Patent ID: 7616776

Claim:
A method for enhancing the robustness of watermark extraction from digital host content, comprising: receiving a digital host content at a reception device; extracting embedded watermarks from the host content, using an extraction device, in accordance with a stego key, the extracting comprising: (a) extracting a first watermark; (b) determining a number of errors in the first extracted watermark; and if the number of errors is above a first pre-determined value; (c) extracting at least a second watermark; (d) determining a number of errors in at least the second extracted watermark; and if the number of errors in at least the second extracted watermark is above a second pre-determined value, combining the extraction results of steps (a) and (c) to cumulatively assess validity of the first extracted watermark and at least the second extracted watermark; and controlling an operation of a content handling device in accordance with the cumulative assessment.