diff -r be35ff24cccc -r d1d07f05325a slides04.tex --- a/slides04.tex Sun Dec 09 13:00:33 2012 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,1014 +0,0 @@ -\documentclass[dvipsnames,14pt,t]{beamer} -\usepackage{beamerthemeplainculight} -\usepackage[T1]{fontenc} -\usepackage[latin1]{inputenc} -\usepackage{mathpartir} -\usepackage[absolute,overlay]{textpos} -\usepackage{ifthen} -\usepackage{tikz} -\usepackage{pgf} -\usepackage{calc} -\usepackage{ulem} -\usepackage{courier} -\usepackage{listings} -\renewcommand{\uline}[1]{#1} -\usetikzlibrary{arrows} -\usetikzlibrary{automata} -\usetikzlibrary{shapes} -\usetikzlibrary{shadows} -\usetikzlibrary{positioning} -\usetikzlibrary{calc} -\usepackage{graphicx} - -\definecolor{javared}{rgb}{0.6,0,0} % for strings -\definecolor{javagreen}{rgb}{0.25,0.5,0.35} % comments -\definecolor{javapurple}{rgb}{0.5,0,0.35} % keywords -\definecolor{javadocblue}{rgb}{0.25,0.35,0.75} % javadoc - -\lstset{language=Java, - basicstyle=\ttfamily, - keywordstyle=\color{javapurple}\bfseries, - stringstyle=\color{javagreen}, - commentstyle=\color{javagreen}, - morecomment=[s][\color{javadocblue}]{/**}{*/}, - numbers=left, - numberstyle=\tiny\color{black}, - stepnumber=1, - numbersep=10pt, - tabsize=2, - showspaces=false, - showstringspaces=false} - -\lstdefinelanguage{scala}{ - morekeywords={abstract,case,catch,class,def,% - do,else,extends,false,final,finally,% - for,if,implicit,import,match,mixin,% - new,null,object,override,package,% - private,protected,requires,return,sealed,% - super,this,throw,trait,true,try,% - type,val,var,while,with,yield}, - otherkeywords={=>,<-,<\%,<:,>:,\#,@}, - sensitive=true, - morecomment=[l]{//}, - morecomment=[n]{/*}{*/}, - morestring=[b]", - morestring=[b]', - morestring=[b]""" -} - -\lstset{language=Scala, - basicstyle=\ttfamily, - keywordstyle=\color{javapurple}\bfseries, - stringstyle=\color{javagreen}, - commentstyle=\color{javagreen}, - morecomment=[s][\color{javadocblue}]{/**}{*/}, - numbers=left, - numberstyle=\tiny\color{black}, - stepnumber=1, - numbersep=10pt, - tabsize=2, - showspaces=false, - showstringspaces=false} - -% beamer stuff -\renewcommand{\slidecaption}{APP 04, King's College London, 16 October 2012} - - -\begin{document} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}<1>[t] -\frametitle{% - \begin{tabular}{@ {}c@ {}} - \\ - \LARGE Access Control and \\[-3mm] - \LARGE Privacy Policies (4)\\[-6mm] - \end{tabular}}\bigskip\bigskip\bigskip - - %\begin{center} - %\includegraphics[scale=1.3]{pics/barrier.jpg} - %\end{center} - -\normalsize - \begin{center} - \begin{tabular}{ll} - Email: & christian.urban at kcl.ac.uk\\ - Of$\!$fice: & S1.27 (1st floor Strand Building)\\ - Slides: & KEATS (also homework is there)\\ - \end{tabular} - \end{center} - - -\end{frame}} - %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{Unix-Style Access Control} - -\begin{itemize} -\item Q: ``I am using Windows. Why should I care?'' \\ A: In Windows you have similar AC: - -\begin{center} -\begin{tabular}{l} -administrators group\\ -\hspace{5mm}(has complete control over the machine)\\ -authenticated users\\ -server operators\\ -power users\\ -network configuration operators\\ -\end{tabular} -\end{center}\medskip - -\item Modern versions of Windows have more fine-grained AC than Unix; they do not have a setuid bit, but -have \texttt{runas} (asks for a password).\pause - -\item OS-provided access control can \alert{\bf add} to your -security. -\end{itemize} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{c}Network Applications:\\[-1mm] Privilege Separation\end{tabular}} - - -\begin{center} - \begin{tikzpicture}[scale=1] - - \draw[line width=1mm] (-.3, 0) rectangle (1.5,2); - \draw (4.7,1) node {Internet}; - \draw (-2.7,1.7) node {\footnotesize Application}; - \draw (0.6,1.7) node {\footnotesize Interface}; - \draw (0.6,-0.4) node {\footnotesize \begin{tabular}{c}unprivileged\\[-1mm] process\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[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] (-0.6,1) -- (-1.6,1); - \end{tikzpicture} -\end{center} - -\begin{itemize} -\item the idea is make the attack surface smaller and -mitigate the consequences of an attack -\end{itemize} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{Shared Access Control} - -\begin{center} -\includegraphics[scale=0.7]{pics/pointsplane.jpg} -\end{center} - -\begin{textblock}{11}(10.5,10.5) -\small -To take an action you\\[-1mm] -need at least either: -\begin{itemize} -\item 1 CEO\\[-5mm] -\item 2 MDs, or\\[-5mm] -\item 3 Ds -\end{itemize} -\end{textblock} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{Lessons from Access Control} - -Not just restricted to Unix: - -\begin{itemize} -\item if you have too many roles (i.e.