This invention relates to security for data objects; more particularly, the present invention relates to improved security based on subliminal and supraliminal channels for data objects. In another embodiment, a method of protecting a data object comprises: steganographically encoding a subset of candidate bits in a digitized sample stream; perceptibly manipulating data in the digitized sample stream; and combining the imperceptible and perceptible data changes to create a secure/unique digital sample stream. In yet another embodiment, a method for securing a data signal comprises: preanalyzing said data signal for candidate watermark/signature bits; steganographically encoding independent data into the data signal into a subset of the candidate watermark bits, at least one time; and encoding the data signal subsequently with a perceptible technique.