A method and system for hiding authentication data within a multimedia data stream
provides for cross-authentication. The method includes the step of obtaining a
first set of authentication data, where the first set of authentication data is
based on data contained in a first media channel of the multimedia data stream.
The method further includes the step of hiding the first set of authentication
data in a second media channel of a multimedia data stream. When dealing with active
data streams, the present invention provides for hiding a first subset of the active
data stream in a visual channel of the multimedia data stream. A second subset
of the active data stream is then hidden in the audio channel of the multimedia
data stream. In one embodiment, the first subset includes executable content, where
the second subset includes a controlled data stream.