Structure monitoring device of password card and password card

Abstract

The invention provides a structure monitoring device of a password card and the password card, the structure monitoring device is arranged in a shell of the password card, the structure monitoring device comprises a constant-current power supply module, at least one strain gauge and a voltage sampling module, the constant-current power supply module is connected with the power end of the at least one strain gauge, and the voltage sampling module is connected with the constant-current power supply module. The sampling end of the at least one strain gauge is connected with the input end of the voltage sampling module, and the output end of the voltage sampling module is connected with a main control chip of the password card, so that structural deformation monitoring is carried out on the password card based on the sampling voltage of the at least one strain gauge. Therefore, tiny deformation in the password card shell can be monitored in real time, and the physical safety of the password card is improved.

Description

Technical Field

[0001] The present application relates to the field of information security technology, and in particular to a structure monitoring device for a password card and a password card. Background Art

[0002] With the development of information security technology, password cards, as a hardware security module, are widely used in key areas such as identity authentication, data encryption and decryption, and key management. Password cards store important encryption keys and data. If they are maliciously disassembled or destroyed by unauthorized personnel, it may lead to key leakage, which in turn brings serious security risks. Therefore, password cards are usually equipped with a variety of physical protection measures to resist physical attacks and prevent information leakage.

[0003] At present, common physical protection technologies for password cards include physical shell reinforcement, anti-tampering seals, etc. However, the physical shell reinforcement design relies on strong materials and complex structural processes, but it is difficult to monitor and effectively protect against minor physical damage and disassembly behaviors in real time. Anti-tampering seals and other means are mainly used to detect significant signs of disassembly, but cannot detect subtle changes in the internal structure. Summary of the invention

[0004] In view of this, the embodiments of the present application provide a structure monitoring device for a password card and a password card, so as to monitor the tiny deformation inside the password card housing in real time and improve the physical security of the password card.

[0005] In a first aspect, an embodiment of the present application provides a structure monitoring device for a password card, wherein the structure monitoring device is arranged in a housing of the password card, and the structure monitoring device comprises: a constant current power supply module, at least one strain gauge and a voltage sampling module;

[0006] The constant current power supply module is connected to the power supply end of the at least one strain gauge, the sampling end of the at least one strain gauge is connected to the input end of the voltage sampling module, and the output end of the voltage sampling module is connected to the main control chip of the password card, so as to monitor the structural deformation of the password card based on the sampling voltage of the at least one strain gauge.

[0007] In an optional embodiment, the at least one strain gauge is encapsulated in a structural member.

[0008] In an optional embodiment, the number of the strain gauges is multiple, and the multiple strain gauges are divided into at least two groups, the power supply ends of at least two groups of strain gauges are respectively connected to at least two output ends of the constant current power supply module, and the sampling ends of the at least two groups of strain gauges are respectively connected to at least two input ends of the voltage sampling module.

[0009] In an optional embodiment, at least two groups of strain gauges include: a first group of strain gauges, wherein the power supply end after the strain gauges in the first group of strain gauges are connected in series is connected to the first output end of the constant current power supply module, and the sampling end after the strain gauges in the first group of strain gauges are connected in series is connected to the first input end of the voltage sampling module.

[0010] In an optional embodiment, at least two groups of strain gauges include: a second group of strain gauges, wherein the power supply end after the strain gauges in the second group of strain gauges are connected in series is connected to the second output end of the constant current power supply module, and the sampling end after the strain gauges in the second group of strain gauges are connected in series is connected to the second input end of the voltage sampling module.

[0011] In an optional implementation, the constant current power supply module includes: at least two constant current units, and the output ends of the at least two constant current units are at least two output ends of the constant current power supply module.

[0012] In an optional embodiment, each constant current unit includes a comparator, a transistor, and a sampling resistor, the non-phase input terminal of the comparator is connected to a preset power supply, the inverting input terminal of the comparator is grounded through the sampling resistor, the output terminal of the transistor is grounded through the sampling resistor, the input terminal of the transistor is connected to the negative power supply terminal of the corresponding strain gauge, and the control terminal of the transistor is connected to the output terminal of the comparator.

[0013] In an optional implementation, the voltage sampling module is a voltage sampling chip, and at least two analog-to-digital conversion interfaces of the voltage sampling chip are output ends of the voltage sampling module.

