4,283 research outputs found

    Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments

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    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

    Blindspot: Indistinguishable Anonymous Communications

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    Communication anonymity is a key requirement for individuals under targeted surveillance. Practical anonymous communications also require indistinguishability - an adversary should be unable to distinguish between anonymised and non-anonymised traffic for a given user. We propose Blindspot, a design for high-latency anonymous communications that offers indistinguishability and unobservability under a (qualified) global active adversary. Blindspot creates anonymous routes between sender-receiver pairs by subliminally encoding messages within the pre-existing communication behaviour of users within a social network. Specifically, the organic image sharing behaviour of users. Thus channel bandwidth depends on the intensity of image sharing behaviour of users along a route. A major challenge we successfully overcome is that routing must be accomplished in the face of significant restrictions - channel bandwidth is stochastic. We show that conventional social network routing strategies do not work. To solve this problem, we propose a novel routing algorithm. We evaluate Blindspot using a real-world dataset. We find that it delivers reasonable results for applications requiring low-volume unobservable communication.Comment: 13 Page

    Deepening Dialogue in Silent Spaces: Ireland’s pedagogy of peace.

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    Ireland has emerged from an era of protracted conflict, which claimed almost 4,000 lives and left a legacy of thousands of victims. It is difficult for people who lived through this era to speak openly with each other about what went wrong. This thesis acknowledges the presence of deep-rooted societal silence that accompanies violent conflict and explores the role of silence in post conflict communities. It describes the significance of education in enabling dialogue to deepen between communities of ‘others’. It describes the transitional processes impacting on the lead up to the most recent peace agreement, the Good Friday Agreement (1998). This thesis is an analysis of the dialogical process involved in it’s negotiation. It illuminates post peace building challenges for the community education sector. This research provides insights for community educators into ways to negotiate silence and to transcend difference through dialogue. The Agreement (GFA) promised parity of esteem to nationalist and unionist communities. Fifteen years after the GFA was signed and endorsed by both communities, the spiral of violence spins out of control during contentious commemorative parades. This thesis examines the complexities of conflict transformation as experienced by protagonists. It describes a philosophy of education that emerged within communities as a response to the challenges they faced. This philosophy of education is Ireland’s pedagogy of peace. As we face into an epoch of truth recovery and dealing with the past the role of community education in imagining a philosophy of unity is critical

    The Life of the Law - A Moving Story

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    Spycatcher’s Little Sister: The Thatcher government and the Panorama affair, 1980-81

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    This article investigates the Thatcher government’s attempts to suppress or censor BBC reporting on secret intelligence issues in the early 1980s. It examines official reactions to a BBC intrusion into the secret world, as the team behind the long-running Panorama documentary strand sought to examine the role and accountability of Britain’s clandestine services. It also assesses the nature and extent of any collusion between the government and the BBC’s senior management and contributes to the ongoing evaluation of how the Thatcher government’s approaches to press freedom, national security, and secrecy evolved. It is also argued that the Panorama affair was an important waypoint on the journey towards the dramatic Spycatcher episode of the mid-1980s, when Margaret Thatcher’s efforts to suppress embittered former MI5 officer Peter Wright’s memoir resulted in huge public embarrassment. The key players on the government side – Thatcher and Cabinet Secretary Robert Armstrong – failed to learn the lessons of the 1980-81 affair, that it was often more dangerous to attempt suppression than to simply let events run their course

    Ethics in a Global Society (Chapter 12 of Organizational Ethics: A Practical Approach

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    Globalization is having a dramatic impact on life in the 21st century. We inhabit a global society knit together by free trade, international travel, immigration, satellite communication systems, and the Internet. In this interconnected world, ethical responsibilities extend beyond national boundaries. Decisions about raw materials, manufacturing, outsourcing, farm subsidies, investments, marketing strategies, suppliers, safety standards, and energy use made in one country have ramifications for residents of other parts of the world. Organizational citizenship is now played out on a global stage. Businesses, in particular, are being urged to take on a larger role in solving the world\u27s social problems

    Defending against Sybil Devices in Crowdsourced Mapping Services

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    Real-time crowdsourced maps such as Waze provide timely updates on traffic, congestion, accidents and points of interest. In this paper, we demonstrate how lack of strong location authentication allows creation of software-based {\em Sybil devices} that expose crowdsourced map systems to a variety of security and privacy attacks. Our experiments show that a single Sybil device with limited resources can cause havoc on Waze, reporting false congestion and accidents and automatically rerouting user traffic. More importantly, we describe techniques to generate Sybil devices at scale, creating armies of virtual vehicles capable of remotely tracking precise movements for large user populations while avoiding detection. We propose a new approach to defend against Sybil devices based on {\em co-location edges}, authenticated records that attest to the one-time physical co-location of a pair of devices. Over time, co-location edges combine to form large {\em proximity graphs} that attest to physical interactions between devices, allowing scalable detection of virtual vehicles. We demonstrate the efficacy of this approach using large-scale simulations, and discuss how they can be used to dramatically reduce the impact of attacks against crowdsourced mapping services.Comment: Measure and integratio
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