A security tag, a security system comprising the same, a method of manufacture and use

Abstract

The present application relates to a kind of anti-counterfeit labels, the anti-counterfeit system comprising it, preparation method and purposes.The anti-counterfeit label includes the two-dimensional chalcogen nanocrystal film of chemical formula MX n , the MX n Crystal of triangle type is dispersed in the two-dimensional chalcogen nanocrystal film, the MX n Crystal is randomly stacked, spliced to form two-dimensional chalcogen nanocrystal film.The anti-counterfeit label has random binary matrix, and spatial coding density is high, can carry more coding information, can be used for safer anti-counterfeit label and higher efficiency information encryption.

Description

Technical Field

[0001] This invention relates to the field of anti-counterfeiting, specifically to an anti-counterfeiting label, an anti-counterfeiting system including the label, a preparation method therein, and its uses. Background Technology

[0002] The core idea of ​​Physically Unclonable Functions (PUFs) is to utilize unavoidable, randomly distributed physical defects (such as microstructural inhomogeneities) during the fabrication process to generate a unique and unpredictable response signal, much like a "physical fingerprint." PUFs make each tag naturally unique and impossible to clone or replicate. In the field of anti-counterfeiting authentication, optical anti-counterfeiting tags based on physically unclonable functions have become the preferred choice due to their uncopyable uniqueness. In existing technologies, one type of PUF mainly relies on randomly distributed three-dimensional scattering particles within the material or complex three-dimensional micro / nano structures on the surface, generating unique speckle patterns under specific light irradiation as identification features. This relies on micrometer-scale structures and far-field optics, resulting in low spatial coding density (typically <1 bit / μm). 2 (It has limited information entropy and insufficient resistance to attacks.)

[0003] There is a need in this field to develop a PUF technology with nanometer-level spatial resolution and higher spatial coding density to improve encryption security and information storage efficiency. Summary of the Invention

[0004] To address the shortcomings of existing technologies, one objective of this invention is to provide an anti-counterfeiting label, wherein the anti-counterfeiting label comprises chemical formula MX n Two-dimensional chalcogenide nanocrystalline thin films, wherein M is Mo or W, X is S or Se, and n is any value between 1 and 2;

[0005] The two-dimensional chalcogenide nanocrystalline film contains triangular-like MX particles. n Crystal, the MX n Crystals are randomly stacked and spliced ​​to form a two-dimensional chalcogenide nanocrystalline thin film.

[0006] The anti-counterfeiting label provided in this application utilizes randomly stacked and spliced ​​MX... n The crystal formation layer exhibits randomized thickness, interlayer spacing, size, defects, and angles in a two-dimensional chalcogenide nanocrystalline film. Due to the randomness of the structural characteristics of the crystal at each location, it emits a spectrum of random light intensity and wavelength after receiving laser irradiation, becoming a naturally unique and unreplicable physical non-clonable function as an anti-counterfeiting label. The anti-counterfeiting label provided in this application possesses five dimensions of performance randomness (five-dimensional chaos), thus enabling it to carry more information and achieve a higher spatial coding density.

[0007] The MX nWhen a crystal is defect-free, it has a hexagonal lattice structure. When defects are present, such as Mo site defects (where a molybdenum atom is missing or replaced by another element, such as sulfur), or S site defects (where a sulfur atom is missing or replaced by another element, such as molybdenum), the hexagonal lattice structure appears triangular or triangular-like when viewed in two dimensions.

[0008] Preferably, the domain size of the two-dimensional chalcogenide nanocrystalline thin film is ≤70nm, typically but not limited to 58nm, 55nm, 52nm, 48nm, 42nm, 37nm, 30nm, 25nm, 18nm, 14nm, 10nm, etc.

[0009] Crystal domains below 70nm can reduce the pixel size of spatial coding and increase coding capacity.

[0010] The thin film exhibits randomness in five dimensions: thickness, domain size, domain orientation, domain atomic defects, and interlayer distance. This imparts the performance of the two-dimensional chalcogen nanocrystalline film PUF, resulting in a high spatial coding density for the anti-counterfeiting label.

[0011] Preferably, the thickness of the two-dimensional chalcogen nanocrystalline film at any position is randomly selected from the range of 0.7~5nm, for example, randomly selected from 0.8nm, 1.0nm, 1.3nm, 1.8nm, 2.2nm, 2.7nm, 3.3nm, 3.8nm, 4.5nm, 4.8nm, etc.

[0012] Preferably, the size of the crystal domains at any position of the two-dimensional chalcogenide nanocrystalline thin film is randomly selected from the range of 10 to 70 nm, for example, randomly selected from 12 nm, 18 nm, 24 nm, 29 nm, 35 nm, 41 nm, 45 nm, 48 nm, 55 nm, etc.