[0014] In an optional implementation, the transistor is an NPN transistor.

[0015] In the second aspect, an embodiment of the present application also provides a password card, comprising: a shell, a main control chip arranged in the shell, a password chip and a password card structure monitoring device, the main control chip is connected to the password chip, and the main control chip is connected to the output end of the voltage sampling module in the password card structure monitoring device.

[0016] The present application provides a structure monitoring device for a password card and a password card, wherein the structure monitoring device is arranged in the housing of the password card, and the structure monitoring device comprises: a constant current power supply module, at least one strain gauge and a voltage sampling module, the constant current power supply module is connected to the power supply end of at least one strain gauge, the sampling end of at least one strain gauge is connected to the input end of the voltage sampling module, and the output end of the voltage sampling module is connected to the main control chip of the password card, so as to monitor the structural deformation of the password card based on the sampling voltage of at least one strain gauge. Thus, the slight deformation inside the housing of the password card can be monitored in real time, and the physical security of the password card can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the structure monitoring device of the password card provided in the embodiment of the present application Figure 1 ;

[0019] Figure 2 A schematic diagram of a strain gauge provided in an embodiment of the present application;

[0020] Figure 3 Schematic diagram of the structure monitoring device of the password card provided in the embodiment of the present application Figure 2 ;

[0021] Figure 4 A circuit diagram of a constant current unit provided in an embodiment of the present application;

[0022] Figure 5 A circuit diagram of a sampling chip provided in an embodiment of the present application;

[0023] Figure 6 A schematic diagram of a password card provided in an embodiment of the present application;

[0024] Figure 7 A schematic diagram of the flow of structural monitoring of a password card provided in an embodiment of the present application.

[0025] Reference numerals:

[0026] 10-structural monitoring device; 100-constant current power supply module; 200-strain gauge; 300-voltage sampling module; 400-structural component; 20-main control chip; 110-comparator; 120-transistor; 130-sampling resistor; 210-first set of strain gauges; 220-second set of strain gauges; 30-password chip; 40-housing; 410-card slot. DETAILED DESCRIPTION

[0027] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0028] In response to the problem of untimely and inaccurate detection of minor physical damage and disassembly behaviors in the protection of password cards, this application applies strain gauges to the physical security protection of password cards. By real-time monitoring of the tiny deformation inside the password card shell, it can effectively detect whether the password card is subjected to external force or malicious disassembly, thereby improving the physical security of the password card and achieving more precise physical protection and higher security.

[0029] Figure 1 Schematic diagram of the structure monitoring device of the password card provided in the embodiment of the present application Figure 1 The structure monitoring device 10 is arranged in the housing of the password card. The structure monitoring device 10 includes: a constant current power supply module 100 , at least one strain gauge 200 and a voltage sampling module 300 .

[0030] The constant current power supply module 100 is connected to the power supply end of at least one strain gauge 200, the sampling end of at least one strain gauge 200 is connected to the input end of the voltage sampling module 300, and the output end of the voltage sampling module 300 is connected to the main control chip 20 of the password card to monitor the structural deformation of the password card based on the sampling voltage of at least one strain gauge 200.

[0031] Among them, the strain gauge (SG) 200 is a resistive strain sensor, which is arranged in the shell of the password card and can convert the deformation of the structure into an electrical signal. When the password card is deformed by force, the resistance value of the strain gauge will change accordingly. Therefore, the strain gauge 200 can monitor the tiny deformation inside the card body in real time, and can effectively detect whether the password card is subjected to external force or malicious disassembly, thereby improving the physical security of the password card.

[0032] The constant current power supply module 100 can be a constant current source (CCS), an electronic device that can output a constant current. The power supply end of each strain gauge 200 is connected to the constant current power supply module 100 to use the constant current power supply module 100 to provide a constant current for each strain gauge 200.

[0033] The voltage sampling module 300 may be a voltage sampling chip, a sampling end of each strain gauge 200 and an input end of the voltage sampling module 300 . The voltage sampling module 300 is used to sample the voltage signal of each strain gauge 200 to obtain the sampled voltage of each strain gauge 200 .

