20 research outputs found

    Directional Dark Matter Detection Beyond the Neutrino Bound

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    Coherent scattering of solar, atmospheric and diffuse supernovae neutrinos creates an irreducible background for direct dark matter experiments with sensitivities to WIMP-nucleon spin-independent scattering cross-sections of 10^(-46)-10^(-48) cm^2, depending on the WIMP mass. Even if one could eliminate all other backgrounds, this "neutrino floor" will limit future experiments with projected sensitivities to cross-sections as small as 10^(-48) cm^2. Direction-sensitive detectors have the potential to study dark matter beyond the neutrino bound by fitting event distributions in multiple dimensions: recoil kinetic energy, recoil track angle with respect to the sun, and event time. This work quantitatively explores the impact of direction-sensitivity on the neutrino bound in dark matter direct detection.Comment: matches the published version, figure 4 updated plus extended discussion about neutrino flux uncertainties and detector resolutions, 13 pages, 11 figure

    Performance analysis of wireless intrusion detection systems

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    Wireless intrusion detection system (WIDS) has become a matter of increasing concern in recent years as a crucial element in wireless network security. WIDS monitors 802.11 traffic to identify the intrusive activities, and then alerts the complementary prevention part to combat the attacks. Selecting a reliable WIDS system necessitates inevitably taking into account a credible evaluation of WIDSs performance. WIDS effectiveness is considered the basic factor in evaluating the WIDS performance, thus it receives great attention in this thesis. Most previous experimental evaluations of intrusion detection systems (IDSs) were concerned with the wired IDSs, with an apparent lack of evaluating the wireless IDSs (WIDSs). In this thesis, we try to manipulate three main critiques of most pervious evaluations; lack of comprehensive evaluation methodology, holistic attack classification, and expressive evaluation metrics. In this thesis, we introduce a comprehensive evaluation methodology that covers all the essential dimensions for a credible evaluation of WIDSs performance. The main pivotal dimensions in our methodology are characterizing and generating the evaluation dataset, defining reliable and expressive evaluation metrics, and overcoming the evaluation limitations. Basically, evaluation dataset consists of two main parts; normal traffic (as a background) and malicious traffic. The background traffic, which comprises normal and benign activities in the absence of attacks, was generated in our experimental evaluation tests as real controlled traffic. The second and important part of the dataset is the malicious traffic which is composed of intrusive activities. Comprehensive and credible evaluation of WIDSs necessitates taking into account all possible attacks. While this is operationally impossible, it is necessary to select representative attack test cases that are extracted mainly from a comprehensive classification of wireless attacks. Dealing with this challenge, we have developed a holistic taxonomy of wireless security attacks from the perspective of the WIDS evaluator. The second pivotal dimension in our methodology is defining reliable evaluation metrics. We introduce a new evaluation metric EID (intrusion detection effectiveness) that manipulates the drawbacks of the previously proposed metrics, especially the common drawback of their main notion that leads to measuring a relative effectiveness. The notion of our developed metric EID helps in measuring the actual effectiveness. We also introduce another metric RR (attack recognition rate) to evaluate the ability of WIDS to recognize the attack type. The third important dimension in our methodology is overcoming the evaluation limitations. The great challenge that we have faced in the experimental evaluation of WIDSs is the uncontrolled traffic over the open wireless medium. This uncontrolled traffic affects the accuracy of the measurements. We overcame this problem by constructing an RF shielded testbed to take all the measurements under our control without any interfering from any adjacent stations. Finally, we followed our methodology and conducted experimental evaluation tests of two popular WIDSs (Kismet and AirSnare), and demonstrated the utility of our proposed solutions

