The world鈥檚 first quantum encryption computer network has been expanded to include a wireless link that uses quantum communications codes.
Most modern cryptography rests upon the difficulty of solving very complex mathematical problems used to encrypt data. This makes it theoretically vulnerable to being hacked using dramatic mathematical or computing breakthroughs. By contrast, quantum cryptography near guarantees communications security, using quirks of quantum physics to thwart eavesdropping attempts.
The wireless connection was added to the DARPA Quantum Network, a quantum fibre-optic network buried beneath the ground in Massachusetts, US. The network was built by US company BBN Technologies with funding from the US Defense Advanced Research Projects Agency (DARPA). It now links 10 different sites, including BBN鈥檚 offices, Harvard University and Boston University.
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The wireless connection was installed by UK defence research company QinetiQ. Brian Lowans, at QinetiQ says introducing the wireless link represents a 鈥渃ritical first step toward global networks protected by quantum cryptography鈥�.
Satellite link
Qinetiq has already demonstrated a wireless quantum link over 25 kilometres. But eventually researchers hope to extend the range to be able to reach satellites that orbit at an altitude of hundreds or even thousands of kilometres.
Tim Spiller a researcher at Hewlett Packard鈥檚 labs in Bristol, UK this could be used to secure communications between over long distances on the ground. 鈥淚t鈥檚 a long term aim,鈥� he told 快猫短视频. 鈥淚t really expands your options for sharing crytographic keys.鈥�
Quantum cryptography guarantees security by encoding information as polarised photons which can be sent down a fibre optic cable or through the air. Intercepting these photons disturbs their quantum state, alerting both sides to an eavesdropper鈥檚 presence.
鈥淎n uncrackable information network has long been a goal for government and financial institutions,鈥� says Chip Elliot, principal engineer at BBN Technologies. 鈥淲ith the addition of the free space link nodes, we have demonstrated the potential for a complete quantum cryptography network that鈥檚 both wired and wireless.鈥�
