riksbank.tex (21409B)
1 \documentclass[c]{beamer} 2 3 %\usepackage{helvet} 4 \usepackage{calc} 5 \usepackage[utf8]{inputenc} % set your input encoding differently, if you want 6 \usepackage[english]{babel} 7 8 \usepackage{enumitem} 9 \usepackage{eurosym} 10 \usepackage{tikz} 11 \usepackage{pgfgantt} 12 \usepackage{amsmath,amssymb} 13 \usetikzlibrary{shapes,arrows,fit} 14 \usetikzlibrary{positioning} 15 \usetikzlibrary{calc} 16 \usepackage[absolute,overlay]{textpos} 17 18 %\setbeameroption{show notes} 19 20 \setlist[itemize]{label=$\bullet$} 21 22 23 \def\checkmark{\tikz\fill[scale=0.4](0,.35) -- (.25,0) -- (1,.7) -- (.25,.15) -- cycle;} 24 25 \setbeamertemplate{navigation symbols}{} 26 %\setbeamercovered{transparent=10} 27 \setbeamertemplate{navigation symbols}{\url{taler.net}} 28 %\setbeamertemplate{section in toc}[sections numbered] 29 30 % Adapt title information 31 % ======================= 32 \title{GNU Taler \\ Payments for the Common Good} 33 \institute{Taler Systems SA} 34 \author{Dr. Christian Grothoff \& Leon Schumacher} 35 \date{22.2.2018} 36 37 % Some common packages 38 % ==================== 39 \usepackage{units} 40 \usepackage{amsbsy} 41 \usepackage{amsmath} 42 \usepackage{amssymb} 43 \usepackage{graphics} 44 \usepackage{epsf} 45 \usepackage{epsfig} 46 \usepackage{fixmath} 47 \usepackage{wrapfig} 48 49 50 \usetikzlibrary{snakes} 51 52 53 \begin{document} 54 55 \begin{frame} 56 \begin{center} 57 GNU Taler: Payments for the Common Good 58 59 % \includegraphics[width=0.66\textwidth]{logo-2017-fr.pdf} 60 \includegraphics[width=0.66\textwidth]{taler-logo-2017.pdf} 61 \end{center} 62 \begin{textblock*}{4cm}(.5cm,7.5cm) % {block width} (coords) 63 {\Large {\bf \url{taler.net}} \\ 64 % IRC{\bf \#taler} \\ 65 % {\small (on freenode)} \\ 66 twitter@taler \\ 67 mail@taler.net } 68 \end{textblock*} 69 70 \begin{textblock*}{4cm}(10cm,7.5cm) % {block width} (coords) 71 \includegraphics[width=2cm]{ashoka.png} 72 \end{textblock*} 73 \end{frame} 74 75 76 % Organization / Supplier 77 78 \begin{frame} 79 \frametitle{Organization} 80 \begin{center} 81 \begin{tikzpicture} 82 \tikzstyle{def} = [node distance= 1.8em and 1.3em, inner sep=1em, outer sep=.3em]; 83 \node (origin) at (0,0) {}; 84 \node (cg) [def,orange,above=of origin,draw]{CG}; 85 \node (gnu) [def, draw, above=of cg]{GNU}; 86 \node (pep) [def, draw, above right=of cg]{PEP SA}; 87 \node (ashoka) [def, draw, above left =of cg]{Ashoka}; 88 \node (ls) [def,orange,above right=of origin,draw]{LS}; 89 \node (mw) [def,orange,above left=of origin,draw]{MW}; 90 \node (fd) [def,orange, draw, below left=of origin] {FD}; 91 \node (jb) [def,orange, draw, below =of origin] {JB}; 92 \node (ue) [def,orange, draw, below right=of origin] {UE}; 93 \node (ms) [def,orange, draw, right=of ue] {MS}; 94 \node (bl) [def,orange, draw, right=of ms] {BL}; 95 \node (pepf) [def, draw, below=of bl]{PEP Foundation}; 96 \node (inria) [def, draw, below =of fd]{Inria}; 97 \node (bfh) [def, draw, below =of ue]{BFH}; 98 99 100 % grouping invividuals 101 \node[def,draw,orange,fit=(ls)(mw)(fd)(jb)(ue)(ms)(bl)](group){}; 102 103 % comment right 104 % \draw[line width=1pt,orange,decorate,decoration={amplitude=7pt,brace}] 105 % (group.north east) -- (group.south east); 106 % \node[right=of group,anchor=center,rotate=90]{Implementation partners}; 107 108 109 \tikzstyle{C} = [color=black, line width=1pt] 110 111 %\draw [->, C] (cg) -- (fd) node [midway, above, sloped] (TextNode) {}; 112 %\draw [->, C] (cg) -- (jb) node [midway, above, sloped] (TextNode) {}; 113 %\draw [->, C] (cg) -- (ms) node [midway, above, sloped] (TextNode) {}; 114 %\draw [->, C] (cg) -- (ue) node [midway, above, sloped] (TextNode) {}; 115 %\draw [->, C] (ls) -- (bl) node [midway, above, sloped] (TextNode) {}; 116 \draw [<-, C] (cg) -- (gnu) node [midway, above, sloped] (TextNode) {}; 117 \draw [<-, C] (cg) -- (ashoka) node [midway, above, sloped] (TextNode) {}; 118 \draw [<-, C] (jb) -- (inria) node [midway, above, sloped] (TextNode) {}; 119 \draw [<-, C] (fd) -- (inria) node [midway, above, sloped] (TextNode) {}; 120 \draw [<-, C] (ls) -- (pep) node [midway, above, sloped] (TextNode) {}; 121 \draw [<-, C] (ue) -- (bfh) node [midway, above, sloped] (TextNode) {}; 122 \draw [<-, C] (bl) -- (pepf) node [midway, above, sloped] (TextNode) {}; 123 \end{tikzpicture} 124 \end{center} 125 \end{frame} 126 127 128 \begin{frame} 129 \frametitle{Dr. Christian Grothoff} 130 \begin{itemize} 131 \item Co-founder of Taler Systems SA 132 \item 16+ years of experience in network security and privacy 133 \item Software deployed in millions of computers and devices 134 \item PhD in Computer Science, from UCLA, degrees in Mathematics and Chemistry 135 \item GNU maintainer, GNU advisory board member 136 \item Ashoka fellow, former Emmy-Noether scholar 137 \item Lived and worked in USA, Germany, France and Switzerland 138 \item Professor for network security at University of Applied Sciences, Bern 139 \end{itemize} 140 \end{frame} 141 142 143 \begin{frame} 144 \frametitle{Leon Schumacher} 145 \begin{itemize} 146 \item Co-founder of Taler Systems SA 147 \item Co-founder of p$\equiv$p Security / pretty Easy privacy 148 \item Founder of DigitalEklo 149 \item Former Group CIO of Novartis 150 \item Former Group CIO ArcelorMittal 151 \end{itemize} 152 \end{frame} 153 154 155 \begin{frame} 156 \frametitle{Senior Team \hfill \& \hfill advisory board \hfill} 157 \begin{minipage}{5cm} 158 \setlist[description]{leftmargin=1cm,labelindent=0cm} 159 \begin{description} 160 \item[Leon Schumacher]\ \\ co-founder, executive 161 \item[Dr. Christian Grothoff]\ \\ co-founder, executive 162 \item[Michael Widmer]\ \\ Lawyer, executive 163 \item[Dr. Jeff Burdges]\ \\ PostDoc 164 \item[Florian Dold]\ \\ PhD Student 165 \end{description} 166 167 \end{minipage} 168 \begin{minipage}{5.5cm} 169 {\tiny 170 \begin{description} 171 \item[Prof. Mikhail Atallah] \ \\ 172 Cryptographer, co-founder 173 Arxan Technologies Inc. 174 \item[Prof. Roberto Di Cosmo] \ \\ 175 Director IRILL 176 \item[Greg Framke] \ \\ 177 CIO Manulife, \\ 178 former COO Etrade 179 \item[Ante Gulam] \ \\ 180 Global Head of Information Security --- CISO \\ 181 MetaPack Group 182 \item[Dr. Richard Stallman]\ \\ 183 Founder of the \\ \mbox{Free Software movement} 184 \item[Chris Pagett] \ \\ 185 former Group Head Security/ \ \\ 186 Fraud/Geo Risk HSBC 187 \item[Prof. Alex Pentland] \ \\ 188 MIT Media Lab 189 \end{description} 190 } 191 \end{minipage} 192 \vfill 193 \includegraphics[height=0.1\textwidth]{team-images/leon-schumacher.jpg} \hfill 194 \includegraphics[height=0.1\textwidth]{team-images/christian-grothoff.jpg}\hfill 195 \includegraphics[height=0.1\textwidth]{team-images/michael-widmer.jpg}\hfill 196 \includegraphics[height=0.1\textwidth]{team-images/jeff-burdges.jpg}\hfill 197 \includegraphics[height=0.1\textwidth]{team-images/florian-dold.jpg}\hfill 198 \includegraphics[height=0.1\textwidth]{board-images/mja.jpg} \hfill 199 \includegraphics[height=0.1\textwidth]{board-images/roberto-di-cosmo.jpg} \hfill 200 \includegraphics[height=0.1\textwidth]{board-images/greg-framke.jpg} \hfill 201 \includegraphics[height=0.1\textwidth]{board-images/ante-gulam.jpg} \hfill 202 \includegraphics[height=0.1\textwidth]{board-images/alex-pentland.jpg} 203 %\note{Advisory board still under construction.