3D - Playfair cipher with additional bitwise operation

Abstract

3D-Playfair cipher is multiple letter encryption cipher. In this, trigraphs of plaintext are treated as single units and converted into corresponding cipher text trigraphs. 3D-Playfair Ciphers originates due to the limitations in classical Playfair as it supports only alphabets and may not support two alphabets at the same time. It also eliminates the fact that a diagram and its reverse will encrypt in a similar fashion. 3D-Playfair cipher supports all 26 alphabets, 10 digits and 28 special characters. The theme of research is to furnish security to data which contains alphabets numerals and special characters during transmission that's why additional bitwise operations are introduced and applied on the cipher text of 3D-Playfair cipher with a random key. Linear Feedback Shift Register is a good candidate for generation of random sequences and is selected for generating random keys for bitwise operations to offer better security to cipher text before transmission over the internet. Here X-OR or X-NOR operations are taken into consideration for the bitwise operations based on the key.