Towards Automating the Construction & Maintenance of Attack Trees: a Feasibility Study

Security risk management can be applied on well-defined or existing systems; in this case, the objective is to identify existing vulnerabilities, assess the risks and provide for the adequate countermeasures. Security risk management can also be applied very early in the system's development life-cycle, when its architecture is still poorly defined; in this case, the objective is to positively influence the design work so as to produce a secure architecture from the start. The latter work is made difficult by the uncertainties on the architecture and the multiple round-trips required to keep the risk assessment study and the system architecture aligned. This is particularly true for very large projects running over many years. This paper addresses the issues raised by those risk assessment studies performed early in the system's development life-cycle. Based on industrial experience, it asserts that attack trees can help solve the human cognitive scalability issue related to securing those large, continuously-changing system-designs. However, big attack trees are difficult to build, and even more difficult to maintain. This paper therefore proposes a systematic approach to automate the construction and maintenance of such big attack trees, based on the system's operational and logical architectures, the system's traditional risk assessment study and a security knowledge database.Comment: In Proceedings GraMSec 2014, arXiv:1404.163

Rank-Dependent Measures of Bi-Polarization and Marginal Tax Reforms

In this paper, we investigate a dual class of bi-polarization indices, namely rank-dependent bi-polarization indices. We show that these indices may be characterized with the generalized positional transfer sensitivity property. We find necessary and sufficient conditions in order to identify bi-polarization-reducing marginal tax reforms. Precisely, we propose inverse positional dominance criteria based on the comparison of bi-polarization concentration curves. An illustration is presented using the Jordanian Household Expenditure and Income Survey 2002/2003.

Decomposition of s - Concentration Curves

For any given order of stochastic dominance, standard concentration curves are decomposed into contribution curves corresponding to within-group inequalities, between-group inequalities, and transvariational inequalities. We prove, for all orders, that contribution curve dominance implies systematically welfare-improving tax reforms and conversely. Accordingly, we point out some undesirable fiscal reforms since a welfare expansion may be costly in terms of particular inequalities.Concentration curves, Contribution curves, Stochastic dominance, Tax reforms

Between-Group Transfers and Poverty-Reducing Tax Reforms

In this paper, we propose the conception of within-group CD-curve, to apprehend the impact of indirect tax reforms on truncated distributions of consumption expenditures. This confers decision makers the ability to perform within-group transfers as well as between-group transfers to reduce poverty in particular groups or to obtain an overall poverty alleviation. Between-group transfers are implemented in order to introduce a fairness element into the indirect tax framework, allowing to test for the robustness of reducing-tax reforms, for any order of stochastic dominance.CD-curve ; Redistribution ; Stochastic dominance ; Tax reforms

Decomposition of s-Concentration Curves

For any given order of stochastic dominance, standard concentration curves are decomposed into contribution curves corresponding to within-group inequalities, between-group inequalities, and transvariational inequalities. We prove, for all orders, that contribution curve dominance implies systematically welfare-improving tax reforms and conversely. Accordingly, we point out some undesirable fiscal reforms since a welfare expansion may be costly in terms of particular inequalities.Concentration curves ; Contribution curves ; Stochastic dominance ; Tax reforms

Between-Group Transfers and Poverty-Reducing Tax Reforms

In this paper, we propose the conception of within-group CD-curve, to apprehend the impact of indirect tax reforms on truncated distributions of consumption expenditures. This confers decision makers the ability to perform within-group transfers as well as between-group transfers to reduce poverty in particular groups or to obtain an overall poverty alleviation. Between-group transfers are implemented in order to introduce a fairness element into the indirect tax framework, allowing to test for the robustness of reducing-tax reforms, for any order of stochastic dominance.Between-group redistribution, CD-curves, Stochastic dominance of order s, Tax reforms

Rank-Dependent Measures of Bi-Polarization and Marginal Tax Reforms

In this paper, we investigate a dual class of bi-polarization indices, namely rank-dependent bipolarization indices. We show that these indices may be characterized with the generalized positional transfer sensitivity property. We find necessary and sufficient conditions in order to identify bipolarization- reducing marginal tax reforms. Precisely, we propose inverse positional dominance criteria based on the comparison of bi-polarization concentration curves. An illustration is presented using the Jordanian Household Expenditure and Income Survey 2002/2003.Bi-polarization, Stochastic Dominance, Tax Reform