A Modified Encryption Technique using Playfair Cipher 10 by 9 Matrix with Six Iteration Steps
Subhajit Bhattacharyya, Nisarga Chand, Subham Chakraborty · KTH Publication Database DiVA (KTH Royal Institute of Technology) · 2014
One of the well-known digraph substitution cipher is the Playfair Cipher. It secures information mathematically by mangling message with key. The privacy of intended sender and receiver information is protected from eavesdropper. However the original 5 x 5 Playfair Cipher can support only 25 uppercase alphabets. Here we have implemented a new technique which includes a rectangular matrix having 10 columns and 9 rows and six iteration steps for encryption as well as decryption purpose. This 10 x 9 rectangular matrix includes all alphanumeric characters and some special characters. Cryptanalysis is done to show that the modified cipher is a strong one. Finally we have implemented this concept with the help of MATLAB.