基于混沌的自嵌入安全水印算法

A chaos-based self-embedding secure watermarking algorithm

利用混沌系统的伪随机性和初值敏感性,提出一种基于混沌的自嵌入安全水印算法.该算法以混沌初值为密钥生成混沌序列,根据混沌序列的索引有序序列随机生成图像块的水印嵌入位置.与现有的自嵌入算法相比,该算法实现了水印嵌入位置的随机选取,有效扩大了算法的密钥空间,且解决了自嵌入水印算法如何准确定位篡改块的问题.理论分析和仿真结果表明,该算法不仅提高了自嵌入水印算法的篡改定位的能力,而且进一步增强了算法抵抗向量量化攻击和同步伪造攻击的能力.

This paper presents a novel chaos-based self-embedding secure watermarking algorithm based on the chaotic pseudorandom ness and sensitivity to initial value of chaotic map. In the proposed approach, the real-valued chaotic sequence, which is generated by the given initial value as secret key, is used to produce the ordered indices as the watermark embedding positions. The proposed algorithm has a larger key space than the existing self-embedding watermarking algorithms due to its watermark embedding positions being randomly selected by the secret key. Furthermore, the problem, how to locate the tampered image block in the self-embedding watermarking algorithm has been solved successfully. Theoretical analysis and simulation results show that our scheme not only improves the abilities of tamper localization, but also has better security against many attacks, including the vector quantization and synchronous counterfeiting attacks.