基于多重元胞自动机的图像水印加密算法

Encryption for Image Watermarking Based on Multiple Cellular Automata

针对目前基于直方图平移类可逆水印算法存在的安全问题,提出一种基于多重元胞自动机(Cellular automata,CA)的图像水印加密算法.该算法综合考虑辅助信息、水印及水印图像三方面的安全性,利用不同的元胞自动机规则进行逐级加密,建立多重加密模型生成加密水印图像.仿真结果表明,该算法在密钥空间、直方图分布、相关性、信息熵及灰度变化等安全评估标准下均具有较高的安全性,有效克服了基于直方图平移类可逆水印算法在安全性方面存在的不足.

An encryption method for image watermarking using multiple cellular automata （CA） was proposed in order to solve the security problem, which is faced by most of the existing reversible watermarking methods based on histogram shifting （RW-HS）. The proposed method made a security analysis of RW-HS from three aspects including side information, watermarks and watermarked images. Based on this, three CAs with different rule numbers were employed to build a multiple encryption model and thus to generate the encrypted watermarked images. Experimental results illustrate that the proposed method is highly secure in terms of key space, histogram distribution, correlation, information entropy and gray scale change, and that it effectively solves the security problems of RW-HS.