Method for generating PUF characteristic value and PUF key of piezoresistive sensor

Abstract

The present application provides a method for generating PUF characteristic values ​​of a piezoresistive sensor and a method for generating a PUF key. The method comprises: the processor adjusts the ambient temperature of the piezoresistive sensor by controlling the temperature adjustment module; the ambient temperature of the piezoresistive sensor is set to the test temperature T1 through the temperature adjustment module, and at the test temperature T1, the pressure simulation structure simulates the M1 group of external pressure groups, obtains the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressure, obtains the M1 group of resistance-pressure coefficient K, adjusts the test temperature, repeats step B-step C1, until multiple resistance-pressure coefficients K under the J group of test temperatures are obtained, and the J group of test temperatures are used as excitation, and multiple K values ​​under each test temperature are used as response to generate PUF characteristic values. This method can solve the problem of effective implementation of PUF on the sensor.

Description

Technical Field

[0001] The present application relates to the field of information security technology, and in particular to a method for generating a PUF characteristic value of a piezoresistive sensor and a method for generating a PUF key. Background Art

[0002] Physically Unclonable Function (PUF) has the characteristics of uniqueness and non-replicability, and has been successfully applied in the field of information security. It is a safe and effective encryption technology. The hardware identity is managed through the hardware PUF, and the root key is generated based on this feature. The key generation technology based on PUF allows the key to be kept within the device, which is highly secure. In addition, the cost of using PUF is low, and it is also suitable for low-cost terminal devices, such as wireless sensor devices.

[0003] In the related art, PUF has been used in some large mobile terminal devices, such as using the data value after SRAM and DRAM initialization as PUF source data. However, this method is not suitable for small terminals, such as sensors. Therefore, an effective implementation method for PUF on sensors is needed. Summary of the invention

[0004] Based on this, it is necessary to provide a piezoresistive sensor PUF characteristic value generation method, a piezoresistive sensor PUF key generation method and a piezoresistive sensor security verification method that can solve the above-mentioned technical problems and effectively implement the PUF on the sensor.

[0005] In a first aspect, the present application provides a method for generating a PUF characteristic value of a piezoresistive sensor, comprising:

[0006] Step A: providing a piezoresistive sensor, turning on the power of the piezoresistive sensor, wherein the piezoresistive sensor comprises a power module, a processor, a temperature adjustment module and a piezoresistive sensor structure; the processor adjusts the ambient temperature of the piezoresistive sensor by controlling the temperature adjustment module; the piezoresistive sensor structure comprises a pressure simulation structure and a Wheatstone bridge, wherein the pressure simulation structure is used to simulate the change of the external pressure to which the piezoresistive sensor is subjected;

[0007] Step B: The temperature of the environment in which the piezoresistive sensor is located is set to the test temperature T1 through the temperature adjustment module;

[0008] Step C1: at the test temperature T1, the pressure simulation structure simulates M1 group of external pressure groups, obtains the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressure, and obtains the M1 group of resistance-pressure coefficient K, each group of external pressure groups includes 2 different pressure values, and the resistance value under each group of external pressure is 2;

[0009] Step D: adjusting the test temperature, repeating steps B-C1, until a plurality of resistance-pressure coefficients K under J sets of test temperatures are obtained, the number of K being M1+M2+......+Mj, where J and M1-Mj are both positive integers;

[0010] Step E: Using the test temperature of group J as an excitation and multiple K values ​​at each test temperature as a response to generate a PUF characteristic value.

[0011] In one embodiment, step B further includes:

[0012] Step C2: measuring an initial output voltage V0 of the piezoresistive sensor at a test temperature T1, wherein the initial output voltage V0 is an output voltage when an additional external pressure applied to the piezoresistive sensor is zero;

[0013] The step D is to adjust the test temperature, and repeat the steps B, C1 and C2 until J initial output voltages V0 at the J test temperature group and a plurality of resistance-pressure coefficients K at the J test temperature group are obtained, wherein the number of K is M1+M2+......+Mj;

[0014] The step E is to use the J groups of test temperatures as excitations, and the initial output voltage V0 and multiple K values ​​at each test temperature as responses to generate a PUF characteristic value.

[0015] In one embodiment, the initial output voltage V0=V+-V-, wherein V+ is the potential of the positive electrode of the output voltage terminal measured when the negative electrode of the output voltage terminal of the piezoresistive sensor is grounded, and V- is the potential of the negative electrode of the output voltage terminal measured when the positive electrode of the output voltage terminal of the piezoresistive sensor is grounded.

[0016] In one embodiment, step B further includes:

[0017] Step C3: When the external pressure applied to the piezoresistive sensor is zero and the test temperature T1, measure the potential V+ of the positive electrode of the output voltage end of the piezoresistive sensor when the negative electrode of the output voltage end of the piezoresistive sensor is grounded, and measure the potential V- of the negative electrode of the output voltage end of the piezoresistive sensor when the positive electrode of the output voltage end of the piezoresistive sensor is grounded;

[0018] The step D is to adjust the test temperature, repeat the steps B, C1 and C3, until J V+ and J V- of the J group of test temperatures and a plurality of resistance-pressure coefficients K at the J group of test temperatures are obtained, and the number of K is M1+M2+......+Mj;

[0019] The step E is to use the test temperatures of group J as excitations, and V+ and V- at each test temperature, as well as multiple K values ​​as responses, to generate PUF characteristic values.

[0020] In one embodiment, the piezoresistive sensor further includes a driving voltage adjustment circuit, and the driving voltage adjustment circuit is used to adjust the driving voltage input to the piezoresistive sensor; the step C1 includes:

[0021] Step C11: at the test temperature T1, inputting a driving voltage U1 to the piezoresistive sensor via the driving voltage adjustment circuit;

[0022] Step C12: When the external pressure applied to the piezoresistive sensor is zero, under the driving voltage U1, measuring the potential V+ of the positive electrode of the output voltage end of the piezoresistive sensor when the negative electrode of the output voltage end of the piezoresistive sensor is grounded, and measuring the potential V- of the negative electrode of the output voltage end of the piezoresistive sensor when the positive electrode of the output voltage end of the piezoresistive sensor is grounded;

[0023] Step C13: Under the driving voltage U1, the pressure simulation structure simulates the M1 group of external pressure groups, obtains the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressure, and obtains the M1 group resistance-pressure coefficient K;

[0024] Step C14: adjusting the driving voltage, repeating steps C11 to C14, until a plurality of resistance-pressure coefficients K and a plurality of groups of V+ and V- under N groups of driving voltages are obtained, and the number of K is M1+M2+......+Mn;

[0025] Step D is to adjust the test temperature and repeat steps B to C14 until a plurality of resistance-pressure coefficients K and a plurality of groups of V+ and V- under J groups of test temperatures are obtained, wherein the number of K is J×(M1+M2+......+Mn), and the number of V+ and V- is J×N;

[0026] The step E is to use the J groups of test temperatures and the N groups of driving voltages as excitations, and use V+ and V- at each test temperature and driving voltage, as well as multiple K values ​​as responses to generate PUF characteristic values.

[0027] In one embodiment, the resistance-pressure coefficient K=(R2-R1) / (P2-P1), wherein R1 is the resistance of the piezoresistive sensor when the external pressure is P1, and R2 is the resistance of the piezoresistive sensor when the external pressure is P2;

[0028] The pressure simulation structure comprises:

[0029] A first pressure simulation electrode disposed at a diaphragm end of the cavity structure of the piezoresistive sensor;

[0030] A second pressure simulation electrode is disposed at a fixed end of the cavity structure of the piezoresistive sensor.

[0031] In one embodiment, the pressure simulation structure simulates the external pressure group of group M1 specifically as follows:

[0032] The voltage value between the first pressure simulation electrode and the second pressure simulation electrode is equivalent to the external pressure value borne by the piezoresistive sensor;

[0033] By adjusting the potential and / or current connected to the first pressure simulation electrode and the second pressure simulation electrode, different external pressure values ​​borne by the piezoresistive sensor are simulated to obtain the M1 group of external pressure groups.

