WASHINGTON: Credit card frauds are very common these days. A system based on quantum physics has been developed for identification of credit cards that will soon prove impossible to hack. Researchers in the Netherlands are applying quantum physics in an attempt to create fraud-proof credit cards and ID cards.
Technologists are fighting a continuous battle with people with malicious intent to secure bank cards, credit cards, identification cards and locks (example, car locks). The magnetic stripes of some bank cards have been replaced with a chip that contains a small microprocessor and a secret code, but the chip can still be copied; hackers have recently managed to discover the accompanying code. Car thieves are able to steal cars by turning the digital door lock to suit their purpose. To achieve this they don’t use a copy of the key but, armed with just a laptop, imitate the ‘question-answer’ game that the lock plays with the key.
Researchers have developed a method which makes it impossible to hack cards or imitate their properties, even if those with malicious intent have all the necessary information at their disposal, such as the complete structure of the card. The method uses the quantum-physical fact that light particles (photons) can be in multiple locations at the same time. This fact is known from the famous double-slit experiment that forms the basis of quantum physics.
A card is equipped with a paper-thin layer of dry white paint which contains millions of nanoparticles. If a light particle is sent into the paint it will, like in a pinball machine, ‘bounce’ between the nanoparticles until it escapes. If a bank sends a complicated pattern of light dots that’s unique for each transaction (a ‘question’) into the paint, a new unique pattern of escaping light particles (the ‘answer’) will be detected at the surface. The bank will only approve of the card if this pattern of dots is correct.
If the bank uses ‘normal’ light in this with a lot more photons than just the light dots, an attacker can measure the entering dot pattern and return the correct dot pattern with, for example, a projector, so that the bank will not be able to see a difference between the real card and the signal of the attacker. The clever solution of the researchers springs from quantum physics. Because a photon can be in multiple locations at the same time it’s possible to send a pattern into the paint that consists of fewer photons than light dots. Because there aren’t enough photons in that case, an attacker can no longer measure the entire pattern, and will therefore not know which question the bank is asking. He will therefore have no idea which answer to send back, while the bank could check the answer with even just one photon.
