An encrypted smart card swiping method, access control device, and circuit based on LPCD mode

Abstract

The present invention relates to an encrypted smart card swiping method, access control equipment, and circuit based on an LPCD mode. The method comprises the following steps: S1, setting a working mode of a radio frequency unit to periodically send a card detection signal, and configuring the radio frequency unit so that the card detection distance is greater than the card reading distance; S2, if the radio frequency unit detects that an encrypted smart card exists within the current card detection distance, maintaining the working mode of the radio frequency unit to periodically send a card detection signal, reducing the card detection distance of the radio frequency unit, and increasing the card reading distance of the radio frequency unit, so that the card detection distance of the radio frequency unit is less than or equal to the card reading distance; S3, if the radio frequency unit detects that an encrypted smart card exists within the current card detection distance, setting the working mode of the radio frequency unit to periodically send a card reading signal, receiving a radio frequency signal returned by the encrypted smart card, parsing the radio frequency signal returned by the encrypted smart card after secret key authentication, and obtaining electronic information in the encrypted smart card.

Description

Technical Field

[0001] The present invention relates to the field of card swiping methods, and in particular to an encrypted smart card swiping method based on an LPCD mode, an access control device, and a circuit. Background Art

[0002] Access control hosts, smart door locks and other devices can identify user permissions and issue unlocking commands by swiping a card. Existing access control hosts and smart door locks have low power consumption requirements. Existing devices read card information through card swiping and polling. In this mode, the antenna continuously radiates electromagnetic fields outward, periodically opens the field for communication, and consumes a lot of current. In order to reduce power consumption, the existing technology adopts the LPCD (Low Power Card Detection, low-power external card detection function / ultra-low power card detection) mode. Before searching for a card, a card detection signal is first sent out. When the card approaches and the card detection is successful, the card search mode is entered. The time required to open the field required only to detect whether a card exists is much shorter than the time required to open the field required for card search, which can reduce the average power consumption of the card reader and meet the low power consumption requirements.

[0003] An encrypted smart card is a key that works with a card reader. It stores a secret key, which is encrypted and requires decryption for use. Access control hosts, smart door locks, and other devices add data transmission and key authentication by swiping an encrypted smart card. The access control host and smart door lock first detect the presence of an encrypted smart card within a preset range. However, in LPCD mode, to meet low power requirements, if the user slowly brings the card close to the access control host and smart door lock, the card reader cannot complete the complex data transmission and key authentication processes within the card reading time. The access control host and smart door lock then determine that the user did not swipe the card, and the card reader returns to sleep mode, causing the card swipe to fail.

[0004] The purpose of the present invention is to design an encrypted smart card swiping method, system and circuit based on the LPCD mode to solve the problems existing in the above-mentioned prior art. Summary of the Invention

[0005] In response to the problems existing in the above-mentioned prior art, the present invention provides an encrypted smart card swiping method, system and circuit based on the LPCD mode, which can effectively solve at least one problem existing in the above-mentioned prior art.

[0006] The technical solution of the present invention is:

[0007] A method for swiping an encrypted smart card based on the LPCD mode includes the following steps:

[0008] S1, setting the working mode of the radio frequency unit to periodically send a card detection signal, and configuring the radio frequency unit so that the card detection distance is greater than the card reading distance;

[0009] S2, if the radio frequency unit detects that there is an encrypted smart card within the current card detection distance, maintaining the working mode of the radio frequency unit to periodically send a card detection signal, and configuring the radio frequency unit so that the card detection distance is less than or equal to the card reading distance;

[0010] S3. If the radio frequency unit detects that there is an encrypted smart card within the current detection distance, the radio frequency unit is set to a working mode of periodically sending a card reading signal, receiving a radio frequency signal returned by the encrypted smart card, parsing the radio frequency signal returned by the encrypted smart card after secret key authentication, and obtaining the electronic information in the encrypted smart card.

[0011] Furthermore, the RF unit includes a card swiping coil, and the method for configuring the card detection distance and card reading distance of the RF unit specifically includes: adjusting the field strength emitted by the card swiping coil to adjust the card detection distance and / or card reading distance of the RF unit.

[0012] Furthermore, the radio frequency unit includes a matching network, which is connected to the card swiping coil. The matching network is used to amplify energy and output it to the card swiping coil, so that the card swiping coil emits a signal of corresponding field strength. By adjusting the carrier energy input into the matching network, the field strength emitted by the card swiping coil is adjusted.

[0013] Furthermore, the radio frequency unit includes a card swiping circuit, which is connected to the card swiping coil through a matching network. The card swiping circuit is powered by the output end of the DC-DC circuit, and the field strength emitted by the card swiping coil is adjusted by adjusting the output voltage of the DC-DC circuit.

