The probabilistic model of forming of nonlinear knots of replacements is offered for sectional symmetric cryptoalgorithms. Offered models the probabilistic selection of cryptographic functions is underlaid with the required indexes of firmness. The blocks of nonlinear substitution, which possess the improved cryptographic properties, are formed, that allows to improve the indexes of safety of the modern informative systems and technologies.
nonlinear node of the change, nonlinear, balanced, autocorrelation, correlation immunity, criterion of the spreading
"Veroiatnostnaia model formyrovanyia nelyneinыkh uzlov zamen dlia symmetrychnыkh kryptohrafycheskykh sredstv zashchytы ynformatsyy" ,
Information Processing Systems,