--- a/handouts/ho07.tex Thu Dec 03 13:46:18 2015 +0000
+++ b/handouts/ho07.tex Tue Jan 05 01:37:31 2016 +0000
@@ -12,6 +12,7 @@
%http://www.cs.cmu.edu/~yuxiangw/docs/Differential%20Privacy.pdf
%https://www.youtube.com/watch?v=Gx13lgEudtU
%https://fpf.org/wp-content/uploads/Differential-Privacy-as-a-Response-to-the-Reidentification-Threat-Klinefelter-and-Chin.pdf
+%http://research.neustar.biz/2014/09/08/differential-privacy-the-basics/
\section*{Handout 7 (Privacy)}
--- a/handouts/ho08.tex Thu Dec 03 13:46:18 2015 +0000
+++ b/handouts/ho08.tex Tue Jan 05 01:37:31 2016 +0000
@@ -877,3 +877,6 @@
The Bitcoin Backbone Protocol: Analysis and Applications
https://eprint.iacr.org/2014/765.pdf
+
+Bitcoin book
+http://chimera.labs.oreilly.com/books/1234000001802/ch04.html#public_key_derivation
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--- a/hws/hw05.tex Thu Dec 03 13:46:18 2015 +0000
+++ b/hws/hw05.tex Tue Jan 05 01:37:31 2016 +0000
@@ -49,19 +49,6 @@
Write down three facts that $A$ can infer after this protocol has been
successfully completed?
-\item (\textbf{Deleted}: same as 2) Before starting a TCP connection, client and servers
-perform a three-way handshake:
-
-\begin{center}
-\begin{tabular}{rl}
-$A \rightarrow S$: & SYN\\
-$S \rightarrow A$: & SYN-ACK\\
-$A \rightarrow S$: & ACK\\
-\end{tabular}
-\end{center}
-
-How can this protocol be abused causing trouble on the server?
-
\item Write down a protocol which establishes a secret key
between $A$ and $B$ using a mutually trusted third party $S$.
You can assume $A$ and $S$, respectfully $B$ and $S$, share
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--- a/hws/hw08.tex Thu Dec 03 13:46:18 2015 +0000
+++ b/hws/hw08.tex Tue Jan 05 01:37:31 2016 +0000
@@ -3,6 +3,13 @@
\begin{document}
+
+% For Alice to cheat, she has to get her transaction into the blockchain.
+% For this she has to solve proof-of-work puzzles faster than anybody
+% else. Is it possible for her to precompute several blocks that would
+% validate a fraudulent transaction by her? Give a short explanation
+% for your reasoning.
+
\section*{Homework 8}
\begin{enumerate}
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--- a/slides/slides12.tex Thu Dec 03 13:46:18 2015 +0000
+++ b/slides/slides12.tex Tue Jan 05 01:37:31 2016 +0000
@@ -81,6 +81,29 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{frame}[t]
+\frametitle{Bitcoins for Real}
+
+\begin{itemize}
+\item you need a public-private key (the hash of the
+public key to determines your bitcoin address)
+
+\item if you want to receive bitcoins, you publicise
+this address
+
+\item there are $2^{160}$ possibilities\\
+(no check for duplicates)\bigskip\pause
+
+\item transactions contain ``payment scripts''
+ (non-Turing-complete scripting language)\bigskip
+
+ \small simplest script: pay-to-public-key
+\end{itemize}
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[t]
\frametitle{Bitcoin Keys}
\begin{center}
@@ -349,8 +372,8 @@
\small
\[
-\bl{\begin{array}{@{}l@{}}\text{New}\\ \text{Difficulty}\end{array} \dn
-\begin{array}{@{}l@{}}\text{Old}\\ \text{Difficulty}\end{array}
+\bl{\begin{array}{@{}l@{}}\text{New}\\ \text{Hardness}\end{array} \dn
+\begin{array}{@{}l@{}}\text{Old}\\ \text{Hardness}\end{array}
* \frac{\text{Actual time for the last 2016 blocks}}{20160}}
\]
@@ -561,29 +584,6 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[t]
-\frametitle{Bitcoins for Real}
-
-\begin{itemize}
-\item you need a public-private key (the hash of the
-public key to determines your bitcoin address)
-
-\item if you want to receive bitcoins, you publicise
-this address
-
-\item there are $2^{160}$ possibilities\\
-(no check for duplicates)\bigskip\pause
-
-\item transactions contain ``payment scripts''
- (non-Turing-complete scripting language)\bigskip
-
- \small simplest script: pay-to-public-key
-\end{itemize}
-
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{frame}[t]
@@ -682,7 +682,8 @@
(you cannot charge them back)\ldots{} bad luck
\item you can send bitcoins to a ``non-existing'' address
- (Mt.~Gox)
+
+\item you send them to a script that can never be satisfied
\end{itemize}
\end{frame}
@@ -715,6 +716,7 @@
\begin{itemize}
\item Don't gamble! I am not a first mover in such things.
\item Cool idea, but I am sure there will be a Bitcoin~2.0.
+ (can for example mining pools force to be paid more?)
\item It still depends on a lot of old-fashioned security
(e.g.~keeping private-keys secret)\bigskip
--- a/style.sty Thu Dec 03 13:46:18 2015 +0000
+++ b/style.sty Tue Jan 05 01:37:31 2016 +0000
@@ -41,7 +41,8 @@
\newcommand{\HEADER}{{\bf Please submit your solutions to the
-email address 7ccsmsen at gmail dot com. Please submit only
+email address 7ccsmsen at gmail dot com. Please submit only one
+homework per email. Please also submit only
ASCII text or PDFs. Every solution should be preceded by the
corresponding question, like: