A polarization multiplexing dynamic PUF device based on AAO confined perovskite, preparation method and authentication system

Abstract

The application discloses a polarization multiplexing dynamic PUF device based on AAO confined perovskite, a preparation method and an authentication system, and belongs to the technical field of information security and micro-nano photonics. The device comprises a liquid crystal modulation unit and a light-emitting layer unit which are laminated and integrated; the liquid crystal modulation unit is configured to control the polarization state of incident light through an applied voltage, so as to realize dynamic reading or signal hiding of PUF polarization coding; and the light-emitting layer unit comprises an AAO template, anisotropic light-emitting nanomaterial filled in the template channel and a surface polymer encapsulation layer. The device has the advantages of exponential capacity of coding, active concealment function, strong resistance to machine learning modeling attack, good environmental stability, easy low-cost large-scale integration and the like.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of information security and micro-nano photonics, specifically relating to a polarization multiplexing dynamic PUF device based on AAO confined perovskite, its fabrication method, and authentication system. Background Technology

[0002] With the rapid development of IoT, AI, and edge computing technologies, hardware-level identity authentication and data security have become core issues that urgently need to be addressed. Traditional encryption methods typically store keys digitally in non-volatile memory (NVM), which is vulnerable to invasive physical attacks, side-channel attacks, and reverse engineering, posing significant security risks. Against this backdrop, Physical Unclonable Functions (PUFs) have emerged as a "hardware root of trust" technology. PUFs utilize unavoidable and unreplicable random physical differences during hardware manufacturing (such as doping concentration fluctuations, lattice defects, and micro / nano structure morphology differences) as "entropy sources," extracting unique, random, and tamper-proof "digital fingerprints" through a challenge-response mechanism.

[0003] Among various PUF technologies, optical PUFs based on all-inorganic halide perovskites have attracted much attention due to their extremely high information density, non-contact readout, and parallel processing capabilities. Current technologies have mainly gone through the following development stages: The first type is perovskite polycrystalline thin film PUF based on random film-forming defects. This technology uses spin coating to prepare perovskite polycrystalline thin films on a substrate. Relying on the uncontrollable nature of the crystallization process, randomly distributed grain boundaries, pinholes, or phase-separated impurities naturally form on the film surface. The spatial distribution of fluorescence intensity on the film surface is read under a microscope as static fingerprint information. Although this type of PUF is simple to prepare, it usually only produces a single static fluorescence pattern, resulting in a limited coding capacity (CRPs). In addition, exposed polycrystalline perovskite materials are extremely sensitive to water and oxygen, exhibiting poor long-term stability.

[0004] The second type is static laser array PUF based on anodic aluminum oxide (AAO) templates. To improve signal readability and device consistency, researchers introduce porous templates such as AAO, filling the micropores with luminescent material and utilizing the random distribution of the channels on a macroscopic scale as an entropy source. However, most existing templated PUFs are still static systems with a "single input, single output." During authentication, they are typically excited using unpolarized or single-polarized light of a fixed wavelength, resulting in a fixed output response pattern for the same device. Once the fluorescence distribution of this static physical entity is intercepted by an attacker and modeled using machine learning, the entire security system fails.

[0005] In summary, the existing technology mainly has the following technical problems: First, the "static" mechanism leads to limited coding capacity and insufficient security: most existing optical PUFs are static systems with a limited number of challenge-response pairs (CRPs) and lack a "dynamically reconfigurable" mechanism, making them vulnerable to high-order modeling attacks based on machine learning. Although there are solutions that achieve dynamic responses by changing temperature or time, these often rely on complex external excitation devices or sacrifice response speed.

[0006] Secondly, there is a contradiction between material stability and practicality: high-performance perovskite materials are extremely easy to degrade in the natural environment, while existing packaging technologies often destroy their micro-nano optical properties, making it difficult to achieve long-life packaging while ensuring high-quality optical signal output and low-cost integration with commercial read / write components (such as LCD cells).

[0007] It is evident that how to utilize low-cost commercial components to construct dynamic optical PUFs that combine high coding capacity, high environmental stability, and high signal-to-noise ratio remains a major technical challenge in this field. Summary of the Invention

[0008] The present invention aims to provide a polarization multiplexing dynamic PUF device, a fabrication method and a certification system based on AAO confined perovskite, in order to overcome the shortcomings of the prior art. The technical problem to be solved by the present invention is achieved through the following technical solutions.

[0009] This invention provides a polarization multiplexing dynamic PUF device based on AAO confined perovskite, comprising: A liquid crystal modulation unit (100) and an emissive layer unit (200) are stacked together. The liquid crystal modulation unit (100) is electrically connected to an external driving circuit and is configured to modulate the polarization state of the incident excitation light under different driving voltages, thereby achieving polarization angle rotation or signal hiding. The light-emitting layer unit (200) includes a substrate (201), an AAO template (202), an anisotropic light-emitting nanomaterial (203) filled in the nanopores of the AAO template (202), and a polymer encapsulation layer (204) located on the surface of the AAO template (202). The anisotropic luminescent nanomaterial (203) forms a polarization-sensitive random luminescent array under the geometric confinement effect in the nanopores; the polymer encapsulation layer (204) fills the micropores on the surface of the AAO template and forms a protective layer, and the luminescent layer unit (200) is connected to the light-emitting side surface of the liquid crystal modulation unit (100).

[0010] In a preferred embodiment, the anisotropic luminescent nanomaterials (203) are randomly stacked in a sideways or inclined state along the long axis of the nanopores under the geometric confinement of the nanopores, forming a polarization-sensitive array with randomly oriented dipoles.

[0011] In a preferred embodiment, the anisotropic luminescent nanomaterial (203) is selected from all-inorganic perovskite nanosheets or II-VI group semiconductor nanorods with linearly polarized luminescence characteristics; the AAO template (202) has a pore size of 100nm-250nm, and the pore size is matched with the size of the anisotropic luminescent nanomaterial to generate a steric hindrance effect.

[0012] In a preferred embodiment, the polymer encapsulation layer (204) is made of polymethyl methacrylate (PMMA); the polymer encapsulation layer (204) is a hydrophobic barrier layer formed by an in-situ spin coating process, and the adhesion of the polymer encapsulation layer (204) is used to physically bond the light-emitting layer unit (200) to the glass substrate of the liquid crystal modulation unit (100).

[0013] A second aspect of the present invention provides a method for fabricating a polarization-multiplexed dynamic PUF device based on AAO-confined perovskite, comprising the following steps: Step S1: Place the AAO template on the substrate, cover the surface of the AAO template with a cover sheet, and apply vertical pressure over the cover sheet; Step S2: A colloidal solution containing anisotropic luminescent nanomaterials (perovskite nanosheets) is dropped onto the contact edge between the cover plate and the AAO template. The solution is spread into the interface by lateral capillary force, and the solution is drawn into the depth of the pores by longitudinal capillary force of the nanopores. Step S3: During the solvent evaporation process, the geometric constraints of the AAO template pore walls are used to cause the anisotropic luminescent nanomaterials to physically flip and randomly stack along the pore direction. After the solvent has completely evaporated, the cover is removed to form a filling layer with randomly locked orientation. Step S4: A polymer solution is dropped onto the surface of the AAO template and spin-coated to form a polymer encapsulation layer; before the polymer encapsulation layer is completely cured, the AAO template is bonded to the surface of the prefabricated liquid crystal modulation unit by utilizing the adhesiveness of the polymer encapsulation layer.

[0014] In a preferred embodiment, in step S4, the polymer solution is a polymethyl methacrylate (PMMA) solution, and after spin coating, the PMMA penetrates into the micropores of the AAO template surface to form a hydrophobic protective film.

[0015] A third aspect of the present invention provides an authentication system based on a polarization multiplexing dynamic PUF device, comprising: On the server side, it is used to generate challenge signals containing working mode instructions and excitation polarization angle instructions, and stores a preset reference key database. The terminal device includes the PUF device, an electronically controlled drive module, and a detection module; the electronically controlled drive module is used to receive the challenge signal and is configured to output a frequency-adjustable AC square wave drive signal to the liquid crystal modulation unit; the detection module is used to acquire the fluorescence intensity matrix of the PUF device under the excitation light and extract the linear polarization feature map. The authentication system is configured to quantize the linear polarization feature map into a binary real-time key and calculate the Hamming distance between the real-time key and the corresponding reference key in the reference key database. If the Hamming distance is less than a preset threshold, the authentication is successful.

[0016] In a preferred embodiment, the electronically controlled drive module is configured to: in authentication mode, output an AC square wave with an amplitude of a first operating voltage to modulate the excitation light into linearly polarized light at a corresponding angle; and in reconstruction mode, output an AC square wave with an amplitude of a second operating voltage to change the birefringence state of the liquid crystal molecules to generate a new key.

[0017] In a preferred embodiment, the formula for calculating the degree of linear polarization is:

[0018] in, and These represent the maximum and minimum fluorescence intensities of a pixel at different detection angles.

[0019] In a preferred embodiment, the quantization threshold for the linear polarization feature map into a binary real-time key is the median or mean of the statistical linear polarization distribution map. If the linear polarization degree value of a certain pixel is greater than or equal to If it is less than 1, it is mapped to the number "1"; if ... If the value is 0, it is mapped to the number "0", thus generating a binary digital fingerprint.

[0020] The technical solutions provided by the embodiments of the present invention bring at least the following beneficial effects: 1. An exponential expansion of encoding capacity was achieved, significantly improving resistance to modeling attacks. This invention breaks through the static limitation of traditional optical PUFs ("single input, single output") and proposes a dynamic mechanism based on "source-end polarization multiplexing". By controlling the polarization state of the excitation light through a liquid crystal modulation unit and combining the polarization-sensitive characteristics of anisotropic nanomaterials within the AAO channel, multiple independent key channels that do not interfere with each other were successfully constructed on a single physical entity. Compared to the static schemes in existing technologies that rely solely on the spatial distribution of fluorescence intensity, spatial-polarization-electric domain multidimensional multiplexing: unlike schemes that rely solely on the spatial distribution of fluorescence intensity (2... N The present invention introduces an excitation polarization angle (θ) as a static scheme. ex The driving electrical signal (V,f) and the driving electrical signal (V,f) are used as orthogonal challenge dimensions. The theoretical coding capacity expands exponentially: due to the random orientation distribution of nanopoles within the AAO channel, each discrete polarization state and voltage state can illuminate a different subset of dipoles. Theoretical calculations show that the theoretical coding space can be expanded from a static 2... N Expand to 2 N M K (Where N is the number of feature pixels, M is the number of polarization channels, and K is the number of electronically controlled drive states), thus expanding the CRP (challenge-response pair) resources.

