基于图像特征和公钥密码系统的易损水印算法

Fragile watermarking for image authentication based on image feature and public key cryptography

提出一种基于图像特征和公钥密码系统的易损水印算法,在图像认证中能够定位图像被篡改的位置。水印算法根据图像特征和私钥信息,将用于完整性验证和局部篡改检测的图标嵌入到图像中。水印提取过程中使用与嵌入过程中私钥相对应的公钥提取水印信息。该算法不仅能解决现有易损水印算法存在的安全问题,而且在不需要交换密钥的情况下允许水印的公共检测,可用于数码相机、互联网图像的真实性认证。最后,通过理论分析和实验论证该算法的有效性。

A new invisible watermarking technique which could localize tampered areas for image authentication was proposed, based on image feature and public key cryptography. According to image feature and secret key a logo was embedded as watermark for the integrity verification and localized tamper detection. The watermark extraction used a public key corresponding to the private key in embedding procedure. The new scheme not only resolves the security problem of most existing scheme to this day, but also permits public detection of the watermark by any person without the exchange of a secret key, which is very important in many applications such as trusted camera and Web image authentication. Theoretical analysis and experiment results demonstrate its outstanding performance.