Issues of Replacement Blocks Quality Assessment for Stochastic Information Security

The article is devoted to the issues of building and quality assessment of replacement block or S-box, which is one of the main blocks of cryptographic transformation. The principles of S-box designing are considered, examples of their using in modern block ciphers are given. The issues of assessing the statistical safety of S-boxes, in particular, the criteria used for the analysis of S-blocks are investigated. The structure of the program system for the study of the statistical properties of S-boxes is proposed. The results of the S-boxes analysis for the main modern cryptographic algorithms are given. Assumptions about the possibility of mathematical apparatus using for the statistical properties of S-boxes analyzing are made.