EGOIST: Overlay Routing Using Selfish Neighbor Selection

A foundational issue underlying many overlay network applications ranging from routing to P2P file sharing is that of connectivity management, i.e., folding new arrivals into an existing overlay, and re-wiring to cope with changing network conditions. Previous work has considered the problem from two perspectives: devising practical heuristics for specific applications designed to work well in real deployments, and providing abstractions for the underlying problem that are analytically tractable, especially via game-theoretic analysis. In this paper, we unify these two thrusts by using insights gleaned from novel, realistic theoretic models in the design of Egoist – a prototype overlay routing system that we implemented, deployed, and evaluated on PlanetLab. Using measurements on PlanetLab and trace-based simulations, we demonstrate that Egoist's neighbor selection primitives significantly outperform existing heuristics on a variety of performance metrics, including delay, available bandwidth, and node utilization. Moreover, we demonstrate that Egoist is competitive with an optimal, but unscalable full-mesh approach, remains highly effective under significant churn, is robust to cheating, and incurs minimal overhead. Finally, we discuss some of the potential benefits Egoist may offer to applications.National Science Foundation (CISE/CSR 0720604, ENG/EFRI 0735974, CISE/CNS 0524477, CNS/NeTS 0520166, CNS/ITR 0205294; CISE/EIA RI 0202067; CAREER 04446522); European Commission (RIDS-011923

Novel Attacks and Defenses for Enterprise Internet-of-Things (E-IoT) Systems

This doctoral dissertation expands upon the field of Enterprise Internet-of-Things (E-IoT) systems, one of the most ubiquitous and under-researched fields of smart systems. E-IoT systems are specialty smart systems designed for sophisticated automation applications (e.g., multimedia control, security, lighting control). E-IoT systems are often closed source, costly, require certified installers, and are more robust for their specific applications. This dissertation begins with an analysis of the current E-IoT threat landscape and introduces three novel attacks and defenses under-studied software and protocols heavily linked to E-IoT systems. For each layer, we review the literature for the threats, attacks, and countermeasures. Based on the systematic knowledge we obtain from the literature review, we propose three novel attacks and countermeasures to protect E-IoT systems. In the first attack, we present PoisonIvy, several attacks developed to show that malicious E-IoT drivers can be used to compromise E-IoT. In response to PoisonIvy threats, we describe Ivycide, a machine-learning network-based solution designed to defend E-IoT systems against E-IoT driver threats. As multimedia control is a significant application of E-IoT, we introduce is HDMI-Walk, a novel attack vector designed to demonstrate that HDMI\u27s Consumer Electronics Control (CEC) protocol can be used to compromise multiple devices through a single connection. To defend devices from this threat, we introduce HDMI-Watch, a standalone intrusion detection system (IDS) designed to defend HDMI-enabled devices from HDMI-Walk-style attacks. Finally, this dissertation evaluates the security of E-IoT proprietary protocols with LightingStrike, a series of attacks used to demonstrate that popular E-IoT proprietary communication protocols are insecure. To address LightningStrike threats, we introduce LGuard, a complete defense framework designed to defend E-IoT systems from LightingStrike-style attacks using computer vision, traffic obfuscation, and traffic analysis techniques. For each contribution, all of the defense mechanisms proposed are implemented without any modification to the underlying hardware or software. All attacks and defenses in this dissertation were performed with implementations on widely-used E-IoT devices and systems. We believe that the research presented in this dissertation has notable implications on the security of E-IoT systems by exposing novel threat vectors, raising awareness, and motivating future E-IoT system security research

Applications of Temporal Graph Metrics to Real-World Networks

Real world networks exhibit rich temporal information: friends are added and removed over time in online social networks; the seasons dictate the predator-prey relationship in food webs; and the propagation of a virus depends on the network of human contacts throughout the day. Recent studies have demonstrated that static network analysis is perhaps unsuitable in the study of real world network since static paths ignore time order, which, in turn, results in static shortest paths overestimating available links and underestimating their true corresponding lengths. Temporal extensions to centrality and efficiency metrics based on temporal shortest paths have also been proposed. Firstly, we analyse the roles of key individuals of a corporate network ranked according to temporal centrality within the context of a bankruptcy scandal; secondly, we present how such temporal metrics can be used to study the robustness of temporal networks in presence of random errors and intelligent attacks; thirdly, we study containment schemes for mobile phone malware which can spread via short range radio, similar to biological viruses; finally, we study how the temporal network structure of human interactions can be exploited to effectively immunise human populations. Through these applications we demonstrate that temporal metrics provide a more accurate and effective analysis of real-world networks compared to their static counterparts.Comment: 25 page

Manipulating the Online Marketplace of Ideas

Social media, the modern marketplace of ideas, is vulnerable to manipulation. Deceptive inauthentic actors impersonate humans to amplify misinformation and influence public opinions. Little is known about the large-scale consequences of such operations, due to the ethical challenges posed by online experiments that manipulate human behavior. Here we introduce a model of information spreading where agents prefer quality information but have limited attention. We evaluate the impact of manipulation strategies aimed at degrading the overall quality of the information ecosystem. The model reproduces empirical patterns about amplification of low-quality information. We find that infiltrating a critical fraction of the network is more damaging than generating attention-grabbing content or targeting influentials. We discuss countermeasures suggested by these insights to increase the resilience of social media users to manipulation, and legal issues arising from regulations aimed at protecting human speech from suppression by inauthentic actors.Comment: 25 pages, 8 figures, 80 reference