~too finegrained AC), then - hierarchy is too complex\\ - \textcolor{gray}{you invite situations like\ldots let's be root}\bigskip - -\item you can still abuse the system\ldots - -\end{itemize} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}A ``Cron''-Attack\end{tabular}} - -The idea is to trick a privileged person to do something on your behalf: - -\begin{itemize} -\item root:\\\texttt{rm /tmp/*/*}\bigskip\bigskip\pause - -\footnotesize -\begin{minipage}{1.1\textwidth} -\textcolor{gray}{the shell behind the scenes:}\\ -\textcolor{gray}{\texttt{rm /tmp/dir$_1$/file$_1$ /tmp/dir$_1$/file$_2$ /tmp/dir$_2$/file$_1$ \ldots}}\bigskip\\ - -\textcolor{gray}{this takes time} -\end{minipage} -\end{itemize} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}A ``Cron''-Attack\end{tabular}} - -\begin{enumerate} -\item attacker \textcolor{gray}{(creates a fake passwd file)}\\ -\texttt{mkdir /tmp/a; cat > /tmp/a/passwd}\medskip -\item root \textcolor{gray}{(does the daily cleaning)}\\ -\texttt{rm /tmp/*/*}\medskip\\ -\hspace{2cm}\textcolor{gray}{\small records that \texttt{/tmp/a/passwd}}\\ -\hspace{2cm}\textcolor{gray}{\small should be deleted, but does not do it yet}\medskip\\ - -\item attacker \textcolor{gray}{(meanwhile deletes the fake passwd file, and establishes a link to -the real passwd file)}\\ -\texttt{rm /tmp/a/passwd; rmdir /tmp/a;}\\\texttt{ln -s /etc /tmp/a}\\ -\item root now deletes the real passwd file -\end{enumerate} - -\only<2>{ -\begin{textblock}{11}(2,5) -\begin{tikzpicture} -\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm] -{\normalsize\color{darkgray} -\begin{minipage}{9cm}\raggedright -To prevent this kind of attack, you need additional -policies (don't do such operations as root). -\end{minipage}}; -\end{tikzpicture} -\end{textblock}} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}Schneier Analysis\end{tabular}} - -\textcolor{gray}{There is no absolutely secure system and security almost never comes for free.} - -\begin{itemize} -\item What assets are you trying to protect? -\item What are the risks to these assets? -\item How well does the security solution mitigate those risks? -\item What other risks does the security solution cause? -\item What costs and trade-offs does the security solution impose? -\end{itemize} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Example: Credit Cards\end{tabular}} - -You might have the policy of not typing in your credit card online. Worthwhile or not? -\begin{itemize} -\item<2->What assets are you trying to protect?\\ -\only<2>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}your credit card number\end{tabular}} -\item<3->What are the risks to these assets?\\ -\only<3>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -With credit cards you loose a fixed amount \pounds{50}. Amazon \pounds{50}. \end{tabular}} -\item<4->How well does the security solution mitigate those risks?\\ -\only<4>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Well, hackers steal credit cards from databases. They usually do not attack you individually.\end{tabular}} -\item<5->What other risks does the security solution cause? -\only<5>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright None (?)\end{tabular}} -\item<6->What costs and trade-offs does the security solution impose? -\only<6>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright Internet shopping is convenient and sometimes cheaper.\end{tabular}} -\item<7>[]{\bf\large No!} -\end{itemize}\pause\pause - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}Example: Firewalls\end{tabular}} - -\begin{center} -\includegraphics[scale=0.5]{pics/firewall.png} -\end{center} - -A firewall is a piece of software that controls incoming and outgoing traffic according to some rules. -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Example: Firewalls\end{tabular}} - -\begin{itemize} -\item<1->What assets are you trying to protect?