Dutch researchers have described a new method to fight cyber-crime using quantum physics principles.
Relying on the famous entangled photons effect, which allows a particle of light to appear simultaneously in multiple places, the team from the universities of Eindhoven and Twente in the Netherlands has managed to propose a system that will perfectly protect credit cards and electronic systems in the future against unauthorised use.
The system, described in the latest issue of the Optical Society’s journal Optica, will protect the credit cards and electronic keys even if the attackers get hold of all necessary information including the complete structure of the card.
“The best thing about our method, which we've called Quantum Secure Authentication (QSA), is that secrets aren't necessary,” explained Professor Pepijn Pinkse, the project’s leader. “So they can't be filched either."
The technology relies on a paper-thin layer of nanoparticle-based dry white paint, which can capture a photon and keep it bouncing within its structure until it escapes like in a pinball machine.
In a practical implementation, a bank could send security ‘questions’ in the form of a complex pattern of light dots unique for each transaction into the paint. Subsequently, the users would be able to detect a new unique pattern of escaping light particles at the surface, providing the answer to the security question. The bank will only approve of the card if this pattern of dots is correct.
The researchers said relying on quantum properties of photons guarantees the method’s security. If normal light was used instead of individual light dots, the amount of photons would allow the attacker to measure the entering dot pattern and alter it with, for example, a projector. The bank would then not be able to distinguish between the real card and the signal of the attacker.
However, as photons can appear in multiple places at the same time, the pattern sent by the bank into the paint can consist of fewer photons than light dots. As there are too few photons, the attacker can no longer measure the entire pattern, and will therefore not know what question the bank is asking.
QSA can be employed in numerous situations relatively easily, as it uses simple and low-cost technology which is already available. The layer of paint is cheap and easy to apply and the readers can be made using simple lasers such as those used in CD players combined with simple image sensors and image-forming chips as present in every modern projector.