} 204 \end{frame} 205 206 207 \begin{frame} 208 \frametitle{History of Taler Systems SA} 209 \begin{itemize} 210 \item Software development started at TU Munich (2013) 211 \item Grant from Renewable Freedom Foudation to develop core system (2014-2017) 212 \item Inria decision to create startup in (2015) 213 \item Company founded 2016 by Dr. Christian Grothoff and Leon Schumacher 214 \item Copyright agreement with Inria, GNUnet e.V. and other stakeholders (2017) 215 %\item Swedish community member informs us about e-Krona project (9'2017) 216 %\item First hire from former Inria team (2018) 217 \item Core team assisted by many volunteers ($\Rightarrow$ easy to grow) 218 \end{itemize} 219 \end{frame} 220 221 222 % ``References and experience within the field'' 223 \begin{frame} 224 \frametitle{Strategic partners} 225 \begin{itemize} 226 \item GNU Taler: We are a GNU package within the GNU project 227 \item Hacker community: supported by CCC, Tor project, Enigmail, GnuPG, Nitrokey, etc. 228 \item Ashoka: Prof. Grothoff is part of a global network of social entrepreneurs 229 \item p$\equiv$p: Taler partners with pEp for e-mail integration 230 \item Roots in academia: partners at TUM (I8), Inria (TAMIS team), ETH Zurich (Helbing) and MIT (Media Lab) 231 \item Roots in industry: Leon Schumacher, Group CIO of ArcelorMittal \& Novartis 232 \item Roots in banking: Michael Widmer, Chief of Staff of Adecco Group; Bank Gutenberg, AIG, EUREX, Chicago Board of Trade/Eurex Alliance 233 \end{itemize} 234 \end{frame} 235 236 237 \section{What is GNU Taler?} 238 \begin{frame}{What is GNU Taler?} 239 \vfill 240 \begin{center} 241 GNU Taler is an electronic instant payment system. 242 \end{center} 243 \begin{itemize} 244 \item Uses electronic coins stored in {\bf wallets} on customer's device 245 \item Think electronic {\bf cash}, with a few twists 246 \item Pay in {\bf existing currencies} (i.e. EUR, USD, BTC) 247 % or use it to create new regional currencies 248 \end{itemize} 249 \vfill 250 \begin{center} 251 Taler is {\bf not} a cryptocurrency. 252 \end{center} 253 \end{frame} 254 255 256 \begin{frame} 257 \frametitle{GNU Taler Overview} 258 \begin{center} 259 \begin{tikzpicture} 260 \tikzstyle{def} = [node distance= 5em and 6.5em, inner sep=1em, outer sep=.3em]; 261 \node (origin) at (0,0) {}; 262 \node (exchange) [def,above=of origin,draw]{Exchange}; 263 \node (customer) [def, draw, below left=of origin] {Customer}; 264 \node (merchant) [def, draw, below right=of origin] {Merchant}; 265 \node (auditor) [def, draw, above right=of origin]{Auditor}; 266 267 \tikzstyle{C} = [color=black, line width=1pt] 268 269 \draw [<-, C] (customer) -- (exchange) node [midway, above, sloped] (TextNode) {withdraw coins}; 270 \draw [<-, C] (exchange) -- (merchant) node [midway, above, sloped] (TextNode) {deposit coins}; 271 \draw [<-, C] (merchant) -- (customer) node [midway, above, sloped] (TextNode) {spend coins}; 272 \draw [<-, C] (exchange) -- (auditor) node [midway, above, sloped] (TextNode) {verify}; 273 274 \end{tikzpicture} 275 \end{center} 276 \end{frame} 277 % Demo here 278 279 280 \begin{frame} 281 \frametitle{Components in Depth} 282 \begin{itemize} 283 \item Exchange: payment service provider 284 \begin{itemize} 285 \item Wire plugins: integration with register based system 286 \item Database plugins: persist cryptographic proofs 287 \item Auditor: verifies correct operation 288 \end{itemize} 289 \item Wallet: customer user interface 290 \begin{itemize} 291 \item Browser extension 292 \item E-mail client integration (future work) 293 \item NFC payments (future work) 294 \end{itemize} 295 \item Merchant: shop 296 \begin{itemize} 297 \item Front end (custom) 298 \item Backend (RESTful service, performs cryptography) 299 \item Backend database: persists cryptographic proofs 300 \item Back office Web service: access to business data 301 \end{itemize} 302 \item Protocol specification (generally JSON-based) 303 \end{itemize} 304 \end{frame} 305 306 307 308 % ``References