Modeling Security and Resource Allocation for Mobile Multi-hop Wireless Neworks Using Game Theory

This dissertation presents novel approaches to modeling and analyzing security and resource allocation in mobile ad hoc networks (MANETs). The research involves the design, implementation and simulation of different models resulting in resource sharing and security’s strengthening of the network among mobile devices. Because of the mobility, the network topology may change quickly and unpredictably over time. Moreover, data-information sent from a source to a designated destination node, which is not nearby, has to route its information with the need of intermediary mobile nodes. However, not all intermediary nodes in the network are willing to participate in data-packet transfer of other nodes. The unwillingness to participate in data forwarding is because a node is built on limited resources such as energy-power and data. Due to their limited resource, nodes may not want to participate in the overall network objectives by forwarding data-packets of others in fear of depleting their energy power. To enforce cooperation among autonomous nodes, we design, implement and simulate new incentive mechanisms that used game theoretic concepts to analyze and model the strategic interactions among rationale nodes with conflicting interests. Since there is no central authority and the network is decentralized, to address the concerns of mobility of selfish nodes in MANETs, a model of security and trust relationship was designed and implemented to improve the impact of investment into trust mechanisms. A series of simulations was carried out that showed the strengthening of security in a network with selfish and malicious nodes. Our research involves bargaining for resources in a highly dynamic ad-hoc network. The design of a new arbitration mechanism for MANETs utilizes the Dirichlet distribution for fairness in allocating resources. Then, we investigated the problem of collusion nodes in mobile ad-hoc networks with an arbitrator. We model the collusion by having a group of nodes disrupting the bargaining process by not cooperating with the arbitrator. Finally, we investigated the resource allocation for a system between agility and recovery using the concept of Markov decision process. Simulation results showed that the proposed solutions may be helpful to decision-makers when allocating resources between separated teams

Basics of coalitional games with applications to communications and networking

Game theory is the study of decision making in an interactive environment. Coalitional games fulfill the promise of group efficient solutions to problems involving strategic actions. Formulation of optimal player behavior is a fundamental element in this theory. This paper comprises a self-instructive didactic means to study basics of coalitional games indicating how coalitional game theory tools can provide a framework to tackle different problems in communications and networking. We show that coalitional game approaches achieve an improved performance compare to non-cooperative game theoretical solutions

TEEvil: Identity Lease via Trusted Execution Environments

We investigate identity lease, a new type of service in which users lease their identities to third parties by providing them with full or restricted access to their online accounts or credentials. We discuss how identity lease could be abused to subvert the digital society, facilitating the spread of fake news and subverting electronic voting by enabling the sale of votes. We show that the emergence of Trusted Execution Environments and anonymous cryptocurrencies, for the first time, allows the implementation of such a lease service while guaranteeing fairness, plausible deniability and anonymity, therefore shielding the users and account renters from prosecution. To show that such a service can be practically implemented, we build an example service that we call TEEvil leveraging Intel SGX and ZCash. Finally, we discuss defense mechanisms and challenges in the mitigation of identity lease services.Comment: 21 pages, 5 figure

Barriers to Entry

Entry of firms into a market is an important economic mechanism that influences industry dynamics and contributes to allocative and dynamic efficiency. However, there are barriers that can prevent companies from entering a market, hampering the competitive process. Therefore, it is clear that barriers to entry are an important issue in competition policy. In this report, we studied a number of 37 different barriers with a special focus on the possible size effect of the barrier, the sustainability of the barrier, the way it can be measured and the relation with other barriers to entry.

Security, Privacy and Economics of Online Advertising

Online advertising is at the core of today’s Web: it is the main business model, generating large annual revenues expressed in tens of billions of dollars that sponsor most of the online content and services. Online advertising consists of delivering marketing messages, embedded into Web content, to a targeted audience. In this model, entities attract Web traffic by offering the content and services for free and charge advertisers for including advertisements in this traffic (i.e., advertisers pay for users’ attention and interests). Online advertising is a very successful form of advertising as it allows for advertisements (ads) to be targeted to individual users’ interests; especially when advertisements are served on users’ mobile devices, as ads can be targeted to users’ locations and the corresponding context. However, online advertising also introduces a number of problems. Given the high ad revenue at stake, fraudsters have economic incentives to exploit the ad system and generate profit from it. Unfortunately, to achieve this goal, they often compromise users’ online security (e.g., via malware, phishing, etc.). For the purpose of maximizing the revenue by matching ads to users’ interests, a number of techniques are deployed, aimed at tracking and profiling users’ digital footprints, i.e., their behavior in the digital world. These techniques introduce new threats to users’ privacy. Consequently, some users adopt ad-avoidance tools that prevent the download of advertisements and partially thwart user profiling. Such user behavior, as well as exploits of ad systems, have economic implications as they undermine the online advertising business model. Meddling with advertising revenue disrupts the current economic model of the Web, the consequences of which are unclear. Given that today’s Web model relies on online advertising revenue in order for users to have access and consume content and services for “free”, coupled with the fact that there are many threats that could jeopardize this model, in this thesis we address the security, privacy and economic issues stemming from this fundamental element of the Web. In the first part of the thesis, we investigate the vulnerabilities of online advertising systems. We identify how an adversary can exploit the ad system to generate profit for itself, notably by performing inflight modification of ad traffic. We provide a proof-of-concept implementation of the identified threat on Wi-Fi routers. We propose a collaborative approach for securing online advertising and Web browsing against such threats. By investigating how a certificate-based authentication is deployed in practice, we assess the potential of relying on certificate-based authentication as a building block of a solution to protect the ad revenue. We propose a multidisciplinary approach for improving the current state of certificate-based authentication on the Web. In the second part of the thesis, we study the economics of ad systems’ exploits and certain potential countermeasures. We evaluate the potential of different solutions aimed at protecting ad revenue being implemented by the stakeholders (e.g., Internet Service Providers or ad networks) and the conditions under which this is likely to happen. We also study the economic ramifications of ad-avoidance technologies on the monetization of online content. We use game-theory to model the strategic behavior of involved entities and their interactions. In the third part of the thesis, we focus on privacy implications of online advertising. We identify a novel threat to users’ location privacy that enables service providers to geolocate users with high accuracy, which is needed to serve location-targeted ads for local businesses. We draw attention to the large scale of the threat and the potential impact on users’ location privacy