[0013] Preferably, the orientation of the two-dimensional chalcogen nanocrystalline film at any position is randomly selected from the range of 0 to 60°, for example, randomly selected from 3°, 16°, 26°, 30°, 35°, 38°, 42°, 45°, 48°, 54°, 58°, etc.

[0014] Preferably, the atomic defects at any position of the two-dimensional chalcogenide nanocrystalline film are randomly selected from the range of no defects, Mo site defects, or S site defects.

[0015] Preferably, the interlayer spacing at any position of the two-dimensional chalcogenide nanocrystalline film is randomly selected from the range of 0.6~0.7nm, for example, randomly selected from 0.61nm, 0.62nm, 0.63nm, 0.64nm, 0.65nm, 0.66nm, 0.67nm, 0.68nm, 0.69nm, etc.

[0016] The anti-counterfeiting label provided in this application has the characteristics of long-range order and short-range disorder, which makes the label have high spatial coding density characteristics.

[0017] Preferably, the photoluminescence intensity of the photoluminescence spectrum at any position of the two-dimensional chalcogenide nanocrystalline film is different.

[0018] Preferably, the photoluminescence wavelengths at any position of the two-dimensional chalcogenide nanocrystalline film are different.

[0019] Preferably, the morphological height of the two-dimensional chalcogenide nanocrystalline film is different at any position.

[0020] The randomness of the microscopic structure causes the anti-counterfeiting label to emit a random emission spectrum when excited by excitation light, and the intensity and wavelength of the emission spectrum are also random. Furthermore, due to the random distribution of thickness, its morphological height also varies.

[0021] In an optional embodiment, the anti-counterfeiting label further includes a substrate.

[0022] Preferably, the substrate includes any one or a combination of at least two of the following: sapphire substrate, silicon substrate, and polyimide substrate.

[0023] It should be noted that the anti-counterfeiting label described in this application can be directly set on the object to be protected against counterfeiting / encryption, or it can be set on the object to be encrypted or protected against counterfeiting together with the substrate. For example, when an encryption chip is required, the chip's substrate can be used as the base to directly set the two-dimensional chalcogenide nanocrystalline film of the anti-counterfeiting label, or a substrate with the two-dimensional chalcogenide nanocrystalline film transferred thereon can be set on the chip's substrate.

[0024] The method for preparing the anti-counterfeiting label (where M is molybdenum) described in one of the purposes of this application can be exemplarily carried out according to the following steps:

[0025] (1) Prepare an aqueous solution of 3~4 mg / mL of ammonium salt of M acid ion to obtain a metal source solution; treat the alumina substrate with oxygen plasma to obtain a growth substrate;

[0026] (2) Spin-coating the metal source solution onto the growth substrate (the distribution density of the M element on the surface of the M source growth substrate is 1.2~1.6µg / cm³). 2 On the metal source, the temperature is raised to volatilize the ammonium in the metal source, and the temperature is held (770~830℃, 4~6min) to pyrolyze the metal source into metal oxide nanoclusters, which react with the alumina substrate to form Al-OM bonds, thus obtaining the metal source precursor.

[0027] (3) Place the metal source precursor in an inert atmosphere and heat it to MX.n The growth temperature was maintained at 770~830℃ for 13~17 min, and an X-carrying gas source was introduced to maintain the growth temperature for MX growth. n Two-dimensional chalcogenide nanocrystalline thin film.

[0028] The second objective of this application is to provide an anti-counterfeiting system, including:

[0029] Anti-counterfeiting labels as described in one of the purposes;

[0030] A light source used to generate excitation light;

[0031] Receiver, used to detect photoluminescence;

[0032] The processor is used to digitize the emission spectrum received by the receiver.

[0033] The anti-counterfeiting system provided in this application involves an anti-counterfeiting label being placed on an object to be protected against counterfeiting or encrypted. A light source is used to emit excitation light to scan the anti-counterfeiting label when authentication is required. After being excited by the excitation light, the anti-counterfeiting label emits emitted light. A receiver receives the emitted light to form a spectrum, and a processor digitizes the spectrum to obtain a key.

[0034] Preferably, the pixel size of the anti-counterfeiting label is 10nm × 10nm. That is, the pixel size of the anti-counterfeiting label scanned by the excitation light is 10nm × 10nm. Therefore, the size of the anti-counterfeiting label only needs to be able to present complete pixels, and there is no upper limit.