and experience within the field'' 309 \begin{frame}{Hardware requirements} 310 \begin{itemize} 311 \item[@] Exchange: 312 \begin{itemize} 313 \item high-availablility data center (with replicated database), 314 \item expected amortized average transaction costs $\approx$ \EUR{0.000001} 315 \item transaction latency $\approx$ network RTT 316 \end{itemize} 317 \item[@] Merchant: 318 \begin{itemize} 319 \item database to store contracts and cryptographic proofs 320 \item minimal CPU, hardware and bandwidth requirements 321 \item integration cost small due to reusable backend and backoffice components 322 \end{itemize} 323 \item[@] Customer: 324 \begin{itemize} 325 \item database (IndexedDB) to store coins, contracts and cryptographic proofs 326 \item minimal CPU, hardware and bandwidth requirements 327 \item DesignShift estimated \EUR{300,000} cost for design of 328 mass production ready \EUR{10} NFC hardware wallet in CC format 329 \end{itemize} 330 \end{itemize} 331 \end{frame} 332 333 334 % ``References and experience within the field'' 335 \begin{frame}{Availability / Reliability / Off-line transactions} 336 337 {\bf CAP theorem:} 338 \begin{center} 339 Consistency, Availability, Partition-Tolerance: pick two! 340 \end{center} 341 \vfill 342 \begin{itemize} 343 \item By default, Taler focuses on consistency and detects double-spending online \\ 344 $\Rightarrow$ Network partitions impact availability 345 \item Sharing coins via NFC while offline in principle possible \\ 346 $\Rightarrow$ Double spending detected late, receiver may be defrauded 347 \end{itemize} 348 \vfill 349 \end{frame} 350 351 352 \begin{frame}{Security} 353 \begin{itemize} 354 \item Each party must keep their private keys secure 355 %\item Private keys are never disclosed by the protocol (not even during payments) 356 \item Losses are by design with party where keys were compromised 357 \item Losses are bounded to: 358 \begin{itemize} 359 \item amount of coins carried in wallet (for consumer) 360 \item volume of transactions during compromise (for merchant) 361 \item amount of coins in circulation (for exchange) 362 \end{itemize} 363 \item Denomination key expiration used to limit risk 364 \item Exchange operator typically has escrow account matching issued coins 365 \end{itemize} 366 \end{frame} 367 368 369 \begin{frame}{Scalability} 370 \begin{block}{By design} 371 For exchange operator: 372 \begin{itemize} 373 \item linear scalability (via sharding) of database 374 \item linear scalability of cryptographic operations 375 \end{itemize} 376 System also supports having multiple exchange operators. 377 \end{block} 378 \begin{block}{Implementation limitations} 379 \begin{itemize} 380 \item Auditor implementation is currently sequential 381 \end{itemize} 382 \end{block} 383 All components are {\em free software} with {\em public specifications}. 384 \end{frame} 385 386 387 \begin{frame}{Interoperability} 388 \begin{itemize} 389 \item Database layer abstracted via interface 390 \item Wire transfer layer abstracted via interface 391 \item Open protocol specification 392 \item RESTful JSON-based APIs 393 \item Designed to operate well with HTTP(S) 394 \item Recent changes to better support Apps and non-WebExtension compatible browsers 395 \item Core logic implemented in portable C code (exchange, merchant backend) 396 \item Wallet-specific logic implemented in TypeScript \\ 397 ($\Rightarrow$ WebExtensions, React) 398 \end{itemize} 399 \end{frame} 400 401 402 \begin{frame}{Reliability} 403 \begin{itemize} 404 \item Cryptographic constructions are well-understood 405 \item Cryptographic primitives are state-of-the art 406 \item Protocols have been peer-reviewed by various cryptographers 407 \item State-of-the-art secure software development