Researchers at MIT have developed a new cryptographic ID tag that is cheaper, smaller, and more secure than traditional radio frequency tags (RFIDs). Initially, the researchers developed a tiny tag using terahertz waves, which offered improved security over RFIDs. However, this tag shared a vulnerability with RFID tags: a counterfeiter could peel off the tag from the legitimate product and reattach it to a fake one.
To address this, the researchers invented an anti-tampering tag that uses terahertz waves and microscopic metal particles mixed into the glue that attaches the tag to the product. When these terahertz waves interact with the metal particles in the glue, they form a unique pattern akin to a fingerprint, which is impossible to replicate if the tag is tampered with. This ‘fingerprint’ constitutes the object’s authentication.
Led by Ruonan Han, an Associate Professor in Electrical Engineering and Computer Science (EECS), the research team developed a light-powered anti-tampering tag measuring only 4 square millimeters. Additionally, the team demonstrated a machine learning model that can detect similar glue patterns with over 99% accuracy, aiding in the detection of tampering.
Owing to its small size and the low production cost, the terahertz tag could be implemented across large supply chains. It is also suitable for use on smaller items where traditional RFIDs are impractical, such as specific medical devices.
The team aimed to make the product itself the focus of authentication rather than the tag. In traditional RFID systems, a tag could be easily removed by dissolving the adhesive and reattaching it elsewhere, rendering the security ineffective. The MIT team’s innovation proposes a much more robust solution, with anti-tampering features ensuring the destruction of the unique ‘fingerprint’ if tampered with.
However, the system is not without limitations. For instance, the sensor must be within 4 cm of the tag to get an accurate reading and the angle between the sensor and tag should be less than 10 degrees. The researchers plan to address these issues in future expansions of the project. They also hope that the creation of the terahertz spectrum application will inspire further developments in ID, security, and authentication.
