286 research outputs found

    Reengineering the user: Privacy concerns about personal data on smartphones.

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    Purpose: This paper aims to discuss the privacy and security concerns that have risen from the permissions model in the Android operating system, along with two shortcomings that have not been adequately addressed. Design/methodology/approach: The impact of the applications’ evolutionary increment of permission requests from both the user’s and the developer’s point of view is studied, and finally, a series of remedies against the erosion of users’ privacy is proposed. Findings: The results of this work indicate that, even though providing access to personal data of smartphone users is by definition neither problematic nor unlawful, today’s smartphone operating systems do not provide an adequate level of protection for the user’s personal data. However, there are several ideas that can significantly improve the situation and mitigate privacy concerns of users of smart devices. Research limitations/implications: The proposed approach was evaluated through an examination of the Android’s permission model, although issues arise in other operating systems. The authors’ future intention is to conduct a user study to measure the user’s awareness and concepts surrounding privacy concerns to empirically investigate the above-mentioned suggestions. Practical implications: The proposed suggestions in this paper, if adopted in practice, could significantly improve the situation and mitigate privacy concerns of users of smart devices. Social implications: The recommendations proposed in this paper would strongly enhance the control of users over their personal data and improve their ability to distinguish legitimate apps from malware or grayware. Originality/value: This paper emphasises two shortcomings of the permissions models of mobile operating systems which, in authors’ view, have not been adequately addressed to date and propose an inherent way for apps and other entities of the mobile computing ecosystem to commit to responsible and transparent practices on mobile users’ privacy

    A method for forensic artifact collection, analysis and incident response in environments running Session Initiation Protocol (SIP) and Session Description protocol

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    In this paper, we perform an analysis of SIP, a popular voice over IP (VoIP) protocol and propose a framework for capturing and analysing volatile VoIP data in order to determine forensic readiness requirements for effectively identifying an attacker. The analysis was performed on real attack data and the findings were encouraging. It seems that if appropriate forensic readiness processes and controls are in place, a wealth of evidence can be obtained. The type of the end user equipment of the internal users, the private IP, the software that is used can help build a reliable baseline information database. On the other hand the private IP addresses of the potential attacker even during the presence of NAT services, as well as and the attack tools employed by the malicious parties are logged for further analysis

    Privacy-preserving, User-centric VoIP CAPTCHA Challenges: an Integrated Solution in the SIP Environment

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    Purpose – This work aims to argue that it is possible to address discrimination issues that naturally arise in contemporary audio CAPTCHA challenges and potentially enhance the effectiveness of audio CAPTCHA systems by adapting the challenges to the user characteristics. Design/methodology/approach – A prototype has been designed, called PrivCAPTCHA, to offer privacy-preserving, user-centric CAPTCHA challenges. Anonymous credential proofs are integrated into the Session Initiation Protocol (SIP) protocol and the approach is evaluated in a real-world Voice over Internet Protocol (VoIP) environment. Findings – The results of this work indicate that it is possible to create VoIP CAPTCHA services offering privacy-preserving, user-centric challenges while maintaining sufficient efficiency. Research limitations/implications – The proposed approach was evaluated through an experimental implementation to demonstrate its feasibility. Additional features, such as appropriate user interfaces and efficiency optimisations, would be useful for a commercial product. Security measures to protect the system from attacks against the SIP protocol would be useful to counteract the effects of the introduced overhead. Future research could investigate the use of this approach on non-audio CAPTCHA services. Practical implications – PrivCAPTCHA is expected to achieve fairer, non-discriminating CAPTCHA services while protecting the user’s privacy. Adoption success relies upon the general need for employment of privacy-preserving practices in electronic interactions. Social implications – This approach is expected to enhance the quality of life of users, who will now receive CAPTCHA challenges closer to their characteristics. This applies especially to users with disabilities. Additionally, as a privacy-preserving service, this approach is expected to increase trust during the use of services that use it. Originality/value – To the best of authors’ knowledge, this is the first comprehensive proposal for privacy-preserving CAPTCHA challenge adaptation. The proposed system aims at providing an improved CAPTCHA service that is more appropriate for and trusted by human users

    Effect of polydispersity and bubble clustering on the steady shear viscosity of dilute bubble suspensions in Newtonian media

