Efficient Application of Hybrid 150/90 Cellular Automata to Symmetric Cryptography

In this work, it is shown that a wide class of nonlinear sequence generators, the so called interleaved sequence generators, can be modelled in terms of linear cellular automata. A simple modelling procedure based on the concatenation of automata has been derived. The cryptographic characteristics of the generated sequences (period, linear complexity, number of different sequences) have been also analyzed. The technique is very simple and can be applied to generators in a range of practical applications.