ercim-taler.txt (5693B)
1 GNU Taler: Ethical Online Payments for the Internet Age 2 3 Florian Dold (Inria), Christian Grothoff (Inria) 4 5 GNU Taler is a new digital payment system currently under development at 6 Inria. It aims to strike a balance between radically decentralized 7 technologies such as Bitcoin and traditional payment methods while 8 satisfying stricter ethical requirements such as customer privacy, 9 taxation of merchants and environmental consciousness through 10 efficiency. GNU Taler also addresses micropayments, which are infeasible 11 with currently used payment systems due to high transaction costs. 12 13 Addressing the problem of micropayments is urgent. The overwhelming 14 majority of online journalists, bloggers and content creators currently 15 depend on advertisement revenue for their income. The recent surge of 16 ad-blocking technology is threatening to destroy this primary source of 17 income for many independent online journalists and bloggers. Furthermore 18 the existing advertisement industry is based on the Big Data business 19 model, and users do not only pay with their attention but also with 20 private information about their behavior. This threatens to move our 21 society towards post-democracy [2]. Our goal is to empower 22 consumers and content creators by giving the choice to opt for 23 micropayments instead of advertisements. 24 25 Unlike many recent developments in the field of privacy-preserving 26 online payments, GNU Taler is not based on blockchain technology, but on 27 Chaum-style digital payments [1] with additional 28 constructions based on elliptic curve cryptography. Our work addresses 29 practical problems that previous incarnations of Chaum-style digital 30 payments suffered from. The system is entirely composed of free software 31 components, which facilitates adoption, standardization and community 32 involvement. 33 34 From the consumer’s perspective, GNU Taler’s payment model comes closer to 35 the expectations one has when paying with cash than with credit cards. 36 Customers do not need to authenticate themselves with personally 37 identifying information to the merchant or the payment processor. 38 Instead, individual payments are authorized locally on the customer’s 39 computing device. This rules out a number of security issues associated 40 with identity theft. We expect that this will also lower the barrier for 41 online transactions due to the lower risk for the customer. With current 42 payment solutions, the risk of identity theft accumulates with every 43 payment being made. With our payment system, the only risk involved with 44 each individual payment is the amount being payed for that single 45 transaction. 46 47 In GNU Taler, the paying customer is only required to disclose minimal 48 private information (as required by local law), while the merchant’s 49 transactions are completely transparent to the state and thus taxable. 50 Taxable merely means that the state can obtain the necessary information 51 about the contract to levy common forms of income, sales or value-added 52 taxes, not that the system imposes any particular tax code. When 53 customers pay, they use anonymized digital payment tokens to sign a 54 contract with the merchant. The digitally signed contract is proposed by 55 the merchant and is supposed to contain all the information required for 56 taxation – which typically excludes the identity of the customer. Later, 57 the state can obtain the contract by following a chain of cryptographic 58 tokens, starting from a token in the wire transfer from the GNU Taler 59 payment system operator to the merchant. The payment system operator 60 only learns the total value of a contract, but no further details about 61 the contract or customer. 62 63 To pay with GNU Taler, customers need to install an electronic wallet on 64 their computing device. Once such a wallet is present, the fact that the 65 user does not have to authenticate to pay fundamentally improves 66 usability. We already see today that electronic wallets like GooglePay 67 are being deployed to simplify payments online. However, the dominant 68 players mostly simplify credit card transactions without actually 69 improving privacy or security for citizens. GNU Taler is 70 privacy-preserving free software and both technically and legally 71 designed to protect the interests of its users. 72 73 We plan to use GNU Taler as the basis for future research that investigates 74 censorship-resistant news distribution in decentralized social networks. 75 In addition to online payments, we eventually want to adapt GNU Taler to 76 mobile payments with NFC-enabled devices. We hope that mobile Taler 77 payments will further the proliferation of local currencies (such as the 78 Abeille in France), which are currently popular in parts of Europe, but 79 suffer from practical problems such as easy counterfeiting and the 80 limitation to physical coupons. 81 82 GNU Taler was started at TU Munich in April 2014 and is now being 83 coordinated by the TAMIS team [4] at Inria Rennes, with contributions 84 from the free software community at large and the GNUnet project [4] in 85 particular. The initial research is being funded by ARED and the 86 Renewable Freedom Foundation [5], but we plan to launch a startup to 87 drive the commercial adaptation of the technology. We encourage readers 88 to try our prototype for GNU Taler at <https://demo.taler.net/>. 89 90 References: 91 [1] Chaum et al., "Untraceable electronic cash." Proceedings on Advances in cryptology. Springer-Verlag New York, Inc., 1990. 92 [2] Stallman, Richard, "How Much Surveillance Can Democracy Withstand?." Wired, Oct. 2013. 93 94 Links: 95 [3] https://www.inria.fr/en/teams/tamis 96 [4] https://gnunet.org/ 97 [5] https://renewablefreedom.org/ 98 99 Author contact addresses: 100 101 Florian Dold 102 +33 2 99 84 25 66 103 florian.dold@inria.fr 104 105 Christian Grothoff 106 +33 2 99 84 71 45 107 christian@grothoff.org