# HG changeset patch # User Christian Urban # Date 1451957851 0 # Node ID cceb3d2dcba04cf5c84723a25e47c0de6d87a81d # Parent 80fd3cd5675fdaefcc9b8add0bb997c1a099ba25 updated diff -r 80fd3cd5675f -r cceb3d2dcba0 handouts/ho07.tex --- 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)} diff -r 80fd3cd5675f -r cceb3d2dcba0 handouts/ho08.tex --- 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 diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw01.pdf Binary file hws/hw01.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw02.pdf Binary file hws/hw02.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw03.pdf Binary file hws/hw03.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw04.pdf Binary file hws/hw04.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw05.pdf Binary file hws/hw05.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw05.tex --- 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 diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw06.pdf Binary file hws/hw06.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw07.pdf Binary file hws/hw07.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw08.pdf Binary file hws/hw08.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw08.tex --- 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} diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/hw10.pdf Binary file hws/hw10.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 hws/so04.pdf Binary file hws/so04.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 slides/slides12.pdf Binary file slides/slides12.pdf has changed diff -r 80fd3cd5675f -r cceb3d2dcba0 slides/slides12.tex --- 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 diff -r 80fd3cd5675f -r cceb3d2dcba0 style.sty --- 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: