Modeling Pseudorandom Sequence Generators using Cellular Automata: The Alternating Step Generator
M. E. Pazo-Robles, Amparo Fúster-Sabater, Theodore E. Simos, George B. Maroulis · AIP conference proceedings · 2007
Stream ciphers are pseudorandom bit generators whose output sequences are combined with the sensitive information by means of a mathematical function currently an addition module 2. The Alternating Step Generator is a pseudorandom sequence generator with good cryptographic properties and non‐linear structure. In this work, we propose two different ways to model such a generator by using linear and discrete mathematical functions e.g. Cellular Automata. One of these ways deals with the realization of a linear model from a pair of basic automata provided by the Catell and Muzio algorithm. The other way is a new approach based on automata's addition consisting in the realization of a new automaton with non‐primitive polynomial and short length. Both methods provide linear models able to generate the output sequence of the Alternating Step Generator.