14.1-14.2 due on November 17

1. I thought I understood Identification scheme until it got to the point of where it asks 'what if Peggy doesn't know a square root of y?' I didn't follow the guessing process. Then in the actual Feige-Fiat-Shamir Identification Scheme, I came to realize that I really didn't understand it at all. I think it is compute y that gets me.
2. The story about the fake atm was pretty clever. I think it was just recently that there were people installing code on atms that would record and send peoples' information to the thieves. The Zero-Knowledge Proofs are pretty interesting; it seems like it is based of probability. Yet, there are some differences I feel. 

12.1 - 12.2 due on November 15

1. I didn't understand the Shamir Threshold Scheme at all. I was hoping the example would help me understand, but it didn't. I got lost with the Lagrange interpolating polynomial. With the linear system approach I didn't understand the construction of the matrix. I followed the Blakely method better, but I didn't follow how the plane equations were constructed as well.
2. The whole idea of Threshold schemes are pretty cool. I never really thought about situations that would need such a system, but now after reading, it applies to a lot of different life situations. They seem like a very nice solutions to the problems. 

8.3, 9.5 due on November 10

1. When the author said in 8.3 that "the reader is warned that discussion that follows is fairly technical", I knew I was in trouble. I understood until that padding portion of the SHA-1. I didn't get much after that. With the DSA, I didn't quite understand the verification process and the explanation why it works.
2. It is interesting that both sections we read, that speed was mentioned. The DSA removes one step of modular exponentiation from the ElGamal scheme so it is faster. How much faster are we talking about: milliseconds, seconds, minutes? I am sure it depends on the size of message, so what is the Big-O of it is probably the better question to ask.

8,4-8.5, 8.7 due on November 5

1. When I finished the reading, my summary thoughts were "I guess I don't understand how hash functions work." In 8.7 it didn't sound like like the hash function was much different that the modes of operation found in chapter 4. I also didn't understand the multi-collisions section.
2. The birthday attack is really interesting. It is cool that it is using a probability concept in cryptography. It sounds like there a 70% chance that there are two people in the class with the same birthday.

8.1-8.2 due on November 3

1. I have some difficulty understanding the difference between strongly collision-free and weakly collision-free. They seem to be saying the same thing, but I know there is a significant difference. I also had some difficulty following the example of the discrete log hash.
2. I have heard of hash functions and of MD5 separately. I knew that MD5 had something to do with data integrity. It is cool to piece it all together and get a better understanding. It is interesting that some of the popular hash functions have turned out to fail the strong collision-free requirement. It obviously must be hard to determine. I noticed the text said the the discrete log hash function is "probably" strong collision-free.

7.3-7.5 due November 1

1. I had difficulty understanding how Bob finds the value of b by looking at x mod 4. I followed the example except for that one part. I also didn't understand the Computational Diffie-Hellman Problem and the Decision Diffie-Hellman Problem. What I didn't understand was the significance or how they fit into the rest of it.
2. I was pretty interested in the name of ElGamal. All the algorithms we have covered were named after people. This looked like a code name in Spanish or something. A quick google search revealed this algorithm wasn't any different; it was developed by Dr. Taher ElGamal of Ciaro Egypt, a computer scientist.

7.2 due on October 29

1. What was difficult to understand ... It started at "7.2 Computing Discrete Logs". I felt like I kind of knew what was going in the introductory text, but when I got the the Pohlig-Hellman algorithm, I just got lost. I think the other stuff would follow.
2. Though I didn't understand 7.2.4 the author said that "there is a philosophical reason that we should not expect such an algorithm." It makes wish I understand even more.