--- a/slides/slides02.tex	Sat Sep 30 05:28:58 2017 +0100
+++ b/slides/slides02.tex	Mon Oct 02 10:02:48 2017 +0100
@@ -77,43 +77,6 @@
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c]
-\frametitle{Defence in Depth}
-
-\begin{center}\small
-\pcode{urbanc:$6$3WWbKfr1$4vblknvGr6FcDeF92R5xFn3mskfdnEn...:...}
-\end{center}
-
-\begin{itemize}
-\item hashes help when password databases are leaked
-\item salts help with protecting against dictionary attacks
-  and help people who have the same password on different sites\medskip
-
-\item but they do not protect against a focused attack against a single 
-  password and also do not make poorly chosen passwords any better
-\end{itemize}
-
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c]
-\frametitle{Subtle Points}
-
-\begin{itemize}
-\item in our web-application the salt needed to remain secret;
-  in password files the salt is public\bigskip
-
-\item the NYT has the ``resource'' unlocked at first
-  and locks it depending on the cookie data
-\item our ``web-application'' has the resource locked at first,
-  and unlocks it depending on the cookie data
-
-\end{itemize}
-
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \begin{frame}[c]