A sparse representation based approach for steganography

In recent years, there has been a growing interest in exploiting sparsity of natural signals for use in a large number of applications including encryption and steganography. Steganography refers to the practice of hiding a secret message, known as stegotext, within a simple looking message called plaintext so that it can only be retrieved by the intended user. It is also desired that the hidden data should in no way affect the perceived quality of the cover message. In this paper, we propose an approach to steganography that is based on sparse representation of signals. The proposed method hides data within an audio clip or an image without compromising on their perceived qualities. It is also demonstrated in our experiments that the hidden data can be successfully separated out from the cover message. However, the proposed method is a fragile one in the sense that it is not robust to any sort of lossy processing like compression, cropping, etc.