[0035] Preferably, the emission wavelength of the light source is 500~650nm, more preferably 532.0nm or 632.8nm.

[0036] Preferably, the intensity of the light source is 0.4~0.6 mw / µm. 2 For example, 0.42mw / µm 2 0.45mw / µm 2 0.47mw / µm 2 0.54mw / µm 2 0.58mw / µm 2 etc., preferably 0.5mw / µm 2 .

[0037] A typical but not limiting light source is tip-enhanced photoluminescence (TEPL), which can be achieved using a gold-plated TERS probe (Horiba OMNIAC-RT-NANOP, tip radius ≤10 nm, resonant frequency 320±50 kHz, spring constant 40 N / m) on an atomic force microscope-Raman (AFM-Raman) system. A 532 nm laser (power density 0.5 mW / µm) is focused through a 100x numerical aperture (NA) 0.9 objective lens. 2 ), to obtain excitation light.

[0038] Preferably, the light spot size of the light source is 10nm ± 1nm. The light spot size of the light source matches the pixel size of the anti-counterfeiting label to accurately excite and receive the emitted light from the anti-counterfeiting label.

[0039] Preferably, the receiver is a Raman spectrometer.

[0040] In one optional embodiment, the processor's processing steps include a luminescence intensity processing module for the photoluminescence spectrum, the processing steps including:

[0041] S1 uses the size of the light spot from the light source as a pixel and reads the luminous intensity I of the photoluminescence spectrum of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer;

[0042] S2 calculates the average luminous intensity I of the entire anti-counterfeiting label. 均 ;

[0043] S3 determines the luminous intensity of each pixel. n With average luminous intensity I 均 The relationship, when I n ≥I 均 , denoted as 0, when I n <I 均 , denoted as 1, obtain the light intensity binary matrix key Key1.

[0044] Preferably, after step S3, step S4 is performed to generate a light intensity key QR code based on the obtained light intensity binary matrix key Key1.

[0045] In one optional implementation, the processor's processing steps include a photoluminescence wavelength processing module:

[0046] T1 uses the size of the light spot from the light source as a pixel and reads the emission wavelength λ of the photoluminescence spectrum of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer;

[0047] T2 calculates the average emission wavelength λ of the entire anti-counterfeiting label.均 ;

[0048] T3 determines the emission wavelength λ of each pixel. n With average emission wavelength λ 均 The relationship when λ n ≥λ 均 , denoted as 0, when λ n <λ 均 , denoted as 1, obtain the wavelength binary matrix key Key2.

[0049] Preferably, after step T3, step T4 is performed to generate a wavelength key QR code based on the obtained wavelength binary matrix key Key2.

[0050] In one optional implementation, the processor's processing steps include a topography height processing module:

[0051] K1 uses the size of the light spot from the light source as a pixel, and reads the shape and height H of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer;

[0052] K2 calculates the average morphological height H of the entire anti-counterfeiting label. 均 ;

[0053] K3 determines the shape height H of each pixel. n With average morphological height H 均 The relationship when H n ≥H 均 , denoted as 0, when H n <H 均 , denoted as 1, obtain the high-order binary matrix key Key3.

[0054] Preferably, after step K3, step K4 is performed to generate a height key QR code based on the obtained height binary matrix key Key3.

[0055] It should be noted that the processing steps of the processor may include any one or a combination of at least two of the following: the luminescence intensity processing module of the photoluminescence spectrum, the luminescence wavelength processing module of the photoluminescence spectrum, and the morphology height processing module, which can generate any one or a combination of at least two of Key1, Key2, and Key3.

[0056] Preferably, the processor's processing steps further include a matrix multiplication module:

[0057] By performing pairwise matrix multiplication of the light intensity binary matrix key Key1, the wavelength binary matrix key Key2, and the height binary matrix key Key3, a 15-key sequence is obtained.

[0058] It can be seen that the anti-counterfeiting label provided by this application has three characterization signals at the same position. After signal processing, three basic keys can be obtained. After matrix multiplication, 15 keys can be obtained, resulting in high spatial coding density. On the other hand, the anti-counterfeiting label provided by this application has a pixel size of 10nm×10nm, which is small and can achieve nanometer-level spatial resolution.

[0059] The third objective of this application is to provide an anti-counterfeiting label as described in the first objective or an anti-counterfeiting system as described in the second objective, wherein the anti-counterfeiting label and / or anti-counterfeiting system is used for any one or at least two of anti-counterfeiting and identity authentication, information encryption, and key generation, preferably for encrypting chips, satellite communication modules, luxury goods, and classified graphics and text.

[0060] The key generation refers to using key information obtained from anti-counterfeiting labels or anti-counterfeiting systems as a unique and uncopyable key.

