Analysis of Modified Substitution Encryption Techniques

-In this paper we present some new approach for security enhancement of well known classical substitution cipher (Playfair and Hill cipher). Some drawback inherent the 5x5 Playfair cipher which adversely affect the security of this cipher and also Hill Cipher that succumbs to the known-plaintext attack .It is clear from above line due to some serious security reasons we cannot use these well known encryption techniques in practical life . This paper aim is to focus on modification that can enhance the security level of these classical encryption techniques so these can resist for different cryptanalysis attacks. Keyword-classical substitution cipher, Transposition cipher, Playfair cipher, Hill cipher.