--- a/slides/slides04.tex Mon Oct 21 23:57:41 2013 +0100
+++ b/slides/slides04.tex Tue Oct 22 12:10:01 2013 +0100
@@ -377,13 +377,34 @@
\bl{$O$}'s security level is lower or equal than \bl{$P$}'s.
\end{itemize}\bigskip\bigskip\pause
- E.g.~Generals write orders to officers; officers write oders to solidiers\\
- Firewall: you can read from inside the firewall, but not from outside\\
+ E.g.~Firewalls: you can read from inside the firewall, but not from outside\\
Phishing: you can look at an approved PDF, but not one from a random email\\
\end{frame}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\mode<presentation>{
+\begin{frame}[c]
+\frametitle{\begin{tabular}{@ {}c@ {}}Security Levels (2)\end{tabular}}
+
+\begin{itemize}
+\item Bell --- La Padula preserves data secrecy, but not data integrity\bigskip\pause
+
+\item Biba model is for data integrity
+
+\begin{itemize}
+\item read: your own level and above
+\item write: your own level and below
+\end{itemize}
+\end{itemize}
+
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\mode<presentation>{
\begin{frame}[c]
@@ -434,8 +455,8 @@
\mbox{}
\begin{tabular}{l}
-{\Large \bl{$A\;\text{sends}\; B : \ldots$}}\\
-\onslide<2->{\Large \bl{$B\;\text{sends}\; A : \ldots$}}\\
+{\Large \bl{$A\;\rightarrow\; B : \ldots$}}\\
+\onslide<2->{\Large \bl{$B\;\rightarrow\; A : \ldots$}}\\
\onslide<2->{\Large \;\;\;\;\;\bl{$:$}}\bigskip
\end{tabular}
@@ -462,9 +483,9 @@
\bl{$B \rightarrow A$:} & \bl{$\{N_a, N_b\}_{K_{ab}}$}\\
\bl{$A \rightarrow B$:} & \bl{$N_b$}\\
\end{tabular}
-\end{center}
+\end{center}\pause
-Explain how an attacker \bl{$B'$} can launch an impersonation attack by
+An attacker \bl{$E$} can launch an impersonation attack by
intercepting all messages for \bl{$B$} and make \bl{$A$} decrypt her own challenges.
\end{frame}}
@@ -499,6 +520,135 @@
\begin{frame}[c]
\begin{center}
+\begin{tabular}{ll}
+\bl{$A \rightarrow B$:} & \bl{$N_a$}\\
+\bl{$B \rightarrow A$:} & \bl{$\{N_a, N_b\}_{K_{ab}}$}\\
+\bl{$A \rightarrow B$:} & \bl{$N_b$}\\
+\end{tabular}
+\end{center}
+
+The attack:
+
+\begin{center}
+\begin{tabular}{ll}
+\bl{$A \rightarrow E$:} & \bl{$N_a$}\\
+\textcolor{gray}{$E \rightarrow A$:} & \textcolor{gray}{$N_a$}\\
+\textcolor{gray}{$A \rightarrow E$:} & \textcolor{gray}{$\{N_a, N_a\}_{K_{ab}}$}\\
+\bl{$E \rightarrow A$:} & \bl{$\{N_a, N_a\}_{K_{ab}}$}\\
+\bl{$A \rightarrow E$:} & \bl{$N_a \;\;(= N_b)$}\\
+\end{tabular}
+\end{center}\pause
+
+\small Solutions: \bl{$K_{ab} \not= K_{ba}$} or include an id in the second message
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\mode<presentation>{
+\begin{frame}[c]
+\frametitle{Identify Friend or Foe}
+
+\begin{center}
+\onslide<3->{\mbox{}\hspace{3.4cm}\includegraphics[scale=0.55]{pics/MigInMiddle.jpg}}
+\end{center}
+
+\begin{textblock}{6}(0.3,2)
+\onslide<2->{
+198?: war between Angola (supported by Cuba)
+and Namibia (supported by SA)}
+\end{textblock}
+
+\begin{textblock}{3}(12.5,4.6)
+ \onslide<3->{
+ \begin{tikzpicture}
+ \node at (0,0) [single arrow, fill=red,text=white, rotate=-50, shape border rotate=180]{``bystander''};
+ \end{tikzpicture}}
+ \end{textblock}
+
+\begin{textblock}{3}(10.9,10)
+ \onslide<3->{
+ \begin{tikzpicture}
+ \node at (0,0) [single arrow, fill=red,text=white, rotate=-40, shape border rotate=180]{attacker};
+ \end{tikzpicture}}
+ \end{textblock}
+
+\only<4->{
+\begin{textblock}{6}(0.3,9)
+being outsmarted by Angola/Cuba
+ended SA involvement (?)