[0061] The fourth objective of this application is to provide a chip, wherein the substrate of the chip is provided with an anti-counterfeiting label as described in the first objective.

[0062] Compared with the prior art, this application has the following beneficial effects:

[0063] (1) The anti-counterfeiting label provided in this application has a random binary matrix and a high spatial coding density, which can carry more coding information and can be used for more secure anti-counterfeiting labels and more efficient information encryption.

[0064] (2) The anti-counterfeiting label provided in this application is based on a two-dimensional chalcogen nanocrystalline thin film, which has a stable structure and nanoscale spatial resolution. It has a wide range of applications, especially for encryption and / or anti-counterfeiting of small-sized targets (such as chips). Attached Figure Description

[0065] Figure 1 These are wafer photographs showing the transformation of ammonium molybdate film into molybdenum disulfide film during the label fabrication process. A is a wafer photograph of ammonium molybdate film, B is a wafer photograph of MoOx cluster film, and C is a wafer photograph of molybdenum disulfide film.

[0066] Figure 2 AFM images of the MoS2 two-dimensional nanocrystalline thin film obtained in Example 1 are presented in six regions;

[0067] Figure 3 The luminescence intensity diagram of the photoluminescence spectrum of Example 1 is given;

[0068] Figure 4 The binary matrix key diagram of the photoluminescence spectrum of Example 1 is given;

[0069] Figure 5The emission wavelength diagram of the photoluminescence spectrum of Example 2 is given, with the vertical axis representing the normalized relative emission wavelength;

[0070] Figure 6 The wavelength binary matrix key diagram of the photoluminescence spectrum in Example 2 is given;

[0071] Figure 7 Nanoscale morphology height diagrams of Example 3 are provided, with the vertical axis in nm.

[0072] Figure 8 The high-resolution binary matrix key diagram of Example 3 is given;

[0073] Figure 9 The new binary matrix key matrix obtained by multiplying the Key2 and Key3 matrices (B×C) is given.

[0074] Figure 10 for Figure 9 The binary matrix key matrix generated from the binary matrix key matrix;

[0075] Figure 11 The test results of bit uniformity of the 100 PUF keys provided in Example 1 are shown in the figure;

[0076] Figure 12 The inter-chip Hamming distances for the 100 PUF keys provided in Example 1 are given;

[0077] Figure 13 The on-chip Hamming distances for the 100 PUF keys provided in Example 1 are given;

[0078] Figure 14 Pearson correlation coefficient plots for the 100 PUF keys provided in Example 1 are given. Detailed Implementation

[0079] The technical solution of the present invention will be further explained and described below with reference to specific embodiments. However, it should be noted that the specific embodiments are only a specific implementation and explanation of the essence of the technical solution of the present invention, and should not be construed as a limitation on the scope of protection of the present invention.

[0080] The reagents and instruments used in the examples are all commercially available, and the detection methods are conventional methods well known in the art.

[0081] Preparation Example

[0082] A method for preparing a two-dimensional MoS2 nanocrystalline thin film, comprising:

[0083] (1) Select ammonium molybdate as the source of M, and prepare an aqueous solution of the ammonium molybdate (concentration 3.5 mg / mL) to obtain the source of M solution;

[0084] (2) A 2-inch alumina substrate was subjected to oxygen plasma treatment (power 90W, time 8min) to obtain a growth substrate. The M source solution was then spin-coated (3000rpm, 60s) onto the growth substrate (the distribution density of Mo element is 1.4µg / cm³). 2 The temperature is raised to 800℃ and held for 5 minutes to volatilize the ammonium in source M and to pyrolyze source M into MO. y Nanoclusters were formed and reacted with an alumina substrate to generate Al-OM bonds, thus obtaining the M-source precursor.

[0085] (3) The M source precursor is placed in the high-temperature zone (target temperature 800℃) of a dual-temperature zone tube furnace, and the sulfur powder is placed in the low-temperature zone (target temperature 150℃). Argon gas (300 sccm) is introduced for 10 min to obtain an inert atmosphere, and the temperature is increased to MX at a rate of 30℃ / min. n The growth temperature (i.e., the target temperature) is set. Sulfur powder in the low-temperature zone volatilizes. The argon flow rate is adjusted to 80 sccm, and the argon flow carries sulfur vapor into the high-temperature zone. The zone is held for 15 minutes to grow MX. n Two-dimensional chalcogenide nanocrystalline thin film.

