A system and method for embedding information into digital media and later
detecting the embedded information using a unique spread spectrum
modulation technique. In general, the present invention removes
interference caused by an original signal from the detection process
thereby eliminating a major source of detection error. The interference
caused by the original signal is removed by using the encoder knowledge
about the original signal and modulating the energy of the embedded mark
to compensate for the original signal interference. The present invention
also includes a novel redundant bit representation technique causes a
resulting average over a large sample to tend to zero, thereby reducing
the vulnerability of the present invention to malicious collusion
attacks.