基于混沌的DCT域关系数据库水印算法*

借鉴多媒体数字水印技术,提出了一种基于混沌的DCT域关系数据库水印算法,运用混沌序列对版权图像加密生成水印信息,并嵌入到候选属性的DCT中频系数中。利用DCT在频域中实现水印与载体的融合,隐蔽性更强,弥补了空域水印算法的不足;混沌序列的伪随机性和初值敏感性为数字水印的安全性提供了保证。实验表明,该算法具有较强的鲁棒性和良好的不可见性。

Relational database watermarking algorithm based on chaos and DCT

This paper presented a relational database robust watermarking algorithm based on chaos and DCT,which took the advantage of the frequency domain approach of multimedia digital watermarking into the area of relational database watermar-king.By DCT on grouped and sorted tuples and modifying some of the transformed frequency coefficients to embed image watermark,only affecting one attribute for each tuple,the algorithm had good watermarking invisibility.Pseudo-random,sensitive to initial value of chaotic sequences improved the security of the watermark.The extraction did not need the original data.The experimental results show that the algorithm possesses strong robustness and good invisibility.