Moskovchenko I. Mathematical models and calculation methods of probabilistic forming the nonlinear substitution blocks for symmetric cryptographic means of information security

An object is a process of probabilistic forming of the non-linear substitution boxes with amended properties for symmetric cryptographic means of information security; a purpose is a probabilistic forming of the non-linear substitution boxes with amended properties for symmetric cryptographic means of information security; methods: mathematic modeling and calculating technique, information security theory, mathematic apparatus of Boolean algebra, numeric theory, combinatory, complexity theory, probability theory, mathematical statistic theory methods; novelty: the mathematic model of the non-linear substitution boxes of symmetric cryptographic means of information security obtained future development; the calculating method of gradient search of Boolean functions for non-linear substitution boxes of symmetric cryptographic means of information security has been amended; the probabilistic model of synthesis the non-linear substitution boxes of symmetric cryptographic means of information security which based on the probabilistic selection of formed Boolean functions satisfying the restriction system was first offered, which allows to synthesis the non-linear substitution boxes with amended properties for symmetric cryptographic means of information security; it is implemented in educational process, scientific and research development and production. Area of utilizing: education, research development pointed to construction of new cryptographic means of information security.