Systems and methods are described herein for embedding and detecting a
watermark in a digital content file, such as an audio file or a video
file. If the watermark is detected in the digital content, a certificate
associated with the digital content is located. The certificate contains
copyright information that indicates permissible uses of the digital
content file, e.g., the digital content file may be played one time, five
times, any number of times during a specified time period, etc. If the
watermark is not detected, the file is processed. In one implementation,
a device configured to process the digital content file is also
configured to locate a certificate associated with the digital content
file before processing it. If the certificate is not found, the file is
not played. If the certificate is found, the device only processes the
file in accordance with instructions in the associated certificate.