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Hiding Data with Temporal Cloaking Might Thwart Surveillance

But will this technology ever make it into the hands internet users?
Simulated light waves undergoing a temporal cloaking effect. In the middle, light intensity is reduced to zero. Image from Lukens et. al

As states seek even greater surveillance powers, citizens and civil liberties groups have responded with very public online battles. SOPA, PIPA and more recently CISPA are now dead or in hibernatory periods before eventual resurrection in some form or another. But what if our internet and smartphone communications could be insulated against government peeping Toms? It just might be possible with Purdue University's "temporal cloaking" research, which just scored a pretty big breakthrough.

Purdue graduate student Joseph Lukens, working alongside senior research scientist Daniel E. Leaird and Andrew Weiner, managed to temporally cloak 46 percent of a data stream in optical communications. Previously, temporal cloaking—invented by other researchers in 2012—could only cloak about one 10,000th of a data stream.


"More work has to be done before this approach finds practical application, but it does use technology that could integrate smoothly into the existing telecommunications infrastructure," said Lukens, who used commonly available optical communications equipment (phase modulators and optical fibers) instead of ultrafast-pulsing "femtosecond" lasers.

This diagram shows how the a "signal is modified to have zero intensity when the data are 'on,' cloaking the information," via Lukens et. al

Temporal cloaking works because of the peculiar properties of light, which is simultaneously a particle and a wave. Lukens and other researchers manipulate the phases or time of light waves, creating wave interference. According to Lukens, when you create wave interference, you are then able to make them "add up to a one or a zero."

"The zero is a hole where there is nothing," said Lukens. It is in these zero regions where data can be cloaked.

"It's a potentially higher level of security because it doesn't even look like you are communicating," Lukens noted. "Eavesdroppers won't realize the signal is cloaked because it looks like no signal is being sent."

Lukens' research bears some similarities to recent experiments with cloaking via metamaterials. Unlike metamaterials, however, temporal cloaking only require phase modulators and optical fibers, which are commercially available.

This has obvious military and government applications. In fact, the project has financial support from the U.S. Department of Defense through a National Defense Science and Engineering Graduate Fellowship. Big business would no doubt be interested in temporal cloaking as well. Which has me wondering if temporal cloaking already has governments sweating bullets at the thought of people derailing surveillance.