一种新的第三方双重图像水印算法

提出一种新的第三方双重图像水印算法。该算法依赖于可信任第三方提供的时间戳以及用户的私钥和授权码生成双重水印信息，然后将其嵌入在图像分块除直流分量外的DCT系数上。水印检测时可分别对水印作品时间戳和隶属关系的合法性进行检测。仿真实例和安全分析表明，该算法对嵌入参数敏感，对图像的常规操作具有较好的鲁棒性。在没有第三方的参与下，任何用户都不能构造和检测出合法的水印信息，这限制了恶意盗版者进行分析和攻击的一些前提条件，保证了水印系统的安全。

Novel algorithm of third party's double watermark applied in image

This paper presented a novel algorithm of the third party's double watermark.The algorithm relied on the third party's timestamp and users' secret keys and authorization codes,produced a double watermark.Then it would be embedded into the discrete cosine transform coefficients exception of direct current in digital image blocks.Timestamp and ownership watermark detecting results could be provided separately.Simulation experiments and analysis work reveal that the algorithm sensitizes to embedding parameters...