Sovereign Debt Crises and Vulture Hedge Funds: Issues and Policy Solutions

Since the 1990s, “vulture” hedge funds have made fabulous returns by pursuing a controversial strategy: buying bonds issued by countries in or near default and then suing those countries for full repayment. Vulture funds’ investments have resulted in chaotic, drawn-out default episodes and an enormous redistribution of wealth from developing countries to billionaire investors. Despite the real benefits vultures provide to the secondary market for sovereign debt, something must be done to dull their talons. Lamentably, however, no viable solution currently exists. This Note argues that a nonprofit fund designed to compete with vultures could at least mitigate harm to developing nations during the next wave of defaults

The Disappointments of Networks

The past 25 years have seen a ‘turn to culture’ in copyright scholarship. This cultural turn has produced an expansive account of copyright’s disadvantages with respect to qualitative cultural and political goals such as: promoting democracy, individual self-authorship, expressive diversity, and more inclusive power distribution in shaping culture and discourse. The prevailing view among proponents of the cultural turn is that copyright stands in the way of the democratisation of creative and discursive spheres online. This article challenges that view. I contend that online, ‘free’ content economies—characterised by peer production, decentralised selection, and peer to peer content sharing—have not lived up to the hopes of cultural turn thinkers. I focus on structural matters (structures of incentive, structures of power), critically applying descriptive and normative frameworks of the cultural turn. Proponents of the cultural turn have been concerned about copyright’s role in concentrating cultural power. They should also be concerned about concentrations of cultural and communicative power in ‘free content’ economies. If they were concerned that commercial incentives under copyright regimes privileged bland and homogeneous content, they should also be concerned about the troubling incentives at play in online economies based on harvesting user attention and selling advertisements. This is not to say we should aim for maximalist copyright online. I show that both expansions of exceptions and limitations to copyright, and measures that strengthen copyright owners’ exclusive rights, may entrench problematic incentives and power structures both online and off. The practical implication of my analysis is this. We should carefully assess how developments in law (proposed or actual) affect structures of power and incentive in the creative sphere as a whole, whether they formally ‘weaken’ copyright or ‘strengthen’ it

SOLVING THE SOVEREIGN DEBT CONUNDRUM: NML CAPITAL V. ARGENTINA: A LAW AND ECONOMICS PERSPECTIVE

Sovereign bond contracts create unique legal problems for bondholders, issuers, and courts. Specifically, when a sovereign becomes insolvent, there is no international workout mechanism through which the sovereign\u27s debt can be efficiently restructured. Absent a mechanism similar to bankruptcy for sovereigns, some bondholders may attempt to resist restructuring in an effort to obtain a legal judgment for the full value of their initial investment. Until recently, the legal status and rights of these holdout creditors has been uncertain. However, a recent Second Circuit decision upheld creditors\u27 rights to hold out or resist a sovereign\u27s attempt to restructure its debt. Of course, this decision creates a host of other problems related to collective action and efficiency. International legal scholars remain uncertain whether such judgments are enforceable against a sovereign. The Supreme Court of the United States has accepted a petition for certiorari regarding enforceability issues and is considering a petition for the underlying question of holdout creditors\u27 rights. This paper highlights the complexities and complications that have brought sovereign debt to the forefront of international legal scholarship. Although scholars and politicians have proposed solutions to the sovereign debt dilemma, the paper argues that none of the proposed solutions provides an adequate remedy to the problem. Using an original economic model, the paper argues that an Argentinian default (repudiation) is the socially optimal response to the NML Capital decision and will lend the most stability to the sovereign debt market. However, as a repeat player in the international bond market, Argentina has an individual incentive to comply with the Second Circuit\u27s order and pay the holdout creditors. Finally, the paper considers how the Supreme Court may provide a more realistic avenue to alter the adverse incentives that the Second Circuit\u27s decision created