No. 4/2016

Online archive of Computer Science and Mathematical Modelling

No. 4/2016

  1. A. Ameljańczyk - Presorting as a method of acceleration of algorithms in multi-objective optimization problems
    Pages: 5 - 11
    Abstract: The paper presents a method of algorithms acceleration for determining Pareto-optimal solutions (Pareto Front) multi-criteria optimization tasks, consisting of pre-ordering (presorting) set of feasible solutions. It is proposed to use the generalized Minkowski distance function as a presorting tool that allows build a very simple and fast algorithm Pareto Front for the task with a finite set of feasible solutions.
    Keywords Pareto Front, presorting, Minkowski metric
    Full article: PDF icon 5_11_csmm_4_aameljanczyk.pdf
  2. M. Chudy - Branch and Bound method for binary problems with the picture that redudes dimensions of problem
    Pages: 13 - 18
    Abstract: The relationships between elements of coefficient matrix, elements of vector and elements of vector in general binary problem are considered. Some of them allow us to establish the values of selected elements of feasible or optimal vector . This procedure reduces the dimension of basic problem and can be install in branch and bound method. It gives positive effects.
    Keywords binary problem, branch and bound method, reducing dimension
    Full article: PDF icon 13_18_csmm_4_mchudy.pdf
  3. O. Dzięgielewska, B. Szafrański - A brief overview of basic inference attacks and protection controls for statistical databases
    Pages: 19 - 24
    Abstract: With cyber-attacks on the dramatic rise in the recent years, the number of entities which realize the necessity of protecting their IT assets increases. Individuals are more aware of the potential threats and demand high level of security from the business entities having access to their personal and private data. Such entities have legal obligations to satisfy the confidentiality when processing sensitive data, but many fails to do so. Keeping the statistical data private is a challenge as the approach to the security breaches slightly differs from the classical understanding of data disclosure attacks. The statistical disclosure can be achieved using inference attacks on the not-effectively protected assets. Such attacks do not target the database access itself, i.e. are performed from a perspective of an internal user, but the statistical interface used to retrieve the statistical data from the database records. This paper sums up basic types of inference attacks classifying them in the CVSS standard and provides a series of fundamental countermeasures which can be undertaken to mitigate the risk of performing successful attack.
    Keywords statistical databases, inference control in statistical database, statistical disclosure, data security, data privacy.
    Full article: PDF icon 19_24_csmm_4_odziegielewska_bszafranski.pdf
  4. B. Szafrański, J. Wilk - Electronic services security management for the public administration
    Pages: 25 - 32
    Abstract: The public administration in Poland is constantly extending and improving electronic services provided to citizens, business and itself (e.g. one ministry providing services to another public administration institution). New expectations like integration using the multilateral interoperability model, the service oriented approach, different security categories and groups within different institutions are creating the requirement for the appropriate security model. According to the authors current models do not meet the new requirements, but can be used as a base for the new approach. The lattice and its variations in different models (Denning, Sandhu, Szafrański) was selected by authors to create the new electronic services security management model for integration platforms which are supporting realization of public tasks. This publication focuses on practical aspect of the new model and presents the case study on a public administration e-services example. Detailed definition of the model itself can be found in previous authors’ articles.
    Keywords e-services, security, SOA
    Full article: PDF icon 25_32_csmm_4_bszafranski_jwilk.pdf
  5. M. Wroński - Using Montgomery curve arithmetic over Fp2 for point scalar multiplication on short Weierstrasscurve over Fp with exactly one 2 – torsion point and order not divisible by 4 for IT systems
    Pages: 33 - 38
    Abstract: Montgomery curves are well known because of their efficiency and side channel attacks vulnerability. In this article it is showed how Montgomery curve arithmetic may be used for point scalar multiplication on short Weierstrass curve ESW over Fp with exactly one 2-torsion point and not divisible by 4. If then also . Because has three 2-torsion points (because has one 2-torsion point) it is possible to use 2-isogenous Montgomery curve to the curve for counting point scalar multiplication on . However arithmetic in is much more complicated than arithmetic in , in hardware implementations this method may be much more useful than standard methods, because it may be nearly 45% faster.
    Keywords elliptic curve cryptography, hardware implementations, Montgomery curves
    Full article: PDF icon 33_38_csmm_4_m_wronski.pdf