path: root/presentations/comprehensive/main.tex

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\title{Enabling Secure Web Payments with GNU Taler}
%\subtitle{}

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\author[F. Dold]{J. Burdges, {\bf F. Dold}, C. Grothoff, M. Stanisci}
\date{25. 1. 2017}
\institute{Inria / The GNU Project}


\begin{document}

\justifying
\begin{frame}[plain]
\titlepage

\vfill
\begin{center}
\tiny
``I think one of the big things that we need to do, is we need
to get a way from true-name payments on the Internet. The credit
card payment system is one of the worst things that happened for the
user, in terms of being able to divorce their access from their
identity.'' \hfill --Edward Snowden, IETF 93 (2015)
\end{center}
\end{frame}

\begin{frame}
  \frametitle{Motivation}
  \centering
    \includegraphics[height=6cm]{cash-register-rupee.jpg}
  \begin{center}
    \Large \textbf{Modern economies need currency ...}
  \end{center}
\end{frame}


\begin{frame}{Are credit/debit cards the solution?}
  \begin{itemize}
    % not possible to run your own infrastructure
    \item Oligopoly of a few big, foreign companies
    \item High fees
    \item Cumbersome and expensive for small, frequent online transactions
    \item False positives on fraud detection turns customers away
  \end{itemize}
  \hfill  \includegraphics[width=0.7\textwidth]{cc-volume.jpg}
\end{frame}


\begin{frame}{Bitcoin}

\begin{itemize}
\item Unregulated payment system and currency:
\item[] $\Rightarrow$ lack of regulation is a feature!
\item Implemented in free software
\item Decentralised peer-to-peer system   \pause
\item Decentralised banking requires solving Byzantine consensus
\item Creative solution: tie initial accumulation to solving consensus \pause
\item[] $\Rightarrow$ Proof-of-work advances ledger
\item[] $\Rightarrow$ Slow and very expensive banking
\end{itemize}
\end{frame}


\begin{frame}
  \frametitle{\includegraphics[height=0.5cm]{pics/bitcoin.jpeg}?}
  \centering
\noindent
\includegraphics[width=\textwidth]{pics/btc-transaction-cost.png}

Current average transaction value: $\approx$ 1000 USD
\end{frame}


\begin{frame}
  \frametitle{\includegraphics[height=0.5cm]{pics/zerocoin.png}?}

Cryptography is rather primitive:
\begin{center}
  {\bf All Bitcoin transactions are public and linkable!}
\end{center}

\begin{itemize}
\item[] $\Rightarrow$ no privacy guarantees
\item[] $\Rightarrow$ enhanced with ``laundering'' services
\end{itemize}
ZeroCoin, CryptoNote (Monero) and ZeroCash (ZCoin) offer anonymity.
\end{frame}


\begin{frame}
  \vfill
\begin{center}
{\bf Is society ready for an anarchistic economy?}
\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=0.1]{pics/logo_taler.pdf}
  \end{center}
  \vfill
  \begin{center}
    Taxable, Anonymous, Libre, Practical, Resource Friendly
  \end{center}
 \vfill
 \vfill
\ %
\end{frame}


\begin{frame}
\frametitle{Architecture of GNU Taler}
\begin{figure}[h]
\centering
\begin{tikzpicture}
 \tikzstyle{def} = [node distance= 5em and 7em, inner sep=1em, outer sep=.3em];
 \node (origin) at (0,0) {};
 \node (exchange) [def,above=of origin,draw]{Exchange};
 \node (customer) [def, draw, below left=of origin] {Customer};
 \node (merchant) [def, draw, below right=of origin] {Merchant};
 \node (auditor) [def, draw, above right=of origin]{Auditor};

 \tikzstyle{C} = [color=black, line width=1pt]