[0034] In one embodiment, the adjusting the potential and / or current connected to the first pressure simulation electrode and the second pressure simulation electrode is specifically:

[0035] Grounding the first pressure simulation electrode, and adjusting the potential and / or current of the second pressure simulation electrode;

[0036] Alternatively, the second pressure simulation electrode is grounded, and the potential and / or current of the first pressure simulation electrode is adjusted.

[0037] In one embodiment, the resistance-pressure coefficient K=(V output 2-V output 1) / (V pressure simulation 2-V pressure simulation 1),

[0038] Among them, Vpressure simulation 1 and Vpressure simulation 2 are different voltage values ​​between the first pressure simulation electrode and the second pressure simulation electrode, Voutput 1 is the output voltage of the piezoresistive sensor when the voltage value between the first pressure simulation electrode and the second pressure simulation electrode is Vpressure simulation 1, and Voutput 2 is the output voltage of the piezoresistive sensor when the voltage value between the first pressure simulation electrode and the second pressure simulation electrode is Vpressure simulation 2.

[0039] In one embodiment, the piezoresistive sensor is a MEMS sensor or an NMES sensor; the piezoresistive sensor is a piezoresistive pressure sensor, a piezoresistive force sensor, a piezoresistive displacement sensor, a piezoresistive mass sensor, a piezoresistive strain sensor, a piezoresistive flow sensor, a piezoresistive torque sensor, a piezoresistive vibration sensor, a piezoresistive liquid level sensor, a piezoresistive gyroscope, a piezoresistive gas sensor, a piezoresistive magnetic sensor, a piezoresistive biosensor, a piezoresistive humidity sensor, a piezoresistive temperature sensor, a piezoresistive chemical sensor, a piezoresistive acceleration sensor, or a piezoresistive inertial sensor.

[0040] In a second aspect, the present application also provides a piezoresistive sensor PUF key generation method, comprising:

[0041] Combining the PUF characteristic values ​​obtained by the PUF characteristic value generation method described in the first aspect to obtain a plurality of CRP stimulus-response pairs;

[0042] Performing analog-to-digital conversion on the response in the CRP stimulus-response pair to obtain bit data;

[0043] The bit data is processed using a hash algorithm to generate a PUF key.

[0044] The above-mentioned piezoresistive sensor PUF key generation method can enhance the security and reliability of the PUF key by performing analog-to-digital conversion and hash algorithm processing on the CRP stimulus-response pair.

[0045] In a third aspect, the present application also provides a safety verification method for a piezoresistive sensor, comprising:

[0046] A piezoresistive sensor to be tested is provided, a security verification device is connected to the piezoresistive sensor to be tested, and a power supply of the piezoresistive sensor is turned on, wherein the security verification device stores a PUF key of the piezoresistive sensor to be tested generated by the PUF key generation method in the above embodiment;

[0047] The security verification device generates a first random number and sends the first random number to the piezoresistive sensor to be tested, and the piezoresistive sensor to be tested takes the first random number as a challenge and generates a first response;

[0048] The piezoresistive sensor to be tested encrypts the first random number to obtain a second response, and sends the second response to the security verification device, wherein the encryption key of the first random number is the first response;

[0049] Decrypting the second response using the PUF key stored in the security verification device as a decryption key to obtain a second random number;

[0050] The second random number is compared with the first random number, and if the two are the same, it is determined that the piezoresistive sensor to be tested is a safety device.

[0051] In the above-mentioned security verification method of the piezoresistive sensor, the security verification of the piezoresistive sensor is achieved by using the PUF key and the challenge-response mechanism, thereby ensuring the authenticity of the sensor and the security of the data, thereby enhancing security and anti-attack capabilities.

[0052] In a fourth aspect, the present application further provides a safety verification device for a piezoresistive sensor, wherein the safety verification device can use the safety verification method described in the third aspect to perform safety verification on the piezoresistive sensor, and the safety verification device includes:

[0053] A memory, used to store the PUF keys of multiple piezoresistive sensors generated by the method according to the second aspect;

[0054] A random number generation module, used to generate a first random number;

[0055] A decryption module, configured to decrypt a second response returned by the piezoresistive sensor using the PUF key to obtain a second random number;

[0056] A comparison module, used for comparing the second random number with the first random number to obtain a comparison result;

[0057] A display module is used to display the comparison result and / or display the first random number and the second random number.

[0058] In the above-mentioned security verification device for piezoresistive sensors, by integrating memory, random number generation module, decryption module, comparison module and display module, efficient and accurate identity authentication and response checking of piezoresistive sensors are achieved, thereby enhancing the security and reliability of sensor data, ensuring the safety performance of sensors in various applications, and effectively preventing unauthorized access and data tampering.

[0059] In a fifth aspect, the present application further provides a piezoresistive sensor, which can apply the characteristic value generation method described in the first aspect, and the piezoresistive sensor includes: a power module, a processor, a storage module, an interface module, a temperature adjustment module, and a piezoresistive sensor structure; the power module is used to provide power to the processor, the storage module, the interface module, the temperature adjustment module, and the piezoresistive sensor structure, and the temperature adjustment module includes a temperature detection module and a heating resistor arranged in the area of ​​the piezoresistive sensor structure; the piezoresistive sensor structure includes a pressure simulation structure and a Wheatstone bridge, and the pressure simulation structure is used to simulate the change of the external pressure to which the piezoresistive sensor is subjected; the processor is electrically connected to the piezoresistive sensor structure, and is used to calculate the voltage value of the piezoresistive sensor structure, and is used to control the working state of the power module, and the processor is also used to respond to a first test signal of an external test device, and adjust the ambient temperature of the piezoresistive sensor module by controlling the temperature of the heating resistor;

[0060] Among them, when the piezoresistive sensor is in a testing state, the power module supplies power to the heating resistor, and the power module is electrically connected to the pressure simulation structure of the piezoresistive sensor structure; when the piezoresistive sensor is in a working state, the power module stops supplying power to the heating resistor, and the power module is disconnected from the pressure simulation structure of the piezoresistive sensor structure.

[0061] In one embodiment, the pressure simulation structure includes:

[0062] A first pressure simulation electrode disposed at a diaphragm end of the cavity structure of the piezoresistive sensor structure;

[0063] a second pressure simulation electrode disposed at a fixed end of the cavity structure of the piezoresistive sensor structure;

[0064] In a test state, the power module provides a pressure simulation potential to the first pressure simulation electrode, and the second pressure simulation electrode is grounded, or the power module provides a pressure simulation voltage to the second pressure simulation electrode, and the first pressure simulation electrode is grounded.

[0065] In one embodiment, the power supply module includes: a battery, a first switch module and an analog voltage adjustment module, wherein the first switch module controls the voltage adjustment module to output a corresponding pressure simulation voltage in response to a second test signal sent by the processor; the voltage adjustment module includes n voltage output nodes, and resistors R1, R2...Rn connected in series in sequence, where n is a positive integer, and a voltage output node is arranged between two adjacent resistors, and the first switch module selects to connect the corresponding voltage output node in response to the second test signal sent by the processor to control the voltage adjustment module to output a corresponding pressure simulation voltage.

[0066] In one embodiment, the power supply module also includes a second switch module and a third switch module, the first end of the second switch module is connected to the positive electrode V+ of the output voltage end of the piezoresistive sensor structure, and the second end is grounded; the first end of the third switch module is connected to the negative electrode V- of the output voltage end of the piezoresistive sensor structure, and the second end is grounded; the second switch module is closed in response to the output voltage test signal of V-, and is opened in response to the output voltage test signal of V+; the third switch module is closed in response to the output voltage test signal of V+, and is opened in response to the output voltage test signal of V-.