[0014] Furthermore, the encrypted smart card stores a card reading count, which can be read and written by the radio frequency unit. The electronic information includes the card reading count and the card number. After obtaining the electronic information in the encrypted smart card, the following steps are included:

[0015] The card reading times are compared with the card swiping times corresponding to the card number. If the card reading times are less than the card swiping times, the encrypted smart card is determined to be a duplicate card and the corresponding authorization is stopped; if the card reading times are greater than or equal to the card swiping times, the encrypted smart card is determined to be a valid card and the corresponding authorization is granted.

[0016] Furthermore, after executing step S1, the card detection distance of the radio frequency unit is configured to be 1.5-2.5 cm, and the card reading distance is configured to be 1-2 cm;

[0017] After executing step S2, the card detection distance of the radio frequency unit is configured to be 0.5-1.5 cm, and the card reading distance is configured to be 1.5-2.5 cm.

[0018] Further provided is an encrypted smart card swiping access control device based on the LPCD mode, which is used to implement any one of the encrypted smart card swiping methods based on the LPCD mode, comprising:

[0019] A card detection module is used to set the working mode of the radio frequency unit to periodically send a card detection signal, and configure the radio frequency unit to have a card detection distance greater than a card reading distance;

[0020] a secondary card detection module, configured to maintain the working mode of the radio frequency unit to periodically send a card detection signal if the radio frequency unit detects that there is an encrypted smart card within the current card detection distance, and to configure the radio frequency unit so that the card detection distance is less than or equal to the card reading distance;

[0021] The card reading module is used to set the working mode of the radio frequency unit to periodically send a card reading signal if the radio frequency unit detects the presence of an encrypted smart card within the current card detection distance, receive the radio frequency signal returned by the encrypted smart card, and analyze the radio frequency signal returned by the encrypted smart card after key authentication to obtain the electronic information in the encrypted smart card.

[0022] A circuit for swiping an encrypted smart card based on the LPCD mode, used to implement a method for swiping an encrypted smart card based on the LPCD mode, the circuit comprising:

[0023] A card swiping chip, wherein the card swiping chip integrates a card detection signal sending module and a card reading signal sending module, and the card detection signal sending module and the card reading signal sending module can output carrier waves of different energies;

[0024] A main control chip, communicatively connected to the card swiping chip, the main control chip being used to control the card swiping chip to periodically send a card detection signal and / or a card reading signal, and to control the card swiping chip to output a carrier wave of corresponding energy in the card detection signal sending module and the card reading signal sending module;

[0025] a matching network connected to the card detection signal sending module and the card reading signal sending module, configured to receive carrier waves of corresponding energy output by the card detection signal sending module and the card reading signal sending module, and amplify the carrier waves of corresponding energy;

[0026] The card swiping coil is connected to the matching network and is used to receive the amplified carrier and send out a card detection signal or a card reading signal of corresponding field strength.

[0027] Furthermore, the card swiping chip includes TX1 and TX2 pins, and the card swiping chip is connected to the matching network through the TX1 and TX2 pins. The card swiping chip is integrated with a radio frequency energy configuration register. The card swiping chip outputs a carrier of corresponding energy at the TX1 and TX2 pins according to the value of the radio frequency energy configuration register. The matching network amplifies the carrier of corresponding energy and sends a signal of corresponding field strength through the card swiping coil, thereby reducing or increasing the field strength emitted by the card swiping coil, and further reducing or increasing the card detection distance and card reading distance.

[0028] Furthermore, the card swiping chip includes an SPI pin, and the card swiping chip communicates with the main control chip via the SPI pin. The main control chip configures the value of the radio frequency energy configuration register by sending an instruction to set the radio frequency energy configuration register to a corresponding value.

[0029] Therefore, the present invention provides the following effects and / or advantages:

[0030] Based on the complex card reading characteristics of encrypted smart cards, this application optimizes the card detection logic and card reading logic in LPCD mode. After the card detection is successful, the card detection mode is maintained, and the card detection distance and card reading distance are changed, and the card detection distance is reduced to below the card reading distance. The card detection distance is less than or equal to the card reading distance. That is, no matter where the smart card is located, as long as the smart card can be sensed by the radio frequency unit, the corresponding electronic information of the smart card can be read by the radio frequency unit, which greatly improves the success rate of card swiping.

[0031] This application provides sufficient time and distance for swiping the card, which can greatly reduce the failure of encrypted smart card reading.

[0032] In step S1 of the present application, the card detection distance is configured to be greater than the card reading distance. At this time, the smart card can only be sensed if it is within the card detection distance. More energy can be allocated to the card detection process, reducing unnecessary card reading signal transmission, thereby achieving low power consumption. In step S2, the card detection distance is shortened and the card reading distance is increased. On the one hand, the card detection distance can be reduced, giving the user sufficient time to place the card near the radio frequency unit. On the other hand, the card is already relatively close to the radio frequency unit at this time. According to this situation, this step reduces the energy consumed by the card detection and concentrates the energy consumed by the radio frequency on the card reading process.

[0033] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flowchart illustrating one embodiment of the present invention is provided.

[0035] Figure 2 This is a distance diagram obtained after executing step S1 in one embodiment of the present invention.

