One of the bigger challenges in online security is finding a way to effectively share data and be sure it isn't intercepted. Research led by the Centre for Quantum Dynamics at Griffith University has identified a mechanism for doing this effectively via quantum computing, using a technique known as "quantum steering".
Here's a heavily simplified explanation of the study, published in Nature Communications, courtesy of Professor Geoff Pryde from the centre.
"Quantum physics promises the possibility of absolutely secure information transfer, where your credit card details or other personal data sent over the internet could be completely isolated from hackers," Pryde said in a release announcing the study.
"In an ideal world, such perfectly secure long distance communication between any two parties is simple. They could share strongly entangled quantum systems — such as particles of light called photons — to generate truly random and uncrackable codes.
"Unfortunately, in the real world the two parties cannot share sufficiently strong entanglement over long distances due to transmission and detection losses. As the photons travel through the communication network, some are lost, thus providing a loophole for outsiders to attack their code."
Quantum steering solves that problem by using measurements made on one quantum system to change those on another. The challenge is to do that while being sure that no-one else has intercepted the data.
"Quantum entanglement is a wonderful resource for safe and secure communication, but you need to verify it is really there to be certain any eavesdroppers are kept out of the loop," Pryde said. "Our new technique does so without requiring any trust in the communication devices and it should work in long distance scenarios where standard methods fail."
It's likely to be a while before this kind of approach can be commercialised — but it's a reminder that ways of improving security continue to advance. In the meantime, don't neglect the basics.
Experimental measurement-device-independent verification of quantum steering [Nature Communications]