  In order to improve the data hiding in all types of multimedia data formats
such as image and audio and to make hidden message imperceptible, a novel
method for steganography is introduced in this paper. It is based on Least
Significant Bit (LSB) manipulation and inclusion of redundant noise as secret
key in the message. This method is applied to data hiding in images. For data
hiding in audio, Discrete Cosine Transform (DCT) and Discrete Wavelet Transform
(DWT) both are used. All the results displayed prove to be time-efficient and
effective. Also the algorithm is tested for various numbers of bits. For those
values of bits, Mean Square Error (MSE) and Peak-Signal-to-Noise-Ratio (PSNR)
are calculated and plotted. Experimental results show that the stego-image is
visually indistinguishable from the original cover-image when n<=4, because of
better PSNR which is achieved by this technique. The final results obtained
after steganography process does not reveal presence of any hidden message,
thus qualifying the criteria of imperceptible message.
