
diff -r f7aa15984301 -r 0379bd6f3d21 slides/slides02.tex
--- a/slides/slides02.tex	Mon Sep 29 21:11:06 2014 +0100
+++ b/slides/slides02.tex	Tue Sep 30 02:22:16 2014 +0100
@@ -57,7 +57,7 @@
 \end{bubble}\\[30mm]
 
 \only<2>{
-\begin{textblock}{11}(3,12)
+\begin{textblock}{11}(3.5,12)
 \begin{tabular}{c}
 \includegraphics[scale=0.12]{pics/ariane.jpg}\\[-2mm]
 \footnotesize Murphy's computer
@@ -76,27 +76,69 @@
 \begin{frame}[c]
 \frametitle{Defence in Depth}
 
-\bgein{center}
+\begin{center}\small
 \pcode{urbanc:$6$3WWbKfr1$4vblknvGr6FcDeF92R5xFn3mskfdnEn...:...}
 \end{center}
 
 \begin{itemize}
 \item hashes help when password databases are leaked
 \item salts help with protecting against dictionary attacks
+  and help people who have the same password on different sites\medskip
+
+\item but they do not protect against a focused attack against a single 
+  password and also do not make poorly chosen passwords any better
+\end{itemize}
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[c]
+\frametitle{Subtle Points}
+
+\begin{itemize}
+\item in our web-application the salt needed to remain secret;
+  in password files the salt is public\bigskip
+
+\item the NYT has the ``resource'' unlocked at first
+  and locks it depending on the cookie data
+\item our ``web-application'' has the resource locked at first,
+  and unlocks it depending on the cookie data
 
 \end{itemize}
 
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[t]
+\frametitle{How to Salt?}
+
+\begin{center}\tt\small
+\begin{tabular}{lcl}
+1salt & $\Rightarrow$ & 8189effef4d4f7411f4153b13ff72546dd682c69\\
+2salt & $\Rightarrow$ & 1528375d5ceb7d71597053e6877cc570067a738f\\
+3salt & $\Rightarrow$ & d646e213d4f87e3971d9dd6d9f435840eb6a1c06\\
+4salt & $\Rightarrow$ & 5b9e85269e4461de0238a6bf463ed3f25778cbba\\
+\end{tabular}
+\end{center}
+
+\begin{itemize}
+\item in Unix systems: \texttt{hash(salt + password)}, or even
+\texttt{hash$^{\texttt{1500}}$(salt + password)}
+
+\end{itemize}
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
+
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \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}\\
+\begin{tabular}{ccc}
+\large online banking  & \hspace{3mm}\large{}vs\hspace{3mm} & \large e-voting\\
+\textcolor{gray}{solved} & & \textcolor{gray}{unsolved}\\
 \end{tabular}
 \end{center}
 
@@ -121,10 +163,7 @@
 
 \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{bubble}[5cm]\small
 \begin{center}
 \begin{minipage}{4.5cm}
 \begin{itemize}
@@ -133,16 +172,12 @@
 \end{itemize}
 \end{minipage}
 \end{center}
-\end{minipage}};
-\end{tikzpicture}
+\end{bubble}
 \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{bubble}[5cm]\small
 \begin{center}
 \begin{minipage}{4.5cm}
 \begin{itemize}
@@ -151,16 +186,12 @@
 \end{itemize}
 \end{minipage}
 \end{center}
-\end{minipage}};
-\end{tikzpicture}
+\end{bubble}
 \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{bubble}[5cm]\small
 \begin{center}
 \begin{minipage}{4.5cm}
 \begin{itemize}
@@ -168,16 +199,12 @@
 \end{itemize}
 \end{minipage}
 \end{center}
-\end{minipage}};
-\end{tikzpicture}
+\end{bubble}
 \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{bubble}[5cm]\small
 \begin{center}
 \begin{minipage}{4.5cm}
 \begin{itemize}
@@ -185,16 +212,12 @@
 \end{itemize}
 \end{minipage}
 \end{center}
-\end{minipage}};
-\end{tikzpicture}
+\end{bubble}
 \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{bubble}[5cm]\small
 \begin{center}
 \begin{minipage}{4.5cm}
 \begin{itemize}
@@ -202,15 +225,13 @@
 \end{itemize}
 \end{minipage}
 \end{center}
-\end{minipage}};
-\end{tikzpicture}
+\end{bubble}
 \end{textblock}}
 