[0034] The output end of the voltage sampling module 300 is connected to the main control chip 20 of the password card, so that the main control chip 20 monitors the structural deformation of the password card according to the sampled voltages of the strain gauges 200 .

[0035] Among them, when the structure of the password card is complete, the voltage signal of each strain gauge 200 can be sampled to obtain the reference voltage of each strain gauge 200. The main control chip 20 can monitor the structural deformation of the password card based on the reference voltage of each strain gauge 200 and the sampled voltage of each strain gauge 200. If the voltage difference between the sampled voltage and the reference voltage is within the preset voltage difference range, the password card does not have structural deformation. If the voltage difference between the sampled voltage and the reference voltage is not within the preset voltage difference range, it means that the password card is deformed by force, resulting in a change in the resistance value of the strain gauge 200. It is determined that the password card may have been physically damaged or affected by external force, that is, the password card has structural deformation.

[0036] It is worth noting that by arranging at least one strain gauge 200 inside the password card housing, if the voltage difference between the sampling voltage of any strain gauge 200 and the corresponding reference voltage is not within the preset voltage difference range, the password card has structural deformation; if the voltage difference between the sampling voltage of all strain gauges 200 and the corresponding reference voltage is within the preset voltage difference range, the password card has no structural deformation, which further improves the accuracy of deformation monitoring of the password card.

[0037] In this embodiment, by installing a strain gauge inside the password card housing, the strain gauge can detect tiny structural changes of the password card, improve the sensitivity of physical protection, and effectively determine whether the password card is damaged by external force or maliciously disassembled, thereby improving the physical security of the password card and preventing sensitive data leakage and unauthorized use of the device. The device has the advantages of strong real-time performance, high detection accuracy, and low cost, and can be widely used in various encryption devices with high security requirements.

[0038] In an optional embodiment, at least one strain gauge 200 is encapsulated in the structural component 400 .

[0039] The structural member 400 is disposed in the housing of the password card, such as on the circuit board of the password card, so as to provide physical protection for the strain gauge 200 and prevent the strain gauge 200 from being damaged when the password card is damaged by external force.

[0040] Take two strain gauges 200 as an example, Figure 2A schematic diagram of a strain gauge provided in an embodiment of the present application, such as Figure 2 As shown, two slots 410 are provided in the structural component 400 , and the strain gauges 200 can be packaged in the structural component 400 by inserting two strain gauges 200 into the corresponding slots 410 .

[0041] In an optional embodiment, there are multiple strain gauges 200, and the multiple strain gauges 200 are divided into at least two groups. The power supply ends of at least two groups of strain gauges are respectively connected to at least two output ends of the constant current power supply module 100, and the sampling ends of at least two groups of strain gauges are respectively connected to at least two input ends of the voltage sampling module 300.

[0042] Among them, a group of strain gauges includes strain gauges 200, and the power supply end of a group of strain gauges can be the power supply end of each strain gauge 200 in a group of strain gauges. The power supply end of a group of strain gauges is connected to an output end of a constant current power supply module 100, so that the constant current power supply module 100 is used to provide a constant current for each strain gauge 200 in a group of strain gauges.

[0043] The sampling end of a group of strain gauges is connected to an input end of the voltage sampling module 300. The sampling end of a group of strain gauges can be the sampling end of each strain gauge 200 in a group of strain gauges, so that the voltage sampling module 300 is used to sample the voltage signal of each strain gauge 200 in a group of strain gauges to obtain the sampling voltage of each strain gauge 200 in a group of strain gauges.

[0044] In an optional implementation, each strain gauge 200 in each group of strain gauges is packaged in a structural component 400 .

[0045] Figure 3 Schematic diagram of the structure monitoring device of the password card provided in the embodiment of the present application Figure 2 ,like Figure 3 As shown, in an optional embodiment, at least two groups of strain gauges include: a first group of strain gauges 210, the power supply end after the strain gauges 200 in the first group of strain gauges 210 are connected in series is connected to the first output end of the constant current power supply module 100, and the sampling end after the strain gauges 200 in the first group of strain gauges 210 are connected in series is connected to the first input end of the voltage sampling module 300.

[0046] The strain gauges 200 in the first group of strain gauges 210 may be connected in series, and the power supply end of the strain gauges 200 in the first group of strain gauges 210 after being connected in series includes the positive power supply end of the first strain gauge 200 connected in series and the negative power supply end of the last strain gauge 200.

