2,729 research outputs found
Centrally Banked Cryptocurrencies
Current cryptocurrencies, starting with Bitcoin, build a decentralized
blockchain-based transaction ledger, maintained through proofs-of-work that
also generate a monetary supply. Such decentralization has benefits, such as
independence from national political control, but also significant limitations
in terms of scalability and computational cost. We introduce RSCoin, a
cryptocurrency framework in which central banks maintain complete control over
the monetary supply, but rely on a distributed set of authorities, or
mintettes, to prevent double-spending. While monetary policy is centralized,
RSCoin still provides strong transparency and auditability guarantees. We
demonstrate, both theoretically and experimentally, the benefits of a modest
degree of centralization, such as the elimination of wasteful hashing and a
scalable system for avoiding double-spending attacks.Comment: 15 pages, 4 figures, 2 tables in Proceedings of NDSS 201
Contour: A Practical System for Binary Transparency
Transparency is crucial in security-critical applications that rely on
authoritative information, as it provides a robust mechanism for holding these
authorities accountable for their actions. A number of solutions have emerged
in recent years that provide transparency in the setting of certificate
issuance, and Bitcoin provides an example of how to enforce transparency in a
financial setting. In this work we shift to a new setting, the distribution of
software package binaries, and present a system for so-called "binary
transparency." Our solution, Contour, uses proactive methods for providing
transparency, privacy, and availability, even in the face of persistent
man-in-the-middle attacks. We also demonstrate, via benchmarks and a test
deployment for the Debian software repository, that Contour is the only system
for binary transparency that satisfies the efficiency and coordination
requirements that would make it possible to deploy today.Comment: International Workshop on Cryptocurrencies and Blockchain Technology
(CBT), 201
Tracing Transactions Across Cryptocurrency Ledgers
One of the defining features of a cryptocurrency is that its ledger,
containing all transactions that have evertaken place, is globally visible. As
one consequenceof this degree of transparency, a long line of recent re-search
has demonstrated that even in cryptocurrenciesthat are specifically designed to
improve anonymity it is often possible to track money as it changes hands,and
in some cases to de-anonymize users entirely. With the recent proliferation of
alternative cryptocurrencies, however, it becomes relevant to ask not only
whether ornot money can be traced as it moves within the ledgerof a single
cryptocurrency, but if it can in fact be tracedas it moves across ledgers. This
is especially pertinent given the rise in popularity of automated trading
platforms such as ShapeShift, which make it effortless to carry out such
cross-currency trades. In this paper, weuse data scraped from ShapeShift over a
thirteen-monthperiod and the data from eight different blockchains to explore
this question. Beyond developing new heuristics and creating new types of links
across cryptocurrency ledgers, we also identify various patterns of
cross-currency trades and of the general usage of these platforms, with the
ultimate goal of understanding whetherthey serve a criminal or a profit-driven
agenda.Comment: 14 pages, 13 tables, 6 figure
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