
diff -r 9d1cf03d1b32 -r 851a22e8d570 slides/slides07.tex
--- a/slides/slides07.tex	Tue Nov 11 11:50:52 2014 +0000
+++ b/slides/slides07.tex	Tue Nov 11 12:51:33 2014 +0000
@@ -7,6 +7,9 @@
 
 \begin{document}
 
+%% Differential privacy
+%% http://www.cis.upenn.edu/~aaroth/Papers/privacybook.pdf
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \begin{frame}[t]
 \frametitle{%
@@ -18,7 +21,7 @@
 
   \normalsize
   \begin{center}
-  \begin{tabular}{ll}
+  \begin{tabular}{ll}Ch
   Email:  & christian.urban at kcl.ac.uk\\
   Office: & S1.27 (1st floor Strand Building)\\
   Slides: & KEATS (also homework is there)\\
@@ -273,7 +276,7 @@
 \item a company called Datasift is allowed to mine all tweets since 2010
 \item they charge 10k per month for other companies to target advertisement
 \end{itemize}
-\end{itemize}\pause
+\end{itemize}
 
 
 \end{frame}
@@ -365,10 +368,15 @@
 
 
 \begin{itemize}
-\item in 1990 medical databases were made public with names removed, but  birth dates, 
-gender, ZIP-code were retained\medskip
-\item could be cross referenced with public voter registration data in order to find out what the
-medical record of the governor of Massachusetts was (in 1997 Latanya Sweeney)
+
+\item in 1990 medical databases were routinely made public
+      with names removed, but birth dates, gender, ZIP-code
+      were retained\medskip
+
+\item could be cross referenced with public voter registration
+      data in order to find out what the medical record of the
+      governor of Massachusetts was (in 1997 Latanya Sweeney)
+
 \end{itemize}
 
 \end{frame}}
@@ -405,8 +413,9 @@
 \item In 2006, AOL published 20 million Web search queries 
   collected of 650,000 users (names had been deleted)\medskip
   
-\item \ldots{}within days an old lady, Thelma Arnold, from 
-  Lilburn, Georgia, was identified as user No.~4417749\medskip
+\item \ldots{}within days an old lady, Thelma Arnold, from
+      Lilburn, Georgia, (11,596 inhabitants) was identified as
+      user No.~4417749\medskip
   
 \item some of the queries that identified her away:  
 \begin{itemize}
@@ -448,8 +457,7 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}<2>[c]
+\begin{frame}[c]
 \frametitle{\Large We cannot exclude all Harm}
 
 \begin{itemize}
@@ -461,10 +469,28 @@
 \item \ldots of course she is also helped; she might quit smoking
 \end{itemize}
 
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
      
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[c]
+\frametitle{\Large We cannot exclude all Harm}
+
+Supervising queries will also not work in general:
+
+\begin{itemize}
+\item denying a request can already disclose information
+
+\item in general it is not decidable, whether a sequence
+  of queries can identify a person
+\end{itemize}
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+     
+     
+     
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \mode<presentation>{
 \begin{frame}<2>[c]
 \frametitle{Differential Privacy}
@@ -537,7 +563,6 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[c]
 \frametitle{Adding Noise}
 
@@ -563,74 +588,49 @@
 then one individual can change the dataset by \bl{$5$}
 \end{itemize}
 
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
-\begin{frame}[t]
-\frametitle{\begin{tabular}{@{}c@{}}Tor (private web browsing)\end{tabular}}
+\begin{frame}[c]
+\frametitle{\Large Differential Privacy Problems}
 
 \begin{itemize}
-\item initially developed by US Navy Labs, but then opened up to the world 
-\item network of proxy nodes
-\item a Tor client establishes a ``random'' path to the destination server (you cannot trace back where the information came from)\bigskip\pause
+\item How to do differential privacy ``offline'' is still
+an active research question?
+
+\item What constitutes a single entry in the database?
+
+\item Evolution of a database:
 \end{itemize}
 
-\only<2>{
-\begin{itemize}
-\item malicious exit node attack: someone set up 5 Tor exit nodes and monitored the traffic:
-\begin{itemize}
-\item a number of logons and passwords used by embassies (Usbekistan `s1e7u0l7c', while
-Tunesia `Tunesia' and India `1234')
-\end{itemize}
-\end{itemize}}
-\only<3>{
-\begin{itemize}
-\item bad apple attack: if you have one insecure application, your IP can be tracked through Tor
-\begin{itemize}
-\item background: 40\% of traffic on Tor is generated by BitTorrent
-\end{itemize}
-\end{itemize}}
+\begin{center}\small
+\begin{tabular}{l|ll}
+Name	 & Has the disease?\\\hline
+Alice          & yes\\ 
+Bob     	 & no\\
+Charlie	 & yes\\
+Eve	         & no\\
+Chandler	 & yes\\
+Marc       & yes & $\Leftarrow$ new entry\\
+\end{tabular}
+\end{center}
 
-
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[c]
-\frametitle{Tor Nodes}
+\frametitle{Tor}
 
-Dan Egerstad wrote:\bigskip
-
-\it ``If you actually look in to where these Tor nodes are hosted and how big they are, some of these nodes cost thousands of dollars each month just to host because they're using lots of bandwidth, they're heavy-duty servers and so on. Who would pay for this and be anonymous?" 
-
-
-\end{frame}}
+\begin{center}
+??
+\end{center}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
 
 
-
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[t]
-\frametitle{\begin{tabular}{@{}c@{}}Skype\end{tabular}}
-
-\begin{itemize}
-\item Skype used to be known as a secure online communication (encryption cannot be disabled), 
-but \ldots\medskip
-
-\item it is impossible to verify whether crypto algorithms are correctly used, or whether  there are backdoors.\bigskip
- 
-\item recently someone found out that you can reset the password of somebody else's
-account, only knowing their email address (needed to suspended the password reset feature temporarily)
-\end{itemize}
-
-
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
      
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \begin{frame}[c]