[0067] In the above-mentioned piezoresistive sensor, the piezoresistive sensor structure includes a pressure simulation structure and a Wheatstone bridge, and the pressure simulation structure is used to simulate the changes in the external pressure to which the piezoresistive sensor is subjected; the processor is electrically connected to the piezoresistive sensor structure, and is used to calculate the voltage value of the piezoresistive sensor structure, and is used to control the working state of the power supply module. The processor is also used to respond to a first test signal from an external test device, and to adjust the ambient temperature of the piezoresistive sensor module by controlling the temperature of the heating resistor. The piezoresistive sensor can use the test temperature as an excitation, and use multiple resistance-pressure coefficients K at each test temperature as a response to generate a PUF characteristic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0069] Figure 1 This is a schematic diagram of the structure of a piezoresistive sensor in one embodiment of the present application;

[0070] Figure 2A schematic diagram of a pressure simulation structure in one embodiment of the present application;

[0071] Figure 3 A circuit diagram of a power module in one embodiment of the present application;

[0072] Figure 4 A schematic diagram of the connection between the pressure simulation structure and the piezoresistive sensor structure in one embodiment of the present application;

[0073] Figure 5 A schematic diagram of a process for generating a PUF characteristic value in one embodiment of the present application;

[0074] Figure 6 A function curve of testing temperature-resistance in one embodiment of the present application;

[0075] Figure 7 A resistance-pressure function curve when the initial voltage of the pressure sensor remains unchanged in one embodiment of the present application;

[0076] Figure 8 It is a schematic diagram of a resistance-pressure function curve at different test temperatures in one embodiment of the present application;

[0077] Fig. 9 This is a schematic diagram of a resistance-pressure function curve under different driving voltages in one embodiment of the present application;

[0078] Fig.10 A schematic diagram of a PUF key generation method in one embodiment of the present application;

[0079] Fig.11 A schematic flow chart of a safety verification method for a piezoresistive sensor in one embodiment of the present application;

[0080] Fig.12 It is a schematic diagram of the structure of a security verification device in one embodiment of the present application. DETAILED DESCRIPTION

[0081] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0082] It is understandable that Physical Unclonable Functions (PUF) is an important type of hardware security technology. It uses the inherent properties of silicon-based semiconductors to randomly extract unclonable physical features, similar to biological fingerprints, which are unique identifiers for each chip. It uses the inevitable small differences in semiconductor devices during the manufacturing process (such as transistor threshold voltage, interconnect length, capacitance, etc.) to generate unique and unpredictable outputs. These differences make the response of each device unique and cannot be completely replicated even using the same manufacturing process. Therefore, PUF can be used as a "fingerprint" of the device for security applications such as identity authentication, key generation, and data encryption.

[0083] In the related art, PUFs based on other hardware features include static RAM static random access memory (SRAM), ring oscillator (RO), arbitration PUFs (arbiterPUFs), and dynamic random access memory (coating PUFs and dynamic RAM dynamic random access memory, DRAM). However, the limitation of sensor hardware resources makes it impossible to effectively use PUFs based on SRAM and DRAM. Secondly, RO PUF technology that increases additional design and production costs is not suitable. Therefore, in order to solve the technical problem of the lack of effective implementation methods for PUF on sensors in the related art, a method for generating PUF characteristic values ​​for piezoresistive sensors is proposed, which can solve the effective implementation of PUF applications on sensors while realizing the application of PUF key technology on piezoresistive sensors at a low cost.

[0084] In an exemplary embodiment, Figure 1 As shown, in order to solve the above technical problems, the technical solution of the present application redesigns the existing piezoresistive sensor. In an exemplary embodiment, as shown in FIG. Figure 1As shown, a piezoresistive sensor applicable to a PUF characteristic value generation method is provided, the piezoresistive sensor comprising: a power module 10, a processor 20, a storage module 30, an interface module 40, a temperature adjustment module 50, and a piezoresistive sensor structure 60; the power module 10 is used to provide power to the processor 20, the storage module 30, the interface module 40, the temperature adjustment module 50, and the piezoresistive sensor structure 60, the temperature adjustment module 50 comprises a temperature detection module, and a heating resistor arranged in the region of the piezoresistive sensor structure 60; the piezoresistive sensor structure 60 comprises a pressure simulation structure and a Wheatstone bridge, the pressure simulation structure is used to simulate the change of the external pressure to which the piezoresistive sensor is subjected; the processor 20 is electrically connected to the piezoresistive sensor structure 60, and is used to calculate the voltage value of the piezoresistive sensor structure 60, and is used to control the working state of the power module 10, and the processor 20 is also used to respond to a first test signal of an external test device, and to adjust the ambient temperature of the piezoresistive sensor module by controlling the temperature of the heating resistor.

[0085] Among them, when the piezoresistive sensor is in a testing state, the power module 10 supplies power to the heating resistor, and the power module 10 is electrically connected to the pressure simulation structure of the piezoresistive sensor structure 60; when the piezoresistive sensor is in a working state, the power module 10 stops supplying power to the heating resistor, and the power module 10 is disconnected from the pressure simulation structure of the piezoresistive sensor structure 60.

[0086] The temperature detection module is, for example, an integrated temperature sensor.

[0087] It is understandable that changes in the ambient temperature of the piezoresistive sensor structure 60 will cause changes in the voltage value to which it responds. In this exemplary embodiment, a heating resistor is provided in the piezoresistive sensor, and different current values ​​are output to the heating resistor by the temperature adjustment module 50, causing its temperature to change, thereby causing changes in the voltage value of the piezoresistive sensor structure 60. At the same time, a pressure simulation structure is provided to simulate changes in the external pressure to which the piezoresistive sensor is subjected, thereby causing changes in the voltage value to which the piezoresistive sensor structure 60 responds.

[0088] Wheatstone bridge circuit: Four piezoresistive elements are usually connected to form a Wheatstone Bridge circuit. When the pressure changes, the resistance value of the piezoresistive element changes, and then the output voltage of the bridge changes. By detecting the output voltage of the bridge, the pressure can be indirectly measured. Conversely, the output voltage value of the Wheatstone bridge (i.e., the output voltage of the piezoresistive sensor structure) can be equivalent to the resistance value of the Wheatstone bridge (i.e., the resistance value of the piezoresistive sensor). The drive voltage adjustment circuit can adjust the drive voltage of the input piezoresistive sensor by adjusting the size of the resistor in the power control circuit (i.e., the drive voltage adjustment circuit) connected to the piezoresistive sensor, thereby adjusting the drive voltage of the input piezoresistive sensor. Among them, the resistors in the drive voltage adjustment circuit can be set in parallel or in series, or a variable resistance structure such as a sliding rheostat can be used.

[0089] The pressure simulation structure may include two pressure simulation electrodes, and the simulation form of the external pressure may be, but is not limited to, represented by the pressure difference of the simulated voltage of the two pressure simulation electrodes. It is understandable that the way to simulate the change of the external pressure on the MEMS piezoresistive sensor structure 60 may also be to add a pressure-applying structure on the upper surface of the diaphragm of the MEMS piezoresistive sensor structure 60 to achieve pressure simulation.

[0090] In one embodiment, Figure 2 As shown, the pressure simulation structure includes: a first pressure simulation electrode arranged at the diaphragm end of the cavity structure of the piezoresistive sensor structure 60; and a second pressure simulation electrode arranged at the fixed end of the cavity structure of the piezoresistive sensor structure 60.

[0091] In the test state, the power module 10 provides a pressure simulation potential to the first pressure simulation electrode, and the second pressure simulation electrode is grounded, or the power module 10 provides a pressure simulation voltage to the second pressure simulation electrode, and the first pressure simulation electrode is grounded.

[0092] The first pressure simulation electrode and the second pressure simulation electrode are, for example, electromagnets, which generate different suction forces under different pressure simulation potential differences, thereby simulating external pressure.

[0093] The embodiment of the present application applies different pressure simulation potentials to the first pressure simulation electrode 11 and the second pressure simulation electrode 21 to form an attractive force between the two pressure simulation electrodes. Under the action of the attractive force, the sensitive film 12 is deformed to simulate the application of different pressures to the piezoresistive sensor structure 1. Compared with the solution of directly applying pressure to the piezoresistive sensor structure 1, the solution of applying voltage in the present embodiment is easier to quantify and easier to reproduce.

