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[Display omitted] • Unclonable plasmonic security labels with multiscale random features are designed for high encoding capacity. • A robotic wet-chemical system is invented for mass-produced fabrication. • Plasmonic nanostructures and random features are variously modulated by in situ substrate growth. Plasmonic physical unclonable function (PUF) labels have been proven to be an effective anti-counterfeiting strategy, but their high tunability and multi-encoded capabilities remain to be explored for higher encoding capacity (EC). Herein, the PUF labels with high security level are prepared, which are constructed by the micro-domains of plasmonic nanostructures. The micro-domains are formed by mask-assisted ultraviolet (UV) exposure and 50 nm gold nanoparticles (Au NPs) electrostatic adsorbed on the unexposed area. And a robotic wet-chemical system is invented to modulate the in situ epitaxial growth of Au NPs by programming the growth conditions for human-free preparation and mass production. Three random processes, including mask-assisted UV photochemical reaction, electrostatic self-assembly, and in situ epitaxial growth, make sure multiscale random features. Thus, two-dimensional views with different resolutions can be obtained by three random optical imaging signals-bright field (BF), Raman imaging (RI), and dark field (DF), and the random signals will change with the modulation methods, leading to higher EC. Through analyzing the random features, a robust image authentication system is built, and the EC is calculated as 1.8 × 104966 in a 50 × 50 μm2 domain for each modulation method. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structural color-based PUF labels (SCPLs) labels fabricated by colloidal crystals for anti-counterfeiting. • SCPLs exhibit low optical loss and accomplish the safety and practicability of optical PUF labels. • Hiding function of SCPLs prevent the information of SCPL from being leaked. • A high-security mutual authentication system for supply chain realized by SCPLs. Optical physical unclonable functions (PUFs) have been considered to be one of the powerful tools to curb counterfeiting due to the unpredictable preparation process and identifiable information content. Responsive colloidal photonic crystals capable of controlling and manipulating light propagation exhibit low optical loss, stability and hiding function, which are more suitable to accomplish the safety and practicability of optical PUF labels. Herein, structural color-based PUF labels (SCPLs) prepared by injection-casting colloidal crystals propose a highly efficient and stable PUF authentication. With the decimal encode of the reflection intensity level at each pixel, the SCPL can achieve a theoretical encoding capacity of 102500 at 50 × 50 pixels. Utilizing the responsiveness of SCPLs, the PUF features can be switched between invisible and visible states to hide PUF information. Moreover, authentication experiments confirmed that the robustness of SCPL reached 0.994 and 0.960 in tensile test and wetting–drying cycle test, respectively, indicating that SCPL with hiding function, low optical loss and stability can be authenticated multiple times in practical applications. Interestingly, a high-security mutual authentication system for supply chain based on digital storage secret keys is proposed to showcase the strong application potential of SCPLs for various fields such as confidentiality of materials/technologies, dynamic anti-counterfeiting/camouflage, etc. [ABSTRACT FROM AUTHOR]