[0086] Performance characterization:

[0087] (1) Macroscopic photographs: Figure 1 Optical images of the thin films on the growth substrates in steps (1), (2), and (3) are given, where A is the ammonium molybdate thin film in step (1), and B is the MoO2 thin film in step (2). x The intermediate nanocluster, C is the MoS2 thin film from step (3). It can be seen that the two-dimensional MoS2 nanocrystalline thin film prepared in Example 1 has macroscopic uniformity.

[0088] (2) MX n Two-dimensional chalcogenide nanocrystalline films were subjected to AFM scanning with a scanning range of 1 μm × 1 μm, a scanning rate of 0.5–1 Hz, and a resolution of 512 × 512 pixels. To evaluate the uniformity and surface roughness of the film, six different locations were randomly selected on the sample surface for scanning to obtain height maps.

[0089] Figure 2 AFM images of the MoS2 two-dimensional nanocrystalline film obtained in Preparation Example 1, collected from six random regions, are presented. It can be seen that the MoS2 two-dimensional nanocrystalline film prepared in Preparation Example 1 exhibits randomness in thickness, morphology, domain size, dimensions, and orientation.

[0090] Example 1

[0091] An anti-counterfeiting system, comprising:

[0092] MX obtained from Preparation Example 1 n One hundred non-repeating 320nm×320nm regions were selected on the two-dimensional chalcogen nanocrystalline film as anti-counterfeiting labels 100;

[0093] The light source was 200, using a gold-plated TERS probe (HoribaOMNIAC-RT-NANOP, tip radius 10 nm, resonant frequency 320±50 kHz, spring constant 40 N / m) equipped with an atomic force microscope-Raman (AFM-Raman) system. A 532 nm laser (power density 0.5 mW / µm) was focused through a 100x numerical aperture (NA) 0.9 objective lens. 2 ), to obtain a tip-enhanced photoluminescence source;

[0094] The receiver 300 uses a 600-line / mm grating and a liquid nitrogen-cooled charge-coupled device detector to receive photoluminescence spectra.

[0095] Processor 400 includes an intensity processing module for photoluminescence spectra, and the processing steps include:

[0096] S1 uses the spot size of the light source 200 as pixel 101 to read the luminous intensity I of the photoluminescence spectrum of each pixel 101 of the anti-counterfeiting label. n n is the position index of each pixel 101, and n is a positive integer; Figure 3 The luminescence intensity diagram of the photoluminescence spectrum of Example 1 is given, with the vertical axis representing the normalized relative luminescence intensity;

[0097] S2 calculates the average luminous intensity I of the entire anti-counterfeiting label 100. 均 ;I 均 For each pixel, I = 101 n The average of the numbers;

[0098] S3 determines the luminous intensity of each pixel. n With average luminous intensity I 均 The relationship, when I n ≥I 均 , denoted as 0, when I n <I 均 , denoted as 1, obtain the light intensity binary matrix key Key1, Figure 4 The photoluminescence spectrum intensity binary matrix key diagram of Example 1 is given.

[0099] Example 2

[0100] The difference in Example 1 lies in the processor 400, which includes a wavelength processing module for photoluminescence spectrum, and the processing steps include:

[0101] T1 uses the size of the light spot from the light source as a pixel and reads the emission wavelength λ of the photoluminescence spectrum of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer; Figure 5 The emission wavelength diagram of the photoluminescence spectrum of Example 2 is given, with the vertical axis in nm;

[0102] T2 calculates the average emission wavelength λ of the entire anti-counterfeiting label. 均 ;λ 均 For each pixel, I = 101 n The average of the numbers;

[0103] T3 determines the emission wavelength λ of each pixel. n With average emission wavelength λ 均 The relationship when λ n ≥λ 均 , denoted as 0, when λ n <λ 均 Let 1 be the value of the wavelength binary matrix key Key2. Figure 6 The wavelength binary matrix key diagram of the photoluminescence spectrum of Example 2 is given.

[0104] Example 3

[0105] The difference in Example 1 lies in the processor 400, which includes a topography height processing module, and the processing steps include:

[0106] K1 uses the size of the light spot from the light source as a pixel, and reads the shape and height H of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer; Figure 7 Nanoscale morphology height diagrams of Example 3 are provided, with the vertical axis in nm.

[0107] K2 calculates the average morphological height H of the entire anti-counterfeiting label. 均 ;

[0108] K3 determines the shape height H of each pixel. n With average morphological height H 均 The relationship when H n ≥H 均 , denoted as 0, when H n <H 均 , denoted as 1, obtain the high-order binary matrix key Key3. Figure 8 The high-resolution binary matrix key diagram of Example 3 is given.

