Researchers at Massachusetts Institute of Technology (MIT) have developed a small, low-cost cryptographic ID tag that improves the security of product authentication. The new design mitigates a common security issue where counterfeiters could transfer an ID tag from an authentic product to a fake one, deceiving authentication systems. This ID tag uses terahertz waves and microscopic metal particles mixed into the adhesive expertly mitigating this issue.
The metallic particles, described as “mirrors” for terahertz waves, reflect unique patterns dependent on their orientation, size, and location. If a counterfeiter attempts to remove and reapply the tag, the metallic reflection pattern will be destroyed, preventing the counterfeit item from passing the authentication process.
In addition to increasing the level of security, the ID tag is exceptionally small at around 4 square millimeters. The researchers have also introduced a machine-learning model to detect signs of tampering by identifying similar glue patterns with over 99% accuracy. Considering its cost-effectiveness and small size, the antitampering ID tag can be implemented across vast supply chains, including those involving tiny objects, like specific medical devices.
To improve authentication further, the team targeted the adhesive substance at the point of contact between the tag and the item’s surface. The antitampering tag incorporates a series of tiny slots that enable terahertz waves to hit the microscopic metal particles in the glue. The behavior of the reflected waves, which are backscattered upon hitting the item’s surface, depends on the metal particles’ distribution. Various slots were incorporated into the chip to allow waves to hit several points on an object’s surface, thereby capturing comprehensive information about the random distribution of particles.
The researchers store initial data readings of the antitampering tag, once it is affixed to an item, into cloud storage; this data is later used for verification. However, the authentication system faces a few challenges, with terahertz waves suffering from high-loss levels during transmission. In a practical scenario, the sensor reading the tag must remain within a 4-centimeter range from the tag for an accurate reading. Furthermore, the angle between the sensor and the tag must not exceed 10 degrees or the terahertz signal quality will diminish. The researchers are aiming to overcome these limitations in their future work.
