# HG changeset patch
# User Christian Urban <urbanc@in.tum.de>
# Date 1352807620 0
# Node ID 53e7d51dbc108d1a1fd38ec750ea2dbf961bff1a
# Parent  bc48791bb3a9d60eda486f0628a3c9f86f89e2ce
updated

diff -r bc48791bb3a9 -r 53e7d51dbc10 slides07.pdf
Binary file slides07.pdf has changed
diff -r bc48791bb3a9 -r 53e7d51dbc10 slides07.tex
--- a/slides07.tex	Tue Nov 13 10:46:08 2012 +0000
+++ b/slides07.tex	Tue Nov 13 11:53:40 2012 +0000
@@ -828,16 +828,19 @@
   \begin{frame}[c]
   \frametitle{Exchange of a Fresh Key}
 
+\bl{$A$} and \bl{$B$} share the key \bl{$K_{AB}$} and want to share another key
+
  \begin{itemize}
  \item assumption \bl{$K_{AB}$} is only known to \bl{$A$} and \bl{$B$}\bigskip 
  \item \bl{$A \,\text{sends}\, B :  A, \{N_A\}_{K_{AB}}$} 
  \item \bl{$B\,\text{sends}\, A : \{N_A + 1, N_B\}_{K_{AB}}$}
  \item \bl{$A \,\text{sends}\, B : \{N_B + 1\}_{K_{AB}}$}
   \item \bl{$B \,\text{sends}\, A : \{K^{new}_{AB}, N^{new}_B\}_{K_{AB}}$}
- \end{itemize}\bigskip\pause	
+  \item<2> \bl{$A \,\text{sends}\, B : \{msg\}_{K^{new}_{AB}}$}
+ \end{itemize}\bigskip
   
-  We hope \bl{$K^{new}_{AB}$} is only known to \bl{$A$} and \bl{$B$}.\\
-  \bl{$N^{new}_B$} is to be used in future messages
+  \bl{$N^{new}_B$} is to be used in future messages\\
+  Assume \bl{$K^{new}_{AB}$} is compromised by \bl{$I$}
   \end{frame}}
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    
      
@@ -846,14 +849,22 @@
   \begin{frame}[c]
   \frametitle{The Attack}
 
-An intruder \bl{$I$} convinces \bl{$B$} to accept an old compromised key 
+An intruder \bl{$I$} convinces \bl{$A$} to accept the compromised key \bl{$K^{new}_{AB}$}\medskip 
 
+\begin{minipage}{1.1\textwidth}
 \begin{itemize}
  \item \bl{$A \,\text{sends}\, B :  A, \{N_A\}_{K_{AB}}$} 
  \item \bl{$B\,\text{sends}\, A : \{N_A + 1, N_B\}_{K_{AB}}$}
  \item \bl{$A \,\text{sends}\, B : \{N_B + 1\}_{K_{AB}}$}
-  \item \bl{$B \,\text{sends}\, A : \{K^{new}_{AB}, N^{new}_B\}_{K_{AB}}$}\pause
+  \item \bl{$B \,\text{sends}\, A : \{K^{new}_{AB}, N^{new}_B\}_{K_{AB}}$}\;\;recorded by \bl{$I$}\pause
+  \item \bl{$A \,\text{sends}\, B :  A, \{M_A\}_{K_{AB}}$} 
+ \item \bl{$B\,\text{sends}\, A : \{M_A + 1, M_B\}_{K_{AB}}$}
+ \item \bl{$A \,\text{sends}\, B : \{M_B + 1\}_{K_{AB}}$}
+  \item \bl{$B \,\text{sends}\, I : \{K^{anew}_{AB}, N^{anew}_B\}_{K_{AB}}$}\;intercepted by \bl{$I$}
+  \item \bl{$I \,\text{sends}\, A : \{K^{new}_{AB}, N^{new}_B\}_{K_{AB}}$}\pause
+   \item \bl{$A \,\text{sends}\, B : \{msg\}_{K^{new}_{AB}}$}
  \end{itemize}	
+ \end{minipage}
 
   \end{frame}}
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%