Multiple watermarks for digital rights management (DRM) and content tracking

A method of sharing a digital asset comprising:

• conducting a purchase transaction during which a first user and a second user each purchase first and second copies of a digital asset, wherein the first and second copies of the digital asset are watermarked with a content specific watermark;
• watermarking the first copy of the digital asset with a first user specific watermark unique to the first user to provide a first watermarked copy of the digital asset that is watermarked with the content specific watermark and the first user specific watermark;
• watermarking the second copy of the digital asset with a second user specific watermark unique to the second user to provide a second watermarked copy of the digital asset that is watermarked with the content specific watermark and the second user specific watermark;
• generating a first digital certificate including content specific watermark information corresponding to the content specific watermark and first user specific watermark information corresponding to the first user specific watermark;
• generating a second digital certificate including the content specific watermark information corresponding to the content specific watermark and second user specific watermark information corresponding to the second user specific watermark;
• and
• providing the first watermarked copy of the digital asset and the first digital certificate to a first user device associated with the first user such that access to the copy of the digital asset at the first user device is controlled based on a comparison of the content specific watermark and the first user specific watermark to the content specific watermark information and the first user specific watermark information in the first digital certificate, wherein first portions of the copy of the digital asset are watermarked with the content specific watermark and the user specific watermark and second portions of the copy of the digital asset are watermarked with the content specific watermark but not the user specific watermark;
• providing the first watermarked copy of the digital asset to a second user device associated with the second user;
• comparing the content specific watermark in the first watermarked copy of the digital asset to the content specific watermark information in the second digital certificate and comparing the first user specific watermark in the first watermarked copy of the digital asset to the second user specific watermark information in the second digital certificate;
• and
• providing access to the second portions of the copy of the digital asset but not the first portions of the copy of the digital asset if the content specific watermark matches the content specific watermark information in the digital certificate but the user specific watermark does not match the user specific watermark information in the digital certificate.

A method comprising:

• conducting a registration process during which a user registers a copy of a digital asset previously purchased by the user, the copy of the digital asset having a content specific watermark and a user specific watermark;
• generating a digital certificate including content specific watermark information corresponding to the content specific watermark and user specific watermark information corresponding to the user specific watermark, wherein first portions of the copy of the digital asset are watermarked with the content specific watermark and the user specific watermark and second portions of the copy of the digital asset are watermarked with the content specific watermark but not the user specific watermark;
• and
• providing the digital certificate to a user device associated with the user, such that access to the copy of the digital asset at the user device is controlled based on a comparison of the content specific watermark and the user specific watermark to the content specific watermark information and the user specific watermark information in the digital certificate, wherein access is provided to the second portions of the copy of the digital asset but not the first portions of the copy of the digital asset if the content specific watermark matches the content specific watermark information in the digital certificate but the user specific watermark does not match the user specific watermark information in the digital certificate.