2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/32633We investigate the lattice of machine invariant classes. This is an infinite completely distributive lattice but it is not a Boolean lattice. We show the subword complexity and the growth function create machine invariant classes. So the lattice would serve as a measure of words cryptographic quality if we like to identify new stream ciphers suitable for widespread adoption.9 pages, extended abstract published in 67th Workshop on General AlgebraCryptography and SecurityComputational ComplexityDiscrete MathematicsD.2.8;D.4.6;E.3;F.1.1;F.1.3;F.4.3text