Scanner may reveal passport forgeries

British scientists have announced that they have discovered a relatively inexpensive and surprisingly robust new way to defeat forgers attempting to fake birth certificates, passports and other documents.

The scientists have built a laser scanner that sweeps across the surface of paper, cardboard or plastic, recording all of the unique microscopic imperfections that are a ntatural part of manufacturing such materials.

This scan serves as a "fingerprint" which, the scientists say, has two surprising properties: the fingerprints are robust, surviving scorching, dousing in water, crumpling and scribbling over with pens. And these fingerprints depend on structures that are so complex and so small - on the scale of between one-tenth and one ten-thousandth the diameter of a human hair- that noone will be able to copy one for the forseeable future.

To authenticate a passport, for example, someone would scan one of the pages at a predetermined spot and compare the results to a scan made when the passport was first issued.

"This is a whole new approach to countering fraud and counterfeiting," said Russell Cowburn, who led the research and is aprofessor of nonotechnology at Imperial College London.

The Government Printing Office is planning to conduct an independent test of the scanner in the next few months, according to Michael L. Walsh, the chief technical officer there.

The technique is described in the journal Nature.

from the Indianapolis Star, page A22, no date notation made when I saved the article, probably sometime in the last few months, just catching up.