Method and apparatus for detecting processing stages applied to a signal

A method for providing a signal with a watermark layer, comprising the steps of:

• analyzing an intrinsic fragility of the signal, which is a carrier of the watermark layer;
• and
• determining a fragility profile in response to said analyzing step;
• wherein the fragility profile denotes a relationship between a bit error rate of the watermark layer and a signal to noise ratio of the signal after the watermark layer and the signal are degraded.

An apparatus for using a watermark to estimate a nature and/or an amount of processing that is applied to a signal, comprising:

• means for embedding a watermark with a degree of redundancy into the signal to form a steganographic signal;
• means for measuring a deterioration of the embedded watermark in the steganographic signal after the steganographic signal undergoes the processing, said deterioration of the embedded watermark being based on recovered data bits from a plurality of said redundantly embedded watermarks;
• and
• means for estimating the nature and/or the amount of the processing based on the measured deterioration.

An apparatus for providing a signal with a watermark layer, comprising:

• means for analyzing an intrinsic fragility of the signal, which is a carrier of the watermark layer;
• and
• means for determining a fragility profile in response to said analyzing step;
• wherein the fragility profile denotes a relationship between a bit error rate of the watermark layer and a signal to noise ratio of the signal after the watermark layer and the signal are degraded.