849 resultados para 802.11 security protocols


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We blend research from human-computer interface (HCI) design with computational based crypto- graphic provable security. We explore the notion of practice-oriented provable security (POPS), moving the focus to a higher level of abstraction (POPS+) for use in providing provable security for security ceremonies involving humans. In doing so we high- light some challenges and paradigm shifts required to achieve meaningful provable security for a protocol which includes a human. We move the focus of security ceremonies from being protocols in their context of use, to the protocols being cryptographic building blocks in a higher level protocol (the security cere- mony), which POPS can be applied to. In order to illustrate the need for our approach, we analyse both a protocol proven secure in theory, and a similar proto- col implemented by a �nancial institution, from both HCI and cryptographic perspectives.

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Security of RFID authentication protocols has received considerable interest recently. However, an important aspect of such protocols that has not received as much attention is the efficiency of their communication. In this paper we investigate the efficiency benefits of pre-computation for time-constrained applications in small to medium RFID networks. We also outline a protocol utilizing this mechanism in order to demonstrate the benefits and drawbacks of using thisapproach. The proposed protocol shows promising results as it is able to offer the security of untraceableprotocols whilst only requiring the time comparable to that of more efficient but traceable protocols.

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Our daily lives become more and more dependent upon smartphones due to their increased capabilities. Smartphones are used in various ways from payment systems to assisting the lives of elderly or disabled people. Security threats for these devices become increasingly dangerous since there is still a lack of proper security tools for protection. Android emerges as an open smartphone platform which allows modification even on operating system level. Therefore, third-party developers have the opportunity to develop kernel-based low-level security tools which is not normal for smartphone platforms. Android quickly gained its popularity among smartphone developers and even beyond since it bases on Java on top of "open" Linux in comparison to former proprietary platforms which have very restrictive SDKs and corresponding APIs. Symbian OS for example, holding the greatest market share among all smartphone OSs, was closing critical APIs to common developers and introduced application certification. This was done since this OS was the main target for smartphone malwares in the past. In fact, more than 290 malwares designed for Symbian OS appeared from July 2004 to July 2008. Android, in turn, promises to be completely open source. Together with the Linux-based smartphone OS OpenMoko, open smartphone platforms may attract malware writers for creating malicious applications endangering the critical smartphone applications and owners� privacy. In this work, we present our current results in analyzing the security of Android smartphones with a focus on its Linux side. Our results are not limited to Android, they are also applicable to Linux-based smartphones such as OpenMoko Neo FreeRunner. Our contribution in this work is three-fold. First, we analyze android framework and the Linux-kernel to check security functionalities. We survey wellaccepted security mechanisms and tools which can increase device security. We provide descriptions on how to adopt these security tools on Android kernel, and provide their overhead analysis in terms of resource usage. As open smartphones are released and may increase their market share similar to Symbian, they may attract attention of malware writers. Therefore, our second contribution focuses on malware detection techniques at the kernel level. We test applicability of existing signature and intrusion detection methods in Android environment. We focus on monitoring events on the kernel; that is, identifying critical kernel, log file, file system and network activity events, and devising efficient mechanisms to monitor them in a resource limited environment. Our third contribution involves initial results of our malware detection mechanism basing on static function call analysis. We identified approximately 105 Executable and Linking Format (ELF) executables installed to the Linux side of Android. We perform a statistical analysis on the function calls used by these applications. The results of the analysis can be compared to newly installed applications for detecting significant differences. Additionally, certain function calls indicate malicious activity. Therefore, we present a simple decision tree for deciding the suspiciousness of the corresponding application. Our results present a first step towards detecting malicious applications on Android-based devices.

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Threats against computer networks evolve very fast and require more and more complex measures. We argue that teams respectively groups with a common purpose for intrusion detection and prevention improve the measures against rapid propagating attacks similar to the concept of teams solving complex tasks known from field of work sociology. Collaboration in this sense is not easy task especially for heterarchical environments. We propose CIMD (collaborative intrusion and malware detection) as a security overlay framework to enable cooperative intrusion detection approaches. Objectives and associated interests are used to create detection groups for exchange of security-related data. In this work, we contribute a tree-oriented data model for device representation in the scope of security. We introduce an algorithm for the formation of detection groups, show realization strategies for the system and conduct vulnerability analysis. We evaluate the benefit of CIMD by simulation and probabilistic analysis.

