An Experiment with Some Rule 30 and Rule 150 Hybrid Non-linear 461Cellular Automata for Cryptography
Here, Cellular Automata (CA) are studied as pseudo-random sequence generators as generation of pseudo-random sequences is the key to any cryptographic system.
In recent literature, hybrid non-linear CA were studied for cryptographic applications. In this paper, we investigate some hybrid nonlinear CA constructed using rules 30 and 150, to show that widely spaced non-linear rules are more cryptographically robust than closely spaced non-linear rules up to a point.
In accordance to the literature, we have modeled CA as Boolean function generators and analyzed the important cryptographic properties (balancedness, nonlinearity, resiliency and algebraic degree of the generated Boolean functions) over iterations. Further, d-monomial test  and  has been experimented.
We have experimented up to five iterations which is more than usually reported in related literature, which gives a clearer indication towards the fact that widely-spaced nonlinear rules are better for cryptographic applications than closely-spaced non-linear rules up to a point.
Keywords: Cellular automata, non-uniform nonlinear CA, cryptographic properties of cellular automata, pseudo-randomness, d-monomial test, cryptography