\\ -\only<1>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}Whatever is behind the firewall -(credit cards, passwords, blueprints, \ldots)\end{tabular}} -\item<2->What are the risks to these assets?\\ -\only<2>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -With a small online shop you are already at risk. Pentagon, definitely.\end{tabular}} -\item<3->How well does the security solution mitigate those risks?\\ -\only<3>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Well, at home so not much. Everywhere else, if properly configurated then it does.\end{tabular}} -\item<4->What other risks does the security solution cause? -\only<4>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright There might be backdoors or bugs in the firewall, -but generally they are secure. You choose to prevent certain traffic.\end{tabular}} -\item<5->What costs and trade-offs does the security solution impose? -\only<5>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Minimal to modest. Firewalls are part of free software. You need a knowledgeable -person to set them up.\end{tabular}} -\item<7>[]{\bf\large Yes!} -\end{itemize}\pause\pause - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Ex: Two-Factor Authentication\end{tabular}} - -Google uses nowadays two-factor authentication. But it is an old(er) -idea. It is used for example in Germany and Netherlands for online transactions. - -\begin{center} -\includegraphics[scale=0.6]{pics/tan1.jpg}\hspace{5mm} -\includegraphics[scale=0.2]{pics/tan2.jpg} -\end{center} - -\pause -Or nowadays by SMS (restricts the validity of the numbers) or with a secure generator - -\begin{center} -\includegraphics[scale=0.08]{pics/pinsentry.jpg} -\end{center} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Ex: Two-Factor Authentication\end{tabular}} - -\begin{itemize} -\item<1->What assets are you trying to protect?\\ -\only<1>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}Your bank account.\end{tabular}} -\item<2->What are the risks to these assets?\\ -\only<2>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Nowadays pretty high risk.\end{tabular}} -\item<3->How well does the security solution mitigate those risks?\\ -\only<3>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -It prevents problems when passwords are stolen. Man-in-the-middle attacks -still possible.\end{tabular}} -\item<4->What other risks does the security solution cause? -\only<4>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright Your mobile phone or credit card/pin might -be stolen. SIM card becomes more valuable.\end{tabular}} -\item<5->What costs and trade-offs does the security solution impose? -\only<5>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Banks need to establish an infrastructure. For you it might be inconvenient.\end{tabular}} -\item<7>[]{\bf\large Yes!} -\end{itemize} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Security Seals\end{tabular}} - -According to Ross Anderson: ``\ldots is a tamper-indicating device -designed to leave non-erasable, unambiguous evidence of unauthorized -entry or tampering.'' - -\begin{center} -\includegraphics[scale=0.45]{pics/seal.jpg} -\end{center}\mbox{}\\[-12mm] - -They also need some quite sophisticated policies (seal regiment). -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Security Seals (2)\end{tabular}} - -\begin{itemize} -\item at the Argonne National Laboratory they tested 244 different security seals -\begin{itemize} -\item meantime to break the seals for a trained person: 100 s -\item including 19\% that were used for safeguard of nuclear material -\end{itemize}\bigskip - -\item Andrew Appel defeated all security seals which were supposed to keep -voting machines safe -\end{itemize} - - -\only<2>{ -\begin{textblock}{11}(1,1) -\begin{tikzpicture} -\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm] -{\normalsize -\begin{minipage}{11cm}\raggedright\small -\begin{center} -\includegraphics[scale=0.25]{pics/appelseals.jpg} -\end{center} -\begin{center} -\begin{minipage}{10.5cm} -\begin{itemize} -\item The tamper-indicating tape can be lifted using a heat gun. -\item The security screw cap can be removed using a screwdriver, then the -serial-numbered top can be replaced (undamaged) onto a fresh (unnumbered) base. -\item The wire seal can be defeated using a \#4 wood screw. -\item The plastic strap seal can be picked using a jeweler's screwdriver. -\end{itemize} -\end{minipage} -\end{center} -\end{minipage}}; -\end{tikzpicture} -\end{textblock}} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Example: Security Seals\end{tabular}} - -\begin{itemize} -\item<1->What assets are you trying to protect?