A hierarchical key pre-distribution scheme for fog networks

Security in fog computing is multi-faceted, and one particular challenge is establishing a secure communication channel between fog nodes and end devices. This emphasizes the importance of designing efficient and secret key distribution scheme to facilitate fog nodes and end devices to establish secure communication channels. Existing secure key distribution schemes designed for hierarchical networks may be deployable in fog computing, but they incur high computational and communication overheads and thus consume significant memory. In this paper, we propose a novel hierarchical key pre-distribution scheme based on “Residual Design” for fog networks. The proposed key distribution scheme is designed to minimize storage overhead and memory consumption, while increasing network scalability. The scheme is also designed to be secure against node capture attacks. We demonstrate that in an equal-size network, our scheme achieves around 84% improvement in terms of node storage overhead, and around 96% improvement in terms of network scalability. Our research paves the way for building an efficient key management framework for secure communication within the hierarchical network of fog nodes and end devices. KEYWORDS: Fog Computing, Key distribution, Hierarchical Networks

A cyber-kill-chain based taxonomy of crypto-ransomware features

In spite of being just a few years old, ransomware is quickly becoming a serious threat to our digital infrastructures, data and services. Majority of ransomware families are requesting for a ransom payment to restore a custodian access or decrypt data which were encrypted by the ransomware earlier. Although the ransomware attack strategy seems to be simple, security specialists ranked ransomware as a sophisticated attack vector with many variations and families. Wide range of features which are available in different families and versions of ransomware further complicates their detection and analysis. Though the existing body of research provides significant discussions about ransomware details and capabilities, the all research body is fragmented. Therefore, a ransomware feature taxonomy would advance cyber defenders’ understanding of associated risks of ransomware. In this paper we provide, to the best of our knowledge, the first scientific taxonomy of ransomware features, aligned with Lockheed Martin Cyber Kill Chain (CKC) model. CKC is a well-established model in industry that describes stages of cyber intrusion attempts. To ease the challenge of applying our taxonomy in real world, we also provide the corresponding ransomware defence taxonomy aligned with Courses of Action matrix (an intelligence-driven defence model). We believe that this research study is of high value for the cyber security research community, as it provides the researchers with a means of assessing the vulnerabilities and attack vectors towards the intended victims

Increasing the order of convergence of iterative schemes for solving nonlinear systems

[EN] A set of multistep iterative methods with increasing order of convergence is presented, for solving systems of nonlinear equations. One of the main advantages of these schemes is to achieve high order of convergence with few Jacobian and functional evaluations, joint with the use of the same matrix of coefficients in the most of the linear systems involved in the process. Indeed, the application of the pseudocomposition technique on these proposed schemes allows us to increase their order of convergence, obtaining new high-order, efficient methods. Finally, some numerical tests are performed in order to check their practical behavior. (C) 2012 Elsevier B.V. All rights reserved.This research was supported by Ministerio de Ciencia y Tecnología MTM2011-28636-C02-02 and FONDOCYT 2011-1-B1-33 República DominicanaCordero Barbero, A.; Torregrosa Sánchez, JR.; Penkova Vassileva, M. (2013). Increasing the order of convergence of iterative schemes for solving nonlinear systems. Journal of Computational and Applied Mathematics. 252:86-94. https://doi.org/10.1016/j.cam.2012.11.024S869425

Psychometric properties of the Farsi version of Attitudes to Aging Questionnaire in Iranian older adults

Nahid Rejeh,1 Majideh Heravi-Karimooi,1 Mojtaba Vaismoradi,2 Pauline Griffiths,3 Maryam Nikkhah,4 Tahereh Bahrami4 1Elderly Care Research Centre, Faculty of Nursing and Midwifery, Shahed University, Tehran, Iran; 2Faculty of Nursing and Health Sciences, Nord University, Bodø, Norway; 3College of Human and Health Sciences, Swansea University, Swansea, UK; 4Faculty of Nursing and Midwifery, Shahed University, Tehran, Iran Background: Attitudes to the aging process are affected by the individual’s sociocultural background. The measurement of this important concept among older people in various societies requires the use of tools that are able to demonstrate both reliability and validity.Objective: The objectives of this study were to translate and validate the Attitudes to Aging Questionnaire (AAQ) and investigate its psychometric features among Iranian older people.Methods: In this methodological study, the Farsi version of the AAQ was validated among 400 Iranian older adults who were members of citizen clubs in an urban area of Iran. Content, face and construct (exploratory factor analysis) validities of the AAQ were assessed. In addition, its reliability was assessed in terms of internal consistency and stability. For discriminant validity, the discriminant power of the AAQ in terms of gender and education levels was evaluated. Criterion validity showed a significant correlation between the most subscales of the AAQ and the Short Form 36 (SF-36) and World Health Organization Quality of Life (WHOQOL) questionnaires. Descriptive and inferential statistics were used for data analysis.Results: The exploratory factor analysis confirmed the construct validity of the AAQ. The result of the test–retest reliability with a 2-week interval was satisfactory and reported as r=0.90 (p<0.001). The Cronbach’s alpha coefficient was reported as 0.75 for the whole instrument and 0.85–0.93 for its dimensions. There were associations between the AAQ subscales, SF-36 quality of life (r=0.56, p<0.001) and WHOQOL-BREF (r=0.78, p<0.001), indicating an appropriate convergent validity. The ability to discriminate between male and female participants and those with lower and higher education levels was demonstrated, thus lending support to claims for adequate known-group validity.Conclusion: The Farsi version of the AAQ showed favorable validity and reliability. Therefore, it can be used for assessing attitudes toward aging among older adults. Keywords: aging, Attitudes to Aging Questionnaire, older adults, psychometrics properties, reliability, validity, elderl