 \end{frame}}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[t]
 \frametitle{\begin{tabular}{@ {}c@ {}}Problems with Voting\end{tabular}}
 
@@ -230,66 +251,143 @@
 \item convenience
 \item intelligibility 
 \end{itemize}
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[t]
-\frametitle{\begin{tabular}{@ {}c@ {}}Traditional Ballot Boxes\end{tabular}}
-
+\frametitle{Traditional Ballot Boxes}
 
 \begin{center}
 \includegraphics[scale=2.5]{pics/ballotbox.jpg}
 \end{center}\pause\bigskip
 
-they need a ``protocol''
+mechanical, but they need a ``protocol''
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}
+\frametitle{Motives for E-Voting}
+
+\begin{itemize}
+\item 76\% of pensioners in the UK vote, but only 44\% of the under-25s\bigskip
+\item convenience\bigskip
+\item speed 
+\end{itemize}
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[t]
+\frametitle{E-Voting}
 
-\end{frame}}
+\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 test polls, but
+  abandoned any wide deployment
+\end{itemize}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[t]
-\frametitle{\begin{tabular}{@ {}c@ {}}E-Voting\end{tabular}}
+\frametitle{E-Voting}
 
-
+\mbox{}\\[-12mm]
 \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 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 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 India uses e-voting devices since at least
+  2003\\ \textcolor{gray}{(``keep-it-simple'' machines produced by a
+    government owned company)}
 
-\item UK used optical scan voting systems in a few polls
+\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}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[t]
-\frametitle{\begin{tabular}{@ {}c@ {}}E-Voting\end{tabular}}
+\frametitle{E-Voting in Estonia}
+
+\begin{itemize}
+\item worlds first general election that used internet voting (2007)
+\item builds on the Estonian ID card (a smartcard like CC)
+\item Internet voting can be used before the election (votes can be changed an
+unlimited amount of times, last vote is tabulated, you can even change your
+vote on the polling day in person)
+\item in the 2011 parliamentary election 24\% voted via Internet\bigskip\pause
+
+\item needs to trust the integrity of voters' computers, 
+  central server components and the election staff
+\end{itemize}
 
-\mbox{}\\[-12mm]
-\begin{itemize}
-\item US used mechanical machines since the 30s, later punch cards, now DREs and 
-optical scan voting machines
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[t]
+
+\footnotesize
+\lstinputlisting[language=Python,xleftmargin=0mm]{../progs/estonia.py}
+
+\begin{textblock}{5.5}(7.8,0.5)
+\begin{bubble}[5cm]\small
+from \url{https://github.com/vvk-ehk/evalimine/}
+\end{bubble}
+\end{textblock}
 
-\item Estonia used in 2007 the Internet for national elections 
-\textcolor{gray}{(there were earlier pilot studies in other countries)}
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
-\item India uses e-voting devices  since at least 2003\\
-\textcolor{gray}{(``keep-it-simple'' machines produced by a government owned company)}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[t]
+E-Voting in \textbf{Theory}
+\small
+\begin{itemize}
+\item Alice prepares and audits a ballot, then casts an encrypted 
+  ballot, which requires her to authenticate to a server.
+
+\item A bulletin board posts Alice's name and encrypted ballot. 
+  Anyone, including Alice, can check the bulletin board and find her 
+  encrypted vote posted.
 
