基于完全零知识交互证明系统和位委托方案,提出了可证明的安全水印认证协议.现有文献大都使用基于Cox的扩频数字水印方案或对其进行修改后的扩频水印方案.采用了鲁棒性较强的更适合于版权保护的乘法嵌入规则,在宿主信号中嵌入水印;水印检测时,在充分考虑了不同的变换域、信道特性以及人类视觉特性的基础上,采用基于广义高斯分布和Weibull分布模型的各种变换域的鲁棒优化检测器.使用位委托方案对数字水印信息进行委托,并联合使用随机序列隐藏水印嵌入位置信息.协议确保了在证明相应水印存在的同时,没有泄露任何有关水印的敏感信息,防止了蓄意攻击者利用认证过程中泄露的有关水印的敏感信息(如水印、水印位置、提取密钥等)来移除或伪造水印.数字水印方案对各种变换域的水印检测器给予了较全面的考虑,所以,应用该协议进行水印认证,其安全性、有效性、鲁棒性和实用性都有较大提高.
A proved secure protocol for watermark verification based on perfect zero knowledge interactive proof system and bit commitments scheme is proposed. Most of the existing literature use, Cox' s spread spectrum watermarking scheme or its or its modified ones. In this paper, the multiplication embedding rule is adopted, which is more robust and fits in with copyright protection. In the process of watermarking extraction, under the condition of taking into account, the different transform domains (such as DWT, DCT and DFT), communication channel performance and human visual system, generalized Gaussian distribution model and Weibull distribution model based robust optimum watermarking detectors of different transform domains are adopted. Watermarking information is committed by using bit commitments scheme, and by jointing random sequence, the watermarking embedding position information is hidden. The proposed protocol ensures that a prover soundly convinces a verifier of the presence of a watermark in certain stego-data without revealing any knowledge (including watermarking itself, embedding position, watermarking extraction keys) about the watermark which can be used by a potential attacker to modify, remove or spoil the watermarks. Moreover, various watermarking detectors in different transform domains are adopted. Thus, by using the presented simple and secure protocol, the security and efficiency of watermarks verification of the different watermarking detection schemes can be improved greatly.