[0094] In addition to the influence of temperature on the voltage value of the piezoresistive sensor structure 60 , the voltage applied to the piezoresistive sensor structure 60 also affects its voltage value.

[0095] In another example embodiment, Figure 3 As shown, the power supply module 10 includes: a battery U1, a first switch module S1 and an analog voltage adjustment module. The first switch module S1 responds to the second test signal sent by the processor 20 to control the voltage adjustment module to output a corresponding pressure simulation voltage; the voltage adjustment module includes n voltage output nodes, and resistors R1, R2...Rn connected in series in sequence, where n is a positive integer, and a voltage output node is set between two adjacent resistors. The first switch module S1 responds to the second test signal sent by the processor 20 to select the connection corresponding voltage output node to control the voltage adjustment module to output a corresponding pressure simulation voltage.

[0096] When it is necessary to apply different driving voltages to the piezoresistive sensor structure 60, the voltage division principle can be used to connect different numbers of resistors according to different needs, so that the voltages on different numbers of resistors are applied to the piezoresistive sensor structure 60, thereby meeting the need to apply different driving voltages to the piezoresistive sensor structure 60.

[0097] In other embodiments of the present application, the analog voltage adjustment module is a sliding rheostat. Based on the voltage division principle, the resistance value can be changed by the position of the sliding contact of the sliding rheostat on the resistance wire to meet the need of connecting different resistance values ​​in the circuit, so as to apply voltages at different resistance values ​​to the piezoresistive sensor structure 60, thereby meeting the need of applying different driving voltages to the piezoresistive sensor structure 60, and then obtaining the excitation-response pair required by the PUF technology.

[0098] In one embodiment, if Figure 4 As shown, the power supply module 10 also includes a second switch module S2 and a third switch module S3, wherein the first end of the second switch module S2 is connected to the positive electrode V+ of the output voltage end of the piezoresistive sensor structure 60, and the second end is grounded; the first end of the third switch module S3 is connected to the negative electrode V- of the output voltage end of the piezoresistive sensor structure 60, and the second end is grounded; the second switch module S2 is closed in response to the output voltage test signal of V-, and is opened in response to the output voltage test signal of V+; the third switch module S3 is closed in response to the output voltage test signal of V+, and is opened in response to the output voltage test signal of V-.

[0099] It should be noted that the second switch module S2 can be closed or closed in response to the output voltage test signal of V- or V+, and the third switch module S3 can be closed or closed in response to the output voltage test signal of V- or V+, so as to accurately measure the voltage applied to the capacitive sensor structure 60 at a certain moment. Compared with directly measuring the voltage output to the capacitive sensor structure 60, this solution can effectively eliminate the system errors caused by factors such as power supply voltage fluctuations and resistance temperature coefficient, improve the measurement accuracy, and can effectively reduce the influence of external electromagnetic interference on the measurement results, so as to improve the accuracy of the measurement of the voltage applied to the capacitive sensor structure 60 at a certain moment.

[0100] In an exemplary embodiment, based on the above piezoresistive sensor, as Figure 5 As shown, a method for generating a PUF characteristic value of a piezoresistive sensor is provided, which may include the following steps:

[0101] Step A: Provide a piezoresistive sensor and turn on the power of the piezoresistive sensor, wherein the piezoresistive sensor includes a power module, a processor, a temperature adjustment module and a piezoresistive sensor structure; the processor adjusts the ambient temperature of the piezoresistive sensor by controlling the temperature adjustment module; the piezoresistive sensor structure includes a pressure simulation structure and a Wheatstone bridge, and the pressure simulation structure is used to simulate the changes in the external pressure on the piezoresistive sensor.

[0102] The structural diagram of the piezoresistive sensor in step A can be as follows: Figure 2As shown. Piezoresistive sensor is a sensing technology based on the piezoresistive effect, which measures physical quantities by detecting changes in resistance. The piezoresistive effect refers to the change in resistance of a material when it is subjected to mechanical stress (such as tension, compression or shear force). Piezoresistive MEMS sensors are usually made of silicon material because silicon has good piezoresistive properties and is compatible with existing semiconductor processes, which is convenient for mass production and integration. The piezoresistive sensor can be a wireless piezoresistive sensor and a wired sensor. For piezoresistive sensors with different transmission modes, the piezoresistive sensor can be, but is not limited to, a MEMS sensor or an NMES sensor; the piezoresistive sensor is a piezoresistive pressure sensor, a piezoresistive force sensor, a piezoresistive displacement sensor, a piezoresistive mass sensor, a piezoresistive strain sensor, a piezoresistive flow sensor, a piezoresistive torque sensor, a piezoresistive vibration sensor, a piezoresistive liquid level sensor, a piezoresistive gyroscope, a piezoresistive gas sensor, a piezoresistive magnetic sensor, a piezoresistive biosensor, a piezoresistive humidity sensor, a piezoresistive temperature sensor, a piezoresistive chemical sensor, a piezoresistive acceleration sensor, and a piezoresistive inertial sensor. The type of the piezoresistive sensor is not limited here, and the structure of the piezoresistive sensor is not specifically limited. This application is described with the piezoresistive sensor being a piezoresistive MEMS sensor.

[0103] Furthermore, the piezoresistive MEMS / NMES sensor can be any one of a MEMS / NMES pressure sensor, a MEMS / NMES force sensor, a MEMS / NMES acceleration sensor, a MEMS / NMES displacement sensor, a MEMS / NMES strain sensor, a MEMS / NMES flow sensor, or a MEMS / NMES torque sensor. The embodiments of the present application do not limit the type of the piezoresistive sensor, and do not specifically limit the structure of the piezoresistive sensor. The present application is described as a piezoresistive MEMS sensor.

[0104] Understandably, it is widely used in consumer electronics, industrial automation, medical equipment, aerospace and other fields. The advantages of piezoresistive MEMS sensors are their high sensitivity, high precision, miniaturization and reliability, so they play an important role in many application scenarios. For example, piezoresistive pressure sensors can be widely used in air pressure measurement (e.g., for weather stations, altimeters, drone flight control systems, etc.), hydraulic / pneumatic systems (e.g., for industrial automation, medical equipment, automotive engine management systems, etc.), liquid level measurement (e.g., for liquid level monitoring of containers such as water tanks and oil tanks) and medical equipment (e.g., for pressure monitoring in medical equipment such as sphygmomanometers, ventilators, infusion pumps, etc.).

[0105] Step B: The temperature of the environment in which the piezoresistive sensor is located is set to the test temperature T1 through the temperature adjustment module.

[0106] Step C1: At the test temperature T1, the pressure simulation structure simulates the M1 group of external pressure groups to obtain the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressures, and obtains the M1 group of resistance-pressure coefficient K. Each group of external pressure groups includes 2 different pressure values, and the resistance value under each group of external pressures is 2.

[0107] The resistance under each set of external pressure can be understood as the equivalent resistance of the piezoresistive sensor, which can be represented by R1 and R2, and each set of external pressure group includes two different pressure values, which can be represented by P1 and P2. The resistance-pressure coefficient K under each set of external pressure can be determined according to the difference between the two resistances under each set of external pressure and the difference between the two pressure values ​​of each corresponding set of external pressure group.

[0108] Step D: Adjust the test temperature and repeat steps B-C1 until a plurality of resistance-pressure coefficients K under J groups of test temperatures are obtained, where the number of K is M1+M2+......+Mj, where J and M1-Mj are both positive integers.

[0109] It should be noted that, in an exemplary embodiment, the values ​​of M1, M2, ..., Mj are the same or different and can be adjusted according to actual needs to meet the needs of different scenarios.

[0110] Step E: Using the test temperature of group J as an excitation and multiple K values ​​at each test temperature as a response to generate a PUF characteristic value.

[0111] There may be multiple PUF characteristic values, and one PUF characteristic value may include a test temperature and multiple K values ​​at the test temperature, as shown in Table 1.

