Add slides_intro_3.md

2020/2020-02-15_gnuLinuxCourse/slides/ssh_intro_3.md

+# Accessing Computers over Network (Securely)
+
+* Normally, very few ports are open on a modern (LCSB) server
+
+<!-- .element: class="fragment" -->
+* In addition, the communication to and from ports is typically encrypted
+  - Why? Because, between the sender and a recepient there is a whole
+    jungle of transfer network nodes, each of which is potentially
+    [p(owned)][1] by an adversary
+	
+  <!-- .element: class="fragment" -->
+  - For a thorough introduction, see [this set of EFF articles][2]
+  
+  <!-- .element: class="fragment" -->
+  - _Transparency is a virtue of the naive_ 
+	- remember, we're not doing politics
+	
+	<!-- .element: class="fragment" -->
+
+  <!-- .element: class="fragment" -->
+  
+<!-- .element: class="fragment" -->
+* In the context of todays lecture, one type of encrypted
+  communication protocol will help us solve three fundamental
+  questions
+  - How to securely log in to a server?
+  
+  <!-- .element: class="fragment" -->
+  - How to securely interact with a server?
+  
+  <!-- .element: class="fragment" -->
+  - How to securely exchange any kind (and amount) of data with a server?
+  
+  <!-- .element: class="fragment" -->
+  
+<!-- .element: class="fragment" -->
+		
+[1]: https://en.wikipedia.org/wiki/Zombie_(computing)
+[2]: https://ssd.eff.org/