Secured data transmission through audio signal (SDTAS)

In this paper a novel technique has been proposed for secured transmission of sensitive data by hiding any type of message in a carrier audio signal. The proposed algorithm uses Discrete Fourier Transform (DFT) to convert the carrier audio samples into frequency domain after they are decomposed into small non-overlapping frames. Message bits are fabricated in transformed frequency coefficients at pseudo-random bit positions to defeat any unauthorized extraction attempt as the bits can only be retrieved accurately by reproducing the exact sequence of bit positions at receiving end with the help of the same pseudo-random number generator. This technique hugely enhances data security. Also to guarantee the integrity and authenticity of the hidden data a message digest of the hidden message is inserted into the carrier. At receiving end both the message and message digest are extracted. The extraction algorithm regenerates a new message digest of the extracted message and compares it with the one received. Experimentation has been done using various types of carrier audio signal and message data where test results show impressive performance of the proposed algorithm in terms of both subjective and objective metrics.