Stevens' Prototype 'Quantum Lock' May Foreshadow the Next Super-Secure Applications

Stevens proof-of-concept demonstration successfully leverages quantum properties to secure the Internet of Things

3 min read
Stevens Institute of Technology
Stevens Institute of Technology

A line of onlookers stands before a video camera in Stevens Institute of Technology's S.C. Williams Library, hopeful. Their task: crack a lock that could open, say, a safety deposit box or a bank account or a social security record. Each visitor stares intently into the camera lens. Nothing.

Then physics professor Yuping Huang strides up to the mark.

Click. The lock opens instantly.


"Fortunately," smiles Huang, "I am one of only three people whose face is allowed by this system to unlock this lock."

Facial locks are nothing new. Your phone probably has one, or soon will.

But what is remarkable is how this lock works — involving simultaneously creating twin particles of energy that somehow communicate with one another, across distances.

"These quantum properties are going to change the internet," predicts Huang, who directs the university's Center for Quantum Science & Engineering and works with graduate students including Lac Nguyen and Jeeva Ramanathan on the quantum lock project. "One big way it will do that is in the enabling of security applications like this one, except on much larger scales.

"If it turns out this technology can be deployed in our homes and offices, as we believe it can be, eavesdroppers will be nearly powerless to sneak into the ever-more connected networks of devices that help run our lives but also hold much of our personal data."

Welcome to the weird world of quantum communications.

But how does the system work?

When people stand in front of the camera attached to the lock, the Stevens setup captures information about each person's face and sends it over the internet to a server housed in a different part of the university. There, facial-recognition computations and matches are done using open-source software. (However, Huang's team is also working on bringing quantum physics to that step, too; stay tuned.)

While this may seem like a pretty standard computation so far, a key distinction occurs in its networking security: the data exchanged between the two parties is secured by fundamental laws of physics.

As facial photos are taken by the video camera, lasers in Huang's physics lab create twin photons — tiny, power-packed particles of energy — by splitting beams of light with special crystals.

The twin photons are then separated. One photon is kept in the lab while the other is sent through fiber-optic lines back to the library. Complex, secret "keys" are instantly generated as the photons are detected at each site; this process will ensure that the secure information meets up with a trusted partner at the other end of the transaction.

The keys serve as what's known in cryptography as a "one-time pad": a temporary, uncrackable code between the parties that encrypt the images and communications, preventing any hacker from intercepting them. 

"We don't know why quantum properties work this way," explains Huang, shaking his head. "Even Einstein didn't know. But they work, always, so far as we can measure. And a whole host of computing, financial and security applications will be coming down the road in our lifetime to leverage the power of those properties."

"This prototype demonstrates the drop-in compatibility of our quantum key-distribution system for secure networked devices," agrees Nguyen. "Wider adoption of this technology could protect the communications of corporations, governments and intelligence services.

"Some of the potential applications we already see include corporate and government data centers; military base communications; voting processes; and smart-city monitors, to name just a few."

The system could also bring secure privacy to the individual, adds the Stevens team, including for such applications as controlling systems in one's home remotely; communicating with a corporate office from home, or securing a home wireless network.

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How the FCC Settles Radio-Spectrum Turf Wars

Remember the 5G-airport controversy? Here’s how such disputes play out

11 min read
This photo shows a man in the basket of a cherry picker working on an antenna as an airliner passes overhead.

The airline and cellular-phone industries have been at loggerheads over the possibility that 5G transmissions from antennas such as this one, located at Los Angeles International Airport, could interfere with the radar altimeters used in aircraft.

Patrick T. Fallon/AFP/Getty Images

You’ve no doubt seen the scary headlines: Will 5G Cause Planes to Crash? They appeared late last year, after the U.S. Federal Aviation Administration warned that new 5G services from AT&T and Verizon might interfere with the radar altimeters that airplane pilots rely on to land safely. Not true, said AT&T and Verizon, with the backing of the U.S. Federal Communications Commission, which had authorized 5G. The altimeters are safe, they maintained. Air travelers didn’t know what to believe.

Another recent FCC decision had also created a controversy about public safety: okaying Wi-Fi devices in a 6-gigahertz frequency band long used by point-to-point microwave systems to carry safety-critical data. The microwave operators predicted that the Wi-Fi devices would disrupt their systems; the Wi-Fi interests insisted they would not. (As an attorney, I represented a microwave-industry group in the ensuing legal dispute.)

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