Researchers at MIT have created a cryptographic ID tag that offers improved security over traditional radio frequency (RFID) tags. This enhanced tag incorporates the use of terahertz waves and unique glue patterns to authenticate products and prevent counterfeiting. It’s smaller in size, cheaper to produce, and more secure than traditional RFIDs. The ID tag could be implemented throughout massive supply chains due to its low manufacturing costs and its small size allows it to be used on items too small for traditional RFIDs, such as certain medical devices.
The researchers overcame the issue of counterfeiters peeling the tag off a genuine item and reattaching it to a fake one by inventing an anti-tampering ID tag. They mixed microscopic metal particles into the glue that sticks the tag to an item and used terahertz waves to detect the unique pattern these particles form on the item’s surface. This random glue pattern, similar to a fingerprint, is used to authenticate each individual item. The tag’s unique responses are nearly impossible to duplicate.
To produce this tiny anti-tampering tag, they’ve created a series of small slots in the tag that allow the terahertz waves to pass through and strike the metallic particles. As these waves hit the surface of the objects, they are reflected back to a receiver. The way these waves are reflected depends on the distribution of the reflective particles embedded in the glue. Multiple slots were added to capture information on the random distribution of the particles.
A vendor would take an initial reading of the tag and store the data in the cloud for later verification. Furthermore, researchers also developed a machine-learning model that can identify similar glue pattern fingerprints with an accuracy of over 99 percent, making the authentication system more precise and efficient.
However, the authentication system is currently limited by transmission loss, as terahertz waves suffer from high levels of loss during transmission. Therefore, the sensor has to be close to the tag (approximately 4 centimeters) to get an accurate reading. Despite these challenges, researchers hope to inspire others to continue exploring the potential applications of the terahertz spectrum.
The work has been supported, in part, by the U.S. National Science Foundation and the Korea Foundation for Advanced Studies. It was presented at the IEEE Solid State Circuits Conference and resulted from the collaborative efforts of MIT’s Terahertz Integrated Electronics Group, the Energy-Efficient Circuits and Systems Group, electrical engineering and computer science graduate students, as well as the MIT Computer Science and Artificial Intelligence Laboratory.
