http://www.newscientist.com/article.ns?id=dn7756

3D barcodes to identify stolen valuables

30 July 2005
NewScientist.com news service
Mick Hamer

Labelling with nanobarcodesDIAMONDS and valuable works of art could be
protected against theft using a microscopic barcode that stores encrypted
information about the provenance of the items, making ownership easy to
prove if they are stolen.

The barcode, which takes the form of a cube 30 micrometres across, is
being developed by a team at the National Physical Laboratory (NPL) at
Teddington, near London. The cube is made of silicon coated with a
100-nanometre-thick layer of polymethyl methacrylate, a transparent plastic. It can be
attached to hard surfaces using adhesive, or woven into the canvas of paintings.

To create the barcode an electron-beam lithograph drills 90,000 small
squares into the plastic coat of each face at five different depths. The
position and depth of each square is unique, so data can be encrypted
using a key-based code and stored digitally. The cube is scanned line by line
using an electron force microscope, which can detect differences in the
depth of the squares. This scanning process takes around a minute, says
Alexandre Cuenat, one of the team of researchers that developed the
cube.

The technology has huge potential for storing information securely,
says Cuenat. "You could get two copies of the bible, the King James version,
on the sharp end of a pin."

However, in practice storing information on the provenance of an object
would not require anything like this capacity.

The nanobarcode has three levels of security to protect objects against
theft and counterfeit. First, thieves and fences are unlikely to realise
that the item is protected. "You cannot see or feel the cube, even if
you roll it between your finger and thumb," says Cuenat. Second, most
fraudsters are unlikely to have the specialist equipment to read or write the
nanobarcode, and so will be unable to duplicate it. And finally the
encryption will be practically unbreakable.

"Theoretically all codes can be broken," says David Mendels, who led
the NPL team. You just have to test all the different permutations. In this
case, it would be possible to make the encryption extremely complex because of
the cube’s high storage capacity. "You’d need a computer doing a million
calculations a second and it would still take more than 187 billion years,"
says Mendels. For day-to-day use, the encryption could be far less
complex and still be virtually unbreakable, says Cuenat.

“To break the code, it’d take a million calculations a second for 187
billion years”Once in mass production each device will cost about £1.
Diamond traders have already approached the laboratory about the
technology, which NPL hopes to license next year.

The nanobarcode could also protect other high-value items, such as
bearer bonds and banker’s drafts.

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