Phase Encoding, Photon Counting Yield Secure QR Codes
STORRS, Conn. — Microscale QR codes coupled with optical phase and photon-counting encryption could be used to protect the integrity of microchips used in the most sensitive applications.
QR, or Quick Response, codes — those black and white boxes that people scan with a smartphone to learn more about something — have been used to convey information about everything from cereals to cars and new homes. University of Connecticut researchers think the codes can be applied to cybersecurity as well.
“An optical code or QR code can be manufactured in such a way that it is very difficult to duplicate,” said professor Dr. Bahram Javidi. “But if you have the right keys, not only can you authenticate the chip, but you can also learn detailed information about the chip and what its specifications are.”
Corrupted and recycled integrated circuits or microchips pose a significant threat to the international electronics supply chain, the researchers said. Bogus or used computer chips may not matter much when they cause poor cell phone reception or an occasional laptop computer crash in personal use.
But the problem becomes more serious when counterfeit or hacked chips turn up in the U.S. military. In 2012, a Senate Armed Services Committee report found that more than 100 cases of suspected counterfeit electronics parts from China had made their way into the Department of Defense supply chain. In one notable example, officials said counterfeit circuits were used in a high-altitude missile meant to destroy incoming missiles. Fixing the problem cost the government $2.675 million, the report said.
QR codes with black and white boxes as small as a few microns or millimeters could replace the part numbers currently stamped on most microchips, the researcher said.
Information about a chip’s functionality, capacity and part number can be stored in the QR code so it can be obtained by the reader without accessing the Internet. This is important in cybersecurity circles, because linking to the Internet greatly increases vulnerability to hacking or corruption.
To further protect the information in the QR code, an optical imaging mask scrambles the QR code design into a random mass of black-and-white pixels similar to TV static. Random-phase photon-based encryption adds another layer of security by turning the snowy image into a black field with just a few random dots of white.
The end result is a self-contained, highly secure, information-laden microscopic design that is nearly impossible to duplicate. Only individuals who have the special corresponding codes could decrypt the QR image.
Javidi’s team tested the concept using a commercial smartphone to decrypt this kind of QR code, a process that involves “examining the speckle signature of the optical masks using statistical analysis.”
The research was published in the IEEE Photonics Journal (doi: 10.1109/jphot.2013.2294625).
For more information, visit www.uconn.edu.
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