[0021] 2. A high-dimensional physical entropy source based on "geometrically confined orientation randomness" was constructed, resulting in a high level of anti-counterfeiting. This invention utilizes a capillary filling process assisted by a cover plate, leveraging the geometric mismatch between the AAO nanopore size and the nanomaterial size to generate a strong steric hindrance effect during solvent evaporation. This forces anisotropic luminescent nanomaterials (such as perovskite nanosheets) to physically flip within the pores and assume a random, sideways, or tilted stacking state. This "orientation randomness" at the microstructural level is difficult to precisely replicate or clone using macroscopic manufacturing methods. Combined with positional randomness, this constructs a higher-dimensional, physically unclonable feature, significantly improving the physical anti-counterfeiting security of the device.

[0022] 3. This invention resolves the contradiction between the poor environmental stability of perovskite materials and the difficulty of device integration. It innovatively employs an in-situ spin-coating process using PMMA, where a PMMA solution penetrates the micropores of the AAO surface layer. After curing, a dense hydrophobic barrier layer is formed, creating a dual physical and chemical protective barrier. This effectively isolates the perovskite nanomaterials from water and oxygen corrosion, significantly extending the device's lifespan in natural environments. Simultaneously, this PMMA layer combines optical matching and bonding functions, achieving seamless physical bonding between the AAO emitting layer and the commercial liquid crystal cell glass substrate. This eliminates the need for expensive vacuum packaging equipment, significantly reducing the fabrication cost and process threshold of dynamic PUF devices, facilitating large-scale application.

[0023] 4. The authentication system is secure, reliable, and easy to deploy. This invention utilizes a polarization-multiplexed dynamic PUF device to construct an authentication system. The server randomly sends multi-dimensional challenge signals containing polarization angles and driving states. The terminal device generates a response key in real time and completes authentication through Hamming distance comparison. This system can be implemented using mature commercial liquid crystal driving components and standard optical detection modules, resulting in low deployment costs. The authentication threshold can be adaptively determined using statistical methods, and both the false acceptance rate and the rejection rate can be controlled at extremely low levels, making it suitable for large-scale identity authentication applications of IoT terminal devices. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the polarization multiplexing dynamic PUF device structure based on AAO confined perovskite in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the fabrication process steps of a polarization multiplexing dynamic PUF device based on AAO confined perovskite in an embodiment of the present invention. Figure 3 This is a schematic diagram of the fabrication process of the polarization multiplexing dynamic PUF device based on AAO confined perovskite in an embodiment of the present invention; Figure 4 These are the confined orientation characterizations of perovskite micro / nano array perovskite nanomaterials prepared by capillary-assisted template method in the embodiments of the present invention; (a)-(b): Scanning electron microscope (SEM) images; (c)-(d): Experimental curves and polar coordinate plots of normalized fluorescence intensity as a function of polarization angle; Figure 5 This is a pseudo-color image showing the spatial distribution of linear polarization degree (DOLP) within the physical region of the polarization multiplexing dynamic PUF device based on AAO confined perovskite in this embodiment of the invention, and the polarization dependence of typical pixels. Figure 6 This is a schematic diagram of the key extraction and quantization process of the polarization multiplexing dynamic PUF device based on AAO confined perovskite in an embodiment of the present invention; Figure 7 This is a PUF key map and its inter-chip Hamming distance distribution under different excitation polarization angles in the embodiments of the present invention; Figure 8 This demonstrates the digital response and statistical performance evaluation of a polarization-multiplexed dynamic PUF device based on AAO confined perovskite under four different liquid crystal (LC) driving states (challenge). The first row (ad) displays the pixel binary fingerprint (PUFKeys) extracted and quantized from the same physical region. The second line (eh) shows the probability distribution and Gaussian fitting curve of the Hamming distance between different device units under the corresponding driving state. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] This embodiment provides a polarization multiplexing dynamic physically unclonable function (PUF) device based on AAO-confined perovskite. For example... Figure 1 As shown, the device is mainly composed of a light-emitting layer unit 200 and a liquid crystal modulation unit 100 stacked from bottom to top. This stacked structure constructs an "active modulation-passive response" optical architecture, in which the liquid crystal modulation unit 100 acts as a polarization state controller for the source-end excitation light, while the light-emitting layer unit 200 acts as a response carrier with physical randomness. Specifically, the light-emitting layer unit 200 includes a substrate 201 and an AAO template 202 as the main structural component, wherein the substrate 201 is an aluminum substrate. The AAO template 202 has a highly ordered array of nanopores, with the pores distributed perpendicular to the template surface. The liquid crystal modulation unit 100 includes a liquid crystal cell 101, a sealant 102, and liquid crystal 103.

[0028] In this embodiment, a commercially available AAO template with an aperture range of 100 nm to 250 nm is preferably selected. This aperture size is not arbitrary but designed based on the principle of "geometric confinement": the aperture must be large enough to accommodate the luminescent material, while also being small enough to create a significant steric hindrance effect on the anisotropic nanomaterials filling it, thereby restricting their free rotation. Anisotropic luminescent nanomaterials 203 are filled inside the nanopores of the AAO template 202.

