Аннотация:
We propose a simple method of constructing S-boxes using Boolean functions and permutations. Let $\pi$ be an arbitrary permutation on $n$ elements, $f$ be a Boolean function in $n$ variables. Define a vectorial Boolean function $F_{\pi}: \mathbb{F}_2^n \to \mathbb{F}_2^n$ as $F_{\pi}(x) = (f(x), f(\pi(x)), f(\pi^2(x)), \ldots, f(\pi^{n-1}(x)))$. We study cryptographic properties of $F_{\pi}$ such as high nonlinearity, balancedness, low differential $\delta$-uniformity in dependence on properties of $f$ and $\pi$ for small $n$.
Ключевые слова:Boolean function, vectorial Boolean function, S-box, high nonlinearity, balancedness, low differential $\delta$-uniformity, high algebraic degree.