Page 29 - GCN, June/July 2018

Statuscheck ENCRYPTION
Uncrackable encryption
could be on the horizon
Recent experiments have taken big steps toward the goal of quantum cryptography
BEY PATRICK MARSHALL
ventually, even the strongest current encryption techniques will be crackable. For now, to-
day’s state-of-the-art encryption relies on the fact that breaking it requires so many computer resources and so much pro- cessing time that cracking isn’t feasible. But it’s only a matter of time.
What some computer scientists are counting on to keep encrypted data safe- ly out of the reach of hackers — whether criminals or nation-states — is quantum cryptography. The beauty of quantum cryptography is that the flow of encrypt- ed data, which is transmitted in the form of pulses of photons, can’t be tapped without changing it. In other words, a hacker might be able to intercept a signal but won’t be able to decrypt it.
Although there’s plenty of research and engineering still to be done before practical quantum cryptographic sys- tems can send data over long distances, two big steps toward that goal have been taken in recent months.
In September 2017, researchers at Canada’s University of Waterloo beamed photons from the ground to an airplane approximately two miles away. The re- search team encoded data by specifying the orientation of transmitted photons, which could be polarized to align in any of four positions.
Some commercial quantum cryptog- raphy products have been available for
over a decade,
but they are
very limited in
range. “You can
guarantee se-
curity between
the White
House and
the Pentagon,
or from the
corner of one
military base to
another,” Caleb
Christensen,
chief scien-
tist at MagiQ
Technologies,
recently told
Wired. “In the telecom business, that’s way too short.”
After the University of Waterloo’s air- plane test, team leader and physicist Thomas Jennewein said the next step is to beam a key to a satellite 300 miles above the Earth. “The airplane experi- ment is, in some respects, harder than an actual satellite,” the Wired article states. “A satellite has much smoother and more predictable motion than an aircraft.”
And in January, a research team at the University of Southern California an- nounced that it had created a more pow- erful and energy-efficient method of gen- erating those streams of photons by using “frequency combs” to split a single laser
GCN.com
GCN covers quantum computing and other emerging technologies on a daily basis at GCN.com. For more quantum computing updates, go to GCN.com/quantum.
wave into hundreds of beams. The cur- rent state-of-the-art equipment is roughly the size of a refrigerator, but the USC re- searchers found a way to shrink their fre- quency combs to the size of a human hair while using 1,000 times less power.
The key was using carbon-based mol- ecules instead of silicon to build the fre- quency comb, the researchers said.
“Organic optical materials have already transformed the electronics industry, leading to lighter, lower-power TVs and cell phone displays, but previous attempts to directly interface these materials with lasers stumbled,” said Andrea Armani, a member of the team, in a statement. “We solved the interface challenge. Because our approach can be applied to a wide range of organic materials and laser types, the future possibilities are very exciting.” •
The map above plots data from the University of Waterloo research team’s 2017 demonstration. The yellow segment of the arc and the blue portion of the straight line represent where the quantum link was active during two test flights.
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