[0029] In this embodiment, the anisotropic luminescent nanomaterial 203 is preferably an all-inorganic perovskite nanosheet (e.g., CsPbI3 nanosheet) with linearly polarized luminescence characteristics, or a group II-VI semiconductor nanorod (e.g., CdSe / CdS quantum rod). These materials are characterized by anisotropic optical absorption and emission properties (i.e., the dipoles have a specific orientation).

[0030] The anisotropic luminescent nanomaterials 203 are not laid flat or randomly aggregated, but rather, under the geometric confinement of the AAO nanopores, are forced into a "sideways" or "tilted" state and tightly stacked along the long axis of the pores. Due to the lack of directional external field induction during the filling process, although the nanosheets are confined longitudinally by the pore walls, they are completely random in the azimuth direction. Therefore, a massive number of randomly oriented luminescent dipoles are formed within hundreds of millions of nanopores, constituting a physical entropy source that is difficult to replicate in this PUF device. A polymer encapsulation layer 204 is covered on the top surface of the anodic aluminum oxide template 202 (i.e., the side facing the liquid crystal cell).

[0031] In this embodiment, the polymer encapsulation layer 204 is a polymethyl methacrylate (PMMA) layer. This PMMA layer has two key functions: First, microscopic filling and passivation: During spin coating, the PMMA solution penetrates into the micropores of the AAO surface, forming a dense hydrophobic barrier layer after curing. Since halide perovskite materials are extremely sensitive to water and oxygen, the presence of this hydrophobic layer effectively isolates moisture and oxygen from the external environment, solving the problem of poor stability in traditional perovskite PUFs. Second, macroscopic bonding and integration: This PMMA layer also acts as an optically transparent adhesive, physically bonding the rough AAO template surface to the flat glass substrate of the liquid crystal modulation unit 100, achieving integrated device integration and avoiding interface loss or chemical corrosion that may be introduced by using additional optical adhesives. The liquid crystal modulation unit 100 is disposed above the light-emitting layer unit 200 (i.e., on the light incident side).

[0032] In this embodiment, the liquid crystal modulation unit 100 is a standard electrically controlled liquid crystal cell structure, comprising upper and lower transparent conductive glass substrates (such as ITO glass), and a liquid crystal molecule layer (such as commercial nematic liquid crystal SLC1717) filled between the two substrates. An alignment layer (PI layer) is coated on the inner surface of the liquid crystal cell for initial anchoring of the liquid crystal molecules. By applying a driving voltage between the upper and lower ITO electrodes, the deflection angle of the liquid crystal molecules can be changed, thereby continuously or discretely modulating the polarization state of the incident excitation light passing through the unit with precise precision.

[0033] With the above structure, the PUF device in this embodiment is no longer a single static tag, but a programmable optical system. When external excitation light (such as a 488nm laser) is incident, it first passes through the liquid crystal modulation unit 100 and is modulated into linearly polarized light at a specific angle; subsequently, this linearly polarized light enters the light-emitting layer unit 200. According to Malus's law, the nanomaterial can only be effectively excited and emit light when the polarization direction of the incident light is parallel to or close to the absorption dipole moment direction of the nanomaterial within the AAO channel. Since the orientation of the nanomaterial within the channel is random, changing the polarization state of the incident light will "light up" different subsets of nanoparticles at the same physical location, thereby generating a dynamic fluorescence speckle pattern that varies with the polarization angle.

[0034] Example 2

[0035] This embodiment details the fabrication process of the aforementioned dynamic PUF device. This process combines "capillary filling" and "in-situ spin-coating integration" techniques, achieving both microscopic orientation control and macroscopic device packaging. The following refers to... Figure 2 and Figure 3 The process steps are described in detail.

[0036] Step S1: Preparation of Commercial Templates and Materials

[0037] First, select a commercially available AAO template with specific pore size specifications. The preferred pore size is 100nm-250nm, and the thickness is 10-50 μm. The AAO template is ultrasonically cleaned using acetone, ethanol, and deionized water to remove surface organic impurities and dust, and then dried with nitrogen for later use. Simultaneously, prepare a high-concentration colloidal solution of anisotropic luminescent nanomaterials. Taking CsPbI3 perovskite nanosheets as an example, it is synthesized using a hot-injection method or a ligand-assisted reprecipitation method, and the product is dispersed in a non-polar solvent such as n-octane or toluene, with the concentration controlled at 10-20 mg / mL to ensure filling density. Prepare commercial liquid crystal consumables, including ITO conductive glass, spacers (used to control cell thickness, e.g., 5-10 μm), UV-curable adhesive, and commercial nematic liquid crystal materials (such as SLC1717).

[0038] Place the commercial AAO template on the substrate, and then cover the surface of the AAO template with a clean, flat cover sheet. For example... Figure 3 As shown, applying a suitable amount of vertical pressure over the cover plate creates a "substrate-AAO-cover plate" sandwich structure. This pressure helps eliminate macroscopic air gaps between the AAO surface and the cover plate, forming a tight bonding interface.

[0039] Step S2: Capillary-assisted filling

[0040] A high-concentration anisotropic perovskite nanosheet colloidal solution was dropped onto the edge where the cover plate and the AAO template contacted each other (instead of being dropped directly onto the surface). The lateral capillary force generated by the tiny gap between the cover plate and the template drove the solution to spread rapidly and fill the entire contact interface; subsequently, the longitudinal capillary force generated by the AAO nanopores vertically drew the solution containing the nanosheets into the depth of the pores.

