3.8 and 2.5-2.8, due on September 15

1. (Difficult) I initially thought that the concepts of diffusion and confusion were simple to understand, but as I kept reading I became a little more confused.  It makes sense why changing one character in the plain text causing many changes in the ciphertext makes things more difficult.  I don't know that I fully comprehend why, though, not having these properties makes frequency analysis easier.  I think I'm close but not quite there, but could probably understand it better with a little more thought.
2. (Reflective) Having taken CS 465 I am somewhat familiar with more modern cryptosystems than what we have been looking at so far.  It is interesting to notice how they ciphers we are studying are progressing towards what people use today (e.g. putting things in rows an columns, being concerned with the diffusion and confusion principles).  I would be curious to know how creators of various cryptosystems used existing ideas, or perhaps we are just learning things this way to help us understand more complicated systems better, rather than representing what actually happened in the history of the development of cryptosystems?
   (I might have discussed this idea in a previous blog)