Chapter 5, due Sept 30

1. I really enjoy learning about all of these things, although sometimes it is hard for me to wrap my brain around it. I think what I struggle the most with is that I don't think I could ever do one of these by hand, well I'm pretty dang sure that I can't. There are a lot of steps to it, and it's easy to mess up, whereas before I could do it and practice it, which helped me understand what I was doing better. I think that if I saw how to do this on the computer or something it would help me understand even more. Like the one-time pad, I understood how it worked and what it was, but I really got it when we were able to use Dr. Doud's website and actually crack a real one. So I think that if there is some sort of system we could use to crazk a real one, it would help out more. But I still like it all alot, and am very interested!
2. I really liked how we went over half of this in class before I read it. It really helped me understand what I was reading! On the other half, I will admit that I was a little lost in class with what we were doing at first, even though I understood what you were saying and as I watched you go throught the process, I just didn't know where it came from and now I do :) This DES and AES stuff is very interesting, and I thought it was cool how they held a competition to come up with something to replace DES.

Reading Assignment due Sept 28th

* How long have you spent on the homework assignments? Did lecture and the reading prepare you for them?

I spend like 2 to 4 hours on the homework. On the last homework assignment, I did like 3 of the encryptions by hand which took quite a while, until I found out that I was allowed to use the applets, so the last homework assignment was like 5 or 6 hours :) So yeah, it varies, but it's good. Of course the lecture and reading prepare me for my homework. I always have my notes open and helping me through the homework. I love the examples that we get in lecture and in the books, they're great!


* What have you liked or disliked about the class thus far? What contributes most to your learning?

I have LOVED the class so far! It's so much fun, and so interesting!! It's like the first class that I've really look forward to every day! I love the lectures and the fun thing we learn. It's been a little harder lately with the DES stuff, but I think that just because up to then I was able to do everything by hand and crack the ciphers quite quickly, and the DES stuff just seems like it takes a little more time and thought. THe lectures and the reading both contribute to my learning. If I understand the reading, then that helps me a lot and the lectures just add to my understanding of it. If I don't understand the reading, then I depend a lot on the lectures to help me understand and to see examples so that I can really get it down.


* What do you think would help you learn more effectively or make the class better for you?

I think everything is going great. I think that you're doing the best you can and that it can't get better. The thing that would probably make it better and more effective for me would be to re-read the reading if I don't understand it, and write down the examples and take notes while I'm reading. I should do that so that I understand the lecture better.

Sec 3.11, due Sept 25th

1. It was good for me to review fields. We're learning about them in my number theory class, and so it's cool that I can use that knowledge for two classes. The hardest thing for me to understand was probably section 3.11.2 about GF(2^8). I know that was probably the most important, but there were just a few things in there that I didn't quite understand. I could also use a review and some examples tomorrow in class about section 3.11.3, the LFSR sequences using fields. The only thing that isn't difficult for me to understand, but quite frustrating and long at times is polynomial division and finding the multiplicative inverses of polynomials, yeah that is not very fun. I had to do a few this last week in my number theory class, and they were frustrating, and annoying. :) So I hope we don't have to do any of those!
2. This section was really good. I like having a prior knowledge of fields from 371, and then just barely reviewing it in my other class, so hopefully I understand them ok, and can do well. It's nice how all my classes are offering things that I use in other classes, it helps me stay on top of things and not forget.

Sec 4.5-4.8, due Sept 23rd

1.The most difficult part of the reading for me was section 4.5, about the different modes of operation. It was just a lot to take in at once, and there were so many different equations and diagrams that I felt a little lost.
2. I really liked the other sections though! I thought the section about breaking DES was very interesting, and it fascinates me how long it lasted, like 20 years! And how we didn't break it until just a few years ago. I think it's really cool to have something like that around for so long. I also thought it was neat how they had competitions, and gave out prizes, and in return it helped them make their system stronger. I also thought that it was a great idea to double encrypt something, until I found out that it doesn't significantly raise the level of security, that's a bummer! I also was reminded of Birthday Attacks! I'm sure they just as exciting as they sound, so I can't wait to hear about them someday soon! I also found it interesting to read and learn about the one-way functions, and all that stuff about passwords and salt for computers and everything! It was very interesting to learn about!