[0041] Step S3: Geometric confinement orientation locking

[0042] As the solvent slowly evaporates, the solution concentration within the pores gradually increases until saturation. Due to the strong van der Waals forces between the nanosheets and the interactions of surface ligands, the nanosheets tend to self-assemble and stack face-to-face. Simultaneously, constrained by the one-dimensional geometric confinement of the AAO pores (100-250 nm) and the capillary forces guiding the solvent evaporation interface, these nanosheet assemblies cannot grow freely or deposit horizontally in free space. Instead, they are forced to align along the long axis of the pores, resulting in a tightly packed, 'sideways' or tilted arrangement.

[0043] After the solvent has completely evaporated, the nanosheets are locked within the channels at random orientations, forming a microscopic array of randomly oriented dipoles. After the solvent has completely evaporated (requiring 2-8 hours of standing at room temperature), the cover plate is removed. At this point, a structurally stable perovskite filling layer has formed within the AAO channels, completing the construction of the physical entropy source.

[0044] Step S4: PMMA in-situ spin coating integration and interface passivation

[0045] Prepare two clean ITO glass sheets. Reserve the electrode lead areas using photolithography or masking. Coat with PI alignment liquid and perform a friction treatment. Sprinkle spacer particles and bond them together in a staggered manner. During bonding, the two ITO glass sheets should maintain a physical misalignment of 1mm-2mm along their long or short sides to expose the underlying conductive surface as bonding pads. Seal the frame with UV adhesive (leaving a filling port) to create a liquid crystal cell. Heat a commercial liquid crystal material (such as SLC1717) above its clearing point. At this temperature, the liquid crystal transforms from an ordered liquid crystal phase to a disordered isotropic liquid phase, significantly reducing its viscosity. Fill the cell with liquid liquid crystal using capillary siphon or vacuum filling processes. After cooling, the liquid crystal molecules regain their alignment. Finally, seal the filling port with UV adhesive to obtain an independent liquid crystal modulation unit 100.

[0046] Apply a small amount of silver paste or attach conductive gold foil to the exposed ITO pad area. Use fine copper wire as external leads and fix them to the pads by low-temperature soldering or conductive adhesive bonding. Apply a small amount of epoxy resin at the connection point for physical reinforcement and insulation protection to prevent electrode detachment or short circuit during subsequent spin coating or testing.

[0047] The prepared liquid crystal modulation unit 100 was selected, and the outer surface of its lower substrate was cleaned. An AAO template loaded with perovskite nanosheets was placed on the outer surface of the lower substrate of the liquid crystal modulation unit 100. A polymethyl methacrylate (PMMA) solution (the solvent can be chlorobenzene or toluene) was dropped onto the AAO template surface, and a spin-coating process was performed. The preferred spin-coating parameters were: rotation speed 1000-3000 rpm, time 30-60 seconds. Under centrifugal force, the PMMA solution formed a uniform thin film. Some of the PMMA solution penetrated into the micropores of the AAO surface layer, and after curing, sealed the pore openings, forming a hydrophobic protective layer to prevent water and oxygen from entering the pores and corroding the perovskite material. Utilizing the adhesiveness of PMMA during solvent evaporation, the AAO template was firmly bonded to the glass substrate of the liquid crystal cell, eliminating the need for additional adhesives or complex alignment equipment, thus achieving low-cost, high-reliability integration of the functional layer and the modulation layer.

[0048] Figure 4 This is a confined orientation characterization of perovskite micro / nano array perovskite nanomaterials prepared by capillary-assisted template method in the embodiments of the present invention; Figure 4 Figures (a)-(b) show the highly ordered nanopores of the AAO template and the distribution of anisotropic nanomaterials filling them. Figures (c)-(d) confirm the significant linearly polarized luminescence characteristics generated by the randomly oriented dipoles within the pores.

[0049] Example 3

[0050] This embodiment describes the system architecture and complete workflow for security authentication using the aforementioned device. The system includes a server and a terminal device. The server generates a challenge signal containing operating mode instructions and excitation polarization angle instructions, and stores a preset reference key database. The terminal device includes the PUF device, an electronically controlled drive module, and a detection module. The electronically controlled drive module receives the challenge signal and is configured to output a frequency-adjustable AC square wave drive signal to the liquid crystal modulation unit. The detection module acquires the fluorescence intensity matrix of the PUF device under the excitation light and extracts a linear polarization feature map. The terminal device includes the aforementioned polarization-multiplexed dynamic PUF device, an electronically controlled drive module (laser + high-precision function generator), and a detection module (CCD / CMOS camera + analyzer). In this embodiment, the typical hardware configuration of the terminal device is as follows: the excitation source uses a continuous-wave solid-state laser with a wavelength of 488nm and an output power of 5-50mW; the electronically controlled drive module uses a commercially available function generator, outputting a zero-mean AC square wave signal with a frequency range of 100Hz-1kHz, an amplitude range of 0-10V, and an amplitude accuracy of ±0.01V; the detection module uses a research-grade cooled CCD camera or an industrial-grade CMOS camera, coupled with an electrically driven rotating analyzer, with an analysis angle resolution better than 0.5°.

