59 research outputs found

    Service Location and Multiparty Peering for Mobile Ad-hoc Communication

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    Abstract. Flexible personal communications may require dynamically discovering, using, and combining a number of services to support the activities of a mobile user. However, many service discovery and service control protocol frameworks are not designed with requirements for ad-hoc and group communication in a changing environment in mind. In this paper, we motivate the case for personalized group communications based upon a (static) office application scenario featuring simple remote device control and then enhance the scope towards service location and dynamic establishment of group communications for mobile users: ad-hoc multiparty peering. We particularly explore the issues relating to group communication setup and robustness in the presence of changing connectivity and present a framework for mobile multiparty ad-hoc cooperation

    Local Coordination for Interpersonal Communication Systems

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    The decomposition of complex applications into modular units is anacknowledged design principle for creating robust systems and forenabling the flexible re-use of modules in new applicationcontexts. Typically, component frameworks provide mechanisms and rulesfor developing software modules in the scope of a certain programmingparadigm or programming language and a certain computing platform. Forexample, the JavaBeans framework is a component framework for thedevelopment of component-based systems -- in the Java environment.In this thesis, we present a light-weight, platform-independentapproach that views a component-based application as a set of ratherloosely coupled parallel processes that can be distributed on multiplehosts and are coordinated through a protocol. The core of ourframework is the Message Bus (Mbus): an asynchronous, message-orientedcoordination protocol that is based on Internet technologies andprovides group communication between application components.Based on this framework, we have developed a local coordinationarchitecture for decomposed multimedia conferencing applications thatis designed for endpoint and gateway applications. One element of thisarchitecture is an Mbus-based protocol for the coordination of callcontrol components in conferencing applications

    Game Theory Meets Network Security and Privacy

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    This survey provides a structured and comprehensive overview of the research contributions that analyze and solve security and privacy problems in computer networks by game-theoretic approaches. A selected set of works are presented to highlight the application of game theory in order to address different forms of security and privacy problems in computer networks and mobile applications. The presented works are classified into six main categories based on their topics: security of the physical and MAC layers, application layer security in mobile networks, intrusion detection systems, anonymity and privacy, economics of network security, and cryptography. In each category, security problems, players, and game models are identified and the main results of selected works, such as equilibrium analysis and security mechanism designs are summarized. In addition, a discussion on advantages, drawbacks, and the future direction of using game theory in this field is provided. In this survey, we aim to provide a better understanding of the different research approaches for applying game theory to network security. This survey can also help researchers from various fields develop game-theoretic solutions to current and emerging security problems in computer networking

    Towards Practical Privacy-Preserving Protocols

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    Protecting users' privacy in digital systems becomes more complex and challenging over time, as the amount of stored and exchanged data grows steadily and systems become increasingly involved and connected. Two techniques that try to approach this issue are Secure Multi-Party Computation (MPC) and Private Information Retrieval (PIR), which aim to enable practical computation while simultaneously keeping sensitive data private. In this thesis we present results showing how real-world applications can be executed in a privacy-preserving way. This is not only desired by users of such applications, but since 2018 also based on a strong legal foundation with the General Data Protection Regulation (GDPR) in the European Union, that forces companies to protect the privacy of user data by design. This thesis' contributions are split into three parts and can be summarized as follows: MPC Tools Generic MPC requires in-depth background knowledge about a complex research field. To approach this, we provide tools that are efficient and usable at the same time, and serve as a foundation for follow-up work as they allow cryptographers, researchers and developers to implement, test and deploy MPC applications. We provide an implementation framework that abstracts from the underlying protocols, optimized building blocks generated from hardware synthesis tools, and allow the direct processing of Hardware Definition Languages (HDLs). Finally, we present an automated compiler for efficient hybrid protocols from ANSI C. MPC Applications MPC was for a long time deemed too expensive to be used in practice. We show several use cases of real-world applications that can operate in a privacy-preserving, yet practical way when engineered properly and built on top of suitable MPC protocols. Use cases presented in this thesis are from the domain of route computation using BGP on the Internet or at Internet Exchange Points (IXPs). In both cases our protocols protect sensitive business information that is used to determine routing decisions. Another use case focuses on genomics, which is particularly critical as the human genome is connected to everyone during their entire lifespan and cannot be altered. Our system enables federated genomic databases, where several institutions can privately outsource their genome data and where research institutes can query this data in a privacy-preserving manner. PIR and Applications Privately retrieving data from a database is a crucial requirement for user privacy and metadata protection, and is enabled amongst others by a technique called Private Information Retrieval (PIR). We present improvements and a generalization of a well-known multi-server PIR scheme of Chor et al., and an implementation and evaluation thereof. We also design and implement an efficient anonymous messaging system built on top of PIR. Furthermore we provide a scalable solution for private contact discovery that utilizes ideas from efficient two-server PIR built from Distributed Point Functions (DPFs) in combination with Private Set Intersection (PSI)

