Conference Paper

PAR: Payment for Anonymous Routing.

DOI: 10.1007/978-3-540-70630-4_14 Conference: Privacy Enhancing Technologies, 8th International Symposium, PETS 2008, Leuven, Belgium, July 23-25, 2008, Proceedings
Source: DBLP

ABSTRACT Despite the growth of the Internet and the increasing con- cern for privacy of online communications, current deployments of anon- ymization networks depend on a very small set of nodes that volunteer their bandwidth. We believe that the main reason is not disbelief in their ability to protect anonymity, but rather the practical limitations in bandwidth and latency that stem from limited participation. This limited participation, in turn, is due to a lack of incentives to participate. We propose providing economic incentives, which historically have worked very well. In this paper, we demonstrate a payment scheme that can be used to compensate nodes which provide anonymity in Tor, an existing onion routing, anonymizing network. We show that current anonymous pay- ment schemes are not suitable and introduce a hybrid payment system based on a combination of the Peppercoin Micropayment system and a new type of "one use" electronic cash. Our system claims to maintain users' anonymity, although payment techniques mentioned previously - when adopted individually - provably fail.

0 Bookmarks
 · 
60 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Distributed anonymous communication networks like Tor de- pend on volunteers to donate their resources. However, the efforts of Tor volunteers have not grown as fast as the demands on the Tor network. We explore techniques to incentivize Tor users to relay Tor traffictoo; if users contribute resources to the Tor overlay, they should receive faster service in return. In our design, the central Tor directory authorities mea- sure performance and publish a list of Tor relays that should be given higher priority when establishing circuits. Simulations of our proposed design show that conforming users receive significant improvements in performance, in some cases experiencing twice the network throughput of selfish users who do not relay traffic for the Tor network.
    Financial Cryptography and Data Security, 14th International Conference, FC 2010, Tenerife, Canary Islands, January 25-28, 2010, Revised Selected Papers; 01/2010
  • [Show abstract] [Hide abstract]
    ABSTRACT: Bitcoin is a decentralized payment system that relies on Proof-of-Work (PoW) to verify payments. Nowadays, Bitcoin is increasingly used in a number of fast payment scenarios, where the time between the exchange of currency and goods is short (in the order of few seconds). While the Bitcoin payment verification scheme is designed to prevent double-spending, our results show that the system requires tens of minutes to verify a transaction and is therefore inappropriate for fast payments. An example of this use of Bitcoin was recently reported in the media: Bitcoins were used as a form of \emph{fast} payment in a local fast-food restaurant. Until now, the security of fast Bitcoin payments has not been studied. In this paper, we analyze the security of using Bitcoin for fast payments. We show that, unless appropriate detection techniques are integrated in the current Bitcoin implementation, double-spending attacks on fast payments succeed with overwhelming probability and can be mounted at low cost. We further show that the measures recommended by Bitcoin developers for the use of Bitcoin in fast payments are not always effective in detecting double-spending; we show that if those recommendations are integrated in future Bitcoin implementations, double-spending attacks on Bitcoin will still be possible. Finally, we propose and implement a modification to the existing Bitcoin implementation that ensures the detection of double-spending attacks against fast payments.
    Proceedings of the 2012 ACM conference on Computer and communications security; 10/2012
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, many advances have been made in cryptography, as well as in the performance of communication networks and processors. As a result, many advanced cryptographic protocols are now efficient enough to be considered practical, yet research in the area re- mains largely theoretical and little work has been done to use these protocols in practice, despite a wealth of potential applications. This paper introduces a simple description language, ZKPDL, and an interpreter for this language. ZKPDL implements non-interactive zero-knowledge proofs of knowledge, a primitive which has received much atten- tion in recent years. Using our language, a single pro- gram may specify the computation required by both the prover and verifier of a zero-knowledge protocol, while our interpreter performs a number of optimizations to lower both computational and space overhead. Our motivating application for ZKPDL has been the efficient implementation of electronic cash. As such, we have used our language to develop a cryptographic library, Cashlib, that provides an interface for using e- cash and fair exchange protocols without requiring ex- pert knowledge from the programmer.
    19th USENIX Security Symposium, Washington, DC, USA, August 11-13, 2010, Proceedings; 01/2010

Full-text

View
0 Downloads