WO2017197796A1 - Method for protecting pos machine from being refitted and being implant with trojan program for information stealing - Google Patents

Abstract

Provided is a method for protecting a POS machine from being refitted and being provided with a Trojan program for information stealing. The method comprises the steps of: firstly, monitoring the power consumption of a main power supply in real time; secondly, carrying out theoretical power consumption registration and response, including enabling the power consumption values of the main power supply under all operations of the POS machine to be written in a bottom software, and carrying out response during the operations of the POS machine; and finally, judging whether the POS machine is abnormal or not according to the comparison of the power consumption, monitored in real time, of the main power supply and the theoretical power consumption, giving an alarm if the POS machine has an abnormality twice in succession, or else, carrying out the new comparison of the power consumption, monitored in real time, of the main power supply and the theoretical power consumption. The method employs a mode of the comparison of the power consumption, monitored in real time, of the main power supply and the theoretical power consumption, so as to recognize whether there is abnormal monitoring and information stealing or not. The method can effectively prevent the POS machine from working in an abnormal state.

Description

Method for preventing POS machine from being modified and implanting Trojan to steal information Technical field

The invention relates to the field of electronic payment, in particular to a method for preventing a POS machine from being modified and implanting a Trojan horse to steal information.

Background technique

The security of traditional POS devices is directly related to the security of the credit card holders. The crimes of pirating or implanting Trojan viruses in the event of criminals stealing card numbers and passwords occur. The security performance of POS is challenged. At present, most of the security methods of POS use the loop signal change of the detection security circuit to judge whether the abnormality is abnormal, and the criminals can bypass the detection mechanism in various ways.

Summary of the invention

The object of the present invention is to provide a method for preventing the POS machine from being modified and implanting a Trojan to steal information by solving the above-mentioned document. The method uses real-time monitoring of power consumption and rated power consumption to identify whether there is abnormal monitoring. The existence of stolen information can effectively prevent the abnormal working state of the POS machine.

In order to achieve the above object, the technical solution of the present invention is: a method for preventing a POS machine from being modified and implanting a Trojan horse to steal information, including the following steps,

S1: Real-time monitoring of main power consumption;

S2: The theoretical power consumption registration and response, including the main power consumption value of each action of the POS machine is written into the underlying software and the response of the POS operation;

S3: according to step S1 real-time monitoring of the main power consumption compared with the theoretical power consumption of step S2, to determine whether the POS machine is abnormal, and if so, proceed to step S4, and if not, then re-execute step S3;

S4: Comparing the power consumption of the main power source monitored in real time in step S1 with the theoretical power consumption of step S2, determining whether the POS machine has an abnormality, and if so, determining that the POS machine is abnormal, and performing an alarm; if not, re-executing step S3.

In an embodiment of the present invention, in step S1, real-time monitoring of main power consumption is divided into power consumption monitoring mode and efficiency monitoring mode according to different main power supply modes of the POS machine, wherein the POS main power supply adopts an adapter. In the power supply mode, the power consumption monitoring mode is adopted to perform real-time monitoring of the power consumption of the POS main power supply; if the main power supply of the POS machine adopts the battery power supply mode, the efficiency monitoring mode is adopted to perform real-time monitoring of the main power consumption of the POS machine.

即可得出POS机主电源功耗。In an embodiment of the present invention, the power consumption monitoring method calculates the current value at both ends of the test resistor r by detecting the voltage Vab across the test resistor r connected to the POS adapter and the post-stage load of the POS machine.

The power consumption of the POS main power supply can be obtained.

及后级功耗

即可得前级与后级的转换效率

In an embodiment of the present invention, the efficiency monitoring mode is: first, the pre-stage detection resistor r1 is connected between the POS battery and the POS power conversion module, and the POS power conversion module is connected to the post-stage load of the POS machine. The latter detection resistor r2 detects the voltage V1 across the front-end detection resistor r1 and the voltage V2 across the second-stage detection resistor r2, respectively, and obtains the power consumption of the previous stage.

