The Lattice of Machine Invariant Sets and Subword Complexity

摘要

We investigate the lattice of machine invariant classes. This is an infinitecompletely distributive lattice but it is not a Boolean lattice. We show thesubword complexity and the growth function create machine invariant classes. Sothe lattice would serve as a measure of words cryptographic quality if we liketo identify new stream ciphers suitable for widespread adoption.