    Analyse de performance des systĂšmes de dĂ©tection d’intrusion sans-fil

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    La sĂ©curitĂ© des rĂ©seaux sans fil fait l’objet d’une attention considĂ©rable ces derniĂšres annĂ©es. Toutefois, les communications sans fil sont confrontĂ©es Ă  plusieurs types de menaces et d’attaques. Par consĂ©quent, d’importants efforts, visant Ă  sĂ©curiser davantage les rĂ©seaux sans fil, ont dĂ» ĂȘtre fournis pour en vue de lutter contre les attaques sans fil. Seulement, croire qu’une prĂ©vention intĂ©grale des attaques peut s’effectuer au niveau de la premiĂšre ligne de dĂ©fense d’un systĂšme (pare-feux, chiffrement, 
) n’est malheureusement qu’illusion. Ainsi, l’accent est de plus en plus portĂ© sur la dĂ©tection des attaques sans fil au travers d’une seconde ligne de dĂ©fense, matĂ©rialisĂ©e par les systĂšmes de dĂ©tection d’intrusions sans fil (WIDS). Les WIDS inspectent le trafic sans fil, respectant la norme 802.11, ainsi que les activitĂ©s du systĂšme dans le but de dĂ©tecter des activitĂ©s malicieuses. Une alerte est ensuite envoyĂ©e aux briques chargĂ©es de la prĂ©vention pour contrer l’attaque. SĂ©lectionner un WIDS fiable dĂ©pend principalement de l’évaluation mĂ©ticuleuse de ses performances. L’efficacitĂ© du WIDS est considĂ©rĂ©e comme le facteur fondamental lors de l’évaluation de ses performances, nous lui accordons donc un grand intĂ©rĂȘt dans ces travaux de thĂšse. La majeure partie des Ă©tudes expĂ©rimentales visant l’évaluation des systĂšmes de dĂ©tection d’intrusions (IDS) s’intĂ©ressait aux IDS filaires, reflĂ©tant ainsi une carence claire en matiĂšre d’évaluation des IDS sans fil (WIDS). Au cours de cette thĂšse, nous avons mis l’accent sur trois principales critiques visant la plupart des prĂ©cĂ©dentes Ă©valuations : le manque de mĂ©thodologie d’évaluation globale, de classification d’attaque et de mĂ©triques d’évaluation fiables. Au cours de cette thĂšse, nous sommes parvenus Ă  dĂ©velopper une mĂ©thodologie complĂšte d’évaluation couvrant toutes les dimensions nĂ©cessaires pour une Ă©valuation crĂ©dible des performances des WIDSs. Les axes principaux de notre mĂ©thodologie sont la caractĂ©risation et la gĂ©nĂ©ration des donnĂ©es d’évaluation, la dĂ©finition de mĂ©triques d’évaluation fiables tout en Ă©vitant les limitations de l’évaluation. Fondamentalement, les donnĂ©es d’évaluation sont constituĂ©es de deux principales composantes Ă  savoir: un trafic normal et un trafic malveillant. Le trafic normal que nous avons gĂ©nĂ©rĂ© au cours de nos tests d’évaluation Ă©tait un trafic rĂ©el que nous contrĂŽlions. La deuxiĂšme composante des donnĂ©es, qui se trouve ĂȘtre la plus importante, est le trafic malveillant consistant en des activitĂ©s intrusives. Une Ă©valuation complĂšte et crĂ©dible des WIDSs impose la prise en compte de tous les scĂ©narios et types d’attaques Ă©ventuels. Cela Ă©tant impossible Ă  rĂ©aliser, il est nĂ©cessaire de sĂ©lectionner certains cas d’attaque reprĂ©sentatifs, principalement extraits d’une classification complĂšte des attaques sans fil. Pour relever ce dĂ©fi, nous avons dĂ©veloppĂ© une taxinomie globale des attaques visant la sĂ©curitĂ© des rĂ©seaux sans fil, d’un point de vue de l’évaluateur des WIDS. Le deuxiĂšme axe de notre mĂ©thodologie est la dĂ©finition de mĂ©triques fiables d’évaluation. Nous avons introduit une nouvelle mĂ©trique d’évaluation, EID (EfficacitĂ© de la dĂ©tection d’intrusion), visant Ă  pallier les limitations des prĂ©cĂ©dentes mĂ©triques proposĂ©es. Nous avons dĂ©montrĂ© l’utilitĂ© de la mĂ©trique EID par rapport aux autres mĂ©triques proposĂ©es prĂ©cĂ©demment et comment elle parvenait Ă  mesurer l’efficacitĂ© rĂ©elle tandis que les prĂ©cĂ©dentes mĂ©triques ne mesuraient qu’une efficacitĂ© relative. L’EID peut tout aussi bien ĂȘtre utilisĂ© pour l’évaluation de l’efficacitĂ© des IDS filaires et sans fil. Nous avons aussi introduit une autre mĂ©trique notĂ©e RR (Taux de Reconnaissance), pour mesurer l’attribut de reconnaissance