And subsequent power consumption

You can get the conversion efficiency of the front and the back

In an embodiment of the invention, the power consumption value of the main power source in each action of the POS machine is written into the lower layer software, that is, the power consumption value of the main power source in the single action of the POS machine is written into the lower layer software, and the power consumption value is When writing to the underlying software, the power consumption is written in a time-division manner.

In an embodiment of the invention, the method for writing the power consumption in a time-division manner is to divide the time period of the single action of the POS machine, and write the main power consumption value under the single action of the POS machine in the corresponding time period.

In an embodiment of the present invention, the POS operation response, that is, when the POS performs an operation, sends an operation instruction to the POS operating system, and if the POS operating system recognizes the operation instruction as an abnormal instruction, the POS If the POS machine operating system recognizes that the operation instruction is a normal instruction, it continues to judge that the operation instruction includes an action number, and then reads the total power consumption value corresponding to the operation by the underlying software, and returns to the POS operation. system.

In an embodiment of the invention, it is also necessary to use a hidden pad and a main power blind hole inner layer routing mode for the main power source to prevent the implanted module from directly supplying power from the front end of the main power source.

In an embodiment of the invention, the alarm in step S4 includes: the buzzer continues to beep, the liquid crystal display attacks, and the background locks the POS machine to make it impossible to trade.

Compared with the prior art, the present invention has the following beneficial effects: the present invention uses a real-time monitoring method of comparing the power consumption of the power source with the rated power consumption to identify whether there is abnormal monitoring and stealing information, and can effectively prevent the abnormal working state of the POS machine. In order to effectively prevent POS from being modified or implanted in Trojans to steal relevant information.

DRAWINGS

FIG. 1 is a schematic diagram of a connection structure of a main power interface used in the present invention. In the figure, 1 is a power interface, 2 is a solder joint, and 3 is a PCB board.

2 is a schematic diagram of a power consumption monitoring mode circuit used in the present invention.

FIG. 3 is a schematic diagram of the circuit of the efficiency monitoring mode adopted by the present invention.

4 is a flow chart of the pre-registration of the power consumption value writing software of the present invention.

FIG. 5 is a simplified flow chart of the software when the POS is operated according to the present invention.

FIG. 6 is a flow chart of real-time comparison and reduction of power consumption preset current and detection current according to the present invention.

detailed description

The technical solution of the present invention will be specifically described below with reference to the accompanying drawings.

A method for preventing a POS machine from being modified and implanting a Trojan horse to steal information includes the following steps:

S1: Real-time monitoring of main power consumption;

S2: The theoretical power consumption registration and response, including the main power consumption value of each action of the POS machine is written into the underlying software and the response of the POS operation;

S3: according to step S1 real-time monitoring of the main power consumption compared with the theoretical power consumption of step S2, to determine whether the POS machine is abnormal, and if so, proceed to step S4, and if not, then re-execute step S3;

S4: comparing the main power consumption of the real-time monitoring in step S1 with the theoretical power consumption of step S2, determining whether the POS machine has an abnormality, and if so, determining that the POS machine is abnormal, and performing an alarm (including: buzzer continuous tweet, liquid crystal display) The attack and the background lock the POS machine so that it cannot be traded.); if not, re-execute step S3.

In the step S1, the power consumption of the main power source is monitored in real time, and the power consumption monitoring mode and the efficiency monitoring mode are respectively classified according to different power supply modes of the POS machine, wherein the power consumption monitoring is adopted when the main power of the POS machine adopts the adapter power supply mode. The method performs real-time monitoring of the power consumption of the POS main power supply; if the main power supply of the POS machine adopts the battery power supply mode, the efficiency monitoring mode is adopted to perform real-time monitoring of the main power consumption of the POS machine.

即可得出POS机主电源功耗。The power consumption monitoring method is to calculate the current value at both ends of the test resistor r by detecting the voltage Vab across the test resistor r connected to the POS adapter and the post-stage load of the POS machine.

The power consumption of the POS main power supply can be obtained.