Sec 4.1, 4.2, 4.4, due Sept 21st

1. The most difficult thing for me in these sections was probably the expander function, and then the DES algorithm. It was just a lot of information to take in and I think that I just need to see a few examples, but it was a little confusing.
2. I thought that these sections were really interesting! The DES algorithm seems really cool! I also really like block ciphers and am excited to learn more about them and get more practice in using them and breaking them :)

Sec 2.9-2.11, due Sept 18th

1. I had a hard time understanding the Linear Feedback Shift Register Sequences section, probably just because I need to read it again and really focus on understanding it. There were a lot of equations and matrices and stuff, so I should just read it again and try to focus harder, but I'll look forward to learning about it tomorrow in class, because I always understand better in class when you teach it :)
2. I think that the one time pads are really, really cool! It's cool to know that there something out there that is basically unbreakable, unless you screw up and use the key more than once :) I also thought that it was really cool how it was said that they used one time pads for secure communication between DC and Moscow during the Cold War! I also thought about how crazy the Pseudo-random Bit Generation section was, the values for x_j are so huge! Really neat! I love learning about this stuff!

Sec 3.8, 2.5-2.8, due Sept 16th

1. It was difficult at first to remember the matrix stuff, like how to find the determinant, and inverse of larger matrices, but after a couple examples I got it down! The next thing that I didn't really understand was on pg 32, when we're talking about ADFGX ciphers, and in the last paragraph it says that you label the columns on the matrix with the keyword and "put the result of the initial step into another matrix" Now I investigated what I thought the previous step was, but I still didn't really get it, I understand everything else, but just not that part... anyway. When you are doing an ADFGX cipher and put the rest of the letters in a 5x5 matrix, do you put the rest of the letters in any particular order? I guess I just didn't understand that part very well. I'm also glad that we don't have to worry about table 2.4 :)
2. These sections were all really cool! I loved learning about matrices again, and using them to encrypt and decrypt. I thought the Sherlock Holmes section was really fun to read and learn about! I was sad that that man Cubitt died though, that was sad. The Playfair cipher was really cool too, it was very interesting to learn about, and can't wait to see more examples. Block ciphers were really neat too! The more we learn and the more complex they get, the more nervous I get, cause I know you probably will give us some sort of ciphertext to crack, so I gotta make sure I understand it! :) Learning about Binary numbers was fun too! These were a lot of sections, but really interesting! :)

Sec 2.3, due Sept. 14th

1. The most difficult part of this section for me was on page 21, when it gives an explanation of why the procedure given earlier finds the key length. That just kinda got me a little confused, because I felt like I understood everything up until then. The other thing that was a little difficult was the second method to finding the key. Probably just because I was comfortable with the first method, and I didn't really want to pay attention and learn the second method even though it says that it's more efficient and accurate. So I'll probably just need to read through that a few more times, but I was content with finding the key using the first method.
2. I think that Vigenere Ciphers are really cool and interesting! It's so cool how they use vectors and different shift amounts and keys and stuff. This book keeps coming up with new ways to encrypt messages and it's so cool, especially when it uses math. I just am really interested in this stuff. I enjoy reading, and I can't wait to learn more!

Sec. 2.1-2.2, 2.4, Due Sept 11th

1. The most difficult thing for me was just working out the modular arithmetic to crack all the ciphers. It wasn't hard to understand, I mean I understand it, but it just took some remembering and a little bit of arithmetic to solve them. Very interesting though! They keep coming up with stuff that I never would've thought of! The other thing that I would've liked to have seen an example of was #4 on pg 16. So maybe we can do an example of that tomorrow or something :)
2. I thought all 3 of these sections were really cool! I love learning this stuff! It's like I actually enjoy reading this book.. crazy huh? :) I thought the shift ciphers were clever, and the affine ciphers were cool as well, just took a little more busy work with numbers. It was fun writing out the alphabet like it said to do, and then count the numbers and fill in the blanks for alpha and beta, and just work it all out. I also like the substitution cipher. That's what we've been dealing with mostly in class so far, and I like them a lot. I always do the frequency count, as well as if there are spaces, look at the smaller words and start from there. Using that chart and eliminating possibilites was cool. I liked that we were given the charts this time, cause I think it might take a little while to make those ourselves, but if you really needed to crack a code, it's not that bad! They were really fun chapters to read, and it was cool to see how math was related to the cryptography! (Now when some kid asks what modular arithmetic is good for in your next 371 class, you can tell him some cool stuff!)