d’attaque. Un important problĂšme se pose lorsque des tests d’évaluation des WIDS sont menĂ©s, il s’agit des donnĂ©es de trafics incontrĂŽlĂ©s sur le support ouvert de transmission. Ce trafic incontrĂŽlĂ© affecte sĂ©rieusement la pertinence des mesures. Pour outrepasser ce problĂšme, nous avons construit un banc d’essai RF blindĂ©, ce qui nous a permis de prendre des mesures nettes sans aucune interfĂ©rence avec quelconque source de trafic incontrĂŽlĂ©. Pour finir, nous avons appliquĂ© notre mĂ©thodologie et effectuĂ© des Ă©valuations expĂ©rimentales relatives Ă  deux WIDSs populaires (Kismet et AirSnare); nous avons dĂ©montrĂ© Ă  l’issue de ces Ă©valuations pratiques et l’utilitĂ© de nos solutions proposĂ©es. ABSTRACT : Wireless intrusion detection system (WIDS) has become a matter of increasing concern in recent years as a crucial element in wireless network security. WIDS monitors 802.11 traffic to identify the intrusive activities, and then alerts the complementary prevention part to combat the attacks. Selecting a reliable WIDS system necessitates inevitably taking into account a credible evaluation of WIDSs performance. WIDS effectiveness is considered the basic factor in evaluating the WIDS performance, thus it receives great attention in this thesis. Most previous experimental evaluations of intrusion detection systems (IDSs) were concerned with the wired IDSs, with an apparent lack of evaluating the wireless IDSs (WIDSs). In this thesis, we try to manipulate three main critiques of most pervious evaluations; lack of comprehensive evaluation methodology, holistic attack classification, and expressive evaluation metrics. In this thesis, we introduce a comprehensive evaluation methodology that covers all the essential dimensions for a credible evaluation of WIDSs performance. The main pivotal dimensions in our methodology are characterizing and generating the evaluation dataset, defining reliable and expressive evaluation metrics, and overcoming the evaluation limitations. Basically, evaluation dataset consists of two main parts; normal traffic (as a background) and malicious traffic. The background traffic, which comprises normal and benign activities in the absence of attacks, was generated in our experimental evaluation tests as real controlled traffic. The second and important part of the dataset is the malicious traffic which is composed of intrusive activities. Comprehensive and credible evaluation of WIDSs necessitates taking into account all possible attacks. While this is operationally impossible, it is necessary to select representative attack test cases that are extracted mainly from a comprehensive classification of wireless attacks. Dealing with this challenge, we have developed a holistic taxonomy of wireless security attacks from the perspective of the WIDS evaluator. The second pivotal dimension in our methodology is defining reliable evaluation metrics. We introduce a new evaluation metric EID (intrusion detection effectiveness) that manipulates the drawbacks of the previously proposed metrics, especially the common drawback of their main notion that leads to measuring a relative effectiveness. The notion of our developed metric EID helps in measuring the actual effectiveness. We also introduce another metric RR (attack recognition rate) to evaluate the ability of WIDS to recognize the attack type. The third important dimension in our methodology is overcoming the evaluation limitations. The great challenge that we have faced in the experimental evaluation of WIDSs is the uncontrolled traffic over the open wireless medium. This uncontrolled traffic affects the accuracy of the measurements. We overcame this problem by constructing an RF shielded testbed to take all the measurements under our control without any interfering from any adjacent stations. Finally, we followed our methodology and conducted experimental evaluation tests of two popular WIDSs (Kismet and AirSnare), and demonstrated the utility of our proposed solutions

