Science & Engineering Research Support soCiety (SERSC)
Playfair cipher is the form of block cipher which has no limit on the number of characters in a message it can do, but it operates on block of characters encrypting and decrypting two characters at a time cipher. In this, the plain text di-grams are converted to cipher text di-grams and vice versa using a pre-shared key. This is achieved by performing several operations column wise row wise and by creating rectangular form. Even so the traditional 5x5 Playfair cipher supports twenty five uppercase alphabets only. To overcome this drawback, various authors have proposed extended Playfair cipher.