Patent ID: 7349553

Claim:
A method of watermarking digital media content, comprising: (a) generating first, second and third watermark keys at a distribution entity, wherein the first, second and third watermark keys are symmetric keys; (b) embedding a visible first watermark in the media content using the first watermark key at the distribution entity, wherein the visible first watermark can only be removed from the media content using the first watermark key; (c) embedding an invisible second watermark in the media content using the second watermark key at the distribution entity, wherein the invisible second watermark can only be detected from the media content using the second watermark key; and (d) transmitting the media content from the distribution entity to a displaying entity, wherein the displaying entity removes the visible first watermark from the media content using the first watermark key and the displaying entity embeds an invisible third watermark in the media content using the third watermark key, wherein the invisible third watermark can only be detected from the media content using the third watermark key.