[0112] Table 1

[0113]

[0114] The above-mentioned method for generating PUF characteristic values ​​of piezoresistive sensors is to make the ambient temperature of the piezoresistive sensor be the test temperature T1 through the temperature adjustment module. Under the test temperature T1, the pressure simulation structure simulates M1 groups of external pressure groups to obtain the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressures, obtain the M1 group of resistance-pressure coefficient K, adjust the test temperature, repeat steps B-C1 until multiple resistance-pressure coefficients K under J groups of test temperatures are obtained, and the J groups of test temperatures are used as excitations, and multiple K values ​​under each test temperature are used as responses to generate PUF characteristic values. That is, the resistance-pressure coefficient K of the piezoresistive sensor under different test temperatures and external pressures is also different, but K has a unique and stable characteristic under different driving voltages. The driving voltage in the piezoresistive sensor is used as excitation, and the resistance-pressure coefficient under different pressures is used as a response to generate the PUF characteristic value of the sensor. There is no need to increase additional design and production costs, which reduces the PUF cost. Furthermore, the response parameters are increased, and the uniqueness of the PUF and the difference of the PUF characteristic values ​​of different sensors are improved. It can also be used for piezoresistive sensors, as well as anti-counterfeiting, security authentication and device identification including the piezoresistive sensors to ensure network security.

[0115] Optionally, in an exemplary embodiment, a method for determining a PUF characteristic value is provided. Based on the above embodiment, step B further includes:

[0116] Step C2: measuring an initial output voltage V0 of the piezoresistive sensor at a test temperature T1, wherein the initial output voltage V0 is an output voltage when an additional external pressure applied to the piezoresistive sensor is zero;

[0117] Among them, the initial output voltage V0 can be determined according to the potential of the positive pole of the output voltage terminal measured when the negative pole of the output voltage terminal of the piezoresistive sensor is grounded, and the potential of the negative pole of the output voltage terminal measured when the positive pole of the output voltage terminal of the piezoresistive sensor is grounded, that is, it is determined according to the difference between the potential of the positive pole of the voltage terminal and the potential of the negative pole of the output voltage terminal.

[0118] Furthermore, the initial output voltage V0 can be expressed as:

[0119] V0=V+-V-, where V+ is the potential of the positive electrode of the output voltage terminal of the piezoresistive sensor when the negative electrode of the output voltage terminal is grounded, and V- is the potential of the negative electrode of the output voltage terminal of the piezoresistive MEMS sensor when the positive electrode of the output voltage terminal is grounded.

[0120] Step D is to adjust the test temperature, and repeat step B, step C1 and step C2 until J initial output voltages V0 at J groups of test temperatures and multiple resistance-pressure coefficients K at J groups of test temperatures are obtained;

[0121] Step E is to use the test temperatures of group J as excitations, and the initial output voltage V0 and multiple K values ​​at each test temperature as responses to generate a PUF characteristic value.

[0122] As shown in Table 2, the PUF characteristic value includes a test temperature, an output voltage of the piezoresistive sensor at the test temperature when the external pressure applied additionally is zero, and a plurality of K values ​​at the driving voltage.

[0123] Table 2

[0124]

[0125] In this example embodiment, the resistance-pressure coefficient K of the piezoresistive sensor is different at different test temperatures, but K has a unique and stable characteristic at different test temperatures. The test temperature of group J is used as an excitation, and the initial output voltage V0 and multiple K values ​​at each test temperature are used as responses to generate PUF characteristic values. No additional design and production costs are required, which reduces the PUF cost. Furthermore, the response parameters are increased, the uniqueness of the PUF and the difference of the PUF characteristic values ​​of different sensors are improved. It can also be used for piezoresistive sensors, as well as anti-counterfeiting, security authentication and device identification including the piezoresistive sensor to ensure network security.

[0126] Optionally, in an exemplary embodiment, a PUF characteristic value generation method is provided. Based on the above embodiment, step B further includes:

[0127] Step C3: When the external pressure applied to the piezoresistive sensor is zero and at the test temperature T1, measure the potential V+ of the positive electrode of the output voltage end of the piezoresistive sensor when the negative electrode of the output voltage end of the piezoresistive sensor is grounded, and measure the potential V- of the negative electrode of the output voltage end of the piezoresistive sensor when the positive electrode of the output voltage end of the piezoresistive sensor is grounded.

[0128] Step D is to adjust the test temperature, repeat step B, step C1 and step C3, until J V+ and J V- of J test temperature groups and a plurality of resistance-pressure coefficients K at J test temperature groups are obtained, wherein the number of K is M1+M2+......+Mj;

[0129] Step E is to use the test temperature of group J as an excitation, and V+ and V- at each test temperature, as well as multiple K values ​​as responses to generate a PUF characteristic value.

[0130] Among them, a PUF characteristic value includes a test temperature, V+ and V- at the test temperature, and multiple K values ​​at the test temperature. V+ and V- are equivalent to the initial output voltage V0. The stimulus and response in this case are shown in Table 3.

[0131] Table 3

[0132]

[0133] In this example embodiment, the resistance-pressure coefficient K of the piezoresistive sensor is different at different test temperatures, but K has a unique and stable characteristic at different test temperatures. The test temperature of group J is used as an excitation, and V+ and V- at each test temperature, as well as multiple K values, are used as responses to generate PUF characteristic values. No additional design and production costs are required, which reduces the PUF cost. Furthermore, the response parameters are increased, the uniqueness of the PUF and the difference of the PUF characteristic values ​​of different sensors are improved. It can also be used for piezoresistive sensors, as well as anti-counterfeiting, security authentication and device identification including the piezoresistive sensor to ensure network security.

[0134] Optionally, in an exemplary embodiment, a method for generating a PUF characteristic value is provided. Based on the above embodiment, step C1 includes:

[0135] Step C11: at the test temperature T1, inputting a driving voltage U1 to the piezoresistive sensor via the driving voltage adjustment circuit;

[0136] Step C12: When the external pressure applied to the piezoresistive sensor is zero, under the driving voltage U1, measuring the potential V+ of the positive electrode of the output voltage end of the piezoresistive sensor when the negative electrode of the output voltage end of the piezoresistive sensor is grounded, and measuring the potential V- of the negative electrode of the output voltage end of the piezoresistive sensor when the positive electrode of the output voltage end of the piezoresistive sensor is grounded;

[0137] Step C13: Under the driving voltage U1, the pressure simulation structure simulates the M1 group of external pressure groups, obtains the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressure, and obtains the M1 group resistance-pressure coefficient K;

[0138] Step C14: adjusting the driving voltage, repeating steps C11 to C14, until a plurality of resistance-pressure coefficients K and a plurality of groups of V+ and V- under N groups of driving voltages are obtained, and the number of K is M1+M2+......+Mn;

[0139] Step D is to adjust the test temperature and repeat steps B to C14 until a plurality of resistance-pressure coefficients K and a plurality of groups of V+ and V- under J groups of test temperatures are obtained, wherein the number of K is J×(M1+M2+......+Mn), and the number of V+ and V- is J×N;

[0140] The step E is to use the J groups of test temperatures and the N groups of driving voltages as excitations, and use V+ and V- at each test temperature and driving voltage, as well as multiple K values ​​as responses to generate PUF characteristic values.

[0141] Among them, a PUF characteristic value includes a test temperature, a driving voltage, multiple V+ and V- under the test temperature and driving voltage, and multiple K values, V+ and V- are equivalent to the initial output voltage V0, and the stimulus and response in this case are shown in Table 4.

[0142] Table 4

[0143]

[0144] In this example embodiment, the resistance-pressure coefficient K of the piezoresistive sensor is different at different test temperatures, but K has a unique and stable characteristic at different test temperatures. The test temperatures of group J and the driving voltages of group N are used as excitations, and the V+ and V- at each test temperature and driving voltage, as well as multiple K values, are used as responses to generate PUF characteristic values. No additional design and production costs are required, which reduces the PUF cost. Furthermore, the response parameters are increased, and the uniqueness of the PUF and the difference of the PUF characteristic values ​​of different sensors are improved. It can also be used for piezoresistive sensors, as well as anti-counterfeiting, security authentication and device identification including the piezoresistive sensors to ensure network security.

