Authentication using a digital watermark

摘要

A method and apparatus for identifying an object include encoding physical attributes of an object where the encoded information is utilized as at least one element for composing a digital watermark for the object. In another embodiment the physical attributes of an object are utilized as a key for accessing information included in a digital watermark for the object. In a further embodiment, a digital watermark is incorporated into a bar code. As another aspect of this embodiment, information maybe encoded into the digital watermark of the barcode and may be decoded or otherwise retrieved by the use of a key. The digitally watermarked bar code may function in a conventional manner or may also include a "pass key" to allow reading of the bar code itself.