Fluorescent Hierarchical Structures Enable All‐In‐One Multimodal Optical Anti‐Counterfeiting

ABSTRACT Secure and user‐friendly anti‐counterfeiting technologies are critical for safeguarding products in modern society. However, achieving a synergy between high‐level encryption and efficient readability remains a significant challenge. Here, we present an all‐in‐one multimodal optical anti‐counterfeiting strategy based on fluorescent hierarchical structures through a sequential imprinting process. The resulting structures exhibit an intact macroscopic contour while retaining randomly distributed microscopic defects. Macroscopically, hidden photoluminescent (PL) patterns revealed by UV irradiation, together with angle‐dependent nano‐ and micro‐structural color patterns observed under daylight, enable direct visual decoding. Microscopically, random fluorescent inks and structural defects generate two independent physical unclonable functions under UV and daylight, whose encryption capacity is equivalent to the product of two independent keys, providing ultrahigh security. Moreover, the hierarchical structure in multimodal optical anti‐counterfeiting enhances PL emission, provides robust friction resistance, and improves hydrophobicity, collectively enabling reliable performance in practical applications. Using a painting as a platform, we demonstrate a feasible authentication strategy for next‐generation anti‐counterfeiting.