Cloud-based Content Distribution on a Budget

To leverage the elastic nature of cloud computing, a solution provider must be able to accurately gauge demand for its offering. For applications that involve swarm-to-cloud interactions, gauging such demand is not straightforward. In this paper, we propose a general framework, analyze a mathematical model, and present a prototype implementation of a canonical swarm-to-cloud application, namely peer-assisted content delivery. Our system – called Cyclops – dynamically adjusts the off-cloud bandwidth consumed by content servers (which represents the bulk of the provider's cost) to feed a set of swarming clients, based on a feedback signal that gauges the real-time health of the swarm. Our extensive evaluation of Cyclops in a variety of settings – including controlled PlanetLab and live Internet experiments involving thousands of users – show significant reduction in content distribution costs (by as much as two orders of magnitude) when compared to non-feedback-based swarming solutions, with minor impact on content delivery times

Online advertising: analysis of privacy threats and protection approaches

Online advertising, the pillar of the “free” content on the Web, has revolutionized the marketing business in recent years by creating a myriad of new opportunities for advertisers to reach potential customers. The current advertising model builds upon an intricate infrastructure composed of a variety of intermediary entities and technologies whose main aim is to deliver personalized ads. For this purpose, a wealth of user data is collected, aggregated, processed and traded behind the scenes at an unprecedented rate. Despite the enormous value of online advertising, however, the intrusiveness and ubiquity of these practices prompt serious privacy concerns. This article surveys the online advertising infrastructure and its supporting technologies, and presents a thorough overview of the underlying privacy risks and the solutions that may mitigate them. We first analyze the threats and potential privacy attackers in this scenario of online advertising. In particular, we examine the main components of the advertising infrastructure in terms of tracking capabilities, data collection, aggregation level and privacy risk, and overview the tracking and data-sharing technologies employed by these components. Then, we conduct a comprehensive survey of the most relevant privacy mechanisms, and classify and compare them on the basis of their privacy guarantees and impact on the Web.Peer ReviewedPostprint (author's final draft

Distributed Information Retrieval using Keyword Auctions

This report motivates the need for large-scale distributed approaches to information retrieval, and proposes solutions based on keyword auctions

Re-Imagining Journalism: Local News for a Networked World

Details strategies for realizing healthy local information ecologies through for-profit and nonprofit media; higher education and community institutions; emphasis on relevance, research, and revenues; and government support. Includes case summaries

iTeleScope: Intelligent Video Telemetry and Classification in Real-Time using Software Defined Networking

Video continues to dominate network traffic, yet operators today have poor visibility into the number, duration, and resolutions of the video streams traversing their domain. Current approaches are inaccurate, expensive, or unscalable, as they rely on statistical sampling, middle-box hardware, or packet inspection software. We present {\em iTelescope}, the first intelligent, inexpensive, and scalable SDN-based solution for identifying and classifying video flows in real-time. Our solution is novel in combining dynamic flow rules with telemetry and machine learning, and is built on commodity OpenFlow switches and open-source software. We develop a fully functional system, train it in the lab using multiple machine learning algorithms, and validate its performance to show over 95\% accuracy in identifying and classifying video streams from many providers including Youtube and Netflix. Lastly, we conduct tests to demonstrate its scalability to tens of thousands of concurrent streams, and deploy it live on a campus network serving several hundred real users. Our system gives unprecedented fine-grained real-time visibility of video streaming performance to operators of enterprise and carrier networks at very low cost.Comment: 12 pages, 16 figure

Defending Against Denial of Service

Civil Society currently faces significant cyber threats. At the top of the list of those threats are Denial of Service (DoS) attacks. The websites of many organizations and individuals have already come under such attacks, and the frequency of those attacks are on the rise. Civil Society frequently does not have the kinds of resources or technical know-how that is available to commercial enterprise and government websites, and often have to exist in adverse political environments where every avenue available, both legal and illegal, is used against them. Therefore, the threat of DoS attacks is unlikely to go away any time soon.A Denial of Service (DoS) attack is any attack that overwhelms a website, causing the content normally provided by that website to no longer be available to regular visitors of the website. Distributed Denial of Service (DDoS) attacks are traffic volumebased attacks originating from a large number of computers, which are usually compromised workstations. These workstations, known as 'zombies', form a widely distributed attack network called a 'botnet'. While many modern Denial of Service attacks are Distributed Denial of Service attacks, this is certainly not true for all denials of service experienced by websites. Therefore, when users first start experiencing difficulty in getting to the website content, it should not be assumed that the site is under a DDoS attack. Many forms of DoS are far easier to implement than DDoS, and so these attacks are still used by parties with malicious intent. Many such DoS attacks are easier to defend against once the mechanism used to cause the denial of service is known. Therefore, it is paramount to do proper analysis of attack traffic when a site becomes unable to perform its normal function. There are two parts to this guide. The first part outlines preparatory steps that can be taken by Civil Society organizations to improve their website's resilience, should it come under attack. However, we do understand that most Civil Society organizations' first introduction to DoS attacks comes when they suddenly find themselves the victim of an attack. The second part of this guide provides a step-by-step process to assist the staff of NGOs to efficiently deal with that stressful situation