3D — Playfair cipher using LFSR based unique random number generator

3D-Playfair cipher [1] is the multiple letter encryption cipher. Here the trigraphs in the plain text are treated as single units and converted into corresponding cipher text trigraphs. A group of 3 characters are known as trigraph. 3D-Playfair Ciphers came into focus due to the limitation of classical Playfair that it supports only alphabets and may not support “i” and “j” both 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 {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 that´s why a Linear Feedback Shift Register based unique random number generator is coupled with 3D-Playfair cipher for offering better security in transmission over the internet. LFSR based unique random number generator [2] enhances the security up to a considerable level by generating random sequences. These random sequences will be used for transmission on the behalf of the actual cipher text.