[0047] The first output end of the constant current power supply module 100 includes a first positive output end and a first negative output end. The positive power supply end of the first strain gauge 200 is connected to the first positive output end, and the negative power supply end of the last strain gauge 200 is connected to the first negative output end, so that the constant current power supply module 100 is used to provide a constant current for each strain gauge 200 in the first group of strain gauges.

[0048] The sampling ends of the strain gauges 200 in the first group of strain gauges 210 after being connected in series include the positive sampling end of the first strain gauge 200 connected in series and the negative sampling end of the last strain gauge 200. The first input end of the voltage sampling module 300 includes a first positive sampling input end and a first negative sampling input end. The positive sampling end of the first strain gauge 200 after being connected in series is connected to the first positive sampling input end of the voltage sampling module 300, and the negative sampling end of the last strain gauge 200 after being connected in series is connected to the first negative sampling input end of the voltage sampling module 300, so that the voltage sampling module 300 is used to sample the voltage signals of the first group of strain gauges 210 connected in series to obtain the sampling voltage of the first group of strain gauges 210. The sampling voltage of the first group of strain gauges 210 is the sum of the voltages of the strain gauges 200 in the first group of strain gauges.

[0049] In an optional embodiment, at least two groups of strain gauges include: a second group of strain gauges 220, wherein the power supply end after the strain gauges 200 in the second group of strain gauges 220 are connected in series is connected to the second output end of the constant current power supply module 100, and the sampling end after the strain gauges 200 in the second group of strain gauges 220 are connected in series is connected to the second input end of the voltage sampling module 300.

[0050] The strain gauges 200 in the second group of strain gauges 220 may be connected in series, and the power supply end of the strain gauges 200 in the second group of strain gauges 220 after being connected in series includes the positive power supply end of the first strain gauge 200 connected in series and the negative power supply end of the last strain gauge 200.

[0051] The first output end of the constant current power supply module 100 includes a first positive output end and a first negative output end. The positive power supply end of the first strain gauge 200 is connected to the first positive output end, and the negative power supply end of the last strain gauge 200 is connected to the first negative output end, so that the constant current power supply module 100 is used to provide a constant current for each strain gauge 200 in the second group of strain gauges 220.

[0052] The sampling ends of the strain gauges 200 in the second group of strain gauges 220 after being connected in series include the positive sampling end of the first strain gauge 200 connected in series and the negative sampling end of the last strain gauge 200. The second input end of the voltage sampling module 300 includes a second positive sampling input end and a second negative sampling input end. The positive sampling end of the first strain gauge 200 after being connected in series is connected to the second positive sampling input end of the voltage sampling module 300, and the negative sampling end of the last strain gauge 200 after being connected in series is connected to the second negative sampling input end of the voltage sampling module 300, so that the voltage signal of the second group of strain gauges 220 connected in series is sampled by the voltage sampling module 300 to obtain the sampling voltage of the second group of strain gauges 220. The sampling voltage of the second group of strain gauges 220 is the sum of the voltages of the strain gauges 200 in the second group of strain gauges 220.

[0053] In an optional implementation, the constant current power supply module 100 includes: at least two constant current units, and the output ends of the at least two constant current units are at least two output ends of the constant current power supply module 100 .

[0054] Among them, an output end of a constant current unit is an output end of the constant current power supply module 100 .

[0055] Each constant current unit includes a comparator 110, a transistor 120, and a sampling resistor 130. The positive input terminal of the comparator 110 is connected to a preset power supply, the negative input terminal of the comparator 110 is grounded through the sampling resistor 130, the output terminal of the transistor 120 is grounded through the sampling resistor 130, the input terminal of the transistor 120 is connected to the negative power supply terminal of the corresponding strain gauge 200, and the control terminal of the transistor 120 is connected to the output terminal of the comparator 110.

[0056] The corresponding strain gauge 200 is the first strain gauge 200 connected in series in the first group of strain gauges or the first strain gauge 200 in the second group of strain gauges, and the input end of the transistor 120 is the output end of the constant current unit.

