The Polymer Society of Korea

Abstract

The rapid advancement of computational and quantum technologies motivates physical encryption strategies based on unclonable material responses. Here, a magnetically encoded plasmonic hydrogel platform is introduced, in which anisotropic plasmonic magnetic nanorods (PMNs) are aligned by complex magnetic fields and permanently immobilized to record polarization-dependent color patterns. Dual-polarization readout expands the optical key space without complex fabrication, while spatially indexed hydrogel dot arrays enable multiplexing of multiple magnetic configurations within a single tag, requiring both polarization and coordinate keys for decoding. A simulation-augmented dataset establishes a mapping between magnetic configurations and plasmonic responses, enabling a deep-learning decoder to infer magnetic states from partial observations. This cross-domain magnetic-to-optical scheme provides a scalable and physically unclonable platform for authentication and information encryption.