Assignment 5

Probably the things I least understood about the readings in section 2.1-2.2 was how the attack method of chosen plaintext and chosen ciphertext work.  The other methods of attack made sense, especially those in the affine section, since they were related to how one would find the equation for the line, given two points.  The only difficulty in the known plaintext method of attack for me was the problem that arose when there were two solutions, I didn't quite understand that method.

Section 2.4 was especially interesting to me, since it showed me the power of a properly used substitution cipher.  I would have never thought to use digrams to help crack a substitution cipher, but it makes so much sense to do so.  There is much more to cryptography than I realize.