及后级功耗

即可得前级与后级的转换效率

The efficiency monitoring method is: first, the pre-stage detecting resistor r1 is connected between the POS battery and the POS power conversion module, and the post-stage detecting resistor r2 is connected between the POS machine power conversion module and the post-stage load of the POS machine, respectively detecting The pre-stage detection resistor r1 voltage V1, the second-stage detection resistor r2 voltage V2, the pre-stage power consumption

And subsequent power consumption

You can get the conversion efficiency of the front and the back

The main power consumption value of each action of the POS machine is written into the underlying software, that is, the main power consumption value of the POS machine under single action is written into the underlying software, and when the power consumption value is written into the underlying software, the work is taken. The way the time period is written. The method of writing the power consumption in a time-division manner is to divide the time period of the single action of the POS machine for the time period, and write the main power consumption value under the single action of the POS machine in the corresponding time period.

The POS operation response, that is, when the POS performs an operation, it needs to send an operation instruction to the POS operating system. If the POS machine operating system recognizes that the operation instruction is an abnormal instruction, the POS does not operate, and if the POS machine operates The system recognizes that the operation instruction is a normal instruction, and then continues to determine that the operation instruction includes an action number, and then reads the total power consumption value corresponding to the operation by the underlying software, and returns to the POS operating system.

It is also necessary to use a hidden pad and a main power blind via inner wiring to prevent the implanted module from being directly powered by the main power supply front end.

The following is a specific implementation process of the present invention.

The method for preventing the POS machine from being modified and implanting a Trojan horse to steal information includes the following contents:

1. Adopt hidden pad and blind hole routing mode to avoid the modified implantation point of POS machine;

2. The main power consumption is measured by real-time monitoring. The monitoring methods are divided into power consumption monitoring and efficiency monitoring.

3. Software registration for the power consumption (efficiency) of each module action, the POS must report to the system when performing actual actions.

4. Real-time monitoring compares the detected value with the declared value to determine whether the POS has abnormal monitoring power consumption (efficiency);

5, two consecutive real-time comparison abnormalities in 4, POS alarm;

6. The alarm mode can be adopted: buzzer buzzer, liquid crystal display, background lock, etc.

details as follows:

1, hidden interface pads and blind hole routing:

The main power supply interface is currently connected to the circuit board by means of through-hole pads and surface-mount visible pads. To modify the POS to implant a new module, the required power can be obtained directly from the visible solder joints. The Tibetan interface pad method prevents the main power supply from being directly detected at the pad. Hidden interface pads can be used in a variety of ways, such as BGA package, original cover pad, pad blind hole, etc., as shown in Figure 1, where the solder joint is under the main power interface, directly covered by the interface, the interface The power supply is difficult to detect and take out. When the pad is hidden, the main power supply is routed from the inner layer to prevent the secant mode from acquiring the main power signal.

2. Real-time monitoring of main power consumption:

Power consumption is the product of power supply voltage and current. This patent aims to judge whether the device is working abnormally by monitoring the actual power consumption and theoretical power consumption. Therefore, it is necessary to detect the voltage and current values in real time. The POS main power system is divided into two main types: adapter power supply and battery power supply. When the adapter is powered, the mains voltage is constant, and when the power consumption is detected, only the current can be detected. When the battery is powered, the main power supply voltage changes with the battery power. Only detecting the power consumption of the main power supply terminal cannot correctly determine whether it meets the theoretical requirements. Therefore, this patent proposes a way to compare the power consumption efficiency, in short. In order to detect the voltage and current of the front and rear stages, a comparison of power conversion efficiency is performed.

The power consumption monitoring of the power supply needs to be real-time monitoring. The specific method of power consumption monitoring depends on the condition of the device itself, and can be implemented in various ways. For example, the detection resistance method, the Hall sensor, the optocoupler isolation amplifier, the capacitive isolation amplifier, etc., the simpler monitoring method is to determine the magnitude of the monitored current by detecting the voltage across the precision resistor. This patent introduces the detection method of the adapter power supply and voltage power supply mode in the most basic way.

