commit 0aa5191a8c9d75ad1a6a0ea938acbf56a2c27408
parent 67eda62bad31fd331af76db9afd61f7d58042a46
Author: Christian Grothoff <grothoff@gnunet.org>
Date: Fri, 15 Dec 2023 12:19:28 +0800
update cbt slides
Diffstat:
1 file changed, 36 insertions(+), 338 deletions(-)
diff --git a/presentations/comprehensive/cbt.tex b/presentations/comprehensive/cbt.tex
@@ -204,7 +204,24 @@
\title{GNU Taler}
%\subtitle{}
-\setbeamertemplate{navigation symbols}{ \includegraphics[width=1cm]{tud-logo.pdf} \includegraphics[width=0.4cm]{logo-esen.pdf} \includegraphics[width=1cm]{logo-GlsBank.pdf} \includegraphics[width=0.6cm]{logo-MagNetBank.pdf} \includegraphics[width=0.4cm]{logo-ps.pdf} \includegraphics[width=0.4cm]{logo-nlnet.pdf} \includegraphics[width=0.4cm]{logo-HomoDigitalis.pdf} \includegraphics[width=0.4cm]{logo-codeblau.pdf} \includegraphics[width=1.4cm]{logo-tue.pdf} \includegraphics[width=0.6cm]{logo-visualvest.pdf} \includegraphics[width=1cm]{inria.pdf} \includegraphics[width=0.4cm]{logo-bfh.pdf} \includegraphics[width=1.6cm]{fub.pdf} \includegraphics[width=0.4cm]{ashoka.png} \includegraphics[width=0.4cm]{gnu.png} \includegraphics[width=1cm]{taler-logo-2021-inkscape.pdf} \hfill}
+\setbeamertemplate{navigation symbols}{
+ \includegraphics[width=0.4cm]{logo-bfh.pdf}
+ \includegraphics[width=1.6cm]{fub.pdf}
+ \includegraphics[width=1cm]{tud-logo.pdf}
+ \includegraphics[width=1.4cm]{logo-tue.pdf}
+ \includegraphics[width=1cm]{inria.pdf}
+ \includegraphics[width=1cm]{logo-GlsBank.pdf}
+ \includegraphics[width=0.6cm]{logo-MagNetBank.pdf} \
+ \includegraphics[width=0.6cm]{logo-visualvest.pdf}
+ \includegraphics[width=0.4cm]{ashoka.png}
+ \includegraphics[width=0.4cm]{logo-esen.pdf}
+ \includegraphics[width=0.4cm]{gnu.png}
+ \includegraphics[width=0.4cm]{logo-HomoDigitalis.pdf}
+ \includegraphics[width=0.4cm]{logo-nlnet.pdf}
+ \includegraphics[width=0.4cm]{logo-codeblau.pdf}
+ \includegraphics[width=0.4cm]{logo-ps.pdf}
+ \includegraphics[width=1cm]{taler-logo-2021-inkscape.pdf}
+ \hfill}
%\setbeamercovered{transparent=1}
\author[C. Grothoff]{J. Burdges, F. Dold, {\bf C. Grothoff}, M. Stanisci}
@@ -251,34 +268,6 @@
\section{GNU Taler: Introduction}
-\begin{frame}
- \vfill
- \begin{center}
- {\bf GNU Taler: Introduction}
- \end{center}
- \vfill
-\end{frame}
-
-
-\begin{frame}{GNU Taler}
- \vfill
- \begin{center}
- {\huge {\bf Digital} cash, made \textbf{socially responsible}.}
- \end{center}
- \vfill
- \begin{center}
- \includegraphics[scale=0.3]{taler-logo-2021-inkscape.pdf}
- \end{center}
- \vfill
- \begin{center}
- Privacy-Preserving, Practical, Taxable, Free Software, Efficient
- \end{center}
- \vfill
- \vfill
-\ %
-\end{frame}
-
-
\begin{frame}{What is Taler?}
\framesubtitle{\url{https://taler.net/en/features.html}} \noindent
Taler is
@@ -396,6 +385,20 @@ positives in fraud detection
\vfill
\end{frame}
+
+\begin{frame}{A Bachelor's Thesis Video}
+ \begin{center}
+ \movie[%scale=0.6,
+ autostart,
+ poster]
+ {
+ \includegraphics[height=0.6\textwidth,width=0.8\textwidth]{white.png}
+ }
+ {cs-movie.mp4}
+ \end{center}
+\end{frame}
+
+
\begin{frame}{How does it work?}
We use a few ancient constructions:
\begin{itemize}
@@ -409,238 +412,7 @@ But of course we use modern instantiations.