[0051] In a preferred embodiment, the electronically controlled drive module is configured to: in authentication mode, output an AC square wave with an amplitude of a first operating voltage to modulate the excitation light into linearly polarized light at a corresponding angle; and in reconstruction mode, output an AC square wave with an amplitude of a second operating voltage to change the birefringence state of the liquid crystal molecules to generate a new key. The aforementioned AC square wave drive signal is a zero-mean square wave signal with a frequency of 100Hz-1kHz and a duty cycle of 50%; the amplitude range of the first and second operating voltages is 1.0V-4.0V.

[0052] The server-side employs a secure server and interacts with terminal devices via encrypted communication protocols (such as TLS 1.3). The reference key database is stored in encrypted form on non-volatile storage media. The authentication process uses a challenge-response mechanism, with the specific steps as follows: 1. Database Construction Phase: During the device manufacturing or registration phase, a unique "digital fingerprint database" needs to be established.

[0053] (1) Multidimensional polarization scanning: Optical dimension: The system controls the source-end modulation module to determine the linear polarization angle of the excitation light ( ) is used as a variable "challenge" variable. A series of discrete angular step sizes are set (e.g., every 10 degrees is a step size). ).

[0054] Electrical dimension: The output frequency of the electrically driven module (such as a function generator) is... f (Typical value 1kHz), amplitude is V Challenge The zero-mean AC square wave signal is precisely adjusted within the linear response range of the liquid crystal (e.g., 1V to 4V) according to a preset step size (e.g., 0.5V).

[0055] (2) Polarization image acquisition: For each fixed excitation polarization angle The detection module does not directly take a picture, but controls the analyzer to rotate and collect a series of different polarization angles. Fluorescence intensity matrix under) .in These are pixel coordinates.

[0056] (3) Feature Extraction (DOLP Mapping): To eliminate the instability of absolute light intensity caused by light source fluctuations and optical path losses, this embodiment preferably uses "Degree of Linear Polarization (DOLP)" as the fingerprint feature. For each pixel in the image... Based on the intensity variation at different polarization angles, its DOLP value is calculated:

[0057] in, and These represent the maximum and minimum fluorescence intensities of the pixel at different polarization angles. This step yields the excitation angle. The corresponding two-dimensional DOLP distribution plot is shown below. Figure 5 As shown in the left figure.

[0058] (4) Binary quantization encoding: The real-time key is generated using a binary quantization strategy: the median or mean of the linear polarization distribution is used as the quantization threshold. If the linear polarization degree value of a certain pixel is greater than or equal to If it is less than 1, it is mapped to the number "1"; if ... If the value is 0, it is mapped to the number "0", thus generating a binary digital fingerprint. (The text then repeats the process of generating a fingerprint, which is redundant and can be omitted.) Figure 6 The two-color PUF key diagram is shown.

[0059] :like ,but (correspond Figure 6 (in black); like ,but (correspond Figure 6 (white in the middle) (5) Storage: Store the generated binary key graphs at different excitation angles into a secure database.

[0060] 2. Dynamic Authentication Phase

[0061] (1) Challenge Issuance: The server generates a random number pointing to a specific excitation polarization angle pre-stored in the database (e.g., And then send the angle command to the terminal device.

[0062] (2) Physical Response: After receiving the command, the terminal device adjusts the voltage of the liquid crystal modulation unit 100 through the driving circuit to precisely adjust the polarization state of the excitation light to... Irradiate the PUF device.

[0063] (3) Real-time generation: The terminal detection module performs the same data acquisition and processing procedures as the registration phase (image acquisition) DOLP calculation Binary quantization) generates the current response key in real time. .

[0064] (4) Comparison and verification: The terminal will The data is sent back to the server (or compared within the local security domain). The server retrieves the reference key stored in the database. Calculate the normalized Hamming distance between the two.

[0065] For a binary encoding system, if two keys are completely random and unrelated, their theoretical normalized Hamming distance should approach 0.5; if they are the same key, the theoretical Hamming distance should approach 0. The decision logic is: if HD(R) live ,R ref ) <HD threshold If the authentication passes, the authentication is successful; otherwise, the authentication fails.

[0066] To verify the technical effects of the embodiments of the present invention, the performance of the prepared CsPbI3-AAO-liquid crystal composite PUF device was tested.

[0067] Randomness and uniqueness verification: such as Figure 7 As shown, for the same device, under different excitation polarization angles (0°, 10°, and 30° as different physical challenges), the device outputs drastically different 20×20 pixel binary key bitmaps. Figure 7 (ac in the text). Statistical analysis of "inter-chip Hamming distance" was performed on keys generated by a large number of different devices. The results show (...). Figure 7 The histogram of the distribution of Hamming distance between slices (df) exhibits a perfect Gaussian distribution, with its average value closely approaching the ideal random value of 0.5 for binary encoding. This strongly confirms that using the "random orientation dipole" caused by the AAO confinement as an entropy source has extremely high unpredictability and individual variability.

[0068] To systematically evaluate the protective effect of PMMA packaging on device stability, two identical CsPbI3-AAO devices were fabricated. One group underwent in-situ PMMA spin-coating packaging (packaged group), while the other group did not undergo any packaging treatment (control group). Both groups of devices were exposed to a controlled environment with a relative humidity of 60% ± 5% and a temperature of 25°C ± 2°C.

[0069] At time points of 0, 7, 14, 21 and 30 days, the fluorescence peak intensity and the on-chip Hamming distance of the DOLP distribution plot of the two groups of devices were measured (with the key on day 0 as the reference).

