boh.tex (17991B)
1 \pdfminorversion=3 2 \documentclass[fleqn,xcolor={usenames,dvipsnames}]{beamer} 3 \usepackage{amsmath} 4 \usepackage{multimedia} 5 \usepackage[utf8]{inputenc} 6 \usepackage{framed,color,ragged2e} 7 \usepackage[absolute,overlay]{textpos} 8 \definecolor{shadecolor}{rgb}{0.8,0.8,0.8} 9 \usetheme{boxes} 10 \setbeamertemplate{navigation symbols}{} 11 \usepackage{xcolor} 12 \usepackage{tikz,eurosym} 13 \usepackage[normalem]{ulem} 14 \usepackage{listings} 15 \usepackage{adjustbox} 16 17 % CSS 18 \lstdefinelanguage{CSS}{ 19 basicstyle=\ttfamily\scriptsize, 20 keywords={color,background-image:,margin,padding,font,weight,display,position,top,left,right,bottom,list,style,border,size,white,space,min,width, transition:, transform:, transition-property, transition-duration, transition-timing-function}, 21 sensitive=true, 22 morecomment=[l]{//}, 23 morecomment=[s]{/*}{*/}, 24 morestring=[b]', 25 morestring=[b]", 26 alsoletter={:}, 27 alsodigit={-} 28 } 29 30 % JavaScript 31 \lstdefinelanguage{JavaScript}{ 32 basicstyle=\ttfamily\scriptsize, 33 morekeywords={typeof, new, true, false, catch, function, return, null, catch, switch, var, if, in, while, do, else, case, break}, 34 morecomment=[s]{/*}{*/}, 35 morecomment=[l]//, 36 morestring=[b]", 37 morestring=[b]' 38 } 39 40 \lstdefinelanguage{HTML5}{ 41 basicstyle=\ttfamily\scriptsize, 42 language=html, 43 sensitive=true, 44 alsoletter={<>=-}, 45 morecomment=[s]{<!-}{-->}, 46 tag=[s], 47 otherkeywords={ 48 % General 49 >, 50 % Standard tags 51 <!DOCTYPE, 52 </html, <html, <head, <title, </title, <style, </style, <link, </head, <meta, />, 53 % body 54 </body, <body, 55 % Divs 56 </div, <div, </div>, 57 % Paragraphs 58 </p, <p, </p>, 59 % scripts 60 </script, <script, 61 % More tags... 62 <canvas, /canvas>, <svg, <rect, <animateTransform, </rect>, </svg>, <video, <source, <iframe, </iframe>, </video>, <image, </image> 63 }, 64 ndkeywords={ 65 % General 66 =, 67 % HTML attributes 68 charset=, src=, id=, width=, height=, style=, type=, rel=, href=, 69 % SVG attributes 70 fill=, attributeName=, begin=, dur=, from=, to=, poster=, controls=, x=, y=, repeatCount=, xlink:href=, 71 % CSS properties 72 margin:, padding:, background-image:, border:, top:, left:, position:, width:, height:, 73 % CSS3 properties 74 transform:, -moz-transform:, -webkit-transform:, 75 animation:, -webkit-animation:, 76 transition:, transition-duration:, transition-property:, transition-timing-function:, 77 } 78 } 79 80 \lstdefinelanguage{JavaScript}{ 81 basicstyle=\ttfamily\scriptsize, 82 keywords={typeof, new, true, false, catch, function, return, null, catch, switch, var, if, in, while, do, else, case, break, for}, 83 keywordstyle=\color{blue}\bfseries, 84 ndkeywords={class, export, boolean, throw, implements, import, this}, 85 ndkeywordstyle=\color{darkgray}\bfseries, 86 identifierstyle=\color{black}, 87 sensitive=false, 88 comment=[l]{//}, 89 morecomment=[s]{/*}{*/}, 90 commentstyle=\color{purple}\ttfamily, 91 stringstyle=\color{red}\ttfamily, 92 morestring=[b]', 93 morestring=[b]" 94 } 95 96 \usetikzlibrary{shapes,arrows} 97 \usetikzlibrary{positioning} 98 \usetikzlibrary{calc} 99 100 \title{GNU Taler as a Retail CBDC} 101 %\subtitle{} 102 103 \setbeamertemplate{navigation symbols}{\includegraphics[width=1cm]{inria.pdf} \includegraphics[width=2.3cm]{bfh.png} \includegraphics[width=1.6cm]{fub.pdf} \includegraphics[width=0.4cm]{ashoka.png} \includegraphics[width=0.4cm]{gnu.png} \includegraphics[width=1cm]{logo-2020.jpg} \hfill} 104 %\setbeamercovered{transparent=1} 105 106 \author[C. Grothoff]{{\bf C. Grothoff}} 107 \date{10.09.2023} 108 \institute{Bern University of Applied Sciences} 109 110 111 \begin{document} 112 113 \justifying 114 115 \begin{frame} 116 \begin{center} 117 \LARGE {\bf GNU} 118 119 \vfill 120 % \includegraphics[width=0.66\textwidth]{logo-2017-fr.pdf} 121 \includegraphics[width=0.66\textwidth]{logo-2021.pdf} 122 123 as a Retail CBDC 124 \vfill 125 \end{center} 126 \begin{textblock*}{6cm}(.5cm,7.7cm) % {block width} (coords) 127 {\Large {\bf \href{https://taler.net/}{taler.net}} \\ 128 \href{https://taler-systems.com/}{taler-systems.com}} 129 \end{textblock*} 130 131 % Substitute based on who is giving the talk! 132 \begin{textblock*}{6cm}(6.7cm,7.7cm) % {block width} (coords) 133 {%\hfill {\Large {\bf Florian Dold \&} \\ 134 \hfill {\bf Christian Grothoff} \\ 135 \hfill grothoff@taler.net } 136 \end{textblock*} 137 138 \end{frame} 139 140 \section{Introduction} 141 142 \begin{frame}{Main Points} 143 \framesubtitle{\url{https://taler.net/}} 144 Our payment system: 145 \begin{itemize} 146 \item is token-based (no accounts), centrally issued (not DLT); as efficient and cost-effective 147 as modern real-time gross settlement (RTGS) systems operated by central banks; 148 \item is designed to provide an electronic equivalent to banknotes, therefore no material 149 impact on monetary policy and/or financial stability expected; 150 \item guarantees privacy for the payer, combined with KYC/AML/CFT compliance and 151 income transparency to ensure taxes are paid; 152 \item is implemented as Free/Libre and Open Source Software (FLOSS) to provide 153 transparency, accountability, and security (part of the GNU project). 154 \end{itemize} 155 \end{frame} 156 157 158 \begin{frame}{Why?} 159 \begin{itemize} 160 \item National sovereignity: remove control of payment sector from foreign entities 161 \item Limit impact of bank failures on societal financial transaction processing needs, especially in cashless society 162 \item Access for the marginalized: children, unbanked need access to payments as cash disappears 163 \item Financial self-determination: preserve ability to pay without 3rd party approval 164 \item Natural monopoly: high payment fees to oligopoly or high integration costs to many payment service providers? 165 \item Informational self-determination: retail banks fail to offer privacy-preserving solutions due to perceived risk 166 \end{itemize} 167 \end{frame} 168 169 170 \begin{frame}{Why NOT?} 171 \begin{itemize} 172 \item Threat of ``absolute control'' over society by central bank 173 \item Limit innovation in payment services due to central planning 174 \item Risk to central bank reputation in case of product failure 175 \item Destabilization of retail banks due to capital flight into safer CBDC 176 \item Central bank lacks operational capability (especially for KYC) 177 \end{itemize} 178 \end{frame} 179 180 181 182 \section{What is Taler?} 183 \begin{frame}{What is Taler?} 184 \begin{center} 185 Taler is an electronic instant payment system based on tokens. 186 \end{center} 187 \begin{itemize} 188 \item Uses electronic coins stored in {\bf wallets} on customer's device 189 \item Like {\bf cash} 190 \item Pay in {\bf existing currencies} (i.e. CHF, EUR, USD) 191 \end{itemize} 192 \vfill 193 \pause 194 \noindent 195 However, Taler is 196 \begin{itemize} 197 \item \emph{not} a currency 198 \item \emph{not} a long-term store of value 199 \item \emph{not} a network or instance of a system 200 \item \emph{not} decentralized 201 \item \emph{not} based on proof-of-work or proof-of-stake 202 \item \emph{not} a speculative asset / ``get-rich-quick scheme'' 203 \end{itemize} 204 \end{frame} 205 206 207 \begin{frame}{Some of the people behind GNU Taler} 208 {\tiny 209 \begin{itemize} 210 \item Prof. Christian Grothoff (research \& development) 211 \item Prof. Andreas Habegger (research, hardware) 212 \item Prof. Emmanuel Benoist (research, cryptography) 213 \item Prof. Tanja Lange (research, cryptography) 214 \item Prof. Matthias W\"ahlisch (research, embedded systems) 215 \item Dr. Florian Dold (cryptography, systems engineering) 216 \item Dr. Thomas Moser (economics) 217 \item Dr. Richard Stallman (ethics) 218 \item Dr. Michael Widmer, MBA (legal) 219 \item Dr. Belén Barros Pena (UX design, accessibility) 220 \item Leon Schumacher, MBA (business) 221 \item Marcello (bank integration) 222 \item \"Ozg\"ur (security audit, age restrictions) 223 \item Sebastian (Web interface) 224 \item Stefan (documentation, project management) 225 \item Torsten (Andorid wallet) 226 \item Marc (iOS wallet) 227 \item Ivan (backup) 228 \end{itemize} 229 } 230 \end{frame} 231 232 233 \begin{frame}{The Big Picture (SNB)} 234 \begin{center} 235 \includegraphics[width=0.8\textwidth]{bp.png} 236 \end{center} 237 \end{frame} 238 239 240 \begin{frame}{Taler: Unique Regulatory Features for CBs} 241 \framesubtitle{\url{https://www.snb.ch/en/mmr/papers/id/working_paper_2021_03}} 242 \begin{itemize} 243 \item Central bank issues digital coins equivalent to issuing cash \\ 244 $\Rightarrow$ monetary policy remains under CB control 245 \item Architecture with consumer accounts at commercial banks \\ 246 $\Rightarrow$ no competition for commercial banking (S\&L) \\ 247 $\Rightarrow$ CB does not have to manage KYC, customer support 248 \item Withdrawal limits and denomination expiration \\ 249 $\Rightarrow$ protects against bank runs and hoarding 250 \item Income transparency and possibility to set fees \\ 251 $\Rightarrow$ additional insights into economy and new policy options 252 \item Revocation protocols and loss limitations \\ 253 $\Rightarrow$ exit strategy and handles catastrophic security incidents 254 \item Privacy by cryptographic design not organizational compliance \\ 255 $\Rightarrow$ CB cannot be forced to facilitate mass-surveillance 256 \end{itemize} 257 \end{frame} 258 259 260 \begin{frame}[fragile]{Option 1: Central Bank Liability via Supervision} 261 \begin{adjustbox}{max totalsize={.9\textwidth}{.7\textheight},center} 262 \begin{tikzpicture} 263 \tikzstyle{def} = [node distance= 6em and 6.5em, inner sep=1em, outer sep=.3em]; 264 \node (origin) at (0,0) {}; 265 \node (central) [def,above=of origin,draw]{Central Bank}; 266 \node (banka) [def, draw, below right=of central] {Retail Bank B}; 267 \node (bankb) [def, draw, below left=of central] {Retail Bank A}; 268 \node (consumera) [def, draw, below=of banka] {Consumers}; 269 \node (consumerb) [def, draw, below=of bankb] {Consumers}; 270 \tikzstyle{C} = [color=black, line width=1pt] 271 272 \draw [->, C] (central) -- (banka) node [midway, above, sloped] (TextNode) {supervision}; 273 \draw [->, C] (central) -- (bankb) node [midway, above, sloped] (TextNode) {supervision}; 274 \draw [<->, C] (banka) -- (bankb) node [midway, above, sloped] (TextNode) {settlement}; 275 \draw [<->, C] (consumera) -- (banka) node [midway, above, sloped] (TextNode) {KYC}; 276 \draw [<->, C] (consumera) -- (banka) node [midway, below, sloped] (TextNode) {transact}; 277 \draw [<->, C] (consumerb) -- (bankb) node [midway, above, sloped] (TextNode) {KYC}; 278 \draw [<->, C] (consumerb) -- (bankb) node [midway, below, sloped] (TextNode) {transact}; 279 \end{tikzpicture} 280 \end{adjustbox} 281 The central bank could leave the operation of the core system to commercial 282 banks (see Auer, BIS 2021) and focus on (real-time) supervision of the system. 