\end{frame}
-\begin{frame}{Exchange setup: Create a denomination key (RSA)}
- \begin{minipage}{6cm}
- \begin{enumerate}
- \item Pick random primes $p,q$.
- \item Compute $n := pq$, $\phi(n) = (p-1)(q-1)$
- \item Pick small $e < \phi(n)$ such that
- $d := e^{-1} \mod \phi(n)$ exists.
- \item Publish public key $(e,n)$.
- \end{enumerate}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance=1em and 1em, inner sep=0em, outer sep=.3em];
- \node (origin) at (0,0) {\includegraphics[width=0.2\textwidth]{dice.pdf}};
- \node (primes) [draw=none, below = of origin] at (0,0) {$(p, q)$};
- \node (seal) [def, draw=none, below left=of primes]{\includegraphics[width=0.15\textwidth]{seal.pdf}};
- \node (hammer) [def, draw=none, below right=of primes]{\includegraphics[width=0.15\textwidth]{hammer.pdf}};
-
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (primes) -- (origin) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (seal) -- (primes) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (hammer) -- (primes) node [midway, above, sloped] (TextNode) {};
- \end{tikzpicture}
-% \includegraphics[width=0.4\textwidth]{seal.pdf}
- \end{minipage}
-\end{frame}
-
-
-\begin{frame}{Merchant: Create a signing key (EdDSA)}
- \begin{minipage}{6cm}
- \begin{itemize}
- \item pick random $m \mod o$ as private key
- \item $M = mG$ public key
- \end{itemize}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance= 1em and 1em, inner sep=0em, outer sep=.3em];
- \node (origin) at (0,0) {\includegraphics[width=0.2\textwidth]{dice.pdf}};
- \node (m) [draw=none, below = of origin] at (0,0) {$m$};
- \node (seal) [draw=none, below=of m]{M};
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (m) -- (origin) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (seal) -- (primes) node [midway, above, sloped] (TextNode) {};
- \end{tikzpicture}
- \end{minipage}
- \parbox[t]{3cm}{{\bf Capability:} $m \Rightarrow$ }
- \raisebox{\dimexpr-\height+\baselineskip}{\includegraphics[width=0.1\textwidth]{merchant-sign.pdf}}
-\end{frame}
-
-
-\begin{frame}{Customer: Create a planchet (EdDSA)}
- \begin{minipage}{8cm}
- \begin{itemize}
- \item Pick random $c \mod o$ private key
- \item $C = cG$ public key
- \end{itemize}
- \end{minipage}
- \begin{minipage}{4cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance= 1em and 1em, inner sep=0em, outer sep=.3em];
- \node (origin) at (0,0) {\includegraphics[width=0.2\textwidth]{dice.pdf}};
- \node (c) [draw=none, below = of origin] at (0,0) {$c$};
- \node (planchet) [draw=none, below=of c]{\includegraphics[width=0.4\textwidth]{planchet.pdf}};
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (c) -- (origin) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (planchet) -- (c) node [midway, above, sloped] (TextNode) {};
- \end{tikzpicture}
- \end{minipage}
- \parbox[t]{3cm}{{\bf Capability:} $c \Rightarrow$ }
- \raisebox{\dimexpr-\height+\baselineskip}{\includegraphics[width=0.1\textwidth]{planchet-sign.pdf}}
-\end{frame}
-
-
-\begin{frame}{Customer: Blind planchet (RSA)}
- \begin{minipage}{6cm}
- \begin{enumerate}
- \item Obtain public key $(e,n)$
- \item Compute $f := FDH(C)$, $f < n$.
