From 895e24872de95acf255e0746b42f0661697e7f9a Mon Sep 17 00:00:00 2001 From: Christian Grothoff Date: Sun, 12 Jul 2020 18:19:17 +0200 Subject: initial import of thesis-dold --- doc/system/abstract.tex | 52 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 doc/system/abstract.tex (limited to 'doc/system/abstract.tex') diff --git a/doc/system/abstract.tex b/doc/system/abstract.tex new file mode 100644 index 000000000..fcc44c7d0 --- /dev/null +++ b/doc/system/abstract.tex @@ -0,0 +1,52 @@ +\chapter{Abstract} +%As our society becomes more and more digitalized, an electronic version of cash +%becomes inevitable. The design of payment systems is not just a technological +%matter, but has far-reaching sociopolitical consequences. +\begin{samepage} +We describe the design and implementation of GNU Taler, an electronic payment +system based on an extension of Chaumian online e-cash with efficient change. +In addition to anonymity for customers, it provides the novel notion of +\emph{income transparency}, which guarantees that merchants can reliably +receive a payment from an untrusted payer only when their income from the +payment is visible to tax authorities. + +Income transparency is achieved by the introduction of a \emph{refresh +protocol}, which gives anonymous change for a partially spent coin without +introducing a tax evasion loophole. In addition to income transparency, the +refresh protocol can be used to implement Camenisch-style \emph{atomic swaps}, and to +preserve anonymity in the presence of protocol \emph{aborts} and crash faults with +data loss by participants. + +Furthermore, we show the provable security of our income-transparent anonymous +e-cash, which, in addition to the usual \emph{anonymity} and +\emph{unforgeability} properties of e-cash, also formally models +\emph{conservation} of funds and income transparency. + +Our implementation of GNU Taler is usable by non-expert users and integrates +with the modern Web architecture. Our payment platform addresses a range of +practical issues, such as tipping customers, providing refunds, integrating +with banks and know-your-customer (KYC) checks, as well as Web platform +security and reliability requirements. On a single machine, we achieve +transaction rates that rival those of global, commercial credit card +processors. We increase the robustness of the exchange---the component that +keeps bank money in escrow in exchange for e-cash---by adding an auditor +component, which verifies the correct operation of the system and allows to +detect a compromise or misbehavior of the exchange early. + +Just like bank accounts have reason to exist besides bank notes, e-cash only +serves as part of a whole payment system stack. Distributed ledgers have +recently gained immense popularity as potential replacement for parts of the +traditional financial industry. While cryptocurrencies based on proof-of-work +such as Bitcoin have yet to scale to be useful as a replacement for established +payment systems, other more efficient systems based on blockchains with more +classical consensus algorithms might still have promising applications in the +financial industry. + +We design, implement and analyze the performance of \emph{Byzantine Set Union +Consensus} (BSC), a Byzantine consensus protocol that agrees on a (super-)set +of elements at once, instead of sequentially agreeing on the individual +elements of a set. While BSC is interesting in itself, it can also be used as +a building block for permissioned blockchains, where---just like in +Nakamoto-style consensus---whole blocks of transactions are agreed upon at once, +increasing the transaction rate. +\end{samepage} -- cgit v1.2.3