Block Based Information Hiding using Cosine, Hartley, Walsh and Haar Wavelets

Steganography is the art of hiding information within other information in such a way that it is hard or even impossible to tell that it is there. There are many different carriers for steganography but the most popular is digital images. Typically, the message is embedded within another image known as a cover image, by tweaking its properties. The resulting output, known as a stego-image is engineered such that it is a near identical perceptual model of the cover image, but it will also contain the hidden message. It is this stego-image that is sent between the sender and the receiver. Steganography is a science for invisible communication and play vital role on the network security. To improve the embedding capacity as well as to have minimum distortion to carrier media, we have proposed a method of hiding secret message into the wavelet transformed cover image. In the proposed system we have developed a block based information hiding scheme using DCT wavelet, Hartley wavelet, Walsh wavelet and Haar wavelet transform for providing 62.5% of the embedding capacity. The Experimental results show that, the stego-image is visually indistinguishable from the original cover-image obtained in the proposed method. The paper compares block based information hiding schemes that hide secret message into orthogonal wavelet transforms such as DCT [Discreet Cosine Transform] wavelet, Hartley wavelet, Walsh wavelet and Haar wavelet. Our experimental results show that using DCT wavelet transform for block based information hiding achieve much better results as compared to Hartley wavelet, Walsh wavelet and Haar wavelet.