3D — Playfair cipher using Linear Feedback Shift Register

3D-Playfair cipheris the multiple letter encryption cipher. It is an enhancement of classical playfair cipher and it works on trigraphs (combination of three letters) rather than digraphs for additional security. 3D-Playfair cipher is dealing with 64 characters and supports all 26 alphabets {A-Z}, 10 digits {0-9} and 28 special characters { ! “ # $ % & ` ( ) * + , - . / : ; <; = > ? @ [ ] ^ _ | }. The theme of this research is to provide security for the data that contains alphabets numerals and special characters during its transmission. For this purpose a left or right rotationon the ciphertext of 3D-Playfair cipher has been proposed in this approach. These rotations are applied before transmission over the internet and controlled by the random sequences generated by Linear Feedback Shift Register.