29,987 research outputs found

    Byzantine Attack and Defense in Cognitive Radio Networks: A Survey

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    The Byzantine attack in cooperative spectrum sensing (CSS), also known as the spectrum sensing data falsification (SSDF) attack in the literature, is one of the key adversaries to the success of cognitive radio networks (CRNs). In the past couple of years, the research on the Byzantine attack and defense strategies has gained worldwide increasing attention. In this paper, we provide a comprehensive survey and tutorial on the recent advances in the Byzantine attack and defense for CSS in CRNs. Specifically, we first briefly present the preliminaries of CSS for general readers, including signal detection techniques, hypothesis testing, and data fusion. Second, we analyze the spear and shield relation between Byzantine attack and defense from three aspects: the vulnerability of CSS to attack, the obstacles in CSS to defense, and the games between attack and defense. Then, we propose a taxonomy of the existing Byzantine attack behaviors and elaborate on the corresponding attack parameters, which determine where, who, how, and when to launch attacks. Next, from the perspectives of homogeneous or heterogeneous scenarios, we classify the existing defense algorithms, and provide an in-depth tutorial on the state-of-the-art Byzantine defense schemes, commonly known as robust or secure CSS in the literature. Furthermore, we highlight the unsolved research challenges and depict the future research directions.Comment: Accepted by IEEE Communications Surveys and Tutoiral

    Trust economics feasibility study

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    We believe that enterprises and other organisations currently lack sophisticated methods and tools to determine if and how IT changes should be introduced in an organisation, such that objective, measurable goals are met. This is especially true when dealing with security-related IT decisions. We report on a feasibility study, Trust Economics, conducted to demonstrate that such methodology can be developed. Assuming a deep understanding of the IT involved, the main components of our trust economics approach are: (i) assess the economic or financial impact of IT security solutions; (ii) determine how humans interact with or respond to IT security solutions; (iii) based on above, use probabilistic and stochastic modelling tools to analyse the consequences of IT security decisions. In the feasibility study we apply the trust economics methodology to address how enterprises should protect themselves against accidental or malicious misuse of USB memory sticks, an acute problem in many industries

    Collusion in Peer-to-Peer Systems

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    Peer-to-peer systems have reached a widespread use, ranging from academic and industrial applications to home entertainment. The key advantage of this paradigm lies in its scalability and flexibility, consequences of the participants sharing their resources for the common welfare. Security in such systems is a desirable goal. For example, when mission-critical operations or bank transactions are involved, their effectiveness strongly depends on the perception that users have about the system dependability and trustworthiness. A major threat to the security of these systems is the phenomenon of collusion. Peers can be selfish colluders, when they try to fool the system to gain unfair advantages over other peers, or malicious, when their purpose is to subvert the system or disturb other users. The problem, however, has received so far only a marginal attention by the research community. While several solutions exist to counter attacks in peer-to-peer systems, very few of them are meant to directly counter colluders and their attacks. Reputation, micro-payments, and concepts of game theory are currently used as the main means to obtain fairness in the usage of the resources. Our goal is to provide an overview of the topic by examining the key issues involved. We measure the relevance of the problem in the current literature and the effectiveness of existing philosophies against it, to suggest fruitful directions in the further development of the field

    Enforcing reputation constraints on business process workflows

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    The problem of trust in determining the flow of execution of business processes has been in the centre of research interst in the last decade as business processes become a de facto model of Internet-based commerce, particularly with the increasing popularity in Cloud computing. One of the main mea-sures of trust is reputation, where the quality of services as provided to their clients can be used as the main factor in calculating service and service provider reputation values. The work presented here contributes to the solving of this problem by defining a model for the calculation of service reputa-tion levels in a BPEL-based business workflow. These levels of reputation are then used to control the execution of the workflow based on service-level agreement constraints provided by the users of the workflow. The main contribution of the paper is to first present a formal meaning for BPEL processes, which is constrained by reputation requirements from the users, and then we demonstrate that these requirements can be enforced using a reference architecture with a case scenario from the domain of distributed map processing. Finally, the paper discusses the possible threats that can be launched on such an architecture

    Stakeholder involvement, motivation, responsibility, communication: How to design usable security in e-Science

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    e-Science projects face a difficult challenge in providing access to valuable computational resources, data and software to large communities of distributed users. Oil the one hand, the raison d'etre of the projects is to encourage members of their research communities to use the resources provided. Oil the other hand, the threats to these resources from online attacks require robust and effective Security to mitigate the risks faced. This raises two issues: ensuring that (I) the security mechanisms put in place are usable by the different users of the system, and (2) the security of the overall system satisfies the security needs of all its different stakeholders. A failure to address either of these issues call seriously jeopardise the success of e-Science projects.The aim of this paper is to firstly provide a detailed understanding of how these challenges call present themselves in practice in the development of e-Science applications. Secondly, this paper examines the steps that projects can undertake to ensure that security requirements are correctly identified, and security measures are usable by the intended research community. The research presented in this paper is based Oil four case studies of c-Science projects. Security design traditionally uses expert analysis of risks to the technology and deploys appropriate countermeasures to deal with them. However, these case studies highlight the importance of involving all stakeholders in the process of identifying security needs and designing secure and usable systems.For each case study, transcripts of the security analysis and design sessions were analysed to gain insight into the issues and factors that surround the design of usable security. The analysis concludes with a model explaining the relationships between the most important factors identified. This includes a detailed examination of the roles of responsibility, motivation and communication of stakeholders in the ongoing process of designing usable secure socio-technical systems such as e-Science. (C) 2007 Elsevier Ltd. All rights reserved
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