 \draw [<-, C] (customer) -- (exchange) node [midway, above, sloped] (TextNode) {withdraw coins};
 \draw [<-, C] (exchange) -- (merchant) node [midway, above, sloped] (TextNode) {deposit coins};
 \draw [<-, C] (merchant) -- (customer) node [midway, above, sloped] (TextNode) {spend coins};
 \draw [<-, C] (exchange) -- (auditor) node [midway, above, sloped] (TextNode) {verify};
\end{tikzpicture}
\end{figure}
\end{frame}


\begin{frame}{Usability of Taler}
  \vfill
  \begin{center}
    \url{https://demo.taler.net/}
  \end{center}
  \begin{enumerate}
  \item Install Chrome extension.
  \item Visit the {\tt bank.demo.taler.net} to withdraw coins.
  \item Visit the {\tt shop.demo.taler.net} to spend coins.
  \end{enumerate}
  \vfill
\end{frame}


\begin{frame}{Value proposition: Customer}
  \begin{itemize}
  \item Convenient: pay with one click
  \item Guaranteed: never fear being rejected by false-positives in the fraud detection
  \item Secure: like cash, except no worries about counterfeit
  \item Privacy-preserving: payment requires no personal information
  \item Privacy still holds with government-mandated weak encryption
  \item Stable: no currency fluctuations, pay in traditional currencies
  \item Free software: no hidden ``gadgets'', third parties can verify
  \end{itemize}
\end{frame}


\begin{frame}{Value proposition: Merchant}
  \begin{itemize}
  \item Fast: transactions at Web-speed
  \item Secure: signed contracts, no legitimate customer rejected by fraud decection
  \item Free software: competitive pricing and support
  \item Low fees: efficient protocol + no fraud $=$ low costs
  \item Flexible: any currency, any amount
  \item Ethical: no fluctuation risk, no pyramid scheme, not suitable for illegal business
  \item Legal: complies with Regulation (EU) 2016/679 (GDPR)\footnote{Requires privacy by design and data minimization for all data processing in Europe after 25.5.2018.}
  \end{itemize}
\end{frame}


\begin{frame}{Value proposition: Government}
  \begin{itemize}
  \item Free software $=$ commons: no monopoly, preserve independence
  \item Taxabiliy: reduces black markets
    \begin{itemize}
      \item merchant income is visible from deposit, can be taxed
      \item limitation: sharing coins among friends and family
    \end{itemize}
  \item Efficiency: high transaction costs hurt the economy
  \item Security: signed contracts, no counterfeit
  \item Audited: limits fraud potential
  \item Privacy: protection against foreign espionage
  \end{itemize}
  \hfill  \includegraphics[width=4cm]{pics/blog_nsa_swift.jpg}
\end{frame}


\begin{frame}{Detailed Architecture}
  \centering
    \includegraphics[width=\textwidth]{taler-arch-full.pdf}
\end{frame}

\begin{frame}{Merchant Integration: Wallet Detection}
 \lstset{language=JavaScript}
 \lstinputlisting{figs/taler-presence-js.html}
% \caption{Sample code to detect the Taler wallet. Allowing the
%  Web site to detect the presence of the wallet leaks one bit
%  of information about the user. The above logic also works
%  if the wallet is installed while the page is open.}
%  \label{listing:presence}
\end{frame}


\begin{frame}{Merchant Integration: Payment Request}
% \begin{figure}[p!]
 \lstset{language=HTML5}
 \lstinputlisting{figs/taler-402.html}
%  \caption{Sample HTTP response to prompt the wallet to show an offer.}
%   \label{listing:http-contract}
% \end{figure}

% \begin{figure*}[p!]
% \lstset{language=HTML5}
% \lstinputlisting{figs/taler-contract.html}
% \caption{Sample JavaScript code to prompt the wallet to show an offer.
%          Here, the contract is fetched on-demand from the server.
%          The {\tt taler\_pay()} function needs to be invoked
%          when the user triggers the checkout.}
% \label{listing:contract}
% \end{figure*}
\end{frame}


\begin{frame}{Merchant Integration: Contract}
  % \begin{figure*}[t!]
  {\tiny
 \lstset{language=JavaScript}
 \lstinputlisting{figs/taler-contract.json}
%   \caption{Minimal Taler contract over a digital article with a value of \EUR{0.10}. The merchant will pay transaction fees up to \EUR{0.01}.  The hash over the wire transfer information was truncated to make it fit to the page.}
%   \label{listing:json-contract}
 % \end{figure*}
 }
\end{frame}


