Abstract: A system for embedding auxiliary digital information into a primary digital signal to form a composite digital signal. Auxiliary data bits modulate a pseudo-random (e.g., PN) sequence to provide an auxiliary data sequence used to modify the Least Perceptually Significant Bits (LPSBs) of successive multi-bit samples of the primary signal. In a cross-term compensation embodiment, a correlation between the PN sequence and the sample bits is determined, and compared to the auxiliary data bits to determine whether there is a desired correspondence. The LPSBs in the samples are toggled, if necessary, to provide the desired correspondence. The selection of LPSBs to modify accounts for a desired noise level of the auxiliary data in the primary signal. LPSBs may be modified based on a sparse PN sequence to achieve the desired noise level and conceal the presence of the auxiliary data.

Abstract: A system (300, 500) for scrambling digital samples (115, 200, 250, 260, 270) of multimedia data, including audio and video data samples, such that the content of the samples is degraded but still recognizable, or otherwise provided at a desired quality level. The samples may be in any conceivable compressed or uncompressed digital format, including Pulse Code Modulation (PCM) samples, samples in floating point representation, samples in companding schemes (e.g., ?-law and A-law), and other compressed bit streams. The quality level may be associated with a particular signal to noise ratio, or quality level that is determined by objective and/or subjective tests, for example. A number of LSBs can be scrambled in successive samples in successive frames (FRAME A, FRAME B, FRAME C). Moreover, the parameters for scrambling may change from frame to frame. Furthermore, all or part of the scrambling key (310) can be embedded (340) in the scrambled data and recovered at a decoder (400, 600) to be used in descrambling.

Abstract: A system for embedding auxiliary digital information into a primary digital signal to form a composite digital signal. Auxiliary data bits modulate a pseudo-random (e.g., PN) sequence to provide an auxiliary data sequence used to modify the Least Perceptually Significant Bits (LPSBs) of successive multi-bit samples of the primary signal. In a cross-term compensation embodiment, a correlation between the PN sequence and the sample bits is determined, and compared to the auxiliary data bits to determine whether there is a desired correspondence. The LPSBs in the samples are toggled, if necessary, to provide the desired correspondence. The selection of LPSBs to modify accounts for a desired noise level of the auxiliary data in the primary signal. LPSBs may be modified based on a sparse PN sequence to achieve the desired noise level and conceal the presence of the auxiliary data.

Abstract: A system for embedding auxiliary digital information (Di) into an existing primary digitally encoded signal (Xn) to form an unobjectionable composite digital signal (Cn). Auxiliary data bits (Di) modulate a pseudo-random (e.g., PN) sequence (125) to provide an auxiliary data sequence (160) that is used to modify the Least Perceptually Significant Bits (LPSBs) (180) of successive multi-bit samples (120) of the primary signal. In a cross-term compensation embodiment (300, 400, 1000), a correlation (V) between the PN sequence and the sample bits is determined, and compared to the auxiliary data bits (Di) to determine whether there is a desired correspondence. The LPSBs in the samples are toggled (360), if necessary, to provide the desired correspondence. The selection of LPSBs to modify accounts for a desired noise level of the auxiliary data (Di) in the primary signal (Xn).