--- a/slides/slides09.tex	Tue Dec 03 13:18:10 2013 +0000
+++ b/slides/slides09.tex	Tue Dec 03 13:38:28 2013 +0000
@@ -192,11 +192,13 @@
 \begin{frame}[c]
 \frametitle{Zero-Knowledge Proofs}
 
-Two remarkable properties:\bigskip
+Two remarkable properties of \alert{Zero-Knowledge Proofs}:\bigskip
 
 \begin{itemize}
-\item Alice only reveals the fact that she knows a secret, not the secret itself.\bigskip
-\item Having been convinced, Bob cannot use the evidence in order to convince Carol.
+\item Alice only reveals the fact that she knows a secret, not the secret itself (meaning 
+she can convince Bob that she knows the secret).\bigskip
+\item Having been convinced, Bob cannot use the evidence in order to convince Carol 
+that Alice knows the secret.
 \end{itemize}
 
 \end{frame}}
@@ -205,7 +207,7 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \mode<presentation>{
 \begin{frame}[t]
-\frametitle{\begin{tabular}{@{}c@{}}The Idea\end{tabular}}
+\frametitle{\begin{tabular}{@{}c@{}}The Idea \end{tabular}}
 
 \begin{center}
 \begin{tabular}{l@{\hspace{10mm}}r}
@@ -216,6 +218,10 @@
 \end{tabular}
 \end{center}
 
+\begin{textblock}{7}(1,2.5)
+The Alibaba cave:
+\end{textblock}
+
 \small
 \only<2>{
 \begin{textblock}{12}(2,13.3)
@@ -367,8 +373,10 @@
 \frametitle{Problems of ZKPs}
 
 \begin{itemize}
-\item ``grand chess master problem'' (person in the middle)
-\item 
+\item ``grand chess master problem''\\ 
+(person in the middle)\bigskip
+
+\item Alice can have multiple identities; once she committed a fraud she stops using one
 \end{itemize}
 
 \end{frame}}