[0109] Example 4

[0110] The difference in Example 1 is that the processor 400 also includes an intensity processing module for photoluminescence spectrum, a wavelength processing module for photoluminescence spectrum, a morphology height processing module, and a matrix multiplication module.

[0111] Multiply the three binary keys—light intensity key1 (denoted as matrix A), wavelength key2 (denoted as matrix B), and height key3 (denoted as matrix C)—by matrix multiplication to obtain 12 new key matrices: A×B, B×A, A×C, C×A, B×C, C×B, A×B×C, A×C×B, B×C×A, C×B×A, B×A×C, and C×A×B.

[0112] Calculate the average value for each key matrix, then convert pixels greater than the average value to 1 and pixels less than the average value to 0, thus obtaining a binary key matrix. Figure 9 The new binary matrix key matrix obtained by multiplying the Key2 and Key3 matrices (B×C) is given, with the vertical axis having the dimensionless unit of 1; Figure 10 for Figure 9 The binary key matrix generated from the binary key matrix.

[0113] Comparative Example 1

[0114] A reconfigurable scattering optical PUF is provided, with the encoding material being an organic liquid crystal phase change material. The pixel size is 1.7 mm, and the fabrication method is referenced from "All-Optical Multilevel Physical Unclonable Functions" in Nature Materials 2024, Vol. 23, p. 369 (Nat. Nanotechnol. 2023, 18, 1027.).

[0115] Comparative Example 2

[0116] A multicolor optical PUF is provided, with carbon quantum dots as the encoding material and a pixel size of 2μm. The preparation method is described in "Integrated Nanoprinting Method for Synthesis of Nanofilm Library for Non-cloning Anti-counterfeiting Applications" in Nature Nanotechnology, 2023, Vol. 18, p. 1027.

[0117] Comparative Example 3

[0118] A multicolor fluorescent optical PUF is provided, with the encoding material being a rare-earth-doped silica composite. The pixel size is 10 μm. The fabrication method is described in "Bionic Microtexture Replication and RE of Non-clonable Silica Nanocomposites" (Advanced Materials, 2023, Vol. 35, p. 2306003). 3+Spatial selective doping and its application in multi-level encrypted smart authentication (Advanced Materials 2023, 35, 2306003.).

[0119] It can be seen that the pixel size of Comparative Example 1, Comparative Example 2 and Comparative Example 3 is much larger than the pixel size of 10nm in this application.

[0120] Performance testing:

[0121] (1) Bit uniformity: The bit uniformity of the PUF keys provided in Examples 1-4 was calculated using formula (1) to evaluate the entropy source quality of the keys;

[0122] (1)

[0123] Bit Uniformity refers to the uniformity of bits; N0 is the total number of '0' bits in the binary sequence; N1 is the total number of '1' bits in the binary sequence; and N is the total length of the sequence (where N = N0 + N1).

[0124] Figure 11 The test results of the bit uniformity of the 100 PUF keys provided in Example 1 are shown in the figure. Figure 11 As can be seen, the proportion of 0 and 1 is in the range of 0.49 to 0.51, close to 0.5, indicating that the generated key has high entropy source quality. This verifies that the PUF structure of this invention can generate keys with high entropy source quality, laying a solid foundation for hardware security applications.

[0125] The bit uniformity of the PUF keys in Examples 2, 3, and 4 is around 0.5, meaning they can also generate keys with high entropy source quality.

[0126] (2) Hamming distance distribution between and within devices: The inter-chip Hamming distance of the PUF key was calculated using formula (2) to evaluate the randomness of the key; the intra-chip Hamming distance of the PUF key was calculated using formula (3) to evaluate the readability of the key;

[0127] (2)

[0128] (3)

[0129] In equation (2), InterHD (A,B) is the inter-film Hamming distance, R A R B Let R be the binary response sequence of different tags (tag A and tag B) in PUF, where n is the bit length of the response sequence, ⊕ is the XOR operation, and R is the bit length of the response sequence. A (i) ≠RB (i) If the result is 1, the result is 0 otherwise.

[0130] In equation (3), IntraHD (A) is the intra-film Hamming distance, R A1 R A2 This refers to two binary response sequences generated under ambient atmospheric conditions for the same PUF and the same tag (A tag), where n is the bit length of the response sequence, and ⊕ is the XOR operation. A1 (i) ≠R A2 (i) If the result is 1, the result is 0 otherwise.

[0131] Figure 12 The inter-chip Hamming distances of the 100 PUF keys provided in Example 1 are given. It can be seen that the inter-chip Hamming distances are distributed in the range of 0.405 to 0.615, exhibiting a normal distribution, with a median value of 0.4989, close to 0.5, indicating that the generated keys have high randomness. This verifies that the PUF structure of the present invention can generate random and unique keys, laying a solid foundation for hardware security applications.