[0057] For the first group of strain gauges, the input end of the transistor 120 is connected to the negative power supply end of the first strain gauge 200 in the first group of strain gauges, and the positive power supply end of the last strain gauge 200 is connected to the preset power supply. For the second group of strain gauges, the input end of the transistor 120 is connected to the negative power supply end of the first strain gauge 200 in the second group of strain gauges, and the positive power supply end of the last strain gauge 200 is connected to the preset power supply.

[0058] The transistor 120 is an NPN transistor, the input end of the transistor 120 is the collector, the output end of the transistor 120 is the emitter, and the control end of the transistor 120 is the base.

[0059] For example, a set of strain gauges includes a strain gauge 200. Figure 4A circuit diagram of a constant current unit provided in an embodiment of the present application, such as Figure 4 As shown, the positive input terminal (3 port) of the comparator 110 is connected to the power supply VCC3.3V, the negative input terminal (2 port) of the comparator 110 is grounded through the sampling resistor 130, the output terminal of the transistor 120 is grounded through the sampling resistor 130, the input terminal of the transistor 120 is connected to the negative power supply terminal of the strain gauge 200, and the positive power supply terminal of the strain gauge 200 is connected to the power supply VCC3.3V.

[0060] This circuit is a negative feedback circuit, in which the sampling resistor 130 feeds back the load current in real time. When the load current increases, the voltage at the inverting input terminal of the comparator 110 is higher than the voltage at the non-inverting input terminal, and the comparator 110 outputs a low level, which turns off the transistor 120, thereby reducing the load current, that is, the current at the negative power supply terminal of the strain gauge 200 decreases.

[0061] When the load current decreases, the voltage at the inverting input terminal of the comparator 110 is lower than the voltage at the non-inverting input terminal, and the operational amplifier outputs a high level, turning on the transistor 120, which increases the load current, that is, the current at the negative power supply terminal of the first strain gauge 200. Therefore, the load current eventually reaches a constant stable current under the real-time feedback of the sampling resistor 130.

[0062] Among them, the power supply end (1 port) of the comparator 110 can be connected to the power supply VCC3.3V, the ground end (4 port) of the comparator 110 is grounded, the output end of the comparator 110 is connected to the control end of the transistor 120 through the resistor (1k), and the resistance value of the sampling resistor 130 can be 3.3k.

[0063] join Figure 4 The power supply VCC3.3V can also be grounded through filter capacitors connected in parallel, wherein the capacitance values ​​of the filter capacitors connected in parallel are 100nF and 10μF respectively.

[0064] In an optional implementation, the voltage sampling module 300 is a voltage sampling chip, and at least two analog-to-digital conversion interfaces (ADC) of the voltage sampling chip are output ends of the voltage sampling module 300 .

[0065] The voltage sampling chip samples the voltage signal of the strain gauge 200 in real time to obtain the sampled voltage at both ends of the strain gauge 200, and converts the sampled voltage into a digital signal through at least two analog-to-digital conversion interfaces of the voltage sampling chip and transmits it to the main control chip 20, so that the main control chip 20 monitors the structural deformation of the password card according to the digital sampled voltage. The voltage sampling chip is an ADC voltage sampling chip.

[0066] It is worth noting that the sampling frequency of the ADC can be set to ensure that the collected data is real-time enough to capture possible structural changes of the password card.

[0067] Figure 5 A circuit diagram of a sampling chip provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the first input end of the voltage sampling chip includes a first positive sampling input end (port 8) and a first negative sampling input end (port 9), and the second input end of the voltage sampling module 300 includes a second positive sampling input end (port 10) and a second negative sampling input end (port 11).

[0068] The positive sampling end of the first strain gauge 200 in the first group of strain gauges connected in series is connected to the first positive sampling input end (8-port) of the voltage sampling module 300, and the negative sampling end of the last strain gauge 200 in series is connected to the first negative sampling input end (9-port) of the voltage sampling module 300.

[0069] The positive sampling end of the first strain gauge 200 in the second group of strain gauges connected in series is connected to the second positive sampling input end (port 10) of the voltage sampling module 300, and the negative sampling end of the last strain gauge 200 in series is connected to the second negative sampling input end (port 11) of the voltage sampling module 300.