[0145] It can be understood that based on the PUF characteristic values ​​determined in the above-mentioned different ways, in the case of specifically determining the PUF characteristic values, a method for determining the resistance-pressure coefficient K is provided for the piezoresistive sensor. In an exemplary embodiment, the resistance-pressure coefficient can be determined by determining the pressure difference between the second external pressure P2 and the first external force P1, and the resistance difference between the second resistor R2 when the piezoresistive sensor is subjected to the second external pressure P2 and the first resistor R1 when the piezoresistive sensor is subjected to the first external pressure P1, according to the pressure difference and the ratio of the pressure difference.

[0146] Specifically, the resistance-pressure coefficient K can be expressed as:

[0147] K=(R2-R1) / (P2-P1), where R1 is the resistance of the piezoresistive sensor when the external pressure it withstands is P1 (i.e., the first external pressure), and R2 is the resistance of the MEMS piezoresistive sensor when the external pressure it withstands is P2 (i.e., the second external pressure).

[0148] In an exemplary embodiment, Figure 6 As shown in FIG. 1 , a test temperature-resistance function curve is provided, wherein the abscissa represents temperature (test temperature) and the ordinate represents resistance. In an exemplary embodiment, as Figure 7 As shown in FIG. 1 , a resistance-pressure function curve is provided when the initial voltage of the pressure sensor remains unchanged, wherein the horizontal axis represents pressure and the vertical axis represents resistance. When the initial output voltage V0 remains unchanged, the relationship between resistance and pressure is a curve. In an exemplary embodiment, as Figure 8 As shown in FIG. 1 , a resistance-pressure function curve at different test temperatures is provided, wherein the abscissa represents pressure and the ordinate represents resistance. Fig. 9 As shown, a resistance-pressure function curve under different driving voltages is provided, wherein the abscissa represents pressure and the ordinate represents resistance. The above determination method of the resistance-pressure coefficient K ensures the reliability of the data and simplifies the calculation.

[0149] The pressure simulation structure simulates the M1 group external pressure group specifically by: making the voltage value between the first pressure simulation electrode and the second pressure simulation electrode equivalent to the external pressure value that the piezoresistive sensor is borne; by adjusting the potential and / or current connected to the first pressure simulation electrode and the second pressure simulation electrode, the different external pressure values ​​that the piezoresistive sensor is borne are simulated to obtain the M1 group external pressure group.

[0150] It is understandable that a MEMS piezoresistive sensor usually includes a Wheatstone bridge, which includes four piezoresistors. When external pressure acts on the sensor, the resistance of these resistors will change, causing the bridge to be unbalanced, thereby generating a voltage signal proportional to the pressure; under the action of external pressure, the resistance value of the material of the piezoresistive sensor will change. This change can be used to measure pressure. Secondly, within a certain pressure range, there is a linear relationship between the change in resistance and the change in pressure, which enables a direct correspondence between the voltage value and the pressure value, etc., that is, based on the working principle of the MEMS piezoresistive sensor, the application of the piezoresistive effect, the design of the Wheatstone bridge, and the linear relationship between voltage and pressure, the voltage value between the two pressure simulation electrodes can be directly equivalent to the external pressure value to which the MEMS piezoresistive sensor is subjected. This equivalent relationship provides a direct, efficient and accurate method for pressure measurement. Among them, by adjusting the potential and / or current connected to the first pressure simulation electrode and the second pressure simulation electrode, this flexible, accurate and cost-effective method can be used to simulate and test the performance of the MEMS piezoresistive sensor under different pressures.

[0151] Considering that it is difficult to implement different pressure values ​​on the sensor to calculate the pressure-resistance coefficient (or pressure coefficient) in practical applications, the voltage control circuit added to the piezoresistive sensor can be used to change the local voltage of the sensor to simulate the pressure change, and the linear relationship between the pressure and the output voltage can be approximated by the linear relationship between the voltage change and the output voltage. The resistance-pressure coefficient K=(R2-R1) / (P2-P1) is equivalent.

[0152] In an exemplary embodiment, the resistance-pressure coefficient may be:

[0153] K=(Voutput2-Voutput1) / (Vpressure simulation2-Vpressure simulation1), wherein Vpressure simulation1 and Vpressure simulation2 are different voltage values ​​between the first pressure simulation electrode and the second pressure simulation electrode, Voutput1 is the output voltage of the piezoresistive sensor when the voltage value between the first pressure simulation electrode and the second pressure simulation electrode is Vpressure simulation1, and Voutput2 is the output voltage of the piezoresistive sensor when the voltage value between the first pressure simulation electrode and the second pressure simulation electrode is Vpressure simulation2.

[0154] Based on the PUF characteristic value generation method in any of the above embodiments, a PUF key generation method is provided, such as Fig.10 As shown, it includes steps 202 to 206, wherein:

[0155] Step 202: Combine the acquired PUF feature values ​​to obtain a plurality of CRP stimulus-response pairs.

[0156] The PUF characteristic value obtained can be determined based on the PUF characteristic value generation method recorded in any of the above embodiments, which will not be described in detail here. CRP: Challenge and Response Pair, refers to the pairing of independent challenges and responses during the device authentication process. The combination method can be implemented by the existing combination method, which will not be described in detail here.

[0157] Exemplarily, the piezoresistive sensing obtains a PUF characteristic value determined based on the PUF characteristic value generation method recorded in any of the above embodiments.

[0158] Step 204: Perform analog-to-digital conversion on the response in the CRP stimulus-response pair to obtain bit data.

[0159] Step 206: Process the bit data using a hash algorithm to generate a PUF key.

[0160] Among them, the hash algorithm can convert an input of any length into an output of a fixed length. This output is called a hash value or hash value, which is used for authentication. This method can effectively prevent the key from being predicted or copied, thereby improving security. The hash algorithm can be, but is not limited to, any one of SM3, MD5 (Message Digest Algorithm 5), and RIPEMD (RACEIntegrity Primitives Evaluation Message Digest).

[0161] In the above PUF key generation method, the security and reliability of the PUF key can be enhanced by performing analog-to-digital conversion and hash algorithm processing on the CRP stimulus-response pair.

[0162] Furthermore, the PUF key may also be stored in a security verification device, server, or cloud server of the piezoresistive MEMS sensor to perform security verification on the piezoresistive sensor.

[0163] It is worth noting that PUF can be used to verify the identity of the device, ensuring that only legitimate devices can access the system or network, and can be used to verify the integrity of the firmware, ensuring that the device loads authenticated firmware when it starts up, preventing malware or firmware tampering, and can also verify the authenticity of the product, etc. In order to ensure the performance and reliability of the sensor, the sensor needs to be securely verified. In an exemplary embodiment, a security verification method for a piezoresistive sensor is provided, such as Fig.11 As shown, it includes steps 302 to 310, wherein:

[0164] Step 302, provide a piezoresistive sensor to be tested, connect a security verification device to the piezoresistive sensor to be tested, turn on the power of the piezoresistive sensor, and store the PUF key of the piezoresistive sensor to be tested in the security verification device.

[0165] The PUF key may be generated by, but is not limited to, the method described in the above embodiment, which will not be described in detail here.

[0166] Step 304: The security verification device generates a first random number and sends it to the piezoresistive sensor to be tested. The piezoresistive sensor to be tested takes the first random number as a challenge and generates a first response.

[0167] The first random number may be generated by a pseudo-random number generator or a time-based random number generator, which is not specifically limited here.

[0168] Step 306: The piezoresistive sensor to be tested encrypts the first random number to obtain a second response, and sends the second response to the security verification device. The encryption key of the first random number is the first response.

[0169] Step 308: Use the PUF key stored in the security verification device as a decryption key to decrypt the second response to obtain a second random number.

