Tackle forgery by checking paper fingerprint, study suggests
Image credit: Dreamstime
Newcastle University researchers have demonstrated a simple and cost-effective method for preventing forgery of paper documents, by looking at the unique fingerprint marking on each sheet of paper.
Designing documents – such a passports and certificates – which provide high levels of protection against forgery remains a problem, even in the digital age. A common method of protecting against fraud is to embed tiny electronic devices such as RFID chips within the document; these are used to prevent forgery of e-passports for example.
However, the security of these documents can be shattered if the chips are tampered with, so many have begun to require expensive “tamper resistant” RFID chips. When tamper resistant chips were introduced to UK passports in 2006, the price of an adult passport rose from £42 to £72.
The Newcastle University researchers took an entirely different approach to document security by focusing on the paper of the document itself.
When paper is manufactured, wooden particles are stuck together with various substances, rendering every sheet of paper unique.
“Our idea was that the majority of paper used for official and legal documents, certificates, invoices and so on is not completely opaque,” said Ehsan Toreini, a PhD student in Newcastle University’s school of computing science. “Different types let through different levels of light and reflect it in different ways and as a result, each one reveals a unique fingerprint.”
The researchers wrote an algorithm to generate an identifier for each sheet of paper, which could then be converted into a QR code; this can be verified by anybody. The process of converting a photograph into a unique texture fingerprint takes just 1.3 seconds.
The algorithm can also adjust the photograph, rotating it and masking any unnecessary parts to eliminate human error. When the researcher tested their method, they found it 100 per cent successful.
“Since this identifier is basically representative of that paper texture, any illegal modifications – including copying the contents of the document to another paper sheet – could be identified.”
Before a degree certificate is issued to a university graduate for instance, the texture fingerprint could be taken from a photograph, authenticated by the university, and stored on the certificate as a printed barcode. To verify the certificate, an employer could compare a photograph of the paper with the authenticated copy within the barcode.
“A potential employer could easily authenticate the degree certificate by themselves without having to contact the university,” said Dr Hao.