Sections 2.9-2.11 One-Time Pads, Pseudo-random Bit Generation, and Linear Feedback Shift Register Sequences

• The most interesting part was learning how we can use recursive relationships as keys in ciphering. From what I understood, you take a message, write it in binary code, then add the key, which happens to have a recursive relationship, then to decipher the message you re-add the key which yields the original code. It's cool that to decipher you just add the key again.
• It was hard to understand the One-Time Pads idea. I'm not sure how you'd get a random key in the way it described. I was a little confused on that, how do you know that the other party got the same key that you got?