Adding some rough notes and thoughts.

drafts/Chapter03-01-Glossary.md

@@ -35,7 +35,7 @@ Examples of Networks:
 
 Think about what a network sees when it sees you. On some you look like a billing point, little more than an amount of money owed, with a individual ID number. On some you look like a series of paths: think about cell phone towers and ATM withdrawals. In a medical network, you look like a series of diagnoses, vital statistics, and a place where medical professional time and drugs vanish. That's what the you-shaped hole in that network looks like. To the electrical grid your house looks like a point where power vanishes and money comes out. On a smart grid, that portrait is a little more complex. What do you look like on a phone network? You look like data, metadata, and paths from tower to tower. Time stamps, locations, and connections out to nodes on the internet tell the story of your day, and much of your life.
 
-Network surveillance is often vital to make our lives good and healthy, or to simply build this. Most surveillance, good or bad, is built on how networks operate on the physical level. They're not nefarious, they're physics.
+Most surveillance, good or bad, is built on how networks operate on the physical level. They're not nefarious, they're physics.
 
 We live with and in networks every minute of every day. These networks lay over each other and touch all over the place. Once we start thinking about them, what they're shaped like, where we are in them, our contemporary world starts to make more sense.
 
@@ -61,13 +61,17 @@ Wikipedia's [HTTPS entry](https://en.wikipedia.org/wiki/HTTPS)
 
 ## What is Encryption
 
-https://en.wikipedia.org/wiki/Encryption
+[Wikipedia's entry on Encryption](https://en.wikipedia.org/wiki/Encryption) is a solid overview.
 
-## What is Authentication
+### Key Based Authentication
 
-The passwords lesson is a great resource for explaining the process of authentication.
+Seth Schoen leads a great workshop on key based authentication -- the analogy he uses is this: if you remember anything about mathematics, you might remember that one thing that is pretty easy to do is to multiply two really big numbers together. It takes time, if you're only using a pencil, but you can do it. Factoring the product of two primes, however, is a lot harder.  You can think of key-based encryption as taking advantage of this disparity.
 
 
+## What is Authentication
 
+The passwords lesson is a great resource for explaining the process of authentication. But at it's core, "authentication" is just the process that a system uses to determine that you are who you say you are.
 
 ## What is a Computer (& What is Software)
+
+As ever, [Wikipedia's entry on Computers](https://en.wikipedia.org/wiki/Computer) is an excellent resource for thinking about definitions.