The state diagram of $\chi$

ePrint Report: The state diagram of $\chi$

Jan Schoone, Joan Daemen

In symmetric cryptography, block ciphers, stream ciphers and permutations often make use of a round function and many round functions consist of a linear and a non-linear layer.
One that is often used is based on the cellular automaton that is denoted by $\chi$ as a Boolean map on bi-infinite sequences, $\mathbb{F}^{\mathbb{Z}}$.
It is defined by $\sigma \mapsto \nu$ where each $\nu_i = \sigma_i + (\sigma_{i+1}+1)\sigma_{i+2}$.
A map $\chi_n$ …

block cellular ciphers cryptography defined eprint report function functions non report sigma state stream symmetric