[0170] Step 310: compare the second random number with the first random number. If the two are the same, it is determined that the piezoresistive sensor to be tested is a safety device.

[0171] In the above-mentioned security verification method of the piezoresistive sensor, the security verification of the piezoresistive sensor is achieved by using the PUF key and the challenge-response mechanism, thereby ensuring the authenticity of the sensor and the security of the data, thereby enhancing security and anti-attack capabilities.

[0172] Furthermore, according to actual application requirements, the security verification of piezoresistive sensors can be: for the registration of a device (e.g., a piezoresistive sensor), when used for the first time, the device sends a challenge-response pair (CRP) generated by its PUF to the authentication server. The server compares these CRPs with the pre-stored CRPs to verify the authenticity of the device. If the match is successful, the device will be registered as a legitimate device and assigned a unique identifier.

[0173] Then, for actual application needs, there may be a situation where random numbers are used in combination with challenges in CRP. In this case, the verification server will generate a random number and use it as part of the challenge, combined with the random number and the incentive in CRP. Based on the combination of the random number and the incentive in CRP, the challenge is determined, a response is generated, and the response is returned to the server. The server regenerates the expected response with the same random number and compares it with the received response. In this method, random numbers are introduced on the basis of CRP to ensure that the challenge used for each verification is unique and prevent replay attacks. In addition, random numbers increase the security of the system, making it difficult for attackers to predict or guess the content of the challenge.

[0174] Furthermore, in an exemplary embodiment, a security verification device is provided, such as Fig.12 As shown, a schematic diagram of the structure of a safety verification device is provided. The safety verification device can use the above-mentioned safety verification method of the piezoresistive sensor to perform safety verification on the piezoresistive sensor. The safety verification device includes:

[0175] A memory 1002, used to store the PUF keys of the multiple piezoresistive sensors generated in any of the above embodiments;

[0176] The random number generation module 1004 is used to generate a first random number; wherein the first random number is used as an excitation of the piezoresistive sensor to be tested to generate a first response.

[0177] The decryption module 1006 is used to decrypt the second response returned by the piezoresistive sensor using the PUF key to obtain a second random number; the second response is obtained after the piezoresistive sensor to be tested encrypts the first random number.

[0178] A comparison module 1008, configured to compare the second random number with the first random number to obtain a comparison result;

[0179] The display module 1010 is used to display the comparison result and / or display the first random number and the second random number.

[0180] The above-mentioned security verification device uses the first random number as the excitation of the piezoresistive sensor to be tested to generate a first response, and uses the PUF key to decrypt the second response obtained after encryption based on the first random number to obtain a second random number, and performs security verification on the piezoresistive sensor to be tested by comparing the first random number and the second random number. This method uses the PUF key and the challenge-response mechanism to achieve security verification of the piezoresistive sensor, ensure the authenticity of the sensor and the security of the data, thereby enhancing security and anti-attack capabilities.

[0181] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0182] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0183] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0184] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0185] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0186] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0187] In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or equipment.

[0188] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0189] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0190] The technical features of the above embodiments can be combined without changing the basic principles of the present application. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0191] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A method for generating PUF characteristic values ​​of a piezoresistive sensor, characterized in that: include: Step A: providing a piezoresistive sensor, turning on the power of the piezoresistive sensor, wherein the piezoresistive sensor comprises a power module, a processor, a temperature adjustment module and a piezoresistive sensor structure; the processor adjusts the ambient temperature of the piezoresistive sensor by controlling the temperature adjustment module; the piezoresistive sensor structure comprises a pressure simulation structure and a Wheatstone bridge, wherein the pressure simulation structure is used to simulate the change of the external pressure to which the piezoresistive sensor is subjected; Step B: The temperature of the environment in which the piezoresistive sensor is located is set to the test temperature T1 through the temperature adjustment module; Step C1: at the test temperature T1, the pressure simulation structure simulates the M1 group of external pressure groups, obtains the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressure, and obtains the M1 group of resistance-pressure coefficient K, each group of external pressure groups includes 2 different pressure values, and the resistance value under each group of external pressure is 2; wherein, the resistance-pressure coefficient K under each group of external pressure is determined according to the difference between the two resistances under each group of external pressure, and the difference between the two pressure values ​​of each corresponding group of external pressure groups; Step D: adjusting the test temperature, repeating steps B-C1, until a plurality of resistance-pressure coefficients K under J sets of test temperatures are obtained, the number of K being M1+M2+......+Mj, where J and M1-Mj are both positive integers; Step E: Using the test temperature of group J as an excitation and multiple K values ​​at each test temperature as a response to generate a PUF characteristic value.

2. The PUF feature value generation method according to claim 1, characterized in that: Step B also includes: Step C2: measuring an initial output voltage V0 of the piezoresistive sensor at a test temperature T1, wherein the initial output voltage V0 is an output voltage when an additional external pressure applied to the piezoresistive sensor is zero; The step D is to adjust the test temperature, and repeat the steps B, C1 and C2 until J initial output voltages V0 at the J test temperature group and a plurality of resistance-pressure coefficients K at the J test temperature group are obtained, wherein the number of K is M1+M2+......+Mj; The step E is to use the J groups of test temperatures as excitations, and the initial output voltage V0 and multiple K values ​​at each test temperature as responses to generate a PUF characteristic value.

3. The PUF feature value generation method according to claim 2, characterized in that: The initial output voltage V0=V+-V-, wherein V+ is the potential of the positive electrode of the output voltage end measured when the negative electrode of the output voltage end of the piezoresistive sensor is grounded, and V- is the potential of the negative electrode of the output voltage end measured when the positive electrode of the output voltage end of the piezoresistive sensor is grounded.

4. The PUF feature value generation method according to claim 2, characterized in that: Step B also includes: Step C3: When the external pressure applied to the piezoresistive sensor is zero and the test temperature T1, measure the potential V+ of the positive electrode of the output voltage end of the piezoresistive sensor when the negative electrode of the output voltage end of the piezoresistive sensor is grounded, and measure the potential V- of the negative electrode of the output voltage end of the piezoresistive sensor when the positive electrode of the output voltage end of the piezoresistive sensor is grounded; The step D is to adjust the test temperature, repeat the steps B, C1 and C3, until J V+ and J V- of the J group of test temperatures and a plurality of resistance-pressure coefficients K at the J group of test temperatures are obtained, and the number of K is M1+M2+......+Mj; The step E is to use the test temperatures of group J as excitations, and V+ and V- at each test temperature, as well as multiple K values ​​as responses, to generate PUF characteristic values.

5. The PUF feature value generation method according to claim 4, characterized in that: The piezoresistive sensor further includes a driving voltage adjustment circuit, and the driving voltage adjustment circuit is used to adjust the driving voltage input to the piezoresistive sensor; the step C1 includes: Step C11: at the test temperature T1, inputting a driving voltage U1 to the piezoresistive sensor via the driving voltage adjustment circuit; Step C12: When the external pressure applied to the piezoresistive sensor is zero, under the driving voltage U1, measuring the potential V+ of the positive electrode of the output voltage end of the piezoresistive sensor when the negative electrode of the output voltage end of the piezoresistive sensor is grounded, and measuring the potential V- of the negative electrode of the output voltage end of the piezoresistive sensor when the positive electrode of the output voltage end of the piezoresistive sensor is grounded; Step C13: Under the driving voltage U1, the pressure simulation structure simulates the M1 group of external pressure groups, obtains the resistance-pressure coefficient K of the piezoresistive sensor under each group of external pressure, and obtains the M1 group resistance-pressure coefficient K; Step C14: adjusting the driving voltage, repeating steps C11 to C14, until a plurality of resistance-pressure coefficients K and a plurality of groups of V+ and V- under N groups of driving voltages are obtained, and the number of K is M1+M2+......+Mn; Step D is to adjust the test temperature and repeat steps B to C14 until a plurality of resistance-pressure coefficients K and a plurality of groups of V+ and V- under J groups of test temperatures are obtained, wherein the number of K is J×(M1+M2+......+Mn), and the number of V+ and V- is J×N; The step E is to use the J groups of test temperatures and the N groups of driving voltages as excitations, and use V+ and V- at each test temperature and driving voltage, as well as multiple K values ​​as responses to generate PUF characteristic values.

