基于防重复嵌入双水印的DEM完整性认证算法

An Integrity Authentication Algorithm for DEM Based on the Preventing Re-embedded Double Watermarking

针对脆弱水印无法证明自身存在性的问题以及为防止通过先篡改再嵌入水印的篡改抵赖行为,提出一种基于防重复嵌入双水印的DEM完整性认证算法。该算法在水印嵌入前加入鲁棒水印预检测机制,若检测到数据含有鲁棒水印则无法继续对数据进行任何水印嵌入操作;若无,则根据DEM数据特征将载体数据划分为特征区域和非特征区域两部分。其中,特征区域用于嵌入鲁棒水印,由该部分数据生成的脆弱水印嵌入至数据的非特征区域。在水印检测时,首先检测鲁棒水印的存在性,若无则直接判断水印被破坏,说明数据不完整,若存在则继续检测脆弱水印的完整性,根据脆弱水印的检测结果进一步判断数据的完整性。实验结果表明,该算法能够有效防止水印的重复嵌入,同时完整性认证准确性良好。

In this paper,a double watermarking based integrity authentication algorithm is proposed to prevent watermark being embedded repeatedly.The aim is to solve the problem that fragile watermarking cannot prove the existence of itself,and prevent the tampering repudiation behavior by tampering the watermarked data first and then embedding the same watermarking information again.The pre-detection mechanism of robust watermarking is performed before the watermarking is embedded,so that any kind of watermarking cannot be embedded if the robust watermarking is already detected in the carrier data.Otherwise,the carrier data was divided into two parts according to the data features,namely the feature region and the non-feature region.The feature region is used to embed robust watermarking and generate the fragile watermarking,which will be embedded into the non-feature region.During the watermarking detection,the existence of the robust watermarking is detected at first.If there is no the robust watermarking,it shows the watermarking is destroyed and the data is incomplete.Otherwise,the integrity of the fragile watermarking will be detected.The integrity of the data will be further determined by the detecting result of fragile watermarking.The experimental results show that the proposed algorithm is able to prevent the watermarking being embedded repeatedly and has good performance for the integrity certification.