Abstract: The fractal detection boundary is an important countermeasure to the Oracle attack. The paper investigates the effect of the attacking distance between the distorted signals from which the Oracle attack starts and the detection boundaries on the accuracy of watermark estimations. Analysis and experiments show that it is more accurate to estimate the watermarks with high detection values. The Oracle attacks directly launched from the object signals can eliminate the negative effect of fractal boundaries and remove the watermarks successfully.

Key words: digital watermarking, Oracle attack, fractal detection boundary

摘要： 对于扩频水印机制，水印检测边界的分形化是对抗Oracle攻击的一种主要方法。该文研究Oracle攻击的攻击距离对水印信号估计的影响，发现具有高检测值的攻击发起点能够有效地增强水印估计的准确性。分析和实验表明，直接从目标信号处发起的Oracle攻击能够有效地削弱检测边界分形化的影响，并且成功地去除含水印作品中的水印信号。

关键词: 数字水印, Oracle攻击, 分形检测边界

CLC Number: 

• TP309.2