对DCT域水印系统的周期性攻击

Adaptive attacks against DCT-based watermarking

为使水印攻击方法具备自我证明的特性,满足某些有特殊要求的版权保护需求,该文在分析数字图像离散余弦变换(DCT)域自适应水印嵌入原理的基础上,提出了一种水印攻击方法。该方法利用人类视觉系统(HVS)特性选择隐蔽载体(Stego-image)相应的水印嵌入区域,在载体的质量改变不被感知的情况下,利用矩阵变换的周期性理论,对选择的区域进行周期性变换(攻击)。试验结果表明,新的攻击方法在保证视觉质量要求的前提下能很有效地阻止数字水印的检测和提取,具有较好的攻击效果;同时经过多次相同变换(攻击)后,可以完全重构Stego-image,从而可向版权所有者提供攻击成功的证明。

A watermarking attack method was developed based on the adaptive watermarking embedded in the discrete cosine transform （DCT） domain to improve the ability of the watermarking method to resist attacks for improved copyright protection. The watermarking methods embeds the watermark in Stegoimage based on the characteristics of human vision systems with the attack methods using a periodic matrix transformation to attack the watermark area. Experiments show that the method can prevent detection and recovery of the watermark while ensuring the quality of the Stegoimage. The method can recover the original Stegoimage by attacking the same image in the same way many times, to verity the protection afforded the owner of the watermarking image.