process 408 \item Implementation has been (partially) subjected to security audits, more planned 409 \item World-class information security team 410 \end{itemize} 411 \end{frame} 412 413 414 \begin{frame}{Anonymous transactions} 415 \begin{itemize} 416 \item Customer must identify when withdrawing via register system (KYC) 417 \item Merchant must identify to receive via register system (AML) 418 \item Merchant can be compelled to disclose terms of contract 419 \item Customer can be {\em anonymous} when paying 420 \item Multiple transactions of same customer are {\em unlinkable} 421 \item Customer has proof of purchase 422 \item Customer can voluntarily disclose identity, but not be compelled 423 \item Exchange operator must be well-known and certified by auditor 424 \item Auditor keys usually hard-coded in customer and merchant software 425 \end{itemize} 426 \end{frame} 427 428 429 \begin{frame}{Identity Management} 430 \begin{itemize} 431 \item Taler provides electronic cash on top of register-based system 432 \item Typically, customer and merchants have accounts in register-based system \\ 433 $\Rightarrow$ Identification piggy-backs on register-based system 434 \item Customer's wallets have a key to identify them 435 \item Possible to send electronic coins to customer based on wallet key \\ 436 $\Rightarrow$ Possible to provide {\em welfare} to unbanked individuals 437 \item Receiving Taler payments requires account in register (for taxability) 438 \end{itemize} 439 \end{frame} 440 441 442 \begin{frame}{Accessibility} 443 \begin{itemize} 444 \item Anyone can customize wallet, as {\em protocols} enforce security! 445 \item Wallets (HW, SW) will be customized to 446 match accessibility requirements (children, disabled, elderly) 447 \item Prototype was publicly demonstrated and explained by 10 year 448 old kid at hacker conferences (videos available) 449 \item Transaction speed is one click plus network RTT 450 \item Avoiding customer authentication improves privacy and usability! 451 \item Advisory board voiced ethical concerns with payments becoming 452 too easy and need to integrate financial education with wallet. 453 \end{itemize} 454 \end{frame} 455 456 457 \begin{frame}{Social Impact of Taler} 458 \begin{center} 459 \includegraphics[height=0.8\textheight]{social-impact.pdf} 460 \end{center} 461 \end{frame} 462 463 464 \begin{frame} 465 \frametitle{Possible outcomes (optimistic)} 466 \begin{itemize} 467 \item{Replace Mastercard/Visa/Paypal online} \\ 468 $\Rightarrow$ Cheaper transactions $\equiv$ 3\% reduction in VAT 469 \item{Replace cash and credit cards} \\ 470 $\Rightarrow$ Faster business transactions in stores 471 \item{Income via Taler is easily tracked by the government} \\ 472 $\Rightarrow$ Less corruption, less tax evasion possible 473 \item{Nobody can track how you spend your money} \\ 474 $\Rightarrow$ Privacy for citizens! \\ 475 $\Rightarrow$ Industrial espionage defense for business! 476 \end{itemize} 477 \end{frame} 478 479 480 \begin{frame}{} 481 \vfill 482 \begin{center} 483 {Why should {\em Riksbank} be interested?} 484 \end{center} 485 \vfill 486 \begin{center} 487 \includegraphics[height=3cm]{illustrations/usmint.jpeg} 488 \end{center} 489 \vfill 490 \begin{center} 491 {Why not do {\em online} what they do {\em offline}?\footnote{Just better: you can anonymously receive cash, but not Taler coins.