Abstract: Today’s large demand of internet applications requires data to be transmitted in a secure manner. Data transmission in public communication system is not secure because of interception and improper manipulation by eavesdropper. In this thesis we implement two security algorithms they are cryptography and steganography. For secure communication we are providing security by using the RSA which is based on Cryptography. Steganography is an art of sending hidden data or secret messages over a public channel so that a third party cannot detect the presence of the secret messages. Audio signals have a characteristic redundancy and unpredictable nature that make them ideal to be used as a cover to hide secret information. A Steganographic technique for embedding text information in audio using LSB based algorithm is presented in this paper. In the proposed method each audio sample is converted into bits and then the text data is embedded. In embedding process, first the message character is converted into its equivalent binary. By using proposed LSB based algorithm, the capacity of stego system to hide the text increases. The performance of the proposed algorithm is computed using SNR values for various audio input. By using these methods third parties cannot percept the existence of message embedded in the audio file. The properties of the audio file remain the same after hiding the secret message.
Keywords: Cryptography, steganography, LSB, RSA.