphers though. I could memorize but at least it would be nice to know which encryption styles we needed to have memorized before the test.

What do you need to work on understanding better before the exam?
Probably Hill ciphers. If there will be any proofs on the test, definitely those:)

Blog due Wednesday September 26th

I missed this one.

Q & A, due Monday September 24

How long have you spent on the homework assignments?
The first ones weren't too bad; but the last one took eight or nine hours because I got hung up on a few problems like four and five.

Did lecture and the reading prepare you for them?
The decryption process, definitely. There couldn't have been better teaching to prepare for that part. I felt the proofs could have had more focus in class or less focus on the homework. (I've never been good at proofs though, and most people probably didn't have an issue with them)

What has contributed most to your learning in this class thus far?
The step by step process of going through encrypting and decrypting as well as showing us how to use technology to solve them easier.

What do you think would help you learn more effectively or make the class better for you? (This can be feedback for me, or goals for yourself.)
If I did more practice problems from the book, I would be able to solidify processes better.

3.11, due Friday September 21st

1. The hard part for me is why RIjdaenl's technique has 9 bits in it. I was under the impression that it's a lot easier to store bits in factors of 2(i.e. 2^3 bits=byte, 2^6=64 bits, used in DES). Also how can that be represented by GF(2^8)?

2. I best liked this section as I was reading about XORing and division in groups. It reminded me of some of the material we covered in Math 371.

4.5-4.8, due September 19th

1. The trickiest part of the reading for me was understanding the differences between so many modes. The section on Output Feedback clicked the least of all of them.

2.  The concept of salt in password security is very interesting to me. I don't quite know how 4096 of the same word are stored but it seemed kind of cool. Also, I liked reading about Breaking DES and the history behind it.

2.9-2.11, due Friday September 14

1. I really enjoyed the idea of a one-time pad, although it's drawbacks are quite obvious. I also liked how LFSR is in binary and the pseudo-random bit generator concept.

2. What I found most difficult was the LFSR method of encrypting. Not that it is good for speed and not security but the actual method of encryption/decryption.

4.1, 4.2, and 4.4, due September 17th

1.  The reading was great. I really liked reading about the DES and was fascinated by the amount of encryption and how many layers there are. I guess that helps in a system like DES because it's not a group. I'm also excited to see the more complex cryptosystems.

2. I didn't understand all the technical details of how to do everything. I understood the left-right shift and iteration of the L's and R's but don't see the whole picture very well.

2.5-2.8, and 3.8, due September 12th

1. The most difficult part of this reading was understanding the block ciphers and decryption of them. I also didn't quite get how the Binary numbers part related to encryption.

2. The most interesting part was the refresher course on matrices. It has been awhile since I've done any of them, so that was helpful.

2.3, due September 10

1. Amazing!!! I loved the method of lining up the ciphertexts to determine key length. Truly genius! Also, it was great to learn about what I had already done for OCRAI.

2. The thing that was difficult for me to understand is how to find the time to decrypt this manually. Also, I didn't understand the second method to find the key very well.

Guest lecturer report, due September 7th

1. The most difficult part of the guest lecturer was...? umm...nothing? I realized that we did the same encryption as the 'milk' method. I thought it was difficult to expect people to learn the Deseret Alphabet. Yeah.

2. The most interesting part was how Parley P. Pratt's wife went to look for her kids, and the connection to the Deseret Alphabet, and how her husband got shot when whatever his name caught up with him after the court case over clothing. I also loved the story about the Hawaiian translation and how the Church kept messages hidden(mostly;))

2.1, 2.2, and 2.4, due September 7th

1. The most difficult part of the reading for me came in two parts: the first part was the "chosen plaintext" and "chosen ciphertext". I don't understand how you can choose the plaintext or the ciphertext. I thought that was already sent or received. The second part that was difficult for me was not understanding really. I realized how difficult even "simple" ciphertexts can be to break even if you know how to decrypt them.

2. I loved the explanation for how to decrypt affine ciphers.  Also, the substitution ciphers section was very interesting. I realized the ciphertext you gave us would have been much much harder without spaces and that we would have had to use frequency analysis, pretty much exclusively. Also, I love the writing style of the book and how easy it is to follow!