Digital watermark methods for encoding auxiliary data into a host signal are used to authenticate physical and electronic objects. One such method computes a content specific message dependent on the host signal, encodes the content specific message into a watermark signal, and embeds the watermark in...http://www.google.de/patents/US20110091066?utm_source=gb-gplus-sharePatent US20110091066 - Authentication of Physical and Electronic Media Objects Using Digital Watermarks
