A method is provided for authenticating a media signal and related software, systems and applications. A digital watermark is embedded in the media signal. A metric is calculated for the digital watermark as embedded in the media signal. The resulting metric is then embedded in the media signal with the digital watermark. To detect a potential alteration, a detector computes the metric for a potentially corrupted version of the embedded media signal. The detector then compares its computed metric to the embedded metric to detect whether the alteration has occurred.