The Imitation Game

Concerning the actual design of the enigma machine, I am still not completely sure how it works.  From what I understand, there are 26 rotors in the machine and at least one of the rotors shifts every time one letter is encrypted.  Then in order to decrypt, you would need to know the initial settings of the encryption machine, and it would simply go backwards?  Or I guess you would need to know the terminal settings so that it could go backwards?  I am not entirely sure?  And how does the key work?

I actually would like to talk to you about some of these questions, and others that I have including:

-How does the key work?  Our example in class was PGH PGH PGH.  Why was it sent three times?
-Why did eliminating the diagonal help them to solve the message quicker?  What exactly does that mean?
-I understand that if they could predict certain words that would be used in the cipher texts (like weather and Hitler) but how did knowing the ways that people would choose random words help them?  Like that woman who predicted that Cilly was the name of his girlfriend?  Why were they instructed to use 5 random letters at the beginning of every message?  It would make it harder to crack I presume?

I guess that movie was really interesting and moving, but as far as Cryptography goes, it just left me with more questions.  I guess I will see you again in your office!!

Oh and by the way, I was happy to at least know what a Beale cipher was, all because of that tedious, tedious (but fun) project!

16.1, Due November 30

1) Honestly, I am throughly confused.  I am not sure that I really understand how the elliptic curves are even used to factor integers.  I really don't even understand the difference between elliptic integrals and elliptic curves.
2)I think once I understand how this helps us to factor integers, that will be the most interesting part to me, because as of now it is just confusing.  I think it is pretty cool that from an two points on the curve, we can produce a third point on the curve.

18.1-18.2, Due November 24

1)I am not sure I totally understand parity.  What is a two dimensional parity code?  Hopefully we will actually go through all of these codes.  How is this correcting errors?  And what does it mean to go through a noisy channel?
2) It is pretty cool that they have actually found a way to correct errors.

November 20th

1)I don't think I fully understand how finding the period of a sequence will help us to somehow factor n?
2) I really loved the real-life examples that he provided.

19.1,19.2 Due November 181

1)What is a complex conjugate?  I am not sure I fully understand the notation and why a^2+b^2 would equal 1 in chapter 19.1.  Then in chapter two, if alice and Bob agreed on errors in the data previously, why would Bob have a 25% chance that he will measure the wrong value?  Is there a way to be more correct.
2)I really loved reading about the light photons.  Maybe I should be a physics major?

14.1-14.2, Due November 16

1)I understand the general idea but I am not sure I fully understand the algorithm in the Feige-Fiat-Shamir Identification scheme
2) It is interesting now to see the opposite of public key systems with zero-knowledge techniques.

Due November 13

• Which topics and ideas do you think are the most important out of those we have studied?
• What kinds of questions do you expect to see on the exam?
• What do you need to work on understanding better before the exam?

-RSA and the different attacks on RSA, as well as hash and signature functions

-I expect to see a lot of conceptual questions considering the fact that we need a computer to solve a lot of the problems.  I am just not sure how much I will need to memorize before going in.

-1-6 on the study guide, strengths and weaknesses, and memorizing some of the methods.

Dr. Bakker's Talk, November 12

"The Eight" Planet Solar Systems

The 8-planet solar system is part of what inspired people to study mathematics.

Tycho was the last naked-eye astronomer.  Kepler used his this data and studied it for 20 years to get his first, second, and third laws.

Lately gravitational singularities have been studied by mathematicians.

Two types of gravitational singularities: collision and non-collision.

Non-collision singularities have never been observed in the solar system.  Have collision singularities ever been observed in the solar system?

Comet Shoemaker in 1994 is the first ever observed collisions.

It came scarily close to us in October and there are more and more coming close to the earth.

12.1,12.2, Due November 11

1) I guess I don't fully understand how if each person has a different part of the secret, that if only a few members of the group collaborate, they can somehow guess or deduce the other part of the secret?  Also how can we have more than one solution?  The book talks about how if the determinant is not zero, then we have a unique solution, and that happens when we have distinct xk's.  But why would they not be distinct?  Sorry these are probably silly questions.

2) This secret sharing is an idea that I had never really considered before and I think it is really interesting.  Especially when they talked about how they used this same idea to control nuclear weapons in Russia because two out of the three people were needed to actually launch the missiles.  It would be scary to think that one person could have the control to release something like that.

9.1-9.4, due November 9

1) if you sign the message after it has gone through the hash, do we ever get the original message back? Or would we even want to? Because hash functions are not invertible.
2) it's so cool to understand now how the electronic signatures do work that I use in my everyday life.  I am wondering now why we always have to verify we are "not a computer" by typing in weird letters and numbers shown in an image above our text input box.  What does that have to do with our cryptography??

8.4-8.5,8.7 Due November 6

1)I am not sure I fully understand why we are concerned with collisions and the probability of one happening.  How does it apply in real world situations?  What is wrong with two numbers having the same hash value?  I thought the whole point of hash functions is that they are not invertible and it is likely that two values will have the same output.

2) I honestly just thought that the whole probability of two people having the same birthday was pretty interesting and at first unexpected.   But as you observe it further, then you see why it is so plausible.

8.1-8.2, Due November 4

1) I think I understand the main idea of hash functions but I would like to work through examples together in class.  Also, I didn't fully understand the proposition on pg. 221.
2) I think it is interesting that we are looking at a crypto system that is not invertible.  Does this mean that decryption is totally different?

7.3-7.5, Due November 2

1) I definitely had troubles understanding the lea.  I am also wondering why we are focusing specifically on log 4.  And then why is it comparing the values 6 and 16 to L2(9), which are the same mod 4.

2)  I thought exchange between Alice and Bob is interesting, where Alice can make predictions, send it to Bob.  Although it is in his possession, she is still the one to remove the lock.