Secret Key Cryptography with Cellular Automata

The paper presents new results concerning application of cellular automata (CAs) to the secret key cryptography extending results presented in (14, 1.51. One dimensional, nonunifOrm CAs is considered us a generator ofpseudorundam number sequences (PNS) used in cryptography with the secret key. The quality of PNSs highly depends on a set of applied CA rules. Tojnd such rules nonunifOrm CAs with two t+pes of rules is considered. The search of rules is performed with use of evolutionary technique culled cellular programming. As the result of collective behavior of discovered set of CA rules very high quality PNSs are generated. The quality ofPNSs outperforms the quality of known one dimensional CA-bused PNS generators used in the secret key cryptography. The extended set of CA rules which was found makes the cryptography system much more resistant on breaking a cryptography key.