    Telecommunications Networks

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    This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing

    Extended Coverage for Public Safety and Critical Communications Using Multi-hop and D2D Communications

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    In this thesis, we proposed the use of device-to-device (D2D) communications for extending the coverage area of active base stations, for public safety communications with partial coverage. A 3GPP standard compliant D2D system level simulator is developed for HetNets and public safety scenarios and used to evaluate the performance of D2D discovery and communications underlying cellular networks. For D2D discovery, the benefits of time-domain inter-cell interference coordi- nation (ICIC) approaches by using almost blank subframes were evaluated. Also, the use of multi-hop is proposed to improve, even further, the performance of the D2D discovery process. Finally, the possibility of using multi-hop D2D communications for extending the coverage area of active base stations was evaluated. Improvements in energy and spectral efficiency, when compared with the case of direct UE-eNB communi- cations, were demonstrated. Moreover, UE power control techniques were applied to reduce the effects of interference from neighboring D2D links

    Trustworthy Knowledge Planes For Federated Distributed Systems

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    In federated distributed systems, such as the Internet and the public cloud, the constituent systems can differ in their configuration and provisioning, resulting in significant impacts on the performance, robustness, and security of applications. Yet these systems lack support for distinguishing such characteristics, resulting in uninformed service selection and poor inter-operator coordination. This thesis presents the design and implementation of a trustworthy knowledge plane that can determine such characteristics about autonomous networks on the Internet. A knowledge plane collects the state of network devices and participants. Using this state, applications infer whether a network possesses some characteristic of interest. The knowledge plane uses attestation to attribute state descriptions to the principals that generated them, thereby making the results of inference more trustworthy. Trustworthy knowledge planes enable applications to establish stronger assumptions about their network operating environment, resulting in improved robustness and reduced deployment barriers. We have prototyped the knowledge plane and associated devices. Experience with deploying analyses over production networks demonstrate that knowledge planes impose low cost and can scale to support Internet-scale networks

    Applying the repeated game framework to multiparty networked applications

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 145-154).This thesis presents repeated game analysis as an important and practical tool for networked application and protocol designers. Incentives are a potential concern for a large number of networked applications. Well-studied examples include routing and peer-to-peer networks. To the extent that incentives significantly impact the outcome of a system, system designers require tools and frameworks to better understand how their design decisions impact these incentive concerns. Repetition is a prevalent and critical aspect of many networking applications and protocols. Most networked protocols and architectures seek to optimize performance over a longer timescale and many have explicit support for repetition. Similarly, most players in networked applications are interested in longer horizons, whether they be firms building a business or typical individuals trying to use a system. Fortunately, the study of repeated interaction between multiple self-interested parties, repeated games, is a well-understood and developed area of economic and game theoretic research. A key conclusion from that literature is that the outcome of the repeated game can differ qualitatively from that of the one-shot game. Nonetheless, the tools of repeated games have rarely if ever been brought to bear on networking problems. Our work presents the descriptive and prescriptive power of repeated game analysis by making specific contributions to several relevant networking problems.(cont.) The applications considered are inherently repeated in practice, yet our research is the first to consider the repeated model for each particular problem. In the case of interdomain routing, we first show that user-directed routing (e.g., overlays) transforms routing into a meaningfully repeated game. This motivates us to consider protocols that integrate incentives into routing systems. In designing such a routing protocol, we again use repeated games to identify important properties including the protocol period and the format of certain protocol fields. Leveraging this insight, we show how it is possible to address the problem of the repeated dynamic and arrive at a more desirable outcome. In the case of multicast overlay networks, we show how repeated games can be used to explain the paradox of cooperative user behavior. In contrast to prior models, our repeated model explains the scaling properties of these networks in an endogenous fashion. This enables meaningful examination of the impact architecture and protocol design decisions have on the system outcome. We therefore use this model, with simulation, to descry system parameters and properties important in building robust networks. These examples demonstrate the important and practical insights that repeated game analysis can yield. Further, we argue that the results obtained in the particular problems stem from properties fundamental to networked applications - and their natural relationship with properties of repeated games.(cont.) This strongly suggests that the tools and techniques of this research can be applied more generally. Indeed, we hope that these results represent the beginning of an increased use of repeated games for the study and design of networked applications.by Michael Moïse Afergan.Ph.D
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