Patent ID: 7318157

Claim:
A method facilitating protection of digital signals, the method comprising: normalizing amplitude of a subject digital signal; transforming the normalized signal; partitioning the normalized signal transform into segments by pseudorandomly segmenting the normalized signal transform using a secret key, wherein the partitioning comprises pseudorandomly segmenting the normalized signal transform, wherein such segments have the ability to overlap; for one or more segments: calculating statistics of a segment that are representative of that segment; quantizing such statistics of a segment to generate a quantized value of that segment; measuring the distance between such statistics of a segment and the quantized value of that segment; determining whether a watermark is present in the digital signal based upon the quantized values of the one or more segments using quantization index modulation (QIM), wherein such QIM utilizes non-local characteristics of the signal and wherein the non-local characteristics comprise statistics representative of one or more pseudorandomly dimensioned segments of the signal.