\documentclass[dvipsnames,14pt,t]{beamer}

% beamer stuff 

%Bank vs Voting

%http://www.parliament.vic.gov.au/images/stories/committees/emc/2010_Election/submissions/13_VTeague_EMC_Inquiry_No.6.pdf

% first cyber attack

%http://investigations.nbcnews.com/_news/2013/03/18/17314818-cyberattack-on-florida-election-is-first-known-case-in-us-experts-say

\begin{document}

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\frametitle{%

  \begin{tabular}{@ {}c@ {}}

  \\

  \LARGE Access Control and \\[-3mm] 

  \LARGE Privacy Policies (2)\\[-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}

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\begin{frame}[c]

\frametitle{\begin{tabular}{c}This Course is about\\[-2mm]  ``Satan's Computer''\end{tabular}}

Ross Anderson and Roger Needham wrote:\bigskip

``In effect, our task is to program a computer which gives 

answers which are subtly and maliciously wrong at the most 

inconvenient possible moment\ldots{} we hope that the lessons 

learned from programming Satan's computer may be helpful 

in tackling the more common problem of programming Murphy's.''

\only<2>{

\begin{tabular}{c}

\includegraphics[scale=0.12]{pics/ariane.jpg}\\[-2mm]

\footnotesize Murphy's computer

\end{tabular}

\begin{tabular}{c}

\includegraphics[scale=0.15]{pics/mobile.jpg}\;

\includegraphics[scale=0.06]{pics/pinsentry.jpg}\\[-2mm]

\footnotesize Satan's computers

\end{tabular}

\end{textblock}}

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\begin{frame}[c]

\frametitle{Today's Lecture}

\begin{center}

\begin{tabular}{cc}

\large online banking  & \hspace{6mm}\large e-voting\\

\textcolor{gray}{solved} & \hspace{6mm}\textcolor{gray}{unsolved}\\

\end{tabular}

\end{center}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\begin{frame}[t]

\frametitle{\begin{tabular}{@ {}c@ {}}Traditional Ballot Boxes\end{tabular}}

\begin{center}

\includegraphics[scale=2.5]{pics/ballotbox.jpg}

\end{center}\pause\bigskip

they need a ``protocol''

\end{frame}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\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

\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}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\begin{frame}[c]

Which security requirements do paper ballots satisfy better than voice voting?\bigskip

\begin{itemize}

\item Integrity

\item Enfranchisement

\item Ballot secrecy

\item Voter authentication

\item Availability

\end{itemize}

\end{frame}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\begin{frame}[c]

\frametitle{\begin{tabular}{@ {}c@ {}}DREs\end{tabular}}

Direct-recording electronic voting machines\\ 

(votes are recorded for example on memory cards)

typically touchscreen machines

usually no papertrail

\begin{center}

\includegraphics[scale=0.56]{pics/dre1.jpg}

\end{center}

\end{frame}}

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\mode<presentation>{

\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 they try to keep secret the source code running the machine\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}}

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\mode<presentation>{

\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}}

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\mode<presentation>{

\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}