\\ -\only<1>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}Voting machines, doors.\end{tabular}} -\item<2->What are the risks to these assets?\\ -\only<2>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright Casual thieves, insider attacks.\end{tabular}} -\item<3->How well does the security solution mitigate those risks?\\ -\only<3>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Needs a quite complicated security regiment.\end{tabular}} -\item<4->What other risks does the security solution cause? -\only<4>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright You might not notice tampering.\end{tabular}} -\item<5->What costs and trade-offs does the security solution impose? -\only<5>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -The ``hardware'' is cheap, but indirect costs can be quite high.\end{tabular}} -\item<7>[]{\bf\large No!} {\textcolor{gray}{Though in some areas they work: airports, swimming pools, \ldots}} -\end{itemize} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Ex: Security-by-Obscurity\end{tabular}} - -You might think it is a good idea to keep a security relevant algorithm or -software secret. - -\begin{itemize} -\item<1->What assets are you trying to protect?\\ -\only<1>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}Source code, an algorithm and things that depend on it\end{tabular}} -\item<2->What are the risks to these assets?\\ -\only<2>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Can be pretty high (Oystercards).\end{tabular}} -\item<3->How well does the security solution mitigate those risks?\\ -\only<3>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright -Not really. The source code can be reverse engineered, stolen, coerced \ldots{}\end{tabular}} -\item<4->What other risks does the security solution cause? -\only<4>{\begin{tabular}{@{\hspace{1cm}}p{9cm}}\raggedright You prevent -scrutiny and independent advice. You also more likely than not to -get it wrong.\end{tabular}} -\item<5>[]{\bf\large No!} -\end{itemize} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Voting as Security Problem\end{tabular}} - -What are the security requirements of a voting system?\bigskip - -\begin{itemize} -\item<2->Integrity -\item<3->Ballot Secrecy -\item<5->Voter Authentication -\item<6->Enfranchisement -\item<7->Availability -\end{itemize} - -\only<2>{ -\begin{textblock}{5.5}(8,5) -\begin{tikzpicture} -\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm, text centered] -{\small -\begin{minipage}{5cm}\raggedright -\begin{center} -\begin{minipage}{4.5cm} -\begin{itemize} -\item The outcome matches with the voters' intend. -\item There might be gigantic sums at stake and need to be defended against. -\end{itemize} -\end{minipage} -\end{center} -\end{minipage}}; -\end{tikzpicture} -\end{textblock}} - -\only<4>{ -\begin{textblock}{5.5}(8,5) -\begin{tikzpicture} -\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm, text centered] -{\small -\begin{minipage}{5cm}\raggedright -\begin{center} -\begin{minipage}{4.5cm} -\begin{itemize} -\item Nobody can find out how you voted. -\item (Stronger) Even if you try, you cannot prove how you voted. -\end{itemize} -\end{minipage} -\end{center} -\end{minipage}}; -\end{tikzpicture} -\end{textblock}} - -\only<5>{ -\begin{textblock}{5.5}(8,5) -\begin{tikzpicture} -\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm, text centered] -{\small -\begin{minipage}{5cm}\raggedright -\begin{center} -\begin{minipage}{4.5cm} -\begin{itemize} -\item Only authorised voters can vote up to the permitted number of votes. -\end{itemize} -\end{minipage} -\end{center} -\end{minipage}}; -\end{tikzpicture} -\end{textblock}} - -\only<6>{ -\begin{textblock}{5.5}(8,5) -\begin{tikzpicture} -\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm, text centered] -{\small -\begin{minipage}{5cm}\raggedright -\begin{center} -\begin{minipage}{4.5cm} -\begin{itemize} -\item Authorised voters