(1) Adapter power supply:

Detect preamplifier current:

Among the adapter-powered devices, the adapter's supply voltage is constant. Figure 2 is a simplified diagram of a circuit (in Figure 2, 1 is the adapter power supply, 2 is the voltage detection), r represents the test resistance in the access circuit, Rload is the load of the entire power system, and A of the detection resistor r B can detect the voltage Vab across r at two points, and the current value can be calculated.

The detection of the Vab voltage needs to be real-time detection. After the voltage is collected, the software in the description of the third point is calculated, and compared with the preset value I of the driving theory in the description of the third point, it can be determined whether the POS device has an abnormality. Modification and intrusion.

(2) Battery powered:

The power supply voltage of a battery-powered device changes with the change of power. The power consumption of the detection mode in the adapter power supply cannot be accurately compared with the theoretical value. Here, a new way is proposed for real-time power consumption. Set comparison: conversion efficiency, detection simplified block diagram Figure 3 battery-powered power system thumbnail diagram (Figure 3, 1, 2 for voltage detection, r1 for pre-stage detection resistor, r2 for post-stage detection resistor, Rload for post-stage load , Battery represents the main power supply for the battery). In the actual power supply design system, if the main power supply is to be supplied to each module of the device, the voltage must be converted into a voltage that can be used by the module chip through the power conversion system. At this time, there is a problem of conversion efficiency. The conversion efficiency is the same as the power consumption at the beginning of the hardware circuit design. When the voltage changes, the conversion efficiency changes accordingly. Therefore, the power consumption of the pre-stage and the post-stage is detected by software operation. Whether the efficiency is abnormal or not, and then determine whether the POS is working abnormally.

In Fig. 3, the voltage V1 of the two points A and B and the resistance value of the detecting resistor r1 are obtained, and the power consumption P1 of the previous stage can be obtained, and the data of the voltage V2 of the two points C and D and the resistance of the detecting resistor r2 are detected. The convertible power consumption P2, the ratio of P1 to P2 can give the efficiency at the corresponding time.

3. Theoretical power registration and response

Power consumption is an important indicator of a device. In POS design, the power consumption value of each action is fixed. In the second point, the actual power consumption detection method has been proposed. After the actual power consumption detection is completed, the data needs to be compared with the theoretical value to determine whether the device is abnormal. The theoretical power consumption registration is the main power supply under each action. Power consumption (efficiency) is written into the underlying software. When the POS wants to perform an action, it issues an operation command to the OS, calls the corresponding power consumption value, returns the data, and performs a comparison operation.

This power (efficiency) registration consists of two parts: (1) writing the power consumption value to the underlying software; and (2) the response of the POS operation.

Power consumption value write: The power consumption value of Figure 4 is written into the software pre-registration flow chart. The method first writes the power consumption value of a single operation. When a POS device is operated, it is often accompanied by two or more modes. The power consumption is a superposition of two operations, for example, Bluetooth communication while printing, if the power consumption of printing is P1, the power consumption of Bluetooth communication For P2, the power consumption of the main power supply is added: P1+P2, adopting the registration mode of single-operation module power consumption, when the POS performs corresponding operations, the underlying software can accurately return the total power consumption value, and description 2 The measured values in the comparison are performed.

Secondly, when the power consumption value is written into the underlying software, the power consumption is divided into time slots. For example, the power consumption of printing is written. When the duration of the entire printing is 10S, the 10s is divided into several equal time segments, and the total power consumption in 10S is P total = Pt1 + Pt2 + Pt3 + Pt4 + Pt5 + ... .....

The use of time-phased writing can refine the entire power consumption stage and improve the accuracy of the monitoring system.

At the same time, in the method, the power consumption value is written into the underlying software, which can effectively avoid the data change caused by the invasion of the Trojan virus. If power consumption data is written to the application layer, the Trojan virus program can have the opportunity to tamper with the data and process to disable the monitoring system.