+\end{textblock}}
+\only<5->{
+\begin{textblock}{6}(0.3,13)
+IFF opened up a nice side-channel attack
+\end{textblock}}
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+ \mode<presentation>{
+ \begin{frame}[c]
+ \frametitle{Encryption to the Rescue?}
+
+
+ \begin{itemize}
+ \item \bl{$A \,\rightarrow\, B : \{A, N_A\}_{K_{AB}}$}\hspace{1cm} encrypted\bigskip
+ \item \bl{$B\,\rightarrow\, A : \{N_A, K'_{AB}\}_{K_{AB}}$}\bigskip
+ \item \bl{$A \,\rightarrow\, B : \{N_A\}_{K'_{AB}}$}\bigskip
+ \end{itemize}\pause
+
+means you need to send separate ``Hello'' signals (bad), or worse
+share a single key between many entities
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\mode<presentation>{
+\begin{frame}[c]
+\frametitle{Protocol Attacks}
+
+\begin{itemize}
+\item replay attacks
+\item reflection attacks
+\item man-in-the-middle attacks
+\item timing attacks
+\item parallel session attacks
+\item binding attacks (public key protocols)
+\item changing environment / changing assumptions\bigskip
+
+\item (social engineering attacks)
+\end{itemize}
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\mode<presentation>{
+\begin{frame}[c]
+\frametitle{Replay Attacks}
+
+Schroeder-Needham protocol: exchange of a symmetric key with a trusted 3rd-party \bl{$S$}:
+
+\begin{center}
+\begin{tabular}{r@ {\hspace{1mm}}l}
+\bl{$A \rightarrow S :$} & \bl{$A, B, N_A$}\\
+\bl{$S \rightarrow A :$} & \bl{$\{N_A, B, K_{AB},\{K_{AB}, A\}_{K_{BS}} \}_{K_{AS}}$}\\
+\bl{$A \rightarrow B :$} & \bl{$\{K_{AB}, A\}_{K_{BS}} $}\\
+\bl{$B \rightarrow A :$} & \bl{$\{N_B\}_{K_{AB}}$}\\
+\bl{$A \rightarrow B :$} & \bl{$\{N_B-1\}_{K_{AB}}$}\\
+\end{tabular}
+\end{center}\bigskip\pause
+
+at the end of the protocol both \bl{$A$} and \bl{$B$} should be in the possession of the secret key
+\bl{$K_{AB}$} and know that the other principal has the key
+
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\mode<presentation>{
+\begin{frame}[c]
+
+\begin{center}
\begin{tabular}{l}
\bl{$A \rightarrow S :$} \bl{$A, B, N_A$}\\
\bl{$S \rightarrow A :$} \bl{$\{N_A, B, K_{AB},\{K_{AB}, A\}_{K_{BS}} \}_{K_{AS}}$}\\
@@ -519,253 +669,6 @@
talks to \bl{$B$} masquerading as \bl{$A$}
\end{frame}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-\frametitle{\begin{tabular}{c}Privilege Separation in\\ OpenSSH\end{tabular}}
-
-\begin{center}
-\begin{tikzpicture}[scale=1]
-
- \draw[line width=1mm] (0, 1.1) rectangle (1.2,2);
- \draw (4.7,1) node {Internet};
- \draw (0.6,1.7) node {\footnotesize Slave};
- \draw[line width=1mm] (0, 0) rectangle (1.2,0.9);
- \draw (0.6,1.7) node {\footnotesize Slave};
- \draw (0.6,0.6) node {\footnotesize Slave};
- \draw (0.6,-0.5) node {\footnotesize \begin{tabular}{c}unprivileged\\[-1mm] processes\end{tabular}};
- \draw (-2.7,-0.4) node {\footnotesize \begin{tabular}{c}privileged\\[-1mm] process\end{tabular}};
-
- \draw[line width=1mm] (-1.8, 0) rectangle (-3.6,2);
- \draw (-2.9,1.7) node {\footnotesize Monitor};
-
- \draw[white] (1.7,1) node (X) {};
- \draw[white] (3.7,1) node (Y) {};
- \draw[red, <->, line width = 2mm] (X) -- (Y);
-
- \draw[red, <->, line width = 1mm] (-0.4,1.4) -- (-1.4,1.1);
- \draw[red, <->, line width = 1mm] (-0.4,0.6) -- (-1.4,0.9);
-
- \end{tikzpicture}
-\end{center}
-
-\begin{itemize}
-\item pre-authorisation slave
-\item post-authorisation\bigskip
-\item 25\% codebase is privileged, 75\% is unprivileged
-\end{itemize}
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-\frametitle{Network Applications}
-
-ideally network application in Unix should be designed as follows:
-
-\begin{itemize}
-\item need two distinct processes
-\begin{itemize}
-\item one that listens to the network; has no privilege
-\item one that is privileged and listens to the latter only (but does not trust it)
-
-\end{itemize}
-
-\item to implement this you need a parent process, which forks a child process
-\item this child process drops privileges and listens to hostile data\medskip
-
-\item after authentication the parent forks again and the new child becomes the user
-\end{itemize}
-
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-\frametitle{\begin{tabular}{@ {}c@ {}}Security Levels\end{tabular}}
-
-Unix essentially can only distinguish between two security levels (root and non-root).