- \item Pick blinding factor $b \in \mathbb Z_n$
- \item Transmit $f' := f b^e \mod n$
- \end{enumerate}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance= 2em and 0.5em, inner sep=0em, outer sep=.3em];
- \node (origin) at (0,0) {\includegraphics[width=0.2\textwidth]{dice.pdf}};
- \node (b) [def, draw=none, below = of origin] at (0,-0.2) {$b$};
- \node (blinded) [def, draw=none, below right=of b]{\includegraphics[width=0.2\textwidth]{blinded.pdf}};
- \node (planchet) [def, draw=none, above right=of blinded]{\includegraphics[width=0.15\textwidth]{planchet.pdf}};
- \node (exchange) [node distance=4em and 0.5em, draw, below =of blinded]{Exchange};
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (b) -- (origin) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (blinded) -- (planchet) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (blinded) -- (b) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (exchange) -- (blinded) node [midway, above, sloped] (TextNode) {{\small transmit}};
- \end{tikzpicture}
- \end{minipage}
-\end{frame}
-
-
-\begin{frame}{Exchange: Blind sign (RSA)}
- \begin{minipage}{6cm}
- \begin{enumerate}
- \item Receive $f'$.
- \item Compute $s' := f'^d \mod n$.
- \item Send signature $s'$.
- \end{enumerate}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance= 2em and 0.5em, inner sep=0em, outer sep=.3em];
- \node (hammer) [def, draw=none] at (0,0) {\includegraphics[width=0.15\textwidth]{hammer.pdf}};
- \node (signed) [def, draw=none, below left=of hammer]{\includegraphics[width=0.2\textwidth]{sign.pdf}};
- \node (blinded) [def, draw=none, above left=of signed]{\includegraphics[width=0.15\textwidth]{blinded.pdf}};
- \node (customer) [node distance=4em and 0.5em, draw, below =of signed]{Customer};
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (signed) -- (hammer) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (signed) -- (blinded) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (customer) -- (signed) node [midway, above, sloped] (TextNode) {{\small transmit}};
- \end{tikzpicture}
- \end{minipage}
-\end{frame}
-
-
-\begin{frame}{Customer: Unblind coin (RSA)}
- \begin{minipage}{6cm}
- \begin{enumerate}
- \item Receive $s'$.
- \item Compute $s := s' b^{-1} \mod n$ % \\
- % ($(f')^d = (f b^e)^d = f^d b$).
- \end{enumerate}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance= 2em and 0.5em, inner sep=0em, outer sep=.3em];
- \node (b) [def, draw=none] at (0,0) {$b$};
- \node (coin) [def, draw=none, below left=of b]{\includegraphics[width=0.2\textwidth]{coin.pdf}};
- \node (signed) [def, draw=none, above left=of coin]{\includegraphics[width=0.15\textwidth]{sign.pdf}};
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (coin) -- (b) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (coin) -- (signed) node [midway, above, sloped] (TextNode) {};
- \end{tikzpicture}
- \end{minipage}
-\end{frame}
-
-
-\begin{frame}{Customer: Build shopping cart}
- \begin{center}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance= 1em and 1em, inner sep=0em, outer sep=.3em];
- \node (origin) [draw=none] at (0,0) {\includegraphics[width=0.2\textwidth]{cart.pdf}};
- \node (merchant) [node distance=4em and 0.5em, draw, below =of origin]{\includegraphics[width=0.2\textwidth]{shop.pdf}};
- \tikzstyle{C} = [color=black, line width=1pt];
- \draw [<-, C] (merchant) -- (origin) node [midway, above, sloped] (TextNode) {{\small transmit}};
- \end{tikzpicture}
- \end{center}
-\end{frame}
-
-
-\begin{frame}{Merchant: Propose contract (EdDSA)}
- \begin{minipage}{6cm}
- \begin{enumerate}
- \item Complete proposal $D$.
