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 secure than that of AES and DES algorithms

Equivalence of DES and AES Algorithm with Cellular Automata

In this paper we present the equivalence of the operations involved in DES and AES algorithm with operations of cellular automata. We identify all the permutation and substitution operations involved in DES and AES algorithm and compare these operations with the cellular automata rules. Then we find that permutation operations involved in DES and AES are equivalent to linear cellular automata rules providing diffusion property of cryptography whereas substitution operations involved in DES and AES are equivalent to non linear cellular automata rules providing the confusion property of cryptography. Hence instead of using operations involved in DES and AES algorithm, we can apply linear as well as non-linear cellular automata rules in cryptography for better security and parallel processing

Applications of Two Dimensional Cellular Automata rules for Block Cipher in Cryptography

Cellular Automaton is an idealized parallel processing machine which is an array (1-D, 2-D) of numbers or symbols called cell values together with an updating rule. A cell value is updated based on this updating rule, which involves the cell value as well as other cell values in a particular neighborhood. A fundamental objective of cryptography is to enable two people to communicate over an insecure channel (a public channel such as internet) in such a way that any other person is unable to recover their message (called the plaintext) from what is sent in its place over the channel (the cipher text). The transformation of the plaintext into the cipher text is called encryption, or enciphering. The transformation of the cipher text into the plaintext is called decryption, or deciphering. In this paper we present a new encryption and decryption algorithm based on the linear (periodic boundary-PB) and nonlinear Cellular Automata rules. First we apply PB CA rules to plain text and key. The result of both plain text and key is XORed. Then the result of XOR operation is fed to substitution box( S-box) and again PB CA rules are applied for exchange and shift operations. At the end Complement operation is applied for encryption of plain text. The decryption process is carried out just similar to encryption but in the reverse way. Both the process of encryption and decryption is performed for 8 numbers of rounds in order to avoid the dependency between the plain text and cipher text