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Introduction: Evaluating the effectiveness of interventions designed to increase the physical activity in communities is often a difficult and complex task, requiring considerable expertise and investment, and often constrained by methodological limitations. These limitations, in turn, create additional challenges when these studies are used in systematic reviews as they hinder the confidence, precision and interpretation of results. The objective of this paper is to summarise the methodological challenges posed in conducting a systematic review of community-wide physical activity interventions to help inform those conducting future primary research and systematic reviews. Methods: We conducted a Cochrane systematic review of community-wide interventions to increase physical activity. We assessed the methodological quality of the included studies. We will investigate these in greater detail, particularly in relation to the potential impact on measures of effect, confidence in results, generalizability of results and general interpretation. Results: The systematic review was conducted and has been published in the Cochrane Library. A logic model was helpful in defining and interpreting the studies. Many studies of unsuitable study design were excluded; however several important methodological limitations of the primary studies evaluating community-wide physical activity interventions emerged. These included: - the failure to use validated tools to measure physical activity; - issues associated with pre and post test designs; - inadequate sampling of populations; - poor control groups; and - intervention and measurement protocols of inadequate duration. Although it is challenging to undertake rigorous evaluations of complex interventions, these issues result in significant uncertainty over the effectiveness of these interventions, and the possible factors required for a community-wide intervention to be successful. In particular, the combination of several of these limitations (e.g. un-validated tools, inadequate sampling, and short duration) is that studies may lack the sensitivity to detect any meaningful change. Multiple publications of findings for the same study also made interpretation difficult; however, interventions with parallel qualitative publications were helpful. Discussion: Evaluating community wide interventions to increase physical activity in a rigorous way is incredibly challenging. These findings reflect these challenges but have important ramifications for researchers conducting primary studies to determine the efficacy of such interventions, as well as for researchers conducting systematic reviews. This new review shows that the inadequacies of design and evaluation are continuing. It is hoped that the adoption of such suggestions may aid in the development of systematic reviews, but more importantly, in enabling translation of such findings into policy and practice.

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A number of security models have been proposed for RFID systems. Recent studies show that current models tend to be limited in the number of properties they capture. Consequently, models are commonly unable to distinguish between protocols with regard to finer privacy properties. This paper proposes a privacy model that introduces previously unavailable expressions of privacy. Based on the well-studied notion of indistinguishability, the model also strives to be simpler, easier to use, and more intuitive compared to previous models.

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We present a virtual test bed for network security evaluation in mid-scale telecommunication networks. Migration from simulation scenarios towards the test bed is supported and enables researchers to evaluate experiments in a more realistic environment. We provide a comprehensive interface to manage, run and evaluate experiments. On basis of a concrete example we show how the proposed test bed can be utilized.

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A number of security models have been proposed for RFID systems. Recent studies show that current models tend to be limited in the number of properties they capture. Consequently, models are commonly unable to distinguish between protocols with regard to finer privacy properties. This paper proposes a privacy model that introduces previously unavailable expressions of privacy. Based on the well-studied notion of indistinguishability, the model also strives to be simpler, easier to use, and more intuitive compared to previous models.

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Internet services are important part of daily activities for most of us. These services come with sophisticated authentication requirements which may not be handled by average Internet users. The management of secure passwords for example creates an extra overhead which is often neglected due to usability reasons. Furthermore, password-based approaches are applicable only for initial logins and do not protect against unlocked workstation attacks. In this paper, we provide a non-intrusive identity verification scheme based on behavior biometrics where keystroke dynamics based-on free-text is used continuously for verifying the identity of a user in real-time. We improved existing keystroke dynamics based verification schemes in four aspects. First, we improve the scalability where we use a constant number of users instead of whole user space to verify the identity of target user. Second, we provide an adaptive user model which enables our solution to take the change of user behavior into consideration in verification decision. Next, we identify a new distance measure which enables us to verify identity of a user with shorter text. Fourth, we decrease the number of false results. Our solution is evaluated on a data set which we have collected from users while they were interacting with their mail-boxes during their daily activities.