[0070]

[0071] The data above shows that the packaged devices maintained over 90% fluorescence intensity after 30 days, and the on-chip Hamming distance of the key remained below 0.05 (far below the authentication threshold of 0.25), enabling reliable authentication. In contrast, the control group showed more than half of its fluorescence intensity decayed after 14 days and essentially lost its function after 30 days. This comparison strongly demonstrates the significant effectiveness of the PMMA in-situ spin-coating process in addressing the environmental stability issues of perovskite materials.

[0072] Example 4

[0073] 1. Communication-driven strategy

[0074] To prevent ion migration or electrode polarization in the liquid crystal material from causing device failure, this invention uses a zero-mean AC square wave as the driving signal.

[0075] Waveform parameters: Frequency set to 100Hz-1kHz, duty cycle of 50%, no DC bias component.

[0076] Voltage regulation: By adjusting the effective value amplitude (Vrms) of the square wave signal, the tilt angle of the liquid crystal molecules is precisely controlled within the linear response range of 1.0V to 4.0V.

[0077] 2. Dynamic Key Generation Process

[0078] Reference state (Mode 0): A signal with an amplitude of 0V is applied (or the voltage is removed). The liquid crystal molecules are initially aligned in parallel, the PUF outputs a reference texture, and the key Key-0 is generated.

[0079] Reconstructed state (Mode 1): An AC square wave with an amplitude of V1 is applied. The liquid crystal molecules are deflected under the balance of electric field force and anchoring force, changing the polarization ellipticity of the incident light and generating a key Key-1 that is completely different from Key-0.

[0080] Reconstruction state II (Mode 2): An AC square wave with an amplitude of V2 is applied. The tilt angle of the liquid crystal molecules further increases, generating an independent key Key-2.

[0081] Reconstructed state IIl (Mode 3): Apply an AC square wave with an amplitude of V3. Approaching the saturation region, generate key Key-3.

[0082] like Figure 8As shown, the AC modulation states range from an electrostatic field (0V) to different frequencies (100Hz, 1kHz) and amplitudes (4Vpp, 5Vpp). Comparing Figures a, b, c, and d, it is evident that even for the same physical entity, simply changing the amplitude or frequency of the driving voltage of the liquid crystal modulation unit significantly reconstructs the output binarized key pattern. This "one object, multiple codes" characteristic effectively verifies the polarization multiplexing logic and realizes the dynamic expansion of the CRP space.

[0083] Code Capacity (CRP Capacity): The CRP (Challenge-Response Pair) capacity of this device is determined by the following three mutually orthogonal physical parameters: The spatial entropy source (radix N) is determined by the "randomly oriented dipoles" of the perovskite nanosheets within the AAO nanopores. Each pixel (x, y) contains a massive number of nanopores. Due to the geometric confinement effect, the nanosheets are randomly sideways or tilted and stacked, forming a polarization-sensitive array that cannot be replicated at the microscale.

[0084] Polarization Multiplexing Challenge (Dimension M): Utilizing a liquid crystal modulation unit to alter the polarization state of the incident excitation light (e.g., rotating the linear polarization angle θ). ex According to Malus's law, only a subset of dipoles whose orientation matches the excitation polarization direction will be "lit up." Changing the polarization angle is equivalent to extracting independent feature patterns that do not interfere with each other within the same physical region.

[0085] Electric drive reconfiguration challenges (dimensions V / f): such as Figure 8 As shown, by adjusting the amplitude (Vrms) or frequency (f) of the driving voltage, the tilt angle and birefringence state of the liquid crystal molecules are changed, thereby altering the polarization ellipticity or phase delay of the incident light. This means that even in the same spatial coordinates, different electrical signal challenges will produce drastically different binary fingerprints.

[0086] Based on the above physical mechanism, the theoretical coding capacity C of this PUF can be calculated as follows:

[0087] N is the total number of feature pixels (e.g., ... M is the number of discrete polarization excitation channels (e.g., M=9 when the polarization step size is 10°). K is the number of electronically controlled drive states (independent challenge states formed by the combination of voltage amplitude V and frequency f).

[0088] To further verify the advantages of the polarization multiplexing dynamic PUF scheme of the present invention compared with existing dynamic PUF control methods, the following three schemes are compared and analyzed:

[0089] The comparative analysis above shows that the polarization multiplexing dynamic PUF scheme of the present invention has significant advantages over existing temperature control and time decay control schemes in terms of response speed, reconstruction reversibility, encoding dimensionality, environmental adaptability, and resistance to machine learning modeling attacks. Crucially, the "polarization-selective excitation" mechanism and the "geometric confinement orientation randomness" of the present invention have an inherent physical synergistic effect—only when the nanopoles within the AAO channel have a random orientation distribution can excitation light of different polarization states selectively "illuminate" different subsets of dipoles, thereby generating independent, uncorrelated key channels.

[0090] In summary, this invention proposes a dynamic PUF device based on a synergistic mechanism of geometric confinement and source-end polarization multiplexing. A high-dimensional physical entropy source is constructed by microscopically forcing nanomaterials to randomly tilt; dynamic key generation is achieved macroscopically by integrating liquid crystal polarization modulation.

