MIT researchers have created a secure and portable ID tag, utilizing terahertz waves, a technology considered superior compared to traditional RFIDs due to the improved security it offers. The team has bypassed the significant vulnerability of both RFID and terahertz tags, where a counterfeiter can remove the tag from an original item and transfer it onto a fake one, without the authentication system noticing.
The tiny size, cheap production costs, and robust security of the tag make it a feasible candidate for widespread implementation in supply chains. Additionally, its small dimensions allow it to be attached to items that traditional RFIDs are too bulky for, such as some medical devices.
The scientists have enhanced the antitampering feature of the ID tag by integrating microscopic metal particles to the adhesive attaching the tag to an item. The terahertz waves are then used to identify the distinct pattern that the metal particles form on the item’s surface. This unique glue pattern works similar to a fingerprint in authenticating the item. Once the tag is removed, the pattern gets destroyed, thereby maintaining the integrity of the tagged item and disrupting any counterfeit attempts.
The antitampering tag has slots that allow terahertz waves to interact with the microscopic metal particles mixed in the glue. These waves, upon striking the object’s surface, reflect or ‘backscatter’ to a receiver for authentication. The uniqueness and randomness of the metal particle’s distribution enable the ID tag to authenticate individual items effectively.
The team used AI to create a machine-learning model trained to accurately read the metal particles’ distribution and compare glue patterns. However, the terahertz wave technology has limitations, including high levels of loss during transmission which require the sensor to be about four centimeters from the tag to obtain accurate readings and the need for the angle between the sensor and tag to be less than ten degrees.
Despite these challenges, the application of terahertz technology for ID, security, and authentication demonstrates its vast potential. The team aims to continue improving the current design to fully exploit terahertz waves’ capabilities for secure authentication. The research project was partly funded by the U.S. National Science Foundation and the Korea Foundation for Advanced Studies.
