Encryption and Decryption algorithm using two dimensional cellular automata rules in Cryptography

In this paper we present a new encryption and decryption algorithm for block cipher based on the linear(periodic boundary-PB) and nonlinear cellular automata rules.First we apply non linear CA rules (complements) to both plain text and key. Then PB CA rule is applied to the above results separately followed by the XOR operation of above results.After that the result of XOR operation is fed to substitution box(S-box) and again PB CA rules are applied followed by SBox. The decryption process is carried out just similar to that of encryption but in the reverse way. Both the process of encryption and decryption is performed for 8 number of rounds in order to avoid the dependency between the plain text and cipher text so that the our proposed algorithm is more securethan that of AES and DES algorithms.