Guest Speaker, due Sept. 11th

1. The most difficult thing for me to understand is why I didn't know about this stuff earlier! :) I think that was one of the coolest things I've ever learned about! At some times it was diificult to imagine how they came up with some of the things they did, they were so creative! Like George Q Cannon referring back to previous letters and the names in those letters! Genius! I just think it is so awesome, and I would really love to learn more about it! Another thing that was hard to think about was adults learning the deseret alphabet. I guess it might come more easily than I think, but either way, that alphabet was sweet looking!
2. OK, as stated before, learning that stuff was Saaaweeet!!! I loved it!!! Good call on bringing her in to lecture Dr. Jenkins! I have a new motivation and desire to learn this stuff! I loved learning all the different ways that the church members used ciphers and codes! I guess I should've thought that they needed to earlier, but I never thought of it. I can't wait to tell my husband about the crazy code names they used in the D&C and see if he knew that. (I like knowing things about the scriptures that he doesn't, cause he always knows everything!:)) I thought it was really cool/cute how the Kane's wrote letters using a cipher. I know it was probably important stuff and not cute romantic stuff, but I like to think that sometimes it was :) and it makes me want to make up a secret cipher for me and my husband and write cool letters! I never realized why Parley P. Pratt was killed, all because that stupid 1st husband of his wife killed him, that stinks! I wish that they could've got away and pulled everything off. And the last thing, (that I can think of) that I thought was cool, was the Larrabee's Cipher! That would be really fun to do! Make up some code word and then write it all out! I think this stuff is so fun and cool to learn about! Thanks for letting us do that!

Sec 3.2, 3.3, Due Sept 4th

1. The part that was a little more difficult for me to remember and learn again was the Division and fractions with congruences. I understand it, it just requires a little bit of busy work to do the extended EA, and plug stuff in, and find out what is the multiplicative inverse. So it all makes sense pretty much, it just took me a little while to remember and get it down. Also, the section about what if d > 1, it all makes since, but I just think that I'd like to see more examples. So yeah, mostly the division and fractions with congruence, I just need to practice a few examples to really get it down.
2. I really liked that we covered this stuff in 371, it helped me to be able to read it and remember the things that I had learned and go back and look at my homework and make sure that I really know the stuff. It took me a couple examples to remember the extended Euclidean Algorithm, but I remember it. I like all the Congruences and Modular arithmetic, I think that stuff is fun and interesting.

Sec. 1.1-1.2, 3.1, due Sept 2nd

1. The most difficult part of this reading assignment was just getting used to the language used in cryptography and trying to wrap my brain around it's concepts. For example, when I read about Public key communication, I was kind of confused trying to imagine what they were saying in a real life example, but when they gave us a nonmathematical example, it immediately made sense!
It also took me awhile to understand how they tried to explain the other way that you can find the gcd of two numbers. I don't know if it was just the wording of that paragraph (which is was I think) or what, but it took me a little while and I had to look at the examples. I think I understand it, it probably doesn't matter now, but I think I got it down. I just like the way we did it; using the Euclidean algorithm.
2. This stuff is soooo cool to learn about!! I actually enjoyed reading! :) I was wanting to know what a birthday attack was (cause it sounded fun, even though I'm sure it's not as exciting as it sounds). I thought that the one-time pad was really cool to learn about, and would love to learn more. I just didn't know what crazy stuff they had in cryptography, but I've always been fascinated and interested. I also thought it was really interesting to read about all the ways that we're kept safe online with our credit card numbers, digital signatures, and the section about games was pretty sweet too! I can't wait to learn about these things.