-
-\begin{itemize}
-\item In military applications you often have many security levels (top-secret, secret, confidential, unclassified)\bigskip\pause
-
-\item Information flow: Bell --- La Padula model
-
-\begin{itemize}
-\item read: your own level and below
-\item write: your own level and above
-\end{itemize}
-\end{itemize}
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-\frametitle{\begin{tabular}{@ {}c@ {}}Security Levels (2)\end{tabular}}
-
-\begin{itemize}
-\item Bell --- La Padula preserves data secrecy, but not data integrity\bigskip\pause
-
-\item Biba model is for data integrity
-
-\begin{itemize}
-\item read: your own level and above
-\item write: your own level and below
-\end{itemize}
-\end{itemize}
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-\frametitle{\begin{tabular}{@ {}c@ {}}Access Control in 2000\end{tabular}}
-
-According to Ross Anderson (1st edition of his book), some senior Microsoft people held the
-following view:
-
-\begin{center}
-\begin{tikzpicture}
-\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm]
-{\begin{minipage}{10.5cm}
-\small Access control does not matter. Computers are becoming single-purpose
-or single-user devices. Single-purpose devices, such as Web servers that deliver a single service, don't
-need much in the way of access control as there's nothing for operating system access controls
-to do; the job of separating users from each other is best left to application code. As for the PC
-on your desk, if all the software on it comes from a single source, then again there's no need
-for the operating system to provide separation. \hfill{}\textcolor{gray}{(in 2000)}
-\end{minipage}};
-\end{tikzpicture}
-\end{center}
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[t]
-\frametitle{\begin{tabular}{@ {}c@ {}}Research Problems\end{tabular}}
-
-\begin{itemize}
-\item with access control we are back to 1970s\bigskip
-
-\only<1>{
-\begin{tikzpicture}
-\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm]
-{\begin{minipage}{10cm}
-\small Going all the way back to early time-sharing systems we systems people regarded the users, and any code they wrote, as the mortal enemies of us and each other. We were like the police force in a violent slum.\\
-\mbox{}\hfill--- Roger Needham
-\end{minipage}};
-\end{tikzpicture}}\pause
-
-\item the largest research area in access control in 2000-07 has been ``Trusted Computing'', but thankfully it
-is dead now\bigskip
-\item a useful research area is to not just have robust access control, but also usable access control --- by programmers and users\\
-(one possible answer is operating system virtualisation, e.g.~Xen, VMWare)\medskip\pause
-
-\item electronic voting
-\end{itemize}
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[t]
-\frametitle{\begin{tabular}{@ {}c@ {}}Mobile OS\end{tabular}}
-
-\begin{itemize}
-\item iOS and Android solve the defence-in-depth problem by \alert{sandboxing} applications\bigskip
-
-\item you as developer have to specify the resources an application needs
-\item the OS provides a sandbox where access is restricted to only these resources
-\end{itemize}
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-\frametitle{\begin{tabular}{@ {}c@ {}}Security Theatre\end{tabular}}
-
-
-Security theatre is the practice of investing in countermeasures intended to provide the
-\underline{feeling} of improved security while doing little or nothing to actually achieve it.\hfill{}\textcolor{gray}{Bruce Schneier}
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-\frametitle{\begin{tabular}{@ {}c@ {}}Security Theatre\end{tabular}}
-
-\begin{itemize}
-\item for example, usual locks and strap seals are security theatre
-\end{itemize}
-
-\begin{center}
-\includegraphics[scale=0.45]{pics/seal.jpg}
-\end{center}
-
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-
-\begin{minipage}{11cm}
-From: Ross Anderson <Ross.Anderson@cl.cam.ac.uk>\\
-To: cl-security-research@lists.cam.ac.uk\\
-Subject: Tip off\\
-Date: Tue, 02 Oct 2012 13:12:50 +0100\\
-
-I received the following tip off, and have removed the sender's
-coordinates. I suspect it is one of many security vendors who
-don't even get the basics right; if you ever go to the RSA
-conference, there are a thousand such firms in the hall, each
-with several eager but ignorant salesmen. A trying experience.\\
-
-Ross
-\end{minipage}
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[c]
-
-\begin{minipage}{11cm}
-I'd like to anonymously tip you off about this\\
-product:\\
-
-{\small http://www.strongauth.com/products/key-appliance.html}\\
-
-It sounds really clever, doesn't it?\\
-\ldots\\
-
-Anyway, it occurred to me that you and your colleagues might have a
-field day discovering weaknesses in the appliance and their
-implementation of security. However, whilst I'd be willing to help
-and/or comment privately, it'd have to be off the record ;-)
-\end{minipage}
-
-\end{frame}}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\mode<presentation>{
\begin{frame}[c]
@@ -804,7 +707,7 @@
{\bf How well does the security solution mitigate those risks?}\bigskip
-Another seemingly obvious question, but one that is frequently ignored. If the security solution doesnÕt solve the problem, it's no good. This is not as simple as looking at the security solution and seeing how well it works. It involves looking at how the security solution interacts with everything around it, evaluating both its operation and its failures.
+Another seemingly obvious question, but one that is frequently ignored. If the security solution doesn't solve the problem, it's no good. This is not as simple as looking at the security solution and seeing how well it works. It involves looking at how the security solution interacts with everything around it, evaluating both its operation and its failures.
\end{frame}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%