\documentclass[dvipsnames,14pt,t]{beamer}+ −
\usepackage{../slides}+ −
\usepackage{../langs}+ −
\usepackage{../graphics}+ −
\usepackage{../data}+ −
\usepackage{../grammar}+ −
+ −
% beamer stuff + −
\renewcommand{\slidecaption}{APP 11, King's College London}+ −
\newcommand{\bl}[1]{\textcolor{blue}{#1}}+ −
+ −
\begin{document}+ −
+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%+ −
\begin{frame}[t]+ −
\frametitle{%+ −
\begin{tabular}{@ {}c@ {}}+ −
\\+ −
\LARGE Access Control and \\[-3mm] + −
\LARGE Privacy Policies (11)\\[-6mm] + −
\end{tabular}}\bigskip\bigskip\bigskip+ −
+ −
\normalsize+ −
\begin{center}+ −
\begin{tabular}{ll}+ −
Email: & christian.urban at kcl.ac.uk\\+ −
Office: & S1.27 (1st floor Strand Building)\\+ −
Slides: & KEATS (also homework is there)\\+ −
\end{tabular}+ −
\end{center}+ −
+ −
\end{frame}+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%+ −
\begin{frame}[c]+ −
+ −
\begin{itemize}+ −
\item you can still send me your homework\bigskip + −
\item Unix AC question: use a terminal-based editor (vm, + −
vim)\bigskip + −
\item exams: 2 out of 3 questions, 5 or so subquestions + −
each, you can fill in your answers on the question sheet+ −
\end{itemize}+ −
+ −
\end{frame}+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
+ −
+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%+ −
\begin{frame}[c]+ −
\frametitle{Interlock Protocol}+ −
+ −
The interlock protocol (``best bet'' against MITM):+ −
+ −
\begin{center}+ −
\begin{tabular}{ll@{\hspace{2mm}}l}+ −
1. & \bl{$A \to B :$} & \bl{$K^{pub}_A$}\\+ −
2. & \bl{$B \to A :$} & \bl{$K^{pub}_B$}\\+ −
3. & & \bl{$\{A,m\}_{K^{pub}_B} \;\mapsto\; H_1,H_2$}\\+ −
& & \bl{$\{B,m'\}_{K^{pub}_A} \;\mapsto\; M_1,M_2$}\\+ −
4. & \bl{$A \to B :$} & \bl{$H_1$}\\+ −
5. & \bl{$B \to A :$} & \bl{$\{H_1, M_1\}_{K^{pub}_A}$}\\+ −
6. & \bl{$A \to B :$} & \bl{$\{H_2, M_1\}_{K^{pub}_B}$}\\+ −
7. & \bl{$B \to A :$} & \bl{$M_2$}+ −
\end{tabular}+ −
\end{center}\pause+ −
+ −
\footnotesize+ −
\bl{$m$} = How is your grandmother? \bl{$m'$} = How is the+ −
weather today in London?+ −
+ −
\end{frame}+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%+ −
\begin{frame}[c]+ −
+ −
\begin{center}+ −
\begin{tabular}{l@{\hspace{9mm}}l}+ −
\begin{tabular}[t]{@{}l@{}}+ −
\bl{$A \to C : K^{pub}_A$}\\+ −
\bl{$C \to B : K^{pub}_C$}\\+ −
\bl{$B \to C : K^{pub}_B$}\\+ −
\bl{$C \to A : K^{pub}_C$}\medskip\\+ −
\bl{$\{A,m\}_{K^{pub}_C} \;\mapsto\; H_1,H_2$}\\+ −
\bl{$\{B,n\}_{K^{pub}_C} \;\mapsto\; M_1,M_2$}\bigskip\\+ −
\bl{$\{C,a\}_{K^{pub}_B} \;\mapsto\; C_1,C_2$}\\+ −
\bl{$\{C,b\}_{K^{pub}_A} \;\mapsto\; D_1,D_2$}+ −
\end{tabular} &+ −
\begin{tabular}[t]{@{}l@{}}+ −
\bl{$A \to C : H_1$}\\+ −
\bl{$C \to B : C_1$}\\+ −
\bl{$B \to C : \{C_1, M_1\}_{K^{pub}_C}$}\\+ −
\bl{$C \to A : \{H_1, D_1\}_{K^{pub}_A}$}\\+ −
\bl{$A \to C : \{H_2, D_1\}_{K^{pub}_C}$}\\+ −
\bl{$C \to B : \{C_2, M_1\}_{K^{pub}_B}$}\\+ −
\bl{$B \to C : M_2$}\\+ −
\bl{$C \to A : D_2$}+ −
\end{tabular}+ −
\end{tabular}+ −
\end{center}+ −
+ −
\end{frame}+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%+ −
\begin{frame}[c]+ −
+ −
\begin{itemize}+ −
\item you have to ask something that cannot imitated + −
(requires \bl{$A$} and \bl{$B$} know each other)+ −
\item what happens if \bl{$m$} and \bl{$n$} are voice+ −
messages?\bigskip + −
+ −
\item the moral: establishing a secure connection from ``zero'' is+ −
almost impossible---you need to rely on some established + −
trust\medskip+ −
+ −
\item that is why we rely on certificates, which however are+ −
badly, badly realised (just today a POODLE attack against SSL)+ −
+ −
\end{itemize}+ −
+ −
\end{frame}+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
+ −
+ −
+ −
+ −
\end{document}+ −
+ −
+ −
%%% Local Variables: + −
%%% mode: latex+ −
%%% TeX-master: t+ −
%%% End: + −
+ −