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    This work examines the steady shear viscosity of dilute polydisperse bubble suspensions generated in a mixture of mineral oil and span 80. We proved theoretically that, in polydisperse bubble suspensions, the shear-thinning behavior spans a capillary number (Ca) range between 0.01 and 100, instead of occurring at Ca~1, which is the case for monodisperse suspensions. However, for the effect of polydispersity to become apparent, the bubble size distribution should be bimodal, with very small and very large bubbles having similar volume fractions. In any other case, we can consider the polydisperse suspension as monodisperse, with a volume-weighted average diameter (d43). To confirm the theoretical results, we carried out steady shear rheological tests. Our measurements revealed an unexpected double power-law decay of the relative viscosity. To investigate this behavior further, we visualized the produced bubble suspensions under shear. The visualization experiments revealed that bubbles started forming clusters and threads at average capillary number around 0.01, where we observed the first decay of viscosity. CFD simulations confirmed that under the presence of bubble clusters and threads the fluid streamlines distort less, thus resulting in a decrease of the suspension viscosity. Consequently, we can attribute the first decay of the relative viscosity to the formation of bubble clusters and threads, proving that the novel shear-thinning behavior we observed is due to a combination of bubble clustering and deformation

    The Structure of Stellar Coronae in Active Binary Systems

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    A survey of 28 stars using EUV spectra has been conducted to establish the structure of stellar coronae in active binary systems from the EMD, electron densities, and scale sizes. Observations obtained by the EUVE during 9 years of operation are included for the stars in the sample. EUVE data allow a continuous EMD to be constructed in the range log T~5.6-7.4, using iron emission lines. These data are complemented with IUE observations to model the lower temperature range. Inspection of the EMD shows an outstanding narrow enhancement, or ``bump'' peaking around log T~6.9 in 25 of the stars, defining a fundamental coronal structure. The emission measure per unit stellar area decreases with increasing orbital (or photometric) periods of the target stars; stars in binaries generally have more material at coronal temperatures than slowly rotating single stars. High electron densities (Ne>10^12 cm^-3) are derived at ~10 MK for some targets, implying small emitting volumes. The observations suggest the magnetic stellar coronae of these stars are consistent with two basic classes of magnetic loops: solar-like loops with maximum temperature around log T~6.3 and lower electron densities (Ne>10^9-10.5), and hotter loops peaking around log T~6.9 with higher electron densities (Ne>10^12). For the most active stars, material exists at much higher temperatures (log T>6.9) as well. However, current ab initio stellar loop models cannot reproduce such a configuration. Analysis of the light curves of these systems reveals signatures of rotation of coronal material, as well as apparent seasonal changes in the activity levels.Comment: 45 pages, 9 figures (with 20 eps files). Accepted for its publication in ApJ

    Accuracy of self-reported private health insurance coverage

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    Studies on health insurance coverage often rely on measures self-reported by respondents, but the accuracy of such measures has not been thoroughly validated. This paper is the first to use linked Australian National Health Survey and administrative population tax data to explore the accuracy of self-reported private health insurance (PHI) coverage in survey data. We find that 11.86% of individuals misreport their PHI coverage status, with 11.57% of true PHI holders reporting that they are uninsured and 12.37% of true non-insured persons self-identifying as insured. Our results show reporting errors are systematically correlated with individual and household characteristics. Our evidence on the determinants of errors is supportive of common reasons for misreporting. We directly investigate biases in the determinants of PHI enrollment using survey data. We find that, as compared to administrative data, survey data depict a quantitatively different picture of PHI enrollment determinants, especially those capturing age, gender, language proficiency, labor force status, disability status, number of children in the household, or household income. We also show that PHI coverage misreporting is subsequently associated with misreporting of reasons for purchasing PHI, type of cover and length of cover

    The role of a Mediterranean diet on the risk of oral and pharyngeal cancer.

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    BACKGROUND: The Mediterranean diet has a beneficial role on various neoplasms, but data are scanty on oral cavity and pharyngeal (OCP) cancer. METHODS: We analysed data from a case-control study carried out between 1997 and 2009 in Italy and Switzerland, including 768 incident, histologically confirmed OCP cancer cases and 2078 hospital controls. Adherence to the Mediterranean diet was measured using the Mediterranean Diet Score (MDS) based on the major characteristics of the Mediterranean diet, and two other scores, the Mediterranean Dietary Pattern Adherence Index (MDP) and the Mediterranean Adequacy Index (MAI). RESULTS: We estimated the odds ratios (ORs), and the corresponding 95% confidence intervals (CI), for increasing levels of the scores (i.e., increasing adherence) using multiple logistic regression models. We found a reduced risk of OCP cancer for increasing levels of the MDS, the ORs for subjects with six or more MDS components compared with two or less being 0.20 (95% CI 0.14-0.28, P-value for trend <0.0001). The ORs for the highest vs the lowest quintile were 0.20 (95% CI 0.14-0.28) for the MDP score (score 66.2 or more vs less than 57.9), and 0.48 (95% CI 0.33-0.69) for the MAI score (score value 2.1 or more vs value less 0.92), with significant trends of decreasing risk for both scores. The favourable effect of the Mediterranean diet was apparently stronger in younger subjects, in those with a higher level of education, and in ex-smokers, although it was observed in other strata as well. CONCLUSIONS: Our study provides strong evidence of a beneficial role of the Mediterranean diet on OCP cancer
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