-\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)}
+\item When the election closes, all votes are shuffled and the system produces 
+  a non-interactive proof of a correct shuffling. (zero-knowledge-proofs)
+
+\item After a reasonable complaint period to let auditors check the 
+  shuffling, all shuffled ballots are decrypted, and the system provides 
+  a decryption proof for each decrypted ballot. (zero-knowledge-proofs)
+
+\item Perform a tally of the decrypted votes.
+
+\item An auditor can download the entire election data and verify the 
+  shuffle, decryptions and tally.
 \end{itemize}
-\end{frame}}
+
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \mode<presentation>{
 \begin{frame}[t]
@@ -319,7 +417,7 @@
 \begin{frame}[t]
 \frametitle{\begin{tabular}{@ {}c@ {}}Ballot Boxes\end{tabular}}
 
-Security policies involved with paper ballots:
+Security policies 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)
@@ -336,7 +434,6 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
-\mode<presentation>{
 \begin{frame}[c]
 
 Which security requirements do paper ballots satisfy better than voice voting?\bigskip
@@ -349,8 +446,8 @@
 \item Availability
 \end{itemize}
 
-\end{frame}}
-
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \mode<presentation>{
@@ -387,11 +484,9 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 
-
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[t]
-\frametitle{\begin{tabular}{@ {}c@ {}}Mechanical Voting Machines\end{tabular}}
+\frametitle{\Large Mechanical Voting Machines}
 
 \begin{itemize}
 \item<1-> Lever Voting Machines (ca.~1930 - 1990)
@@ -409,9 +504,7 @@
 }
 \end{itemize}
 
-
-
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -469,7 +562,7 @@
 \begin{frame}[c]
 \frametitle{\begin{tabular}{@ {}c@ {}}Diebold Machines\end{tabular}}
 
-The work by J.~Alex Halderman:
+Alex Halderman:
 
 \begin{itemize}
 \item acquired a machine from an anonymous source\medskip
@@ -542,53 +635,73 @@
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}<1-3>[c]
+\begin{frame}[c]
 \frametitle{\begin{tabular}{@ {}c@ {}}Lessons 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)\\
-{\small\mbox{}\hfill source code for Estonian e-vote included\\ 
-\mbox{}\hfill\textcolor{blue}{\url{http://goo.gl/oRMHAI}}}\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{itemize}\pause
 
-\only<2>{
-\begin{textblock}{9}(3.4,7)
-\begin{tikzpicture}
-\draw (0,0) node[inner sep=2mm,fill=cream, ultra thick, draw=red, rounded corners=2mm] 
-{\normalsize\color{darkgray}
-\begin{minipage}{9cm}\consolas\small
-def analyze(ik, vote, votebox):\\
-\\
-    \#   TODO: implement security checks\\
-    \#   such as verifying the correct size\\
-    \#   of the encrypted vote\\
-\\
-    return []
-\end{minipage}};
-\end{tikzpicture}
-\end{textblock}}
+But overall in times of NSA/state sponsered cyber-crime, e-voting is too
+hard with current technology.
 
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[c]
-\frametitle{Online Banking vs.~E-Voting}
+\frametitle{\Large Online Banking vs.~E-Voting}
 
 \begin{itemize}
-\item online banking: if fraud occurred you try to identify who did what (somebody's account got zero)\bigskip
-\item e-voting: some parts can be done electronically, but not the actual voting (final year project: online voting)
+\item online banking: if fraud occurred you try to identify who did
+  what (somebody's account got zero)\bigskip
+\item e-voting: some parts can be done electronically, but not the
+  actual voting
+\end{itemize}
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[c]
+\frametitle{Student In-Lecture Polling}
+
+\begin{center}
+\includegraphics[scale=0.3]{pics/clicker.png}
+\end{center}
+
+\begin{itemize}
+\item guaranties anonymity
+\item integrity by electronic means\bigskip
+
+\item how to achieve the same in ``software''?
 \end{itemize}
 
 
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[c]
+\frametitle{Anonymity}
 
+\begin{itemize}
+\item anonymity through one-time pads
+\begin{center}
+\includegraphics[scale=0.3]{pics/tan.jpg}
+\end{center}\bigskip\pause
+
+\item solving the problem of distribution
+\begin{center}
+\includegraphics[scale=0.3]{pics/bulletin.jpg}
+\end{center}
+
+\end{itemize}
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \mode<presentation>{
@@ -637,6 +750,7 @@
 
 \end{frame}}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \mode<presentation>{
 \begin{frame}[c]