283 \end{frame} 284 285 286 \begin{frame}[fragile]{Option 2: Central Bank as Core System Operator} 287 \begin{adjustbox}{max totalsize={.9\textwidth}{.7\textheight},center} 288 \begin{tikzpicture} 289 \tikzstyle{def} = [node distance= 6em and 6.5em, inner sep=1em, outer sep=.3em]; 290 \node (origin) at (0,0) {}; 291 \node (central) [def,above=of origin,draw]{Central Bank}; 292 \node (banka) [def, draw, below right=of central] {Retail Bank B}; 293 \node (bankb) [def, draw, below left=of central] {Retail Bank A}; 294 \node (consumera) [def, draw, below=of banka] {Consumers}; 295 \node (consumerb) [def, draw, below=of bankb] {Consumers}; 296 \tikzstyle{C} = [color=black, line width=1pt] 297 298 \draw [<->, C] (central) -- (banka) node [midway, above, sloped] (TextNode) {transact}; 299 \draw [<->, C] (central) -- (bankb) node [midway, above, sloped] (TextNode) {transact}; 300 \draw [<->, C] (consumera) -- (banka) node [midway, above, sloped] (TextNode) {KYC}; 301 \draw [<->, C] (consumera) -- (banka) node [midway, below, sloped] (TextNode) {transact}; 302 \draw [<->, C] (consumerb) -- (bankb) node [midway, above, sloped] (TextNode) {KYC}; 303 \draw [<->, C] (consumerb) -- (bankb) node [midway, below, sloped] (TextNode) {transact}; 304 \end{tikzpicture} 305 \end{adjustbox} 306 If the central bank operates the core system, interbank settlements 307 are no longer required. 308 \end{frame} 309 310 311 \begin{frame}[fragile]{Option 3: Regulation-only (no CBDC)} 312 \begin{adjustbox}{max totalsize={.9\textwidth}{.7\textheight},center} 313 \begin{tikzpicture} 314 \tikzstyle{def} = [node distance= 6em and 6.5em, inner sep=1em, outer sep=.3em]; 315 \node (origin) at (0,0) {}; 316 \node (central) [def,above=of origin,draw]{Regulator / Auditor}; 317 \node (banka) [def, draw, below right=of central] {Retail Bank C}; 318 \node (bankb) [def, draw, below left=of central] {Retail Bank A}; 319 \node (bankc) [def, draw, below =of central] {Retail Bank B}; 320 \node (consumera) [def, draw, below=of banka] {Consumers}; 321 \node (consumerb) [def, draw, below=of bankb] {Consumers}; 322 \node (consumerc) [def, draw, below=of bankc] {Consumers}; 323 \tikzstyle{C} = [color=black, line width=1pt] 324 \draw [->, C] (central) -- (banka) node [midway, above, sloped] (TextNode) {regulation}; 325 \draw [->, C] (central) -- (bankb) node [midway, above, sloped] (TextNode) {regulation}; 326 \draw [->, C] (central) -- (bankc) node [midway, above, sloped] (TextNode) {regulation}; 327 \draw [<->, C] (banka) -- (bankc) node [midway, above, sloped] (TextNode) {settlement}; 328 \draw [<->, C] (consumerb) -- (bankb) node [midway, above, sloped] (TextNode) {KYC}; 329 \draw [<->, C] (consumera) -- (banka) node [midway, above, sloped] (TextNode) {KYC}; 330 \draw [<->, C] (consumera) -- (banka) node [midway, below, sloped] (TextNode) {transact}; 331 \draw [<->, C] (consumerc) -- (bankc) node [midway, above, sloped] (TextNode) {KYC}; 332 \draw [<->, C] (consumerc) -- (bankc) node [midway, below, sloped] (TextNode) {transact}; 333 \end{tikzpicture} 334 \end{adjustbox} 335 If participation is voluntary, bank $A$ may not offer GNU Taler, or not 336 settle with other banks. Its customers may of course choose to be onboarded via 337 other banks to avoid being excluded. 338 \end{frame} 339 340 341 \section{Competitor comparison} 342 \begin{frame}{Competitor comparison} 343 \begin{center} \small 344 \begin{tabular}{l||c|c|c|c|c} 345 & Cash & DLT & HW-Token & CB-Account & GNU Taler \\ \hline \hline 346 Online &$-$$-$$-$ & + & $-$ & ++ & +++ \\ \hline 347 Offline & +++ & $-$$-$$-$ & $+$ & $-$$-$ & $+$ \\ \hline 348 Cost & $-$ & $-$$-$$-$ & $-$ & + & ++ \\ \hline 349 Speed & + & $-$$-$$-$ & $+$ & o & ++ \\ \hline 350 Taxation & $-$ & +++ & $-$$-$ & +++ & +++ \\ \hline 351 Payer-anon & ++ & $-$$-$ & ??? & $-$$-$ & +++ \\ \hline 352 Payee-anon & ++ & $-$$-$ & ??? & $-$$-$ & $-$$-$$-$ \\ \hline 353 Security & $-$ & ??? & $-$$-$ & o & ++ \\ \hline 354 Migration & +++ & $-$$-$$-$ & $-$$-$$-$& o & + \\ \hline 355 Libre & $-$ & ??? & $-$$-$$-$& N/A & +++ \\ 356 \end{tabular} 357 \end{center} 358 \end{frame} 359 360 361 \begin{frame} 362 \frametitle{Do you have any questions?