- \item Send $D$, $EdDSA_m(D)$
- \end{enumerate}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance=2em and 0.5em, inner sep=0em, outer sep=.3em];
- \node (cart) [def, draw=none] at (0,0) {\includegraphics[width=0.15\textwidth]{cart.pdf}};
- \node (proposal) [def, draw=none, below right=of cart]{\includegraphics[width=0.5\textwidth]{merchant_propose.pdf}};
- \node (customer) [node distance=4em and 0.5em, draw, below =of proposal]{Customer};
- \tikzstyle{C} = [color=black, line width=1pt];
- \node (sign) [def, draw=none, above right=of proposal] {$m$};
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (proposal) -- (sign) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (proposal) -- (cart) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (customer) -- (proposal) node [midway, above, sloped] (TextNode) {{\small transmit}};
- \end{tikzpicture}
- \end{minipage}
-\end{frame}
-
-
-\begin{frame}{Customer: Spend coin (EdDSA)}
- \begin{minipage}{6cm}
- \begin{enumerate}
- \item Receive proposal $D$, $EdDSA_m(D)$.
- \item Send $s$, $C$, $EdDSA_c(D)$
- \end{enumerate}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{tikzpicture}
- \tikzstyle{def} = [node distance=2em and 0.4em, inner sep=0em, outer sep=.3em];
- \node (proposal) [def, draw=none] at (0,0) {\includegraphics[width=0.15\textwidth]{merchant_propose.pdf}};
- \node (contract) [def, draw=none, below right=of cart]{\includegraphics[width=0.3\textwidth]{contract.pdf}};
- \node (c) [def, draw=none, above=of contract] {$c$};
- \node (merchant) [node distance=4em and 0.5em, draw, below=of contract]{Merchant};
- \node (coin) [def, draw=none, right=of contract]{\includegraphics[width=0.2\textwidth]{coin.pdf}};
- \tikzstyle{C} = [color=black, line width=1pt]
-
- \draw [<-, C] (contract) -- (c) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (contract) -- (proposal) node [midway, above, sloped] (TextNode) {};
- \draw [<-, C] (merchant) -- (contract) node [midway, above, sloped] (TextNode) {{\small transmit}};
- \draw [<-, C] (merchant) -- (coin) node [midway, below, sloped] (TextNode) {{\small transmit}};
- \end{tikzpicture}
- \end{minipage}
-\end{frame}
-
-
-\begin{frame}{Merchant and Exchange: Verify coin (RSA)}
- \begin{minipage}{6cm}
- \begin{equation*}
- s^e \stackrel{?}{\equiv} FDH(C) \mod n
- \end{equation*}
- \end{minipage}
- \begin{minipage}{6cm}
- \begin{minipage}{0.2\textwidth}
- \includegraphics[width=\textwidth]{coin.pdf}
- \end{minipage}
- $\stackrel{?}{\Leftrightarrow}$
- \begin{minipage}{0.2\textwidth}
- \includegraphics[width=\textwidth]{seal.pdf}
- \end{minipage}
- \end{minipage}
+\begin{frame}{Double Spending}
\vfill
The exchange does not only verify the signature, but also
checks that the coin was not double-spent.
@@ -655,15 +427,6 @@ But of course we use modern instantiations.
\section{Offline payments}
-\begin{frame}
- \vfill
- \begin{center}
- {\bf Offline payments}
- \end{center}
- \vfill
-\end{frame}
-
-
\begin{frame}{Requirements: Online vs. Offline Digital Currencies}
\framesubtitle{\url{https://taler.net/papers/euro-bearer-online-2021.pdf}}
\begin{itemize}
@@ -682,22 +445,7 @@ But of course we use modern instantiations.
\end{frame}
-\begin{frame}{Fully Offline Payments {\bf (WiP)}}
-\framesubtitle{\url{https://docs.taler.net/design-documents/030-offline-payments.html}}
-Many central banks today demand offline capabilities for digital payment solutions.
