Quantum cryptography takes flight | Science News

ADVERTISEMENT

SCIENCE NEWS NEEDS YOU

Support nonprofit journalism

Subscribe now


News in Brief

Quantum cryptography takes flight

Successful reading of photon beam sent from airplane may one day lead to encrypted satellite communications

By
6:03pm, April 1, 2013
Sponsor Message

Quantum cryptography has entered the friendly skies. A precise beam of photons sent from an airplane allowed researchers on the ground to create a nearly unbreakable encryption key to protect information. The experiment, reported March 31 in Nature Photonics, is an important step toward creating a secure global communication network based on beaming photons to and from satellites.

“It is a technical tour de force,” says Seth Lloyd, a mechanical engineer at MIT who was not involved in the study.

The idea of exploiting quantum mechanics to secure communication lines is not new: Since the 1980s, scientists have created encryption keys with sets of photons whose individual spins are known only to the sender and receiver. If a third party eavesdrops on the conversation, the photon spins change, alerting the communicating parties to stop exchanging information.

The impediment to any quantum communication, however, is establishing a robust connection that allows sender and receiver to detect and manipulate photons one by one. That’s hard enough to accomplish between stationary points (SN: 6/30/12, p. 10), but physicist Sebastian Nauerth of Ludwig Maximilians University of Munich and his team beamed the photons from an airplane flying at nearly 300 kilometers per hour.

The researchers installed a laser at the bottom of the plane that sent a narrow beam of photons to a ground station 20 kilometers away. The signal was strong enough and the tracking precise enough that a sender on the plane and a receiver on the ground would be able to establish a quantum encryption key, the researchers report. Such a key could one day be used to decode messages sent from anywhere in the world and relayed via satellite.

Citations

S. Nauerth et al. Air-to-ground quantum communication. Nature Photonics. Published online March 31, 2013. [Go to]
Further Reading

A. Witze. Quantum teleportation leaps forward. Science News. Vol. 181, June 30, 2012, p. 10. [Go to]

D. Castelvecchi. Welcome to the quantum internet. Science News. Vol. 174, August 16, 2008, p. 24. [Go to]

T. Siegfried, L. Sanders. Quantum weirdness. Science News. Vol. 178, November 20, 2010, p. 20. [Go to]

Get Science News headlines by e-mail.

More from Science News

From the Nature Index Paid Content