} 363 \vfill 364 References: 365 {\tiny 366 \begin{enumerate} 367 \item{Martin Summer and Hannes Hermanky. 368 {\em A digital euro and the future of cash}. 369 {\bf Monetary Policy \& The Economy Q1-Q2/22}, 2022.} 370 \item{David Chaum, Christian Grothoff and Thomas Moser. 371 {\em How to issue a central bank digital currency}. 372 {\bf SNB Working Papers, 2021}.} 373 \item{Priscilla Huang, Emmanuel Benoist, and Sebastian Javier Marchano. 374 {\em Practical Offline Payments Using One-Time Passcodes}. 375 {\bf SUREF Policy Note}, Issue No 622, June 2023.} 376 \item{Antoine d'Aligny, Emmanuel Benoist, Florian Dold, Christian Grothoff, \"Ozg\"ur Kesim and Martin Schanzenbach. 377 {\em Who comes after us? The correct mindset for designing a Central Bank Digital Currency}. 378 {\bf SUREF Policy Note}, Issue No 279, May 2022.} 379 \item{Christian Grothoff and Alex Pentland. 380 {\em Digital cash and privacy: What are the alternatives to Libra?}. 381 {\bf MIT Media Lab}, 2019.} 382 \item{Christian Grothoff, Bart Polot and Carlo von Loesch. 383 {\em The Internet is broken: Idealistic Ideas for Building a GNU Network}. 384 {\bf W3C/IAB Workshop on Strengthening the Internet Against Pervasive Monitoring (STRINT)}, 2014.} 385 \end{enumerate} 386 } 387 \end{frame} 388 389 390 \begin{frame}{Payment Systems: Accounts vs. Tokens} 391 Two types of payment systems: 392 \begin{enumerate} 393 \item {\bf account-based system}: transfer occurs by charging the payer’s account and crediting 394 the payee’s account (e.g., bank deposits) 395 \item {\bf token-based (value-based) system}: transfer occurs by transferring the value itself, or a 396 token that represents the monetary asset (e.g., banknotes) 397 \end{enumerate} 398 Key Difference is the information carried by the information asset: 399 \begin{itemize} 400 \item account (assets): associated with a transaction history 401 \item token (assets): carry information about value and entity that issued the token 402 \end{itemize} 403 Bitcoin, and Distributed Ledger Technologies (DLTs) in general, are account-based systems! 404 Novelty is that the ledger is distributed (decentralized). 405 \end{frame} 406 407 408 \begin{frame}{Simplistic rCBDC Designs} 409 \framesubtitle{\url{https://edwardsnowden.substack.com/p/cbdcs}} 410 \begin{itemize} 411 \item Account-based rCBDC (e.g., Bindseil 2020, Berentsen and Schär 2018): 412 \begin{itemize} 413 \item simplest solution: central bank account for all 414 \item responsibility to perform KYC and ensure AML/CFT (could be outsourced); 415 \item potential for mass-surveillance (threat to CB independence); 416 \item in direct competition with commercial banks 417 \end{itemize} \pause 418 \item Token-based rCBDC: 419 \begin{itemize} 420 \item requires a system to ensure that electronic tokens are not easily copied 421 (hardware-based or software-based) 422 \item[$\rightarrow$] double-spending problem 423 %\item KYC and AML/CFT compliance? 424 \end{itemize} 425 \end{itemize} 426 \end{frame} 427 428 \begin{frame}{Taler: Project Status} 429 \framesubtitle{\url{https://docs.taler.net/}} 430 \begin{itemize} 431 \item Cryptographic protocols and core exchange component are stable 432 \item Current focus: KYC process polishing, programmability 433 \item Preparations for launch in Basel (as regional currency) 434 \item Pilot project at Bern University of Applied Sciences cafeteria 435 \end{itemize} 436 \begin{center} 437 \includegraphics[width=0.7\textwidth]{taler-in-use.png} 438 \end{center} 439 \end{frame} 440 441 442 443 444 \end{document}