Shape of things to comeQuantum computing nears with European QAP project
QAP co-coordinator Professor Ian Walmsley: “Quantum computing, when it arrives, could make all current cryptographic technology obsolete”
Technologies that exploit the unique weirdness of quantum mechanics could debut in the very near future, thanks to the groundbreaking work of a huge European research consortium. Unbreakable cryptography, unimaginable simulations of profoundly complex problems, and super-fast networks examplify just some of the promise held out by quantum computing. Now, European scientists are poised to deliver on that promise, thanks to the work of the Qubit Applications (QAP) project.
Nonwerk reports that the integrated project has cherry-picked major obstacles in the path of quantum computing, problems that could have immediate applications and could command a ready market. Chief among them is quantum cryptography. “Quantum computing, when it arrives, could make all current cryptographic technology obsolete,” notes QAP co-coordinator Professor Ian Walmsley.
Thankfully, researchers have developed quantum cryptography to deal with that issue. “Quantum cryptography over short distances was demonstrated in a previous project,” explains Walmsley. “The problem is, it only works over a short distance.”
Entangled webs we weave
This is because quantum cryptography relies on entanglement. Entanglement is a concept that explains how two or more particles exhibit correlation — a relationship, if you like — which would be impossible to explain unless you supposed that they belonged to the same entity, even though they might be separated by vast distance.
Nonwerk says is is as if you were playing a game of quantum coin flipping with a colleague: you are heads and the colleague tails. You are two distinct individuals, but if the coin comes up heads your colleague loses, and you win. There is a correlation between the coin tossing. Now, with a quantum coin, it is heads the colleague wins and tails you win at the same time. This is the extra bit that quantum mechanics gives us, and which we use in secure communications, suggests Walmsley.
That explains, with a little inaccuracy, the concept of entanglement, and it is at the core of quantum key distribution, or QKD. It is far too complex to break quantum encryption by brute force, and it is immune to eavesdropping because, at the quantum level, the act of observing an object changes the object observed. It means that encryption is guaranteed by the laws of physics.
The technique was demonstrated in Vienna 2008, but
