16.5, due on December 5

1. (Difficult): I don't remember why x congruent to y2*y1^-a decrypts for the ElGamal Cryptosystem and I forgot how to encrypt a message to a point using Elliptic Curves. The former I can review myself I think but a review of the latter in class would be helpful.

Also, I didn't understand the end of the ElGamal Digital Signatures when it says n=p-1 and when it talks about arbitrary assigned integers to points.

2. (Reflection): The  Elliptic Curve Diffie-Hellman Key Exchange I got! And elliptic addition/multiplication being analogous to regular multiplication/exponentiation makes some sense. That's good.

This is our last blog. Wow time flies!

16.4, due on December 3

1. (Difficult): What does an elliptic curve mod 2 look like? How does it relate to the graph of our other elliptic curves we've dealt with? (How did we know the intersection P=(0,1) on page 361?)

I didn't quite follow the new law of addition. How does it work?

Also, I think I understand the last example of addition in GF(4), but a picture would be really helpful so I know if I'm getting it our not.

2. (Reflection): It is crazy how math builds on each other. Elliptic curves mod 2 seem like such a crazy idea, but it's just a bunch of simple math concepts combined.