Automated Reflective Particle Tag System for Physical Authentication

Year
2010
Author(s)
Jack C. Bartberger - Sandia National Laboratories
Karl Horak - Sandia National Laboratories
Peter Merkle - Sandia National Laboratories
Jason C. Bolles - Sandia National Laboratories
Christopher W. Wilson - Sandia National Laboratories
Charles Q. Little - Sandia National Laboratories
David L. Zamora - Sandia National Laboratories)
Juan A. Romero - Sandia National Laboratories
Robert K. Grubbs - Sandia National Laboratories
Abstract
The Reflective Particle Tag (RPT) was developed during the late 20th century for identifying items accountable under bilateral nuclear weapons treaties.[1, 2] The RPT is a field-applied tag and seal composed of specular hematite particles in an adhesive polymer matrix. When illuminated from different angles, each RPT presents complex patterns of millimeter-scale light reflections unique to the tag. These patterns are suitable as a means of physically authenticating the tagged item. Subsequent advances in imaging and computing technology enable automation of the RPT procedure, enhancing inspection efficiency for wider adoption. In prior work, we discussed the performance of the maximally stable extremal region (MSER) and wide baseline matching (WBM) algorithm approach for tag validation.[3] We report in this paper on the design considerations, development, and testing performance of two new RPT prototype systems, and describe physical and chemical properties of the polymer and particle components. The new RPT system includes automated light control, sample collection, and an image database.