Eye imaging tech can detect fake travel docs ‘in seconds’

An imaging technique developed for medical applications could be repurposed as a speedy way to verify travel documents, according to UK researchers.

Optical coherence tomography (OCT) – used most commonly to diagnose diseases affecting the retina of the eye that is already widely available in ophthalmic clinics and opticians – can distinguish between a genuine and counterfeit document in as little as 10 seconds.

Much like an ultrasound scan uses sound waves, OCT uses near infrared (NIR) light waves to take thousands of images of an item to create 2D and 3D images. Using light with quite a long wavelength makes it possible for the scan to penetrate further under the surface of a sample than other techniques like confocal microscopy.

The team from the University of Kent in the UK used OCT scans to examine multi-layered travel documents like passports and ID cards, and look for the security features embedded within them. Importantly, the scan can be carried out without damaging the document.

“Although more secure than their predecessors, the latest generation of identity documents manufactured using polycarbonate layers remain susceptible to counterfeiting,” according to Robert Green, one of the scientists behind the work.

“Fraudsters tend to adopt tactics such as copying paper or polycarbonate, reproducing documents and hologram images using sophisticated computer technology before re-laminating,” he added.

“Any of these tactics will affect the inner structure of a document, showing the importance of its subsurface characterisation and the benefit that OCT can provide to identify such tampering.”

Previously, there have been reports of OCT being deployed experimentally to detect banknote forgery and art fraud, as well as the detection of fake (spoof) fingerprints used to get around biometric security.

The large number of fraudulent identity documents in circulation continues to be a concern for governments, say the authors of the study, which is published in the journal Science & Justice.

“With organised, transnational crime and the threat of criminals and terrorists crossing international borders undetected still a threat…passport fraud remains one of the greatest threats to global security,” they add.