Statistically Secure Digital Image Data Hiding

In this paper, we propose a novel discrete cosine transform (DCT) based spread spectrum data-hiding algorithm that provides statistical security. Unlike other spread spectrum based data hiding algorithms, the proposed algorithm does not introduce a low-pass filtering effect in the stego image´s histogram, thereby making the presence of hidden data statistically undetectable. The proposed algorithm does not compromise on robustness or capacity to achieve this goal. When compared to the generic block DCT based data-hiding scheme, the proposed algorithm provides a 41% reduction in the relative entropy between the probability mass functions of the host and stego images, thus improving the statistical security of the system. The proposed algorithm is robust against a variety of image manipulating attacks such as noise addition, filtering, blurring, sharpening, JPEG compression etc