[0070] See also Figure 5 Port 1 of the sampling chip is not connected, port 2 and port 3 are configuration ports, port 4 and port 5 are two output ports of the sampling chip, which are used to connect to the main control chip 20, and the two output ports are also connected to the power supply VCC3.3V through a resistor (the resistance value can be 4.7k), port 6, port 7, port 14 (REF-port) and port 15 are grounded, port 12 is the power port, port 13 is the REF-port, connected to the power supply VCC3.3V.

[0071] See also Figure 5 The power supply VCC3.3V of the sampling chip can also be grounded through the filter capacitors connected in parallel, wherein the capacitance values ​​of the filter capacitors connected in parallel are 100nF and 10μF respectively.

[0072] See also Figure 5 The power supply VCC3.3V of the sampling chip can also be grounded through parallel connected resistors. First, connect the 4.7k and 100k resistors in series, and then connect them in parallel with another set of series connected 4.7k and 100k resistors and then ground them.

[0073] Figure 6 A schematic diagram of a password card provided in an embodiment of the present application, such as Figure 6As shown, the password card includes: a shell 40, a main control chip 20 arranged in the shell, a password chip 30 and the above-mentioned password card structure monitoring device 10, the main control chip 20 is connected to the password chip 30, and the output end of the main control chip 20 and the voltage sampling module 300 in the password card structure monitoring device 10 are connected.

[0074] The voltage sampling module 300 is used to sample the voltage signal of the strain gauge 200 in the structure monitoring device 10 to obtain a sampled voltage, and transmit the sampled voltage to the main control chip 20. The main control chip 20 is used to monitor the structural deformation of the password card according to the sampled voltage.

[0075] It is worth noting that the main control chip 20 obtains the quantum key from the quantum key distribution network, and the cryptographic chip 30 is used to obtain the quantum key from the main control chip 20 to perform cryptographic operations and / or key operations.

[0076] The following is an explanation of the working process of the software for structure monitoring of the password card provided by this application. Figure 7 A schematic diagram of the structure monitoring process of the password card provided in the embodiment of the present application is as follows: Figure 7 As shown, the following steps are included:

[0077] S1: ADC real-time sampling

[0078] The voltage signal of the strain gauge is sampled in real time through the ADC voltage sampling chip. The voltage at both ends of the strain gauge changes with the physical changes of the password card structure. The ADC voltage sampling chip converts this voltage signal into a digital signal and transmits it to the main control chip.

[0079] The sampling frequency of the ADC is set to ensure that the collected data is real-time enough to capture any structural changes that may occur in the password card.

[0080] S2: Data processing and judgment

[0081] The main control chip reads the digital signal of the reference voltage when the password card is structurally intact, and after receiving the digital signal from the ADC voltage sampling chip, it compares the digital signal of the reference voltage with the digital signal of the sampling voltage. If the voltage change exceeds the set threshold, the system determines that the password card may have been physically damaged or affected by external force.

[0082] Among them, the main control chip can also use data filtering and environmental compensation algorithms to eliminate voltage signal fluctuations caused by external factors such as temperature and humidity, ensuring the accuracy of judgment.

[0083] It is worth noting that the system software deployed on the main control chip needs to have the function of continuously monitoring and analyzing real-time data to ensure that physical state changes can be captured quickly. The software interacts with the hardware interface, reads the sampled voltage sampled by the ADC, and makes judgments based on the set alarm threshold.

[0084] A fault detection mechanism is designed in the software system to continuously detect the status of sensors, ADCs, and communication links. If the system detects sensor anomalies or data loss during operation, the software will issue a fault alarm and record relevant information.

[0085] The system software should have a log management function to automatically record all sampling data, judgment results and alarm information to facilitate subsequent analysis and debugging.

[0086] S3: Alarm and response mechanism

[0087] When it is determined that the password card structure has abnormal changes, the alarm mechanism is triggered. This alarm can be sent through the indicator light, buzzer in the password card, or through an external communication module.

[0088] Security responses can be automatically executed, such as locking password cards, destroying keys or sensitive data, to ensure that information is not further leaked.

[0089] S4: Data Recording and Storage

[0090] The system records all detected structural change data, including timestamp, change magnitude, and processing results, and stores the data in memory.

