Security analysis of optimal multi-carrier spread-spectrum embedding

This paper considers optimal multi-carrier (multiple messages) spread-spectrum (SS) data embedding on linearly-transformed host. We present information-theoretic security analysis for the optimal SS embedding. The security is quantified by both the Kullback-Leibler distance and Bhat-tacharyya distance between the cover and stego probability distributions. The main results of this paper permit to establish fundamental security limits for the optimal SS embedding. Theoretical analysis and experimental results show the impact of the number of embedding messages, the embedding distortion, and the host transformation in the security level.