Audio Steganography using QR Decomposition and Fast Fourier Transform

Large demand of internet services requires our data to be transmitted in a secure manner. Data can be transmitted secretly using three security methods: Steganography, cryptography and watermarking. Among these, steganography provides better confidentiality. It is the art and science of hiding information in ways that prevents the detection of the hidden message. We focus in this paper on audio steganography where the carrier to hold the secret image is a digital audio file. The novelty of this paper lies on the implementation of QR decomposition technique in audio steganography. To the best of our knowledge no QR technique has been implemented in audio steganography. The paper embeds the bits of the secret image in the lower diagonal elements of the carrier audio file using QR decomposition technique. Three different formats have been specified for input secret image: .jpg, .bmp, .png. The paper also embeds the secret image along the frequency distribution of the carrier audio using Fast Fourier Transform. Another contribution of this paper is comparison between Fast Fourier Transform and QR decomposition technique. The quality of the image is measured using PSNR. The result shows that QR decomposition technique is better than existing Fast Fourier Transform as the calculated PSNR is above 40 dB for all the input images. Further, the paper compares the results obtained from QR technique with other existing methods like SVD. It can be noted that the accuracy of the QR decomposition technique is more than the existing methods and has proven to be very efficient. The system can be used for covert communication or tamper proofing.