[0132] The inter-chip Hamming distance of the PUF keys in Examples 2, 3, and 4 are all around 0.5, which all have high randomness and can generate random and unique keys, laying a solid foundation for hardware security applications.

[0133] Figure 13 The intra-chip Hamming distances of the 100 PUF keys provided in Example 1 are given. It can be seen that their inter-chip Hamming distances are distributed in the range of 0 to 0.00782, exhibiting a normal distribution, with a median value of 2.54 × 10⁻⁶. -3 The value is close to 0, indicating that the generated key has high readability. This verifies that the PUF structure of this invention can generate repeatedly readable keys, laying a solid foundation for hardware security applications.

[0134] The PUF keys in Examples 2, 3, and 4 all have similar inter-chip Hamming distances, high readability, and are repeatedly readable, laying a solid foundation for hardware security applications.

[0135] (3) Pearson correlation coefficient: The Pearson correlation coefficient of the PUF key was calculated using formula (4) to evaluate the predictability of the key;

[0136] (4)

[0137] In equation (4), Φ is the Pearson correlation coefficient; n 11 n is the number of positions in both matrix A and matrix B that are simultaneously 1. 00n is the number of positions in both matrix A and matrix B that are simultaneously zero. 10 n represents the number of positions in matrix A where A is 1 and matrix B is 0. 01 n is the number of positions in matrix A where A is 0 and matrix B is 1. 1• Let n be the total number of 1s in matrix A. 0• Let n be the total number of 0s in matrix A. •1 Let n be the total number of 1s in matrix B. •0 Let be the total number of 0s in matrix B.

[0138] Figure 14 The Pearson correlation coefficient plots for the 100 PUF keys provided in Example 1 are given. It can be seen that the Pearson correlation coefficients are distributed in the range of -0.15 to 0.15, exhibiting a normal distribution, with a median value of 2.00 × 10⁻⁶. -4 The value is close to 0, indicating that the generated key has high unpredictability. This verifies that the PUF structure of this invention can generate unpredictable keys with low correlation, laying a solid foundation for hardware security applications.

[0139] The Pearson correlation coefficients of the PUF keys in Examples 2, 3, and 4 are all close to 0, exhibiting high unpredictability and generating unpredictable keys with low correlation, thus laying a solid foundation for hardware security applications.

[0140] (4) Coding density: The spatial coding density of Example 1 and Comparative Examples 1-3 was calculated using formula (5) for evaluation.

[0141] (5)

[0142] In equation (5), A is the unit area and B is the number of bits per unit area.

[0143] Measurements show that the spatial coding density of the PUF key in this application reaches 1.5 × 10⁻⁶. 5 bits / µm 2 The spatial coding density is 3.46 × 10⁻⁶, while Comparative Example 1 is 3.46 × 10⁻⁶. -6 bits / µm 2 Comparative Example 2 is 1 bit / µm 2 Comparative Example 3 shows 0.1 bits / µm 2 It can be seen that the spatial coding density of the PUF key in this application is increased by approximately 10% compared to Comparative Example 1. 11 This represents an improvement of approximately 10 times compared to Comparative Examples 2 and 3. 5 ~10 6 This may be because the PUF key provided in this application has ultra-small cryptographic primitives (i.e., pixels) exhibiting multidimensional chaotic characteristics on a spatial scale of 10nm.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An anti-counterfeiting label, characterized in that, The anti-counterfeiting label includes a chemical formula MX n Two-dimensional chalcogenide nanocrystalline thin films, wherein M is Mo or W, X is S or Se, and n is any value between 1 and 2; The two-dimensional chalcogenide nanocrystalline film contains triangular-like MX particles. n Crystal, the MX n Crystals are randomly stacked and spliced ​​to form a two-dimensional chalcogenide nanocrystalline thin film.

2. The anti-counterfeiting label as described in claim 1, characterized in that, The domain size of the two-dimensional chalcogenide nanocrystalline film is ≤70nm; The thin film exhibits randomness in five dimensions: thickness, domain size, domain orientation, domain atomic defects, and interlayer distance at any location. Preferably, the thickness of the two-dimensional chalcogenide nanocrystalline film at any location is randomly selected from the range of 0.7~5 nm; Preferably, the domain size at any position of the two-dimensional chalcogenide nanocrystalline film is randomly selected from the range of 10~70 nm; Preferably, the orientation of the two-dimensional chalcogenide nanocrystalline film at any position is randomly selected from the range of 0 to 60°. Preferably, the atomic defects at any position of the two-dimensional chalcogenide nanocrystalline film are randomly selected from the range of no defects, Mo site defects, or S site defects. Preferably, the interlayer spacing at any position of the two-dimensional chalcogenide nanocrystalline film is randomly selected from the range of 0.6~0.7 nm.

