A document authentication station, for use with passports or the like,
includes a 2D image sensor (e.g., CCD- or CMOS-based video camera), and a
computer device. The image sensor produces produce image data
corresponding to a presented document. From this image data, the computer
extracts two or more identification data. One is a digital watermark. The
other can be a bar code, data glyphs, OCR data, etc. The processor then
proceeds to check that the two identification data correspond in an
expected fashion. If not, the document is flagged as suspect or fake.
Reliability of detection may be enhanced by processing plural frames of
data from the image sensor before issuing a result.