A digital watermark detector uses weighting functions to enhance watermark detection. The weighting function applies more weight to parts of a digitally watermarked signal that are more robust to distortion. As such, the method provides for more reliable watermark detection, especially in applications where distortions, such as lossy compression or analog conversion, more accurate detection more difficult. In one version of the method, the detector projects the watermarked signal into a pseudorandom direction specified by a key, applies the weighting function, and extracts auxiliary data symbols from the projected signal by quantizing the projected signal and deriving the symbol values based on the quantization.