should have the opportunity to vote. -\end{itemize} -\end{minipage} -\end{center} -\end{minipage}}; -\end{tikzpicture} -\end{textblock}} - -\only<7>{ -\begin{textblock}{5.5}(8,5) -\begin{tikzpicture} -\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm, text centered] -{\small -\begin{minipage}{5cm}\raggedright -\begin{center} -\begin{minipage}{4.5cm} -\begin{itemize} -\item The voting system should accept all authorised votes and produce results in a timely manner. -\end{itemize} -\end{minipage} -\end{center} -\end{minipage}}; -\end{tikzpicture} -\end{textblock}} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Ballot Boxes\end{tabular}} - - -\begin{center} -\includegraphics[scale=2.5]{pics/ballotbox.jpg} -\end{center} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Problems with Voting\end{tabular}} - - -\begin{center}\large -\begin{tabular}{rcl} -Integrity & vs. & Ballot Secrecy\bigskip\\ -Authentication & vs. &Enfranchisement -\end{tabular} -\end{center}\bigskip\bigskip\pause - -Further constraints: - -\begin{itemize} -\item costs -\item accessibility -\item convenience -\item intelligibility -\end{itemize} -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}E-Voting\end{tabular}} - - -\begin{itemize} -\item The Netherlands between 1997 - 2006 had electronic voting machines\\ -\textcolor{gray}{(hacktivists had found: they can be hacked and also emitted radio signals revealing how you voted)} - -\item Germany had used them in pilot studies\\ -\textcolor{gray}{(in 2007 a law suit has reached the highest court and it rejected electronic voting -on the grounds of not being understandable by the general public)} - -\item UK used optical scan voting systems in a few polls -\end{itemize} -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}E-Voting\end{tabular}} - -\mbox{}\\[-12mm] -\begin{itemize} -\item US used mechanical machines since the 30s, later punch cards, now DREs and -optical scan voting machines \textcolor{gray}{(fantastic ``ecosystem'' for study)} - -\item Estonia used in 2007 the Internet for national elections -\textcolor{gray}{(there were earlier pilot studies in other countries)} - -\item India uses e-voting devices since at least 2003\\ -\textcolor{gray}{(``keep-it-simple'' machines produced by a government owned company)} - -\item South Africa used software for its tallying in the 1993 elections (when Nelson Mandela was elected) -\textcolor{gray}{(they found the tallying software was rigged, but they were able to tally manually)} -\end{itemize} -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}A Brief History of Voting\end{tabular}} - - -\begin{itemize} -\item Athenians -\begin{itemize} -\item show of hands -\item ballots on pieces of pottery -\item different colours of stones -\item ``facebook''-like authorisation -\end{itemize}\bigskip - -\textcolor{gray}{problems with vote buying / no ballot privacy}\bigskip - - -\item French Revolution and the US Constitution got things ``started'' with -paper ballots (you first had to bring your own; later they were pre-printed by parties) -\end{itemize} -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Ballot Boxes\end{tabular}} - -Security policies involved with paper ballots: - -\begin{enumerate} -\item you need to check that the ballot box is empty at the start of the poll / no false bottom (to prevent ballot stuffing) -\item you need to guard the ballot box during the poll until counting -\item tallied by a team at the end of the poll (independent observers) -\end{enumerate} - -\begin{center} -\includegraphics[scale=1.5]{pics/ballotbox.jpg} -\end{center} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Paper Ballots\end{tabular}} - -What can go wrong with paper ballots? - -\only<2>{ -\begin{center} -\includegraphics[scale=0.8]{pics/tweet.jpg}\\ -\footnotesize William M.~Tweed, US Politician in 1860's\\ -``As long as I count the votes, what are you going to do about it?'' -\end{center}} - -\only<3>{ -\medskip -\begin{center} -\begin{minipage}{10cm} -{\bf Chain Voting Attack} -\begin{enumerate} -\item you obtain a blank ballot and fill it out as you want -\item you give it to a voter outside the polling station -\item voter receives a new blank ballot -\item voter submits prefilled ballot -\item voter gives blank ballot to you, you give money -\item goto 1 -\end{enumerate} -\end{minipage} -\end{center} -} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Mechanical Voting Machines\end{tabular}} - -\begin{itemize} -\item<1-> Lever Voting Machines (ca.