[0036] Figure 3 A distance diagram obtained after executing S2 is provided for one embodiment of the present invention.

[0037] Figure 4 A functional block diagram is provided for one embodiment of the present invention.

[0038] Figure 5 To achieve Figure 4 Circuit diagram of the functional block diagram.

[0039] Figure 6 A functional block diagram is provided for another embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to facilitate understanding by those skilled in the art, the structure of the present invention will now be further described in detail with reference to the embodiments and the accompanying drawings. It should be understood that the steps mentioned in this embodiment, unless otherwise specified, can be adjusted in sequence according to actual needs, and can even be executed simultaneously or partially simultaneously.

[0041] refer to Figure 1 , a method for swiping an encrypted smart card based on the LPCD mode, comprising the following steps:

[0042] S1, setting the working mode of the radio frequency unit to periodically send a card detection signal, and configuring the radio frequency unit so that the card detection distance is greater than the card reading distance;

[0043] This step is the existing technology. The radio frequency unit may include a card detection transmitter and a card reader transmitter. In this step, the card reader transmitter may or may not work. The card detection transmitter is set to periodically send a card detection signal. If a smart card approaches the radio frequency unit, the smart card will change the matching network of the card swiping chip, thereby changing the energy emitted by the card detection transmitter. The radio frequency unit includes a receiver. If the change in the field strength of the matching network exceeds the recognition value of the receiver, it can be determined whether a smart card is approaching.

[0044] The card detection distance refers to the maximum distance at which the radio frequency unit can sense whether a smart card is approaching.

[0045] The card reading distance refers to the maximum distance at which the radio frequency unit can read the electronic information carried by the smart card.

[0046] In this step, refer to Figure 2 The radio frequency unit is configured so that the card detection distance D2 is greater than the card reading distance D1. At this time, the smart card can only be sensed if it is within the card detection distance D2. More energy can be allocated to the card detection process, reducing unnecessary card reading signal transmission, thereby achieving low power consumption.

[0047] After executing step S1, the card detection distance of the radio frequency unit is configured to be 1.5-2.5 cm, and the card reading distance is configured to be 1-2 cm. In this embodiment, the card detection distance of the radio frequency unit is configured to be 2 cm, and the card reading distance is configured to be 1.5 cm.

[0048] S2, if the radio frequency unit detects that there is an encrypted smart card within the current card detection distance, maintaining the working mode of the radio frequency unit to periodically send a card detection signal, and configuring the radio frequency unit so that the card detection distance is less than or equal to the card reading distance;

[0049] In the traditional mode, if the RF unit detects that there is an encrypted smart card within the current card detection distance, the working mode of the RF unit is directly changed to the card reading mode. This embodiment is optimized as follows: the working mode of the RF unit is maintained to periodically send out a card detection signal. In this mode, the card detection transmitter is configured to continue to periodically send out a card detection signal to find out whether there is an encrypted smart card near the RF unit. In addition, the card detection distance and the card reading distance of the RF unit are adjusted to reduce the card detection distance of the RF unit and increase the card reading distance of the RF unit, so that the RF unit is configured so that the card detection distance is less than or equal to the card reading distance;

[0050] This is because, when the encrypted smart card has the anti-copy feature enabled, the probability of card swiping failure increases. Because the anti-copy feature is enabled when swiping the card, the card is encrypted, and the data transmission process and key authentication are increased, the energy required for the card reading process increases. If the traditional low-power LPCD mode is used, the RF unit will immediately switch to card reading mode when it detects the approach of a card through the card detection signal. If the user does not immediately bring the encrypted smart card close to the RF unit, for example, if it is placed away from the RF unit or approaches it slowly, the RF unit will not be able to read the smart card, and the card reading will fail. After the card detection is successful, this embodiment maintains the RF unit's operating mode to periodically emit a card detection signal, reduces the RF unit's card detection distance, and increases the RF unit's card reading distance, so that the RF unit is configured so that the card detection distance is less than or equal to the card reading distance.

[0051] After executing step S2, the card detection distance of the radio frequency unit is configured to be 0.5-1.5 cm, and the card reading distance is configured to be 1.5-2.5 cm. Specifically, the card detection distance of the radio frequency unit is configured to be 1 cm, and the card reading distance is configured to be 2 cm.

[0052] At this time, the card reading distance D1 and the card detection distance D2 are referenced Figure 3At this point, the card detection distance is less than or equal to the card reading distance. That is, no matter where the smart card is located, as long as the smart card can be sensed by the RF unit, the corresponding electronic information on the smart card can be read by the RF unit. In the case of step S1, step S2 is added to continue card detection, shorten the card detection distance, and increase the card reading distance. This reduces the card detection distance, giving the user ample time to place the card near the RF unit. Furthermore, since the card is already relatively close to the RF unit, this step reduces the energy consumed by card detection and focuses the energy consumed by the RF on the card reading process.

[0053] S3. If the radio frