The efficiency of a cryptographic algorithm is based on its time taken for encryption / decryption and the way it produces diverse cipher text from a clear text. The RSA, the extensively used public key algorithm and other public key algorithms may not guarantee that the cipher text is copiously secured. As an alternative approach to handling ASCII characters in the cryptosystems, a magic square implementation is deliberated of in this work. It attempts to augment the efficiency by providing add-on security to the cryptosystem. This approach will boost the security due to its complexity in encryption because it deals with the magic square. Here, encryption / decryption is based on numerals generated by magic square rather than ASCII values. In this, we add the ASCII value and the numeral in the consequent magic square. Because to encrypt the plaintext characters, their ASCII values are taken and if a character occurs in numerous places in a plaintext there is a possibility of same cipher text is produced. To surmount the problem, this paper attempts to develop a technique in which a constant is added for the recurring character.