Researchers from the University of South Dakota and South Dakota School of Mines and Technology have developed invisible QR codes that could be used to help fight the trade of counterfeit goods and money.
The codes, composed from nanoparticles combined with fluorescent ink, are undetectable in everyday conditions, but start to shine brightly once exposed to infrared light.
Invented in Japan in 1994, QR (Quick Response) codes are widely used in advertising and technology industries. They are easy to produce, fast to decode and can store virtually any kind of data.
“We can take the level of security from covert to forensic by simply adding a microscopic message in the QR code, in a different coloured upconverting ink, which then requires a microscope to read the upconverted QR code,” lead author of the study Jeevan Meruga told the BBC.
This method is expected to help manufacturers certify the originality of their products, while governments can use it to improve the security of paper currency.
Earlier this year, a team of scientists from University of Montpellier had discovered a cheap way to print Radio Frequency Identification (RFID) chips right onto paper. In the future, this technology could replace both barcodes and QR codes.
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