After the power consumption value is written into the underlying software, the integration is applied to the OS in the entire software system, and the pre-registration of the theoretical power consumption value can be realized.

Response of POS operation: A simple flow chart of the software when the POS is operated as shown in FIG. When the POS wants to perform an operation, it sends an operation instruction to the OS operating system, and the operating system receives the instruction and performs the instruction recognition.

The command recognition portion first discriminates the operation command, whether it is an abnormal command, and the device does not respond when it is determined that the command is abnormal. Secondly, it is judged which operations are included in the operation instruction, and the corresponding signals of each operation are sent to the underlying software to read the total power consumption, and the returned power consumption data is the maximum power consumption of the time division.

After the operating system receives the returned data, it compares the actual collected data with the theoretical data in the underlying software (the specific process is described in detail in the description of point 4), and the alarm mechanism is executed when the abnormality is compared.

4, real-time power consumption comparison judgment

In the description of point 2, the real-time current value of the main power source can be obtained. In the description of point 3, the theoretical operating current value can be obtained. Comparing the real-time current value with the theoretical value, it can be known whether there is abnormal power consumption, and whether the device is modified. Or implant a Trojan. The real-time comparison determination process is shown in Figure 6. The real-time comparison and reduction flow chart of the power consumption preset current and the detection current is shown. When the data is compared for the first time, the new current data is compared and judged again. The data is abnormal, and it is determined that the device has abnormal working behavior, and the alarm and locking mechanism are executed.

5, the alarm method

When the power consumption comparison is abnormal in the description of point 4, it is determined that the device is modified or implanted in the Trojan program, and the alarm mechanism is activated. The alarm mode can be adopted: buzzer alarm, liquid crystal display alarm, background lock cannot be operated, etc.

The following are specific application examples of the present invention.

Embodiment 1, hidden pad and blind hole inner layer trace

1. The main power supply adopts the hidden pad and the inner power blind hole inner layer routing mode to prevent the implanted module from being directly powered by the main power supply front end.

2. When the POS device leaves the factory, the underlying program is registered for each action current, and the operating current is Recorded in the bottom layer;

3. When the POS device sends an operation signal, report to the OS (system) (extract registration and registration current);

4. After the successful application, the real-time monitoring of the refresh current value exceeds the underlying registration value when the POS performs each operation;

5. The monitored value exceeds the underlying registration value, and the acquisition verification is refreshed again. If it is still greater than the registered value, the POS buzzer will alarm. Alarm mode: The buzzer keeps beeping, the liquid crystal display attacks, and the background locks the POS so that it cannot be traded.

Embodiment 2, main power supply current and voltage monitoring

1. When the POS device leaves the factory, the underlying program is registered for each operating current and voltage, and the operating current and voltage are recorded in the bottom layer;

2. When the POS device issues an operation signal, report to the OS (system) (extract the registered current and voltage value);

3. After the successful application, the real-time monitoring of the refresh current and voltage value exceeds the underlying registration value when the POS performs each operation;

4. The monitored value exceeds the underlying registration value, and the acquisition verification is refreshed again. If it is still greater than the registered value, the POS buzzer will alarm. Alarm mode: The buzzer keeps beeping, the liquid crystal display attacks, and the background locks the POS so that it cannot be traded.

Embodiment 3, main power supply current and NTC monitoring (for battery equipment)

1. When the current increases, the NTC (battery temperature monitoring) value will change accordingly. When the POS device leaves the factory, the underlying program is registered for each operating current and NTC value, and the operating current and voltage are recorded in the bottom layer;

2. When the POS device sends an operation signal, it reports to the OS (system) (extracts the registered current and NTC value);

3. After the successful application, the real-time monitoring of the refresh current and the NTC value exceeds the underlying registration value when the POS performs each operation;

4. The monitored value exceeds the underlying registration value, and the acquisition verification is refreshed again. If it is still greater than the registered value, the POS buzzer will alarm. Alarm mode: The buzzer keeps beeping, the liquid crystal display attacks, and the background locks the POS so that it cannot be traded.