    MedLAN: Compact mobile computing system for wireless information access in emergency hospital wards

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    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.As the need for faster, safer and more efficient healthcare delivery increases, medical consultants seek new ways of implementing a high quality telemedical system, using innovative technology. Until today, teleconsultation (the most common application of Telemedicine) was performed by transferring the patient from the Accidents and Emergency ward, to a specially equipped room, or by moving large and heavy machinery to the place where the patient resided. Both these solutions were unpractical, uneconomical and potentially dangerous. At the same time wireless networks became increasingly useful in point-of-care areas such as hospitals, because of their ease of use, low cost of installation and increased flexibility. This thesis presents an integrated system called MedLAN dedicated for use inside the A&E hospital wards. Its purpose is to wirelessly support high-quality live video, audio, high-resolution still images and networks support from anywhere there is WLAN coverage. It is capable of transmitting all of the above to a consultant residing either inside or outside the hospital, or even to an external place, thorough the use of the Internet. To implement that, it makes use of the existing IEEE 802.11b wireless technology. Initially, this thesis demonstrates that for specific scenarios (such as when using WLANs), DICOM specifications should be adjusted to accommodate for the reduced WLAN bandwidth. Near lossless compression has been used to send still images through the WLANs and the results have been evaluated by a number of consultants to decide whether they retain their diagnostic value. The thesis further suggests improvements on the existing 802.11b protocol. In particular, as the typical hospital environment suffers from heavy RF reflections, it suggests that an alternative method of modulation (OFDM) can be embedded in the 802.11b hardware to reduce the multipath effect, increase the throughput and thus the video quality sent by the MedLAN system. Finally, realising that the trust between a patient and a doctor is fundamental this thesis proposes a series of simple actions aiming at securing the MedLAN system. Additionally, a concrete security system is suggested, that encapsulates the existing WEP security protocol, over IPSec

    MedLAN : compact mobile computing system for wireless information access in emergency hospital wards

    Get PDF
    As the need for faster, safer and more efficient healthcare delivery increases, medical consultants seek new ways of implementing a high quality telemedical system, using innovative technology. Until today, teleconsultation (the most common application of Telemedicine) was performed by transferring the patient from the Accidents and Emergency ward, to a specially equipped room, or by moving large and heavy machinery to the place where the patient resided. Both these solutions were unpractical, uneconomical and potentially dangerous. At the same time wireless networks became increasingly useful in point-of-care areas such as hospitals, because of their ease of use, low cost of installation and increased flexibility. This thesis presents an integrated system called MedLAN dedicated for use inside the A;E hospital wards. Its purpose is to wirelessly support high-quality live video, audio, high-resolution still images and networks support from anywhere there is WLAN coverage. It is capable of transmitting all of the above to a consultant residing either inside or outside the hospital, or even to an external place, thorough the use of the Internet. To implement that, it makes use of the existing IEEE 802.11b wireless technology. Initially, this thesis demonstrates that for specific scenarios (such as when using WLANs), DICOM specifications should be adjusted to accommodate for the reduced WLAN bandwidth. Near lossless compression has been used to send still images through the WLANs and the results have been evaluated by a number of consultants to decide whether they retain their diagnostic value. The thesis further suggests improvements on the existing 802.11b protocol. In particular, as the typical hospital environment suffers from heavy RF reflections, it suggests that an alternative method of modulation (OFDM) can be embedded in the 802.11b hardware to reduce the multipath effect, increase the throughput and thus the video quality sent by the MedLAN system. Finally, realising that the trust between a patient and a doctor is fundamental this thesis proposes a series of simple actions aiming at securing the MedLAN system. Additionally, a concrete security system is suggested, that encapsulates the existing WEP security protocol, over IPSec.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Cryptography and Its Applications in Information Security

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    Nowadays, mankind is living in a cyber world. Modern technologies involve fast communication links between potentially billions of devices through complex networks (satellite, mobile phone, Internet, Internet of Things (IoT), etc.). The main concern posed by these entangled complex networks is their protection against passive and active attacks that could compromise public security (sabotage, espionage, cyber-terrorism) and privacy. This Special Issue “Cryptography and Its Applications in Information Security” addresses the range of problems related to the security of information in networks and multimedia communications and to bring together researchers, practitioners, and industrials interested by such questions. It consists of eight peer-reviewed papers, however easily understandable, that cover a range of subjects and applications related security of information