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Could mobile telephony be harnessed for development in Papua New Guinea (PNG)? Could mobile phones be utilised to enhance the security and prosperity of rural communities? Could mobile phones be a useful tool in the achievement of the PNG 2050 Vision targets? This paper is based on literature review around use of mobile phones in development in Asia, Africa, and the Caribbean. It also draws on discussions with key players in PNG, such as NGOs, UN agencies, donor partners, telecommunication companies and the government of PNG. Anticipated benefits of mobile phone availability have not been fully realised in rural areas of PNG to date due to pricing, difficulties with recharging handset batteries in communities which do not have mains electricity supply, and also concerns about negative social changes related to mobile telephony, for example parental stress over youth forming unsuitable relationships. Nonetheless, there are manifest possible ways for mobile phone technology to change user communication patterns positively regarding economic output. In sectors as diverse as health, education and law and justice, discussions are currently underway to establish how mobile phones could be used to increase service delivery, particularly to rural and marginal communities.

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We introduce the Network Security Simulator (NeSSi2), an open source discrete event-based network simulator. It incorporates a variety of features relevant to network security distinguishing it from general-purpose network simulators. Compared to the predecessor NeSSi, it was extended with a three-tier plugin architecture and a generic network model to shift its focus towards simulation framework for critical infrastructures. We demonstrate the gained adaptability by different use cases

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Session Initiation Protocol (SIP) is developed to provide advanced voice services over IP networks. SIP unites telephony and data world, permitting telephone calls to be transmitted over Intranets and Internet. Increase in network performance and new mechanisms for guaranteed quality of service encourage this consolidation to provide toll cost savings. Security comes up as one of the most important issues when voice communication and critical voice applications are considered. Not only the security methods provided by traditional telephony systems, but also additional methods are required to overcome security risks introduced by the public IP networks. SIP considers security problems of such a consolidation and provides a security framework. There are several security methods defined within SIP specifications and extensions. But, suggested methods can not solve all the security problems of SIP systems with various system requirements. In this thesis, a Kerberos based solution is proposed for SIP security problems, including SIP authentication and privacy. The proposed solution tries to establish flexible and scalable SIP system that will provide desired level of security for voice communications and critical telephony applications.

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An engaging narrative is maintained throughout this edited collection of articles that address the issue of militarism in international relations. The book seamlessly integrates historical and contemporary perspectives on militarism with theory and relevant international case studies, resulting in a very informative read. The work is comprised of three parts. Part 1 deals with the theorisation of militarism and includes chapters by Anna Stavrianakis and Jan Selby, Martin Shaw, Simon Dalby, and Nicola Short. It covers a range of topics relating to historical and contemporary theories of militarism, geopolitical threat construction, political economy, and the US military’s ‘cultural turn’.

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We present and analyze several gaze-based graphical password schemes based on recall and cued-recall of grid points; eye-trackers are used to record user's gazes, which can prevent shoulder-surfing and may be suitable for users with disabilities. Our 22-subject study observes that success rate and entry time for the grid-based schemes we consider are comparable to other gaze-based graphical password schemes. We propose the first password security metrics suitable for analysis of graphical grid passwords and provide an in-depth security analysis of user-generated passwords from our study, observing that, on several metrics, user-generated graphical grid passwords are substantially weaker than uniformly random passwords, despite our attempts at designing schemes to improve quality of user-generated passwords.

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Analyzing emotional states under duress or during heightened, life-and-death situations is extremely difficult, especially given the inability of laboratory experiments to replicate the environment and given the inherent biases of post event surveys. This is where natural experiments, such as the pager communications from September 11th can provide the kind of natural experiment emotion researchers have been seeking. We demonstrate that positive and pro-social communications are the first to emerge followed by the slower and lower negative communications. Religious sentiment is the last to emerge, as individual attempt to make sense of event. Additionally we provide a methodological discussion about the preparation and analysis of such natural experiments (the pager message content) and show the importance of using multiple methods to extract the broadest possible understanding.