In partnership with Nokia and Bay Photonics, Oxford University researchers have devised a system for transmitting quantum keys that ensures data security.
While many technologies use encryption to make connections more secure, none can detect eavesdropping. Quantum technology uses millions of single particles of light to send encryption keys. The protocol can detect unusual activities such as eavesdropping, and then shuts down the communication to prevent further hacking.
"When a hacker attempts to tap into the channel it will change the content of the key," says Dr Iris Choi, Technology Associate at Oxford University.
The quantum key distribution system is considered secure because even if someone hacks the code, and attempts to pass it on, the very act of measuring the quantum signal, alters it, and makes it unusable.
The prototype system uses movable mirrors and ultrafast LEDs to send a secret pin-code at a rate of more than 30kbytes/s, over a distance of 0.5m. Made up from a series of overlapping lights, the system contains six pairs of resonant-cavity LEDs, each filtered to a different polarisation and position.
To prevent potential hackers from cracking the code and knowing which light sends which signal, the team created a steering system. The quantum key is said to be long enough to stop hackers from unravelling the key pattern at random.
According to the researchers, the only way to ensure this protection on a device with such a high data transmission rate is to make sure the signals go exactly to the designated location. However even when someone holds their hand completely still, they still have natural motion in their hand.
To counter this, the research team measured the movement, before optimising the design elements of the device's laser beam-steering system, including the bandwidth and field of view.
