University of Toronto technology could foil fraud with laser-sensitive dyes

Working with capsules of dye just a few billionths of a metre in diameter, researchers at University of Toronto and the advanced optical microscopy facility at Toronto’s Princess Margaret Hospital have created a new strategy for encrypting photographs, signatures and fingerprints on security documents.

“This technology will give security or customs authorities the confidence that documents are not fake,” says U of T chemistry professor Eugenia Kumacheva, who holds the Canada Research Chair in Advanced Polymer Materials. “It gives a very high level of data encryption and is relatively cheap to produce.”

A thin film of polymer material is produced from tiny three-layer capsules comprising three different dyes, Kumacheva explains. Each layer is sensitive to light at a particular wavelength – ultraviolet, visible or infrared. Using high-intensity irradiation, Kumacheva uses differing wavelengths to encrypt several different patterns onto a security document. To the naked eye, the identification document (a passport or smart card, for example) might reveal a photograph, but under other detection devices could reveal signatures or fingerprints.

The technology could offer a speedy alternative to waiting in long lineups at security checkpoints or government offices, says Kumacheva, who has secured a patent on the technology. A paper on the technology, which she says could be available within five years, was presented at a recent Particles 2003 meeting in Toronto.

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CONTACT: Professor Eugenia Kumacheva, Department of Chemistry, 416-978-3576, ekumache@chem.utoronto.ca or Nicolle Wahl, U of T public affairs, 416-978-6974, nicolle.wahl@utoronto.ca