E-catalog        

Библиогр.: 3 назв.

Предложены тесты криптоаналитической обратимости всех возможных типов для произвольных функций от двух аргументов. Сформулированы алгоритмы построения функции восстановления и генерации обратимых функций; посчитано количество обратимых функций некоторых типов. Tests of cryptanalytic invertibility of all possible types for functions g : Di x D2 ^ D are proposed. Let Ga = {g{a,X2} : x2 G D2} for any a G Dl. T^hen: 1) function g is invertible with respect to the variable xl of the type W iff Va, b G Dl (a = b ^ Ga П Gb = ^; 2) function g is invertible with respect to the variable xl of the type V3 iff there exists a mapping ^ such that the mapping a ^ g(a, ^(a)) is injective; 3) function g is invertible with respect to the variable x2 of the type 3V iff |Ga| = |D2| for some value a G Dl. Algorithms for constructing a recovering function and generating invertible functions are formulated; some estimates of the number of invertible functions are given.