3,398 research outputs found
Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments
Decentralized systems are a subset of distributed systems where multiple
authorities control different components and no authority is fully trusted by
all. This implies that any component in a decentralized system is potentially
adversarial. We revise fifteen years of research on decentralization and
privacy, and provide an overview of key systems, as well as key insights for
designers of future systems. We show that decentralized designs can enhance
privacy, integrity, and availability but also require careful trade-offs in
terms of system complexity, properties provided, and degree of
decentralization. These trade-offs need to be understood and navigated by
designers. We argue that a combination of insights from cryptography,
distributed systems, and mechanism design, aligned with the development of
adequate incentives, are necessary to build scalable and successful
privacy-preserving decentralized systems
The Reputation, Opinion, Credibility and Quality (ROCQ) Scheme
An implicit assumption of trust in the participants is at the basis of most Peer-to-Peer (P2P) networks. However, in practice, not all participants are benign or cooperative. Identifying such peers is critical to the smooth and effective functioning of a P2P network. In this paper, we present the ROCQ mechanism, a reputation-based trust management system that computes the trustworthiness of peers on the basis of transaction-based feedback. The ROCQ model combines four parameters: Reputation (R) or a peer's global trust rating, Opinion (O) formed by a peer's first-hand interactions, Credibility (C) of a reporting peer and Quality (Q) or the confidence a reporting peer puts on the judgement it provides. We then present a distributed implementation of our scheme over FreePastry, a structured P2P network. Experimental results considering different models for malicious behavior indicate the contexts in which the ROCQ scheme performs better than existing schemes
Efficiency and Nash Equilibria in a Scrip System for P2P Networks
A model of providing service in a P2P network is analyzed. It is shown that
by adding a scrip system, a mechanism that admits a reasonable Nash equilibrium
that reduces free riding can be obtained. The effect of varying the total
amount of money (scrip) in the system on efficiency (i.e., social welfare) is
analyzed, and it is shown that by maintaining the appropriate ratio between the
total amount of money and the number of agents, efficiency is maximized. The
work has implications for many online systems, not only P2P networks but also a
wide variety of online forums for which scrip systems are popular, but formal
analyses have been lacking
A FUNCTIONAL SKETCH FOR RESOURCES MANAGEMENT IN COLLABORATIVE SYSTEMS FOR BUSINESS
This paper presents a functional design sketch for the resource management module of a highly scalable collaborative system. Small and medium enterprises require such tools in order to benefit from and develop innovative business ideas and technologies. As computing power is a modern increasing demand and no easy and cheap solutions are defined, especially small companies or emerging business projects abide a more accessible alternative. Our work targets to settle a model for how P2P architecture can be used as infrastructure for a collaborative system that delivers resource access services. We are focused on finding a workable collaborative strategy between peers so that the system offers a cheap, trustable and quality service. Thus, in this phase we are not concerned about solutions for a specific type of task to be executed by peers, but only considering CPU power as resource. This work concerns the resource management module as a part of a larger project in which we aim to build a collaborative system for businesses with important resource demandsresource management, p2p, open-systems, service oriented computing, collaborative systems
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