}} 492 \end{center} 493 \end{frame} 494 495 496 \begin{frame}{Greatest challenges for Taler Systems SA} 497 \begin{itemize} 498 \item Onboarding of customers \& merchants 499 \item Banking license \& integration with register-based system 500 % \item Funding for non-proprietary (FLOSS) software to establish a 501 % payment systems commons without patents 502 \end{itemize} 503 \end{frame} 504 505 506 \begin{frame}{PoC project} 507 \begin{itemize} 508 \item Taler Systems SA as technological solution provider (expertise) 509 \item Riksbank as operator (escrow account, data center, RIX link) 510 \item Key steps: 511 \begin{itemize} 512 \item Agreement on costs and responsibilities for PoC (1 M) 513 \item Define specifications for small PoC / demonstrator (1 M) 514 \item Setup PoC (1 M) 515 \item Satisfy Riksbank technical security and performance requirements (6-12 M) 516 \item Identification of niche market and partners for public PoC launch (4-6 M) 517 \end{itemize} 518 \end{itemize} 519 \end{frame} 520 521 522 523 \begin{frame} 524 \begin{center} 525 % \includegraphics[width=0.66\textwidth]{logo-2017-fr.pdf} 526 \includegraphics[width=0.66\textwidth]{taler-logo-2018.pdf} 527 \end{center} 528 \vfill 529 \hfill A GNU package 530 \end{frame} 531 532 \end{document} 533 534 535 \section{Comparison} 536 \begin{frame}{Comparison} 537 \begin{center} \small 538 \begin{tabular}{l||c|c|c|c|c} 539 & Cash & Bitcoin & ZCash & Creditcard & GNU Taler \\ \hline \hline 540 Online &$-$$-$$-$ & ++ & ++ & + & +++ \\ \hline 541 Offline & +++ & $-$$-$ & $-$$-$ & + & $-$$-$ \\ \hline 542 Trans. cost & + & $-$$-$$-$ & $-$$-$$-$ & $-$ & ++ \\ \hline 543 Speed & + & $-$$-$$-$ & $-$$-$$-$ & o & ++ \\ \hline 544 Taxation & $-$ & $-$$-$ & $-$$-$$-$ & +++ & +++ \\ \hline 545 Payer-anon & ++ & o & ++ & $-$$-$$-$ & +++ \\ \hline 546 Payee-anon & ++ & o & ++ & $-$$-$$-$ & $-$$-$$-$ {\bf (*)} \\ \hline 547 Security & $-$ & o & o & $-$$-$ & ++ \\ \hline 548 Conversion & +++ & $-$$-$$-$ & $-$$-$$-$ & +++ & +++ \\ \hline 549 Libre & $-$ & +++ & +++ & $-$ $-$ $-$ & +++ \\ 550 \end{tabular} 551 \end{center} 552 {{\bf (*)} Not having payee-anonymity is a good thing as otherwise money laundering 553 becomes a real problem.} 554 \end{frame} 555 556 557 558 559 \section{The Problem} 560 \begin{frame}{The Problem} 561 562 3D secure (``verified by visa'') is a nightmare: 563 \begin{minipage}{5cm} 564 \begin{itemize} 565 \item Complicated process 566 \item Shifts liability to consumer 567 \item Significant latency 568 \item Can refuse valid requests 569 \item Legal vendors excluded 570 \item No privacy for buyers 571 \end{itemize} 572 \end{minipage} 573 \begin{minipage}{5cm} 574 \includegraphics[width=\textwidth]{illustrations/cc3ds.pdf} 575 \end{minipage} 576 \vfill 577 Online credit card payments will be replaced, but with what? 578 \end{frame} 579 580 581 \begin{frame}{The Problem} 582 \vfill 583 \begin{textblock*}{12cm}(0.5cm,1cm) % {block width} (coords) 584 \begin{itemize} 585 \item Global tech companies push oligopolies 586 \item Privacy and federated finance are at risk 587 % \item 30\% fees are conceivable 588 \item Economic sovereignty is in danger 589 \end{itemize} 590 \end{textblock*} 591 \begin{textblock*}{4cm}(3.5cm,5.2cm) % {block width} (coords) 592 {\includegraphics[width=\textwidth]{competitor-logos/amazon.png}} 593 \end{textblock*} 594 \begin{textblock*}{2cm}(7cm,3cm) % {block width} (coords) 595 {\includegraphics[width=\textwidth]{competitor-logos/alipay.jpeg}} 596 \end{textblock*} 597 \begin{textblock*}{2cm}(3cm,3.5cm) % {block width} (coords) 598 {\includegraphics[width=\textwidth]{competitor-logos/paypal.jpeg}} 599 \end{textblock*} 600 \begin{textblock*}{2cm}(9cm,5cm) % {block width} (coords) 601 {\includegraphics[width=\textwidth]{competitor-logos/applepay.jpeg}} 602 \end{textblock*} 603 \begin{textblock*}{2cm}(7.5cm,5.9cm) % {block width} (coords) 604 {\includegraphics[width=\textwidth]{competitor-logos/samsungpay.jpeg}} 605 \end{textblock*} 606 \begin{textblock*}{1cm}(9.5cm,6.3cm) % {block width} (coords) 607 {\includegraphics[width=\textwidth]{competitor-logos/android_pay.png}} 608 \end{textblock*} 609 \vfill 610 \end{frame}