{'fraction_non_alphanumeric': 0.025966850828729283, 'fraction_numerical': 0.0016574585635359116, 'mean_word_length': 6.1299212598425195, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Cracking enabled unclonability in colloidal crystal patterns authenticated with computer vision.

Colloidal crystals with iridescent structural coloration have appealing applications in the fields of sensors, displays, anti-counterfeiting, etc. A serious issue accompanying the facile chemical self-assembly approach to colloidal crystals is the formation of uncontrolled and irregular cracks. In contrast to the previous efforts to avoid cracking, the unfavorable and random micro-cracks in colloidal crystals were utilized here as unclonable codes for tamper-proof anti-counterfeiting. The special structural and optical characteristics of the colloidal crystal patterns assembled with monodisperse poly(styrene-methyl methacrylate-acrylic acid) core-shell nanospheres enabled multi-anti-counterfeiting modes, including angle-dependent structural colors and polarization anisotropy, besides the physically unclonable functions (PUFs) of random micro-cracks. Moreover, by using the random cracks in the colloidal crystals as templates to guide fluorescent silica nanoparticle deposition, an fluorescent anti-counterfeiting mode with PUFs was introduced. To validate the PUFs of the fluorescent micro-cracks in the colloidal crystals, a novel edge-sensitive template matching approach based on a computer vision algorithm with an accuracy of ∼100% was developed, enabling ultimate security immune to forgery. The computer-vision verifiable physically unclonable colloidal crystals with multi-anti-counterfeiting modes are superior to conventional photonic crystal anti-counterfeiting materials that rely on angle-dependent or tunable structural colors, and the conventional PUF labels in the aspect of decorative functions, which will open a new avenue for advanced security materials with multi-functionality.