New insights into quantum physics could help fight the very real problem of credit card fraud.
Researchers used the power of quantum physics to create a "fraud-proof" method for authenticating a physical "key" in a method known as Quantum-Secure Authentication, the Optical Society reported. This revolutionary technique could confirm the identity of any object, such as a credit card, even if the physical entity has been stolen.
The method harnesses the quantum power of light and uses it to create a "fool-proof" and unique question-and-answer exchange that is impossible to copy. Recently, banks have started to issue "smart cards" in place of easy-to-copy magnetic strip ones; these improved cards use a microprocessor chip to authenticate identities. Despite these advances, anyone who obtains these cards could potentially copy the information on it.
This new approach could completely overcome this risk through quantum properties that allow photons to be in multiple locations at the same time in order to convey the authentication of the question-and-answer.
"Single photons of light have very special properties that seem to defy normal behavior," said Pepijn Pinkse, a researcher from the University of Twente and lead author on the paper. "When properly harnessed, they can encode information in such a way that prevents attackers from determining what the information is."
In the process, a small number of photons are placed onto the surface of a specially-designed credit card and then observed to see what pattern takes shape. In this technique, any hacker who tried to observe the unique question-and-answer would "collapse the quantum nature of the light and destroy the information being transmitted," the researchers reported.
These "quantum credit cards" would be outfitted with a strip of white paint containing millions of nanoparticles. Using a laser, researchers could project individual photons of light onto this paint that would bounce around the nanoparticles as if in a pinball machine before escaping back to the surface and forming a unique pattern.
If normal light is projected onto this surface, hackers could measure the entering pattern and return the correct response pattern, making it impossible for a bank to see the difference if using standard light as well. On the other hand, if a bank sends a pattern of "quantum" photons into the paint, the reflected pattern would reveal more information.
"It would be like dropping 10 bowling balls onto the ground and creating 200 separate impacts," Pinkse said. "It's impossible to know precisely what information was sent (what pattern was created on the floor) just by collecting the 10 bowling balls. If you tried to observe them falling, it would disrupt the entire system."
The new method could have applications in protecting government buildings, personal bank and credit cards, and even vehicles.
The findings were published in a recent edition of the journal Optica.
