Symmetrical Cryptosystems based on Cellular Automata

Abstract

This paper deals with the development of two symmetric encryption algorithms on the basis of cellular automata: a block cipher, that is based on AES and uses three-dimensional cellular automata; a stream cipher, that exploits a hardware-software entropy generation (tracking of keystrokes and mouse pointer movement), as well as the developed hash function, based on “cryptographic sponge” architecture of SHA-3, modified by cellular automata transformations. The block cipher is designed in architecture of SP-network and uses the AES substitution block. Permutation layer and key generation is designed on the basis of cellular automata rules (rules “22”, “105” and “150”). The optimal number of rounds to achieve maximum crypto resistance is determined. The stream cipher is designed on the basis of hardware-software entropy generation and uses the cryptographic hash-function in the SHA-3 architecture. Permutation function is developed on the basis of cellular automata rules (rules “30” and “146”). The procedures of shift and permutation of rows and columns is used for better permutation. A final permutation of state elements is used to improve the avalanche effect. The received results are analyzed and summarized; the conclusions and justifications about cipher parameters (like number of rounds, where needed) are made.