6. The method for generating a PUF characteristic value according to any one of claims 2 to 5, characterized in that: The resistance-pressure coefficient K=(R2-R1) / (P2-P1), wherein R1 is the resistance of the piezoresistive sensor when the external pressure is P1, and R2 is the resistance of the piezoresistive sensor when the external pressure is P2; The pressure simulation structure comprises: A first pressure simulation electrode disposed at a diaphragm end of the cavity structure of the piezoresistive sensor; A second pressure simulation electrode is disposed at a fixed end of the cavity structure of the piezoresistive sensor.

7. The PUF feature value generation method according to claim 6, characterized in that: The pressure simulation structure simulates the external pressure group of the M1 group specifically as follows: The voltage value between the first pressure simulation electrode and the second pressure simulation electrode is equivalent to the external pressure value borne by the piezoresistive sensor; By adjusting the potential and / or current connected to the first pressure simulation electrode and the second pressure simulation electrode, different external pressure values ​​borne by the piezoresistive sensor are simulated to obtain the M1 group of external pressure groups.

8. The PUF feature value generation method according to claim 7, characterized in that: The step of adjusting the potential and / or current connected to the first pressure simulation electrode and the second pressure simulation electrode is specifically: Grounding the first pressure simulation electrode, and adjusting the potential and / or current of the second pressure simulation electrode; Alternatively, the second pressure simulation electrode is grounded, and the potential and / or current of the first pressure simulation electrode is adjusted.

9. The PUF feature value generation method according to claim 8, characterized in that: The resistance-pressure coefficient K=(V output 2-V output 1) / (V pressure simulation 2-V pressure simulation 1), Among them, Vpressure simulation 1 and Vpressure simulation 2 are different voltage values ​​between the first pressure simulation electrode and the second pressure simulation electrode, Voutput 1 is the output voltage of the piezoresistive sensor when the voltage value between the first pressure simulation electrode and the second pressure simulation electrode is Vpressure simulation 1, and Voutput 2 is the output voltage of the piezoresistive sensor when the voltage value between the first pressure simulation electrode and the second pressure simulation electrode is Vpressure simulation 2.

10. The PUF feature value generation method according to claim 1, characterized in that: The piezoresistive sensor is a MEMS sensor or an NMES sensor; the piezoresistive sensor is a piezoresistive pressure sensor, a piezoresistive force sensor, a piezoresistive displacement sensor, a piezoresistive mass sensor, a piezoresistive strain sensor, a piezoresistive flow sensor, a piezoresistive torque sensor, a piezoresistive vibration sensor, a piezoresistive liquid level sensor, a piezoresistive gyroscope, a piezoresistive gas sensor, a piezoresistive magnetic sensor, a piezoresistive biosensor, a piezoresistive humidity sensor, a piezoresistive temperature sensor, a piezoresistive chemical sensor, a piezoresistive acceleration sensor or a piezoresistive inertial sensor.

11. A method for generating a PUF key for a piezoresistive sensor, characterized in that: include: Combining the PUF characteristic values ​​obtained by the PUF characteristic value generation method according to any one of claims 1 to 10 to obtain a plurality of CRP stimulus-response pairs; Performing analog-to-digital conversion on the response in the CRP stimulus-response pair to obtain bit data; The bit data is processed using a hash algorithm to generate a PUF key.

12. A safety verification method for a piezoresistive sensor, characterized in that: include: A piezoresistive sensor to be tested is provided, a security verification device is connected to the piezoresistive sensor to be tested, and a power supply of the piezoresistive sensor is turned on, wherein the security verification device stores a PUF key of the piezoresistive sensor to be tested generated by the PUF key generation method in claim 11; The security verification device generates a first random number and sends the first random number to the piezoresistive sensor to be tested, and the piezoresistive sensor to be tested takes the first random number as a challenge and generates a first response; The piezoresistive sensor to be tested encrypts the first random number to obtain a second response, and sends the second response to the security verification device, wherein the encryption key of the first random number is the first response; Decrypting the second response using the PUF key stored in the security verification device as a decryption key to obtain a second random number; The second random number is compared with the first random number, and if the two are the same, it is determined that the piezoresistive sensor to be tested is a safety device.

13. A safety verification device for a piezoresistive sensor, characterized in that: The safety verification device can use the safety verification method described in claim 12 to perform safety verification on the piezoresistive sensor, and the safety verification device includes: A memory for storing PUF keys of a plurality of piezoresistive sensors generated by the method of claim 11; A random number generation module, used to generate a first random number; A decryption module, configured to decrypt a second response returned by the piezoresistive sensor using the PUF key to obtain a second random number; A comparison module, used for comparing the second random number with the first random number to obtain a comparison result; A display module is used to display the comparison result and / or display the first random number and the second random number.

14. A piezoresistive sensor, characterized in that: The characteristic value generation method described in any one of claims 1 to 10 can be applied, and the piezoresistive sensor includes: a power module, a processor, a storage module, an interface module, a temperature adjustment module, and a piezoresistive sensor structure; the power module is used to provide power to the processor, the storage module, the interface module, the temperature adjustment module, and the piezoresistive sensor structure, and the temperature adjustment module includes a temperature detection module and a heating resistor arranged in the area of ​​the piezoresistive sensor structure; the piezoresistive sensor structure includes a pressure simulation structure and a Wheatstone bridge, and the pressure simulation structure is used to simulate the change of the external pressure to which the piezoresistive sensor is subjected; the processor is electrically connected to the piezoresistive sensor structure, and is used to calculate the voltage value of the piezoresistive sensor structure, and is used to control the working state of the power module, and the processor is also used to respond to a first test signal of an external test device, and to adjust the ambient temperature of the piezoresistive sensor module by controlling the temperature of the heating resistor; Among them, when the piezoresistive sensor is in a testing state, the power module supplies power to the heating resistor, and the power module is electrically connected to the pressure simulation structure of the piezoresistive sensor structure; when the piezoresistive sensor is in a working state, the power module stops supplying power to the heating resistor, and the power module is disconnected from the pressure simulation structure of the piezoresistive sensor structure.

15. The piezoresistive sensor according to claim 14, characterized in that: The pressure simulation structure comprises: A first pressure simulation electrode disposed at a diaphragm end of the cavity structure of the piezoresistive sensor structure; a second pressure simulation electrode disposed at a fixed end of the cavity structure of the piezoresistive sensor structure; In a test state, the power module provides a pressure simulation potential to the first pressure simulation electrode, and the second pressure simulation electrode is grounded, or the power module provides a pressure simulation voltage to the second pressure simulation electrode, and the first pressure simulation electrode is grounded.

16. The piezoresistive sensor according to claim 15, characterized in that: The power supply module includes: a battery, a first switch module and an analog voltage adjustment module. The first switch module controls the voltage adjustment module to output a corresponding pressure simulation voltage in response to a second test signal sent by the processor; the voltage adjustment module includes n voltage output nodes, and resistors R1, R2...Rn connected in series in sequence, where n is a positive integer and a voltage output node is arranged between two adjacent resistors. The first switch module selects to connect the corresponding voltage output node in response to the second test signal sent by the processor to control the voltage adjustment module to output a corresponding pressure simulation voltage.

17. The piezoresistive sensor according to claim 15, characterized in that: The power supply module also includes a second switch module and a third switch module, wherein the first end of the second switch module is connected to the positive electrode V+ of the output voltage end of the piezoresistive sensor structure, and the second end is grounded; the first end of the third switch module is connected to the negative electrode V- of the output voltage end of the piezoresistive sensor structure, and the second end is grounded; the second switch module is closed in response to the output voltage test signal of V-, and is opened in response to the output voltage test signal of V+; the third switch module is closed in response to the output voltage test signal of V+, and is opened in response to the output voltage test signal of V-.

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