Conventional physical unclonable functions (PUFs), although delivering unique and non-replicatable identifiers for hardware security authentication and key component anti-counterfeiting applications, struggle to provide long-term reliable support under extreme environments such as nuclear reactors, fusion devices, and space radiation, which feature intense radiation and high temperatures. Here, we report a highly robust PUF architecture derived from the intrinsic crystallographic disorder of polycrystalline diamond microtextures. By analyzing electron backscatter diffraction (EBSD) patterns, a multidimensional security framework is established that integrates three complementary encoding dimensions: multi-base numerical conversion of individual microtexture features for primary key generation; three-dimensional topological reconstruction through fusion of single- and multi-directional EBSD maps; and crystallographic coding based on the statistical distribution of (100), (110), and (111) lattice planes. Together, these elements form a three complementary encoding dimensions with exceptionally high entropy and unclonability. To enable deployment across heterogeneous application scenarios, both rigid polycrystalline diamond substrates and self-supported flexible diamond films are developed. The rigid architecture provides ultrahard chemically inert planar security for chip-level authentication, while the flexible diamond films combine curvature adaptability with extreme durability, enabling secure labeling of complex and deformable surfaces such as medical devices. Sharing a unified microtexture-based encoding mechanism, their complementary platforms establish a versatile security solution that seamlessly integrates rigidity and flexibility for high-value electronic components and advanced anti-counterfeiting applications.

Physical unclonable functions (PUFs) offer a promising defensive measure against the escalating challenges posed by the increasingly rampant counterfeit products. Conventional PUF materials with a singular physical property encounter limitations in encoding flexibility and capacity. Here, we propose a dual-color center diamond-based PUF (D-PUF) ink that exploits four diverse optical characteristics of dual-color center in diamond to design a concealable multi-level cryptographic authentication protocol. Through simple writing, stamping, or spraying, intricate covert random patterns can be directly generated on the objects, which are imperceptible under visible light. When challenged by a 532 nm laser, the D-PUF exhibits four distinct optical responses, including Raman, zero phonon line (ZPL) of germanium vacancies (GeV), ZPL of silicon vacancies (SiV), and the intensity ratios of these ZPLs. These responses were harvested simultaneously to construct the four-level separate encodable matrices. Furthermore, M-ary encoding algorithms were implemented to encrypt PUFs with flexibility. The resulting multi-level PUF system attains notable uniqueness, repeatability, extensive encoding capacity (> 10⁴⁸¹⁶⁴/(100 pixels)²), and ultra-high information entropy (6 bits/pixel). This study inspires designing new generations of multi-level PUFs with enhanced coding flexibility and holds significant promise for applications in print security.