[0091] This solution not only significantly enhances the anti-counterfeiting and anti-attack capabilities of the hardware security system, but also solves the problems of material stability and device manufacturing cost through PMMA in-situ integration technology, making it extremely valuable for industrial applications.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polarization multiplexing dynamic PUF device based on AAO confined perovskite, characterized in that, include: A liquid crystal modulation unit (100) and an emissive layer unit (200) are stacked together. The liquid crystal modulation unit (100) is electrically connected to an external driving circuit and is configured to modulate the polarization state of the incident excitation light under different driving voltages, thereby achieving polarization angle rotation or signal hiding. The light-emitting layer unit (200) includes a substrate (201), an AAO template (202), an anisotropic light-emitting nanomaterial (203) filled in the nanopores of the AAO template (202), and a polymer encapsulation layer (204) located on the surface of the AAO template (202). The anisotropic luminescent nanomaterial (203) forms a polarization-sensitive random luminescent array under the geometric confinement effect in the nanopores; the polymer encapsulation layer (204) fills the micropores on the surface of the AAO template and forms a protective layer, and the luminescent layer unit (200) is connected to the light-emitting side surface of the liquid crystal modulation unit (100).

2. The polarization multiplexing dynamic PUF device based on AAO confined perovskite as described in claim 1, characterized in that, The anisotropic luminescent nanomaterials (203) are randomly stacked in a sideways or inclined state along the long axis of the nanopores under the geometric confinement of the nanopores, forming a polarization-sensitive array with randomly oriented dipoles.

3. The polarization-multiplexing dynamic PUF device based on AAO-confined perovskite as described in claim 1 or 2, characterized in that, The anisotropic luminescent nanomaterial (203) is selected from all-inorganic perovskite nanosheets or II-VI group semiconductor nanorods with linearly polarized luminescence characteristics; the AAO template (202) has a pore size of 100nm-250nm, and the pore size is matched with the size of the anisotropic luminescent nanomaterial to generate a steric hindrance effect.

4. The polarization multiplexing dynamic PUF device based on AAO confined perovskite as described in claim 1, characterized in that, The polymer encapsulation layer (204) is made of polymethyl methacrylate (PMMA). The polymer encapsulation layer (204) is a hydrophobic barrier layer formed by in-situ spin coating. The adhesion of the polymer encapsulation layer (204) is used to physically bond the light-emitting layer unit (200) to the glass substrate of the liquid crystal modulation unit (100).

5. A method for fabricating a polarization-multiplexed dynamic PUF device based on AAO-confined perovskite as described in any one of claims 1-4, characterized in that, Includes the following steps: Step S1: Place the AAO template on the substrate, cover the surface of the AAO template with a cover sheet, and apply vertical pressure over the cover sheet; Step S2: A colloidal solution containing anisotropic luminescent nanomaterials is dropped onto the contact edge between the cover plate and the AAO template. The solution is spread into the interface by lateral capillary force, and the solution is drawn into the depth of the pores by longitudinal capillary force of the nanopores. Step S3: During the solvent evaporation process, the geometric constraints of the AAO template pore walls are used to cause the anisotropic luminescent nanomaterials to physically flip and randomly stack along the pore direction. After the solvent has completely evaporated, the cover is removed to form a filling layer with randomly locked orientation. Step S4: A polymer solution is dropped onto the surface of the AAO template and spin-coated to form a polymer encapsulation layer. The AAO template is then bonded to the surface of the prefabricated liquid crystal modulation unit using the adhesive properties of the polymer encapsulation layer.

6. The preparation method according to claim 5, characterized in that, In step S4, the polymer solution is a polymethyl methacrylate (PMMA) solution. After spin coating, the PMMA penetrates into the micropores of the AAO template surface to form a hydrophobic protective film.

7. A certification system based on the polarization multiplexing dynamic PUF device according to any one of claims 1-4, characterized in that, include: On the server side, it is used to generate challenge signals containing working mode instructions and excitation polarization angle instructions, and stores a preset reference key database. The terminal device includes the PUF device, an electronically controlled drive module, and a detection module; the electronically controlled drive module is used to receive the challenge signal and is configured to output a frequency-adjustable AC square wave drive signal to the liquid crystal modulation unit; the detection module is used to acquire the fluorescence intensity matrix of the PUF device under the excitation light and extract the linear polarization feature map. The authentication system is configured to quantize the linear polarization feature map into a binary real-time key and calculate the Hamming distance between the real-time key and the corresponding reference key in the reference key database. If the Hamming distance is less than a preset threshold, the authentication is successful.

8. The authentication system as described in claim 7, characterized in that, The electronically controlled drive module is configured to: in authentication mode, output an AC square wave with an amplitude of a first working voltage to modulate the excitation light into linearly polarized light at a corresponding angle; in reconstruction mode, output an AC square wave with an amplitude of a second working voltage to change the birefringence state of the liquid crystal molecules to generate a new key.

9. The authentication system as described in claim 7, characterized in that, The formula for calculating the linear polarization degree is: in, and These represent the maximum and minimum fluorescence intensities of a pixel at different detection angles.

10. The authentication system as described in claim 7, characterized in that, The process of quantizing the linear polarization feature map into a binary real-time key uses the median or mean of the statistical linear polarization distribution map as the quantization threshold. If the linear polarization degree value of a certain pixel is greater than or equal to If it is less than 1, it is mapped to the number "1"; if ... If the value is 0, it is mapped to the number "0", thus generating a binary digital fingerprint.

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