3. The anti-counterfeiting label as described in claim 1 or 2, characterized in that, The photoluminescence intensity of the two-dimensional chalcogenide nanocrystalline thin film is different at any position; Preferably, the photoluminescence wavelengths at any position of the two-dimensional chalcogenide nanocrystalline film are different; Preferably, the morphological height of the two-dimensional chalcogenide nanocrystalline film is different at any position.

4. The anti-counterfeiting label as described in any one of claims 1 to 3, characterized in that, The anti-counterfeiting label also includes a substrate; Preferably, the substrate includes any one or a combination of at least two of the following: sapphire substrate, silicon substrate, and polyimide substrate.

5. An anti-counterfeiting system, characterized in that, The anti-counterfeiting system includes: The anti-counterfeiting label as described in any one of claims 1 to 4; A light source used to generate excitation light; Receiver, used to detect photoluminescence; The processor is used to digitize the emission spectrum received by the receiver.

6. The anti-counterfeiting system as described in claim 5, characterized in that, The anti-counterfeiting label has a pixel size of 10nm × 10nm; Preferably, the emission wavelength of the light source is 500~650nm, more preferably 532.0nm or 632.8nm; Preferably, the intensity of the light source is 0.4~0.6 mw / µm. 2 0.5mw / µm is preferred. 2 ; Preferably, the light spot size of the light source is 10nm ± 1nm; Preferably, the receiver is a Raman spectrometer.

7. The anti-counterfeiting system as described in claim 5 or 6, characterized in that, The processor's processing steps include a luminescence intensity processing module for the photoluminescence spectrum, the processing steps including: S1 uses the size of the light spot from the light source as a pixel and reads the luminous intensity I of the photoluminescence spectrum of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer; S2 calculates the average luminous intensity I of the entire anti-counterfeiting label. 均 ; S3 determines the luminous intensity of each pixel. n With average luminous intensity I 均 The relationship, when I n ≥I 均 , denoted as 0, when I n <I 均 , denoted as 1, obtain the light intensity binary matrix key Key1; Preferably, after step S3, step S4 is performed to generate a light intensity key QR code based on the obtained light intensity binary matrix key Key1. And / or, the processing steps of the processor include a photoluminescence spectrum emission wavelength processing module: T1 uses the size of the light spot from the light source as a pixel and reads the emission wavelength λ of the photoluminescence spectrum of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer; T2 calculates the average emission wavelength λ of the entire anti-counterfeiting label. 均 ; T3 determines the emission wavelength λ of each pixel. n With average emission wavelength λ 均 The relationship when λ n ≥λ 均 , denoted as 0, when λ n <λ 均 , denoted as 1, obtain the wavelength binary matrix key Key2; Preferably, after step T3, step T4 is performed to generate a wavelength key QR code based on the obtained wavelength binary matrix key Key2; And / or, the processor's processing steps include a topography height processing module: K1 uses the size of the light spot from the light source as a pixel, and reads the shape and height H of each pixel on the anti-counterfeiting label. n n is the position index of each pixel, and n is a positive integer; K2 calculates the average morphological height H of the entire anti-counterfeiting label. 均 ; K3 determines the shape height H of each pixel. n With average morphological height H 均 The relationship when H n ≥H 均 , denoted as 0, when H n <H 均 , denoted as 1, obtain the high-order binary matrix key Key3; Preferably, after step K3, step K4 is performed to generate a height key QR code based on the obtained height binary matrix key Key3.

8. The anti-counterfeiting system as described in any one of claims 5 to 7, characterized in that, The processor's processing steps also include a matrix multiplication module: By performing pairwise matrix multiplication of the light intensity binary matrix key Key1, the wavelength binary matrix key Key2, and the height binary matrix key Key3, a 15-key sequence is obtained.

9. The use of an anti-counterfeiting label as described in any one of claims 1 to 4 or an anti-counterfeiting system as described in any one of claims 5 to 8, characterized in that, The anti-counterfeiting label and / or anti-counterfeiting system is used for any one or at least two of the following: anti-counterfeiting and identity authentication, information encryption, and key generation. It is preferably used for encrypting chips, satellite communication modules, luxury goods, and classified images and texts.

10. A chip, characterized in that, The chip has an anti-counterfeiting label as described in any one of claims 1 to 4 on its substrate.

Images