The above is a preferred embodiment of the present invention, and the work performed according to the changes made by the technical solution of the present invention When the effect can be made without departing from the scope of the technical solution of the present invention, it is within the scope of protection of the present invention.

Claims (9)

A method for preventing a POS machine from being modified and implanting a Trojan horse to steal information, characterized in that it comprises the following steps: S1: Real-time monitoring of main power consumption; S2: The theoretical power consumption registration and response, including the main power consumption value of each action of the POS machine is written into the underlying software and the response of the POS operation; S3: according to step S1 real-time monitoring of the main power consumption compared with the theoretical power consumption of step S2, to determine whether the POS machine is abnormal, and if so, proceed to step S4, and if not, then re-execute step S3; S4: Comparing the power consumption of the main power source monitored in real time in step S1 with the theoretical power consumption of step S2, determining whether the POS machine has an abnormality, and if so, determining that the POS machine is abnormal, and performing an alarm; if not, re-executing step S3. The method for preventing POS machine from being modified and implanting a Trojan horse to steal information according to claim 1, wherein in the step S1, the main power consumption is monitored in real time, according to the main power supply mode of the POS machine. It is divided into power consumption monitoring mode and efficiency monitoring mode. If the main power supply of the POS machine adopts the adapter power supply mode, the power consumption monitoring mode is adopted to perform real-time monitoring of the main power consumption of the POS machine; if the main power of the POS machine is battery powered The efficiency monitoring method is used to perform real-time monitoring of the power consumption of the POS main power supply. A method for preventing POS machine from being modified and implanting a Trojan horse to steal information according to claim 2, wherein: said power consumption monitoring mode is: detecting access to a POS machine adapter and a POS machine back level load The voltage Vab across the test resistor r is calculated to calculate the current value across the test resistor r

The power consumption of the POS main power supply can be obtained. The method for preventing POS machine from being modified and implanting a Trojan horse to steal information according to claim 2, wherein the efficiency monitoring mode is, firstly, connecting between a POS battery and a POS power conversion module. The pre-stage detection resistor r1, the POS machine power conversion module and the post-stage load of the POS machine are connected to the post-stage detection resistor r2, respectively detecting the voltage V1 across the front-end detection resistor r1 and the voltage V2 across the second-stage detection resistor r2. Pre-stage power consumption

And subsequent power consumption

You can get the conversion efficiency of the front and the back

The POS machine is modified according to claim 1 and the trojan program is stolen to steal information. The method is characterized in that: the main power consumption value of each action of the POS machine is written into the underlying software, that is, the main power consumption value of the POS machine under single action is written into the underlying software, and the power consumption value is written. When entering the underlying software, the power consumption is divided into time slots. The method for preventing POS machine from being modified and implanting a Trojan horse to steal information according to claim 5, wherein: the power consumption is written in a time-division manner, that is, the time during which the POS machine single action lasts. Segment segmentation is performed to write the main power consumption value under the single action of the POS machine in the corresponding time period. The method for preventing POS machine from being modified and implanting a Trojan horse to steal information according to claim 1, wherein the POS machine responds to the operation, that is, when the POS performs an operation, the POS machine needs to be The operating system sends an operation instruction. If the POS machine operating system recognizes that the operation instruction is an abnormal instruction, the POS does not perform an action. If the POS machine operating system recognizes that the operation instruction is a normal instruction, it continues to determine that the operation instruction includes an action number, and then passes The underlying software reads the total power consumption value of the main power supply corresponding to the operation and returns to the POS operating system. The method for preventing POS machine from being modified and implanting a Trojan horse to steal information according to claim 1 is characterized in that: the hidden power pad and the inner power blind hole inner layer routing mode are also required for the main power source. To prevent the implanted module from being powered directly from the main power front end. The method for preventing POS machine from being modified and implanting a Trojan horse to steal information according to claim 1, wherein the alarm in step S4 comprises: continuous buzzer buzzer, liquid crystal display attack, background to POS machine Lock it to make it impossible to trade.

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