14,564 research outputs found

    Quantifying pervasive authentication: the case of the Hancke-Kuhn protocol

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    As mobile devices pervade physical space, the familiar authentication patterns are becoming insufficient: besides entity authentication, many applications require, e.g., location authentication. Many interesting protocols have been proposed and implemented to provide such strengthened forms of authentication, but there are very few proofs that such protocols satisfy the required security properties. The logical formalisms, devised for reasoning about security protocols on standard computer networks, turn out to be difficult to adapt for reasoning about hybrid protocols, used in pervasive and heterogenous networks. We refine the Dolev-Yao-style algebraic method for protocol analysis by a probabilistic model of guessing, needed to analyze protocols that mix weak cryptography with physical properties of nonstandard communication channels. Applying this model, we provide a precise security proof for a proximity authentication protocol, due to Hancke and Kuhn, that uses a subtle form of probabilistic reasoning to achieve its goals.Comment: 31 pages, 2 figures; short version of this paper appeared in the Proceedings of MFPS 201

    The benefits of in silico modeling to identify possible small-molecule drugs and their off-target interactions

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    Accepted for publication in a future issue of Future Medicinal Chemistry.The research into the use of small molecules as drugs continues to be a key driver in the development of molecular databases, computer-aided drug design software and collaborative platforms. The evolution of computational approaches is driven by the essential criteria that a drug molecule has to fulfill, from the affinity to targets to minimal side effects while having adequate absorption, distribution, metabolism, and excretion (ADME) properties. A combination of ligand- and structure-based drug development approaches is already used to obtain consensus predictions of small molecule activities and their off-target interactions. Further integration of these methods into easy-to-use workflows informed by systems biology could realize the full potential of available data in the drug discovery and reduce the attrition of drug candidates.Peer reviewe

    Canopy habitat area effect on the arthropod species densities in the Azores: pondering the contribution of tourist species and other life histories

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    "[…]. We performed a PIAR examining how plant cover area and plant crown structure influence the densities of arthropods in the canopies of one specific island, comparing various distinct natural reserves. Species densities were measured for two functional insect herbivore guilds (sap-sucking and leaf-chewing insects) and the most common predatory assembly in this system (spiders) in three different ways: i) the average number of specimens per plant; ii) the average number of specimens per transect, providing both fine and broad scales of species abundance (see Methods); iii) absolute numbers per reserve. Moreover, we investigated common versus scarce arthropod species distributions between various plant species. […]" (da Introdução)Fundação para a Ciência e a Tecnologia, Portugal

    Food web topology and nested keystone species complexes

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    Important species may be in critically central network positions in ecological interaction networks. Beyond quantifying which one is the most central species in a food web, a multi-node approach can identify the key sets of the most central n species as well. However, for sets of different size n, these structural keystone species complexes may differ in their composition. If larger sets contain smaller sets, higher nestedness may be a proxy for predictive ecology and efficient management of ecosystems. On the contrary, lower nestedness makes the identification of keystones more complicated. Our question here is how the topology of a network can influence nestedness as an architectural constraint. Here, we study the role of keystone species complexes in 27 real food webs and quantify their nestedness. After quantifying their topology properties, we determine their keystones species complexes, calculate their nestedness and statistically analyze the relationship between topological indices and nestedness. A better understanding of the cores of ecosystems is crucial for efficient conservation efforts and to know which networks will have more nested keystone species complexes would be a great help for prioritizing species that could preserve the ecosystem’s structural integrity

    So you've got IPv6 address space. Can you defend it?

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    Internet Protocol version 6 (IPv6) is the successor of Internet Protocol version 4 (IPv4). IPv6 will become the next standard networking protocol on the Internet. It brings with it a great increase in address space, changes to network operations, and new network security concerns. In this thesis we examine IPv6 from a security perspective. The security of IPv6 is important to all protocols that use IPv6 on the Internet. The goal of this thesis is to introduce the reader to existing IPv6 security challenges, demonstrate how IPv6 changes network security and show how IPv6 is being improved.Master i InformatikkMAMN-INFINF39

    The significance of insecure attachment and disorganization in the development of children's externalizing behavior: A meta-analytic study

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    This study addresses the extent to which insecure and disorganized attachments increase risk for externalizing problems using meta-analysis. From 69 samples (N = 5,947), the association between insecurity and externalizing problems was significant, d = 0.31 (95% CI: 0.23, 0.40). Larger effects were found for boys (d = 0.35), clinical samples (d = 0.49), and from observation-based outcome assessments (d = 0.58). Larger effects were found for attachment assessments other than the Strange Situation. Overall, disorganized children appeared at elevated risk (d = 0.34, 95% CI: 0.18, 0.50), with weaker effects for avoidance (d = 0.12, 95% CI: 0.03, 0.21) and resistance (d = 0.11, 95% CI: −0.04, 0.26). The results are discussed in terms of the potential significance of attachment for mental health

    REVIEW ON IPV6 SECURITY VULNERABILITY ISSUES AND MITIGATION METHODS

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    ABSTRACT One of the main purposes of Internet Protocol version 6 (IPv6

    Non-Trivial Off-Path Network Measurements without Shared Side-Channel Resource Exhaustion

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    Most traditional network measurement scans and attacks are carried out through the use of direct, on-path network packet transmission. This requires that a machine be on-path (i.e, involved in the packet transmission process) and as a result have direct access to the data packets being transmitted. This limits network scans and attacks to situations where access can be gained to an on-path machine. If, for example, a researcher wanted to measure the round trip time between two machines they did not have access to, traditional scans would be of little help as they require access to an on-path machine to function. Instead the researcher would need to use an off-path measurement scan. Prior work using network side-channels to perform off-path measurements or attacks relied on techniques that either exhausted the shared, finite resource being used as a side-channel or only measured basic features such as connectivity. The work presented in this dissertation takes a different approach to using network side-channels. I describe research that carries out network side-channel measurements that are more complex than connectivity, such as packet round-trip-time or detecting active TCP connections, and do not require a shared, finite resource be fully exhausted to cause information to leak via a side-channel. My work is able to accomplish this by understanding the ways in which internal network stack state changes cause observable behavior changes from the machine. The goal of this dissertation is to show that: Information side-channels can be modulated to take advantage of dependent, network state behavior to enable non-trivial, off-path measurements without fully exhausting the shared, finite resources they use

    Analysis of security impact of making mShield an IPv4 to IPv6 converter box

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