Wavelet transform is not the best way for extracting watermarking image contour features. Compared with the wavelet transform, the ridgelet transform has better accuracy and sparse approximation performance. We propose a robust zerowatermarking algorithm based on ridgelet transform domain, which combines the twodimensional chaotic system, SVD and bitplane to construct the watermarking. Firstly, the algorithm takes advantage of the wavelet transform to extract the lowfrequency domain in the carrier image. Secondly, we decompose the lowfrequency domain according to the blocking strategy. When all the blocks are transformed by the FRIT, the characteristic matrix can be constructed by the SVD. Moreover, we apply the twodimensional chaotic system to encrypt the characteristic matrix. Finally, we extract the most significant bitplane in the feature matrix, and generate registration zerowatermarking information by combining the encrypted meaningful watermarking, which not only improves the robustness of the watermarking,
but also greatly enhances the security of watermarking through double encryption. Experimental results demonstrate that the algorithm has good robustness, security and easy operation, and that it can effectively resist various types of attacks.