A watermarking algorithm based on chaotic encryption

The digital watermarking technique has attracted extensive attention in copyright protection. A watermarking algorithm based on chaotic encryption is proposed. Chaotic sequences are generated through a chaotic map, which is determined by initial condition and parameters. A large number of uncorrelated, random-like, yet deterministic chaotic sequences can be exploited to encrypt the original watermark signal. The encrypted watermark signals are embedded in the image to form a set of watermarked images that will be distributed to different consumers. So we can trace down the Work´s distribution according to the extracted watermark. To improve the security of the watermarking algorithm, the watermark is added to the middle frequency coefficients of wavelet domain randomly by exploiting a 2D chaotic system, keeping the parameters of the 2D chaotic system as a private key can prevent the watermark from removing illegally. Superposition randomly improves the robustness and security of the watermarking algorithm. Experimental results demonstrate that the watermarking scheme is robust to typical signal processing operations such as lossy JPEG compression, resizing and cropping and so on.