~1930 - 1990) -\only<1>{ -\begin{center} -\includegraphics[scale=0.56]{pics/leavermachine.jpg} -\end{center} -} -\item<2->Punch Cards (ca.~1950 - 2000) -\only<2>{ -\begin{center} -\includegraphics[scale=0.5]{pics/punchcard1.jpg}\;\; -\includegraphics[scale=0.46]{pics/punchcard2.jpg} -\end{center} -} -\end{itemize} - - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[t] -\frametitle{\begin{tabular}{@ {}c@ {}}Electronic Voting Machines\end{tabular}} - -\begin{center} -\begin{tabular}{c} -\includegraphics[scale=0.45]{pics/dre1.jpg}\; -\includegraphics[scale=0.40]{pics/dre2.jpg}\\\hline\\ -\includegraphics[scale=0.5]{pics/opticalscan.jpg} -\end{tabular} -\end{center} - -\only<1->{ -\begin{textblock}{5.5}(1,4) -DREs -\end{textblock}} -\only<1->{ -\begin{textblock}{5.5}(1,11) -Optical Scan -\end{textblock}} - -\only<2>{ -\begin{textblock}{5.5}(0.5,14.5) -all are computers -\end{textblock}} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}DREs\end{tabular}} - -Direct-recording electronic voting machines\\ -(votes are recorded for example memory cards) - -typically touchscreen machines - -usually no papertrail (hard to add: ballot secrecy) - -\begin{center} -\includegraphics[scale=0.56]{pics/dre1.jpg} -\end{center} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}Diebold Machines\end{tabular}} - -The work by J.~Alex Halderman: - -\begin{itemize} -\item acquired a machine from an anonymous source\medskip -\item the source code running the machine was tried to keep secret\medskip\pause - -\item first reversed-engineered the machine (extremely tedious) -\item could completely reboot the machine and even install a virus that infects other Diebold machines -\item obtained also the source code for other machines -\end{itemize} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}Diebold Machines\end{tabular}} - -What could go wrong?\pause \;\;Failure-in-depth.\bigskip\pause - -A non-obvious problem: - -\begin{itemize} -\item you can nowadays get old machines, which still store old polls - -\item the paper ballot box needed to be secured during the voting until counting; -e-voting machines need to be secured during the entire life-time -\end{itemize} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}Paper Trail\end{tabular}} - -Conclusion:\\ Any electronic solution should have a paper trail. - -\begin{center} -\begin{tabular}{c} -\includegraphics[scale=0.5]{pics/opticalscan.jpg} -\end{tabular} -\end{center}\pause - -You still have to solve problems about -Voter registration, voter authentification, guarding against tampering - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}E-Voting in India\end{tabular}} - -Their underlying engineering principle is ``keep-it-simple'': - -\begin{center} -\begin{tabular}{c} -\includegraphics[scale=1.05]{pics/indiaellection.jpg}\;\; -\includegraphics[scale=0.40]{pics/india1.jpg} -\end{tabular} -\end{center}\medskip\pause - -Official claims: ``perfect'', ``tamperproof'', ``no need for technical improvements'' , ``infallible'' -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] -\frametitle{\begin{tabular}{@ {}c@ {}}Lessons to be Learned\end{tabular}} - -\begin{itemize} -\item keep a paper trail and design your system to keep this secure\medskip -\item make the software open source (avoid security-by-obscurity))\medskip -\item have a simple design in order to minimise the attack surface -\end{itemize} - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] - -\begin{center} -\includegraphics[scale=0.56]{pics/Voting1.png} -\end{center} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] - -\begin{center} -\includegraphics[scale=0.56]{pics/Voting2.png} -\end{center} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] - -\begin{center} -\includegraphics[scale=0.56]{pics/Voting3.png} -\end{center} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\mode{ -\begin{frame}[c] - -\begin{center} -\includegraphics[scale=0.56]{pics/Voting4.png} -\end{center} - - -\end{frame}} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - - -\end{document} - -%%% Local Variables: -%%% mode: latex -%%% TeX-master: t -%%% End: -