(A) secure SVD-based watermarking method for image content authentication

Abstract

For image content authentication, a secure watermarking method using quantization-based embedding on the largest singular value (SV) is proposed. Of the many security problems associated with image content authentication, content modification using vector quantization (VQ) attack and information leakage using statistical analysis are examined. Block-wise independent embedding methods can be vulnerable to VQ attack, and quantization-based embedding may leak useful information to attack by statistical analysis. To overcome these security problems, the proposed method places interdependency among embedding blocks and dithers the quantized values with random noise generated by the image features. Moreover, by adjusting the quantized values to be within a certain range, the proposed method can detect tampered areas with high sensitivity and discriminate JPEG compression between a watermarked image that has and has not been compressed using different thresholds of detector. The security analysis and experimental results show that the proposed method is robust against VQ attack and statistical analysis attack, and it can detect tampered areas and determine the authenticity of an image in various cases.