Spread spectrum image data hiding in the encrypted discrete cosine transform coefficients

Abstract

Digital watermarking and data hiding are important tools for digital rights protection of media data. Spread spectrum (SS)-based watermarking and data-hiding approaches are popular due to their outstanding robustness, but their security might not be sufficient. To improve the security of SS, a SS-based image data-hiding approach is proposed by encrypting the discrete cosine transform coefficients of the host image with the piecewise linear chaotic map, before the operation of watermark embedding. To evaluate the performance of the proposed approach, simulations and analyses of its robustness and security are carried out. The average bit-errorrate values on 100 real images from the Berkeley segmentation dataset under the JPEG compression, additive Gaussian noise, salt and pepper noise, and cropping attacks are reported. Experimental results show that the proposed approach can maintain the high robustness of traditional SS schemes and, meanwhile, also improve the security. The proposed approach can extend the key space of traditional SS schemes from 10 19 to 10 47 and thus can resist brute-force attack and unauthorized detection watermark attack.

Correlation-and-bit-aware additive spread spectrum data hiding for Laplacian distributed host image signals

“…(20) should be much weaker than the host signal X, i.e., Sa i o Xj j j j , i ¼ 1; 2, and therefore we approximately have…”

“…In the SS scheme, the watermark signal spreads over many host coefficients so that the energy in any coefficient is weak and certainly undetectable. According to different embedding rules, the SS embedding methods can be mainly divided into the additive Spread Spectrum (ASS) methods [15][16][17] and the multiplicative Spread Spectrum (MSS) methods [18][19][20]. The watermark is added to the host coefficients with equal power in the ASS scheme, while the watermark power is proportional to the value of the host signal in the MSS scheme.…”