An Enhancement to Caesar Cipher using Euler Totient Function

Abstract: In this modern world every communication including financial transactions are taking place through the open unsecured network. In order to communicate securely through open networks the messages need to be concealed by using the cryptographic methods. The mono alphabetic traditional Cipher is Caesar cipher is the simplest and fairly popular among the available cryptographic algorithms but it is prone to brute force attack and frequency analysis test. In this paper we propose an enhancement to Caesar cipher by using the Euler Totient function to generate the key to encrypt a text file. The Euler Totient function is applied on the total number of lines of the plain text file. The key value is generated from the plain text hence for different plain text the key value is different; this makes it difficult for the adversary to guess the key thus making the encryption scheme robust. It needs to design secured key distribution schemes to be taken up as the extension work of this scheme.