Two-Key Dependent Permutation for Use in Symmetric Cryptographic System

This paper deals with a two-key based novel approach for generating a permutation table that can be used in a symmetric cryptographic system to cause diffusion. It also discusses how the permutation table generated using the approach can be applied to character based encryption and binary data block produced at intermediate stages by symmetric cipher algorithms. It also describes the effect of our approach on characters of intermediate text as well as on bits of binary data block along with the impact of a single bit change in key information on producing permutation sequences applied to plaintexts to produce ciphertexts. The results are satisfactory and the proposed approach can be employed in any symmetric block cipher algorithm that uses the predefined permutation tables.