    Security of Smartphones at the Dawn of their Ubiquitousness

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    The importance of researching in the field of smartphone security is substantiated in the increasing number of smartphones, which are expected to outnumber common computers in the future. Despite their increasing importance, it is unclear today if mobile malware will play the same role for mobile devices as for common computers today. Therefore, this thesis contributes to defining and structuring the field mobile device security with special concern on smartphones and on the operational side of security, i.e., with mobile malware as the main attacker model. Additionally, it wants to give an understanding of the shifting boundaries of the attack surface in this emerging research field. The first three chapters introduce and structure the research field with the main goal of showing what has to be defended against today. Besides introducing related work they structure mobile device attack vectors with regard to mobile malicious software and they structure the topic of mobile malicious software itself with regard to its portability. The technical contributions of this thesis are in Chapters 5 to 8, classified according to the location of the investigation (on the device, in the network, distributed in device and network). Located in the device is MobileSandbox, a software for dynamic malware analysis. As another device-centric contribution we investigate on the efforts that have to be taken to develop an autonomously spreading smartphone worm. The results of these investigations are used to show that device-centric parts are necessary for smartphone security. Additionally, we propose a novel device-centric security mechanism that aims at reducing the attack surface of mobile devices to mobile malware. The network-centric investigations show the possibilities that a mobile network operator can use in its own mobile network for protecting the mobile devices of its clients. We simulate the effectiveness of different security mechanisms. Finally, the distributed investigations show the feasibility of distributed computation algorithms with security modules. We give prototypic implementations of protocols for secure multiparty computation as a modularized version with failure detector and consensus algorithms, and for fair exchange with guardian angels

    Last-Mile TLS Interception: Analysis and Observation of the Non-Public HTTPS Ecosystem

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    Transport Layer Security (TLS) is one of the most widely deployed cryptographic protocols on the Internet that provides confidentiality, integrity, and a certain degree of authenticity of the communications between clients and servers. Following Snowden's revelations on US surveillance programs, the adoption of TLS has steadily increased. However, encrypted traffic prevents legitimate inspection. Therefore, security solutions such as personal antiviruses and enterprise firewalls may intercept encrypted connections in search for malicious or unauthorized content. Therefore, the end-to-end property of TLS is broken by these TLS proxies (a.k.a. middleboxes) for arguably laudable reasons; yet, may pose a security risk. While TLS clients and servers have been analyzed to some extent, such proxies have remained unexplored until recently. We propose a framework for analyzing client-end TLS proxies, and apply it to 14 consumer antivirus and parental control applications as they break end-to-end TLS connections. Overall, the security of TLS connections was systematically worsened compared to the guarantees provided by modern browsers. Next, we aim at exploring the non-public HTTPS ecosystem, composed of locally-trusted proxy-issued certificates, from the user's perspective and from several countries in residential and enterprise settings. We focus our analysis on the long tail of interception events. We characterize the customers of network appliances, ranging from small/medium businesses and institutes to hospitals, hotels, resorts, insurance companies, and government agencies. We also discover regional cases of traffic interception malware/adware that mostly rely on the same Software Development Kit (i.e., NetFilter). Our scanning and analysis techniques allow us to identify more middleboxes and intercepting apps than previously found from privileged server vantages looking at billions of connections. We further perform a longitudinal study over six years of the evolution of a prominent traffic-intercepting adware found in our dataset: Wajam. We expose the TLS interception techniques it has used and the weaknesses it has introduced on hundreds of millions of user devices. This study also (re)opens the neglected problem of privacy-invasive adware, by showing how adware evolves sometimes stronger than even advanced malware and poses significant detection and reverse-engineering challenges. Overall, whether beneficial or not, TLS interception often has detrimental impacts on security without the end-user being alerted

    Proceedings of The 13. Nordic Workshop on Secure IT Systems, NordSec 2008, Kongens Lyngby Oct 9-10, 2008

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