diff -r e7e69a217f83 -r d2e522c2bfdf handouts/ho05.tex
--- a/handouts/ho05.tex	Thu Oct 27 11:15:37 2016 +0100
+++ b/handouts/ho05.tex	Thu Oct 27 13:50:11 2016 +0100
@@ -827,6 +827,18 @@
 \subsubsection*{Further Reading}
 
 \begin{itemize}
+\item A nice video explaining the Hellman-Diffie key excahnge technique
+  is here
+
+  \begin{center}
+  \url{https://www.youtube.com/watch?v=YEBfamv-_do}
+  \end{center}  
+
+  The main point of this technique is that no sensitive information
+  is sent over the network---both parties create the key together.
+  While the technique is cryptographic magic, it can be attacked
+  when messages can be manipulated during transit.
+  
 \item A blogpost that describes the first few milliseconds of
       an HTTPS connection is at