Stream Cyphers with One- and Two-Dimensional Cellular Automata

In the age of universal electronic connectivity and the ensuing possibility of message eavesdropping and electronic fraud, cryptography becomes a basic requirement to secure data storage and transmission. In this work we describe a single key cryptographic system based on one- and two-dimensional non-uniform cellular automata that produce high-quality pseudo-random bit sequences. The robustness of the scheme against cryptanalytic attacks is discussed and it is shown that direct cryptanalysis requires an exponentially growing amount of computational resources. The advantage of implementing the proposed scheme in hardware for high-speed operation is also discussed.