[0091] S5: Self-check and recovery

[0092] The system can perform self-checking operations regularly to ensure that components such as strain gauges, constant current sources, and ADC voltage sampling chips are working properly. If a system component is found to be faulty or ineffective, the user will be prompted to perform maintenance or replacement in a timely manner.

[0093] When restoring or restarting the password card, the system will verify the historical data to ensure that the password card has not been physically damaged during use.

[0094] S6: If the voltage signal is normal, it works normally.

[0095] Return to ADC real-time sampling to continue monitoring.

[0096] In this embodiment, strain gauges are used to detect the structural parts of the password card, and the physical state changes are judged by monitoring the slight deformation of the card body structure. This design aims at the physical security issues of the password card, can directly detect structural changes, enhance security, and realize physical protection of the password card, making up for the deficiency that the existing protection measures cannot monitor slight damage in real time. The system collects the voltage signal of the strain gauge in real time, and performs automatic judgment and alarm through software. When an abnormality is detected, the system can quickly trigger response measures. The strain gauge can detect slight structural changes of the password card and improve the sensitivity of physical protection. The system collects data in real time and responds quickly when physical damage occurs to ensure the security of the password card. The system has an automatic alarm function to reduce manual intervention and improve security management efficiency.

[0097] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance.

[0098] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application. They should all be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A structure monitoring device for a password card, characterized in that: The structure monitoring device is arranged in the housing of the password card, and the structure monitoring device comprises: a constant current power supply module, at least one strain gauge and a voltage sampling module; The constant current power supply module is connected to the power supply end of the at least one strain gauge, the sampling end of the at least one strain gauge is connected to the input end of the voltage sampling module, and the output end of the voltage sampling module is connected to the main control chip of the password card, so as to monitor the structural deformation of the password card based on the sampling voltage of the at least one strain gauge.

2. The structure monitoring device of the password card according to claim 1, characterized in that: The at least one strain gauge is encapsulated within the structural member.

3. The structure monitoring device of the password card according to claim 1, characterized in that: The number of the strain gauges is multiple, and the multiple strain gauges are divided into at least two groups. The power supply ends of at least two groups of strain gauges are respectively connected to at least two output ends of the constant current power supply module, and the sampling ends of the at least two groups of strain gauges are respectively connected to at least two input ends of the voltage sampling module.

4. The structure monitoring device of the password card according to claim 3, characterized in that: The at least two groups of strain gauges include: a first group of strain gauges, wherein the power supply end after the strain gauges in the first group of strain gauges are connected in series is connected to the first output end of the constant current power supply module, and the sampling end after the strain gauges in the first group of strain gauges are connected in series is connected to the first input end of the voltage sampling module.

5. The structure monitoring device of the password card according to claim 3 or 4, characterized in that: The at least two groups of strain gauges include: a second group of strain gauges, wherein the power supply end after the strain gauges in the second group of strain gauges are connected in series is connected to the second output end of the constant current power supply module, and the sampling end after the strain gauges in the second group of strain gauges are connected in series is connected to the second input end of the voltage sampling module.

6. The structure monitoring device of the password card according to claim 3, characterized in that: The constant current power supply module comprises: at least two constant current units, and the output ends of the at least two constant current units are at least two output ends of the constant current power supply module.

7. The structure monitoring device of the password card according to claim 6, characterized in that: Each constant current unit includes a comparator, a transistor, and a sampling resistor. The non-phase input end of the comparator is connected to a preset power supply, the inverting input end of the comparator is grounded through a sampling resistor, the output end of the transistor is grounded through the sampling resistor, the input end of the transistor is connected to the negative power supply end of the corresponding strain gauge, and the control end of the transistor is connected to the output end of the comparator.

8. The structure monitoring device of the password card according to claim 1, characterized in that: The voltage sampling module is a voltage sampling chip, and at least two analog-to-digital conversion interfaces of the voltage sampling chip are output ends of the voltage sampling module.

9. The structure monitoring device of the password card according to claim 7, characterized in that: The transistor is an NPN transistor.

10. A password card, characterized in that: It comprises: a shell, a main control chip arranged in the shell, a password chip and the password card structure monitoring device according to any one of claims 1 to 9, wherein the main control chip is connected to the password chip, and the main control chip is connected to the output end of the voltage sampling module in the password card structure monitoring device.

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