27,674 research outputs found

    Security and Privacy Issues in Wireless Mesh Networks: A Survey

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    This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

    Information Technology as Coordination Infrastructure

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    Business information technology is traditionally viewed as information provision technology. In this view, organizations use their IT to implement databases that provide people with information when they want it. This view is persistent even though information provision is never an end in itself but always has the further purpose to support the coordination of activities of people. The role if IT as coordination technology became more prominent in the 1980s with the advent of network technology, that allowed activities across different businesses to be coordinated. This trend has accellerated since the growth of Internet usage, and today IT is used to support an increasingly varied range of processes performed by a variety of partners that do not all have a hierarchical relation to each other. This makes it difficult to analyze requirements for IT support and specify IT solutions: Business processes may not be well-defined, and interests of different businesses may clash. This report argues that to deal with this in requirements engineering and IT solution specification, business information technology should not be viewed as IT support for business processes but as IT support for the coordination of activities in one or more businesses. We will identify three basic coordination mechanisms, namely coordination by price, by management, and by shared norms, and for each of these mechanisms, we will identify requirements for IT support. The advent of flexible and standardized networking technology has facilitated the creation of novel coordination mechanisms within these three general paradigms, and we will give an inventory of generalized coordination mechanisms made possible by current IT. Finally, we will draw conclusions for requirements engineering methods for IT support for each of the coordination mechanisms identified by the framework

    Incentive Mechanisms for Participatory Sensing: Survey and Research Challenges

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    Participatory sensing is a powerful paradigm which takes advantage of smartphones to collect and analyze data beyond the scale of what was previously possible. Given that participatory sensing systems rely completely on the users' willingness to submit up-to-date and accurate information, it is paramount to effectively incentivize users' active and reliable participation. In this paper, we survey existing literature on incentive mechanisms for participatory sensing systems. In particular, we present a taxonomy of existing incentive mechanisms for participatory sensing systems, which are subsequently discussed in depth by comparing and contrasting different approaches. Finally, we discuss an agenda of open research challenges in incentivizing users in participatory sensing.Comment: Updated version, 4/25/201

    Communication, cooperation and collusion in team tournaments - An experimental study

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    We study the effects of communication in an experimental tournament between teams. When teams, rather than individuals, compete for a prize there is a need for intra-team coordination in order to win the inter-team competition. Introducing communication in such situations may have ambiguous effects on effort choices. Communication within teams may promote higher efforts by mitigating the internal free-rider problem. Communication between competing teams may lead to collusion, thereby reducing efforts. In our experiment we control the channels of communication by letting subjects communicate through an electronic chat. We find, indeed, that communication within teams increases efforts and communication between teams reduces efforts. We use team members’ dialogues to explain these effects of communication, and check the robustness of our results

    Big Experimenter Is Watching You! Anonymity and Prosocial Behavior in the Laboratory

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    Social preference research has received considerable attention in recent years. Researchers have demonstrated that the presence of people with social preferences has important implications in many economic domains. However, it is important to be aware of the fact that the empirical basis of this literature relies to a large extent on experiments that do not provide anonymity between experimenter and subject. It has been argued that this lack of experimenter-subject anonymity may create selfish incentives to engage in seemingly other-regarding behavior. If this were the case these experiments would overestimate the importance of social preferences. Previous studies provide mixed results and methodological differences within and across studies make it difficult to isolate the impact of experimenter-subject anonymity on prosocial behavior. In this paper we use a novel procedure that allows us to examine the impact of the exact same ceteris-paribus variation in anonymity on behavior in three of the most commonly used games in the social preference literature. Our data does not support the hypothesis that introducing experimenter-subject anonymity affects observed prosocial behavior. We do not observe significant effects of experimenter-subject anonymity on prosocial behavior in any of our games.scrutiny, prosocial behavior, anonymity, laboratory experiments

    Communication, cooperation and collusion in team tournaments - An experimental study

    Get PDF
    We study the effects of communication in an experimental tournament between teams. When teams, rather than individuals, compete for a prize there is a need for intra-team coordination in order to win the inter-team competition. Introducing communication in such situations may have ambiguous effects on effort choices. Communication within teams may promote higher efforts by mitigating the internal free-rider problem. Communication between competing teams may lead to collusion, thereby reducing efforts. In our experiment we control the channels of communication by letting subjects communicate through an electronic chat. We find, indeed, that communication within teams increases efforts and communication between teams reduces efforts. We use team members’ dialogues to explain these effects of communication, and check the robustness of our results.Tournament; Team decision making; Communication; Collusion; Free-riding; ExperimentKommunikation; Kollusion; Trittbrettfahrerverhalten; Experiment
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