\begin{frame}{How does it work?}
We use a few ancient constructions:
  \begin{itemize}
  \item Cryptographic hash function (1989)
  \item Blind signature (1983)
  \item Schnorr signature (1989)
  \item Diffie-Hellman key exchange (1976)
  \item Cut-and-choose zero-knowledge proof (1985)
  \end{itemize}
But of course we use modern instantiations.
\end{frame}



\begin{frame}{Current developments}
  \begin{itemize}
  \item Improving wallet (error handling, features, browser support)
  \item Ongoing work on exchange auditing
  \item Tutorial for merchants
  \item Tutorial for Web shop integration
  \item Looking into making better marketing materials and explanations for non-technical people
  \end{itemize}
  \vfill
  \begin{center}
    \url{https://docs.taler.net/}
  \end{center}
\end{frame}


\begin{frame}{Call to action}
  You can ...
  \begin{itemize}
  \item Tell people about Taler
  \item Read the documentation on \url{https://docs.taler.net/}
  \item See how Taler would integrate into your webshop
  \item Get a banking license and run an exchange \texttt{;-)}
  \item Talk to us on the \#gnunet IRC channel on freenode
  \end{itemize}
\end{frame}


%\begin{frame}{Community considerations}
%  \begin{itemize}
%  \item Initial accumulation: Who gets to mint currency?
%  \item Speculation: Who controls the money supply?
%  \item Social welfare:
%    \begin{itemize}
%    \item Who gets to set tax rules and rates?
%    \item Who gets to allocate tax revenue?
%    \end{itemize}
%  \end{itemize}
%\end{frame}


\begin{frame}{Conclusion}
  \begin{center}
    {\bf  What can we do?}
   \end{center}
  \vfill
\begin{itemize}
 \item{Suffer mass-surveillance enabled by credit card oligopolies with high fees, and}
 \item{Engage in arms race with deliberately unregulatable blockchains, and}
 \item{Enjoy the ``benefits'' of cash \\
  \hfill  \includegraphics[height=0.3\textheight]{atm-rupee.jpg} \hfill}
\end{itemize}
\vfill
\begin{center}
  {\bf OR}
\end{center}
\vfill
\begin{itemize}
 \item{Establish free software alternative balancing social goals!}
\end{itemize}
\vfill
\end{frame}


\begin{frame}
\frametitle{Do you have any questions?}
\vfill
References:
{\tiny
  \begin{enumerate}
 \item{Christian Grothoff, Bart Polot and Carlo von Loesch.
       {\em The Internet is broken: Idealistic Ideas for Building a GNU Network}.
       {\bf W3C/IAB Workshop on Strengthening the Internet Against Pervasive Monitoring (STRINT)}, 2014.}
 \item{Jeffrey Burdges, Florian Dold, Christian Grothoff and Marcello Stanisci.
       {\em Enabling Secure Web Payments with GNU Taler}.
       {\bf SPACE 2016}.}
 \item{Florian Dold, Sree Harsha Totakura, Benedikt M\"uller, Jeffrey Burdges and Christian Grothoff.
       {\em Taler: Taxable Anonymous Libre Electronic Reserves}.
       Available upon request. 2016.}
 \item{Eli Ben-Sasson, Alessandro Chiesa, Christina Garman, Matthew Green, Ian Miers, Eran Tromer and Madars Virza.
       {\em Zerocash: Decentralized Anonymous Payments from Bitcoin}.
       {\bf IEEE Symposium on Security \& Privacy, 2016}.}
 \item{David Chaum, Amos Fiat and Moni Naor.
       {\em Untraceable electronic cash}.
       {\bf Proceedings on Advances in Cryptology, 1990}.}
  \item{Phillip Rogaway.
       {\em The Moral Character of Cryptographic Work}.
       {\bf Asiacrypt}, 2015.} \label{bib:rogaway}
\end{enumerate}
}
\begin{center}
  {\bf Let money facilitate trade; but ensure capital serves society.}
\end{center}
\end{frame}




\end{document}