Digital hidden data transport (DHDT)

A method for embedding an auxiliary data bit in a plurality of samples of a digital composite signal, comprising the steps of:

• (a.1) multiplying a least perceptually significant bit (LPSB) in each of the plurality of samples by a pseudo-random sequence to provide a corresponding plurality of multiplication values;
• (a.2) accumulating the plurality of multiplication values to obtain a correlation value;
• and
• (b) comparing said correlation value to a value of the auxiliary data bit to determine a correspondence therebetween;
• wherein:
• if said comparing step (b) indicates an undesired correspondence, at least one of the LPSBs is toggled to provide the desired correspondence, the plurality of samples with the at least one toggled LPSB is used to provide a composite signal where the LPSBs, including the at least one toggled LPSB, identify the auxiliary data bit, and
• if said comparing step (b) indicates a desired correspondence, the plurality of samples is passed through with the associated LPSBs unchanged to provide a composite signal where the unchanged LPSBs identify the auxiliary data bit.

An apparatus for decoding an auxiliary data bit embedded in a plurality of samples of a digital composite signal received from an encoder, said bit modulating a pseudo-random sequence at the encoder to provide a pseudo-randomly modulated auxiliary data sequence that replaces at least one least perceptually significant bit (LPSB) of each of the plurality of samples, comprising:

• (a) means for generating a pseudo-random sequence corresponding to the pseudo-random sequence used at the encoder;
• (b) a multiplier for multiplying the auxiliary data sequence by the pseudo-random sequence provided by said generating means (a) to provide corresponding multiplication values;
• (c) an accumulator for accumulating the corresponding multiplication values to obtain a correlation value;
• (d) means for comparing said correlation value to a threshold decision value;
• and
• (e) means for assigning a value to the auxiliary data bit according to said comparing means (d);
• wherein:
• each sample comprises a plurality of bits;
• and
• a number of said LPSBs that is replaced in each of the samples is determined according to a desired perceptibility level of the auxiliary data sequence in the composite signal.

An apparatus for embedding an auxiliary data bit in a plurality of samples of a digital composite signal, comprising:

• (a.1) multiplier means configured to multiply a least perceptually significant bit (LPSB) in each of the plurality of samples by a pseudo-random sequence to provide a corresponding plurality of multiplication values;
• (a.2) accumulator means configured to accumulate the plurality of multiplication values to obtain a correlation value;
• and
• (b) comparing means configured to compare said correlation value to a value of the auxiliary data bit to determine a correspondence therebetween;
• wherein:
• if said comparing means (b) indicates an undesired correspondence, at least one of the LPSBs is toggled to provide the desired correlation, the plurality of samples with the at least one toggled LPSB is used to provide a composite signal where the LPSBs, including the at least one toggled LPSB, identify the auxiliary data bit, and
• if said comparing means (b) indicates a desired correspondence, the plurality of samples is passed through with the associated LPSBs unchanged to provide a composite signal where the unchanged LPSBs identify the auxiliary data bit.