-\vfill
-\noindent
-Three possible approaches:
-\begin{enumerate}
- \item Trust-based offline payments (has counterparty and/or privacy risks)
- \item Full HSM Taler wallet (has hardware costs)
- \item Light-weight HSM balance register
-\end{enumerate}
-\vfill
-\end{frame}
-
-
-\begin{frame}{Partially Offline Payments with GNU Taler\footnote{Joint work with Emmanuel Benoist, Priscilla Huang and Sebastian Marchano}}
+\begin{frame}{Partially Offline Payments with GNU Taler}
\begin{center}
\resizebox{8cm}{7cm}{
@@ -902,28 +650,6 @@ Designed and implemented an age restriction scheme with the following goals:
\end{frame}
-\begin{frame}{Joomla! Taler payment plugin}
-\begin{minipage}{6cm}
- \begin{itemize}
- \item Joomla! is an e-commerce platform
- \item Joomla! payment plugin enables payments via GNU Taler
- \item Features include:
- \begin{itemize}
- \item Trivial configuration
- \item Support for refunds
- \item Full internationalization
- \end{itemize}
- \item Joomla! and its plugins are implemented in PHP
- \end{itemize}
-\end{minipage}
-% FIXME: add screenshots
-%\begin{minipage}{5cm}
-% \includegraphics[width=4cm]{screenshots/woocommerce-cart.png}
-% \includegraphics[width=4cm]{screenshots/woocommerce-settings.png}
-% \end{minipage}
-\end{frame}
-
-
\begin{frame}{Point-of-Sale App for Android}
\begin{minipage}{7cm}
@@ -990,29 +716,13 @@ Designed and implemented an age restriction scheme with the following goals:
\end{frame}
-\begin{frame}{Depolymerization}
- Depolymerization is a bridge between GNU Taler and blockchains,
- making Taler a layer 2 system for crypto-currencies (like Lightning).
-
- \begin{itemize}
- \item Currently implemented for Bitcoin and Ethereum
- crypto-currencies, with the DLTs as the ``RTGS''
- \item Provides same API to Exchange as LibEuFin
-% \item Transaction rate and speed limited by the underlying blockchain
- \item Implemented in Rust
- \end{itemize}
- \begin{center}
- \url{https://bitcoin.ice.bfh.ch/}
- \end{center}
-\end{frame}
-
\section{Performance Experiments}
\begin{frame}
\vfill
\begin{center}
- {\bf Performance}\footnote{Joint work with Marco Boss}
+ {\bf Performance}
\end{center}
\vfill
\end{frame}
@@ -1035,17 +745,6 @@ Designed and implemented an age restriction scheme with the following goals:
\end{frame}
-\begin{frame}{A Bachelor's Thesis Video}
- \begin{center}
- \movie[%scale=0.6,
- autostart,
- poster]
- {
- \includegraphics[height=0.6\textwidth,width=0.8\textwidth]{white.png}
- }
- {cs-movie.mp4}
- \end{center}
-\end{frame}
\section{Future Work \& Conclusion}
@@ -1096,6 +795,7 @@ Designed and implemented an age restriction scheme with the following goals:
\item {\bf The GNU Project}: \\ Integration into FLOSS software
\item {\bf Anastasis SARL}: \\ Distributed key escrow for backups
\item {\bf Fraunhofer Gesellschaft}: \\ Identity management \& SSI \& wallet-to-wallet communication
+ \item {\bf Chelpis (Ming Chih)}: Regional support partner for Taiwan ({\bf new}, \url{https://www.taiwannews.com.tw/en/news/4958467})
% \item {\bf Fiscaltrust GmbH}: \\ Point-of-sale integration ({\bf new})
\end{description}
\end{frame}
@@ -1136,8 +836,6 @@ Designed and implemented an age restriction scheme with the following goals:
\item Parallel verification of RSA signatures on GPUs
\item Tax-deductable receipts for donations to charities
\item Unlinkable anonymous subscriptions and discount tokens
- \item Support for illiterate and innumerate users\footnote{Background: \url{https://myoralvillage.org/}}
- (not yet funded)
\end{itemize}
\end{frame}
