The onslaught of hacking cases just this year has highlighted the frail security that credit card companies are providing consumers. However, researchers from the University of Twente and the Eindhoven University of Technology may have found the solution, improving credit card security with the help of quantum physics.
In a study published in the journal Optica, the researchers developed an authentication method that is impossible to copy, acting as a more secure version of a "Q&A" system. The method works by taking advantage of the quantum-physical fact that it is possible for photons (light particles) to be in several places at once.
For the method to work, a credit card or any card that requires security, such as an identification card or building pass, is fitted with a dry white paint layer. Although paper-thin, the layer of paint contains nanoparticles in the millions. If a photon is directed at the paint, it will bounce around the nanoparticles until it finds a way out.
A bank, for instance, sends out a unique light pattern for every transaction. Think of this as the "question." The "answer" will be the resulting light pattern formed as the photon looks for a path to escape. A transaction will only be approved by the bank if the resulting pattern achieved is correct.
"The best thing about our method, which we've called Quantum Secure Authentication (QSA), is that secrets aren't necessary. So they can't be filched either," said Pepijin Pinkse, lead investigator for the study.
QSA can be utilized in various ways easily because it makes use of a simple and affordable technology that is already available. The paint layer described is not only cheap and easy to apply but also requires relatively standard devices with lasers to read it, such as CD players, a chip that forms images (found in modern projectors) and a basic image sensor.
The study "Quantum-secure authentication of a physical unclonable key" received funding support from the Netherlands Organization for Scientific Research, the European Union, the STW Technology Foundation, and the Foundation for Fundamental Research on Matter.
Aside from Pinkse, authors include Boris Skoric, Allard Mosk, Marcel Horstmann and Sebastianus Goorden. Pinkse, Mosk, Horstmann and Goorden are from the University of Twente's Complex Photonic Systems group's MESA+ Institute for Nanotechnology, while Skoric is from the Eindhoven University of Technology.
