Patent ID: 7587311

Claim:
A device for embedding binary payload into a carrier signal comprising a first sequence of discrete values, the device comprising: a first converter for converting the first sequence of discrete values to a spectral representation using a forward integer transform algorithm configured to provide a set of integer binary spectral representation values representing frequencies in an ascending order, wherein spectral representation values to be modified comprise bits, and wherein a different valency is associated with each bit of a spectral representation value to be modified, wherein a set bit with a highest valency in the bits of the spectral representation value is a leading bit of the spectral representation value, and wherein all remaining bits of the spectral representation value have a lower valency than the leading bit; a determiner for determining signal limit valencies for the spectral representation values, wherein the signal limit valencies are at least one valency level below a valency of the respective leading bit of the spectral representation values; a setter for setting bits of the spectral representation values whose valencies are equal to the signal limit valency or less than the signal limit valency according to the binary payload to obtain modified spectral representation values, wherein bits whose valencies are greater than the signal limit valencies are not available for payload embedding; and a second converter for converting a set of integer binary spectral representation values, in which the modified spectral representation values are contained instead of the spectral representation values to be modified, to a second sequence of discrete values using a backward integer transform algorithm so that the payload is embedded in the second sequence of values.