Countermeasure for collusion attacks in digital watermarking

摘要

The method for creating individually watermarked copies of original media data comprises the following steps of dividing the original media data into consecutive frames, creating a first copy of the original media data by embedding individual bits of a digital watermark into consecutive frames of the original media data wherein into each of these consecutive frames one bit of the digital watermark is embedded, and amending the media data in at least one of its frames provided with an embedded bit of the digital watermark such that the amended media data are free of a perceived loss of quality, and creating at least a second copy of the original media data in the same way as mentioned before but with a digital watermark and an amendment to the media data which are different from the digital watermark and amendment used for any other created copy of the original media data, wherein when performing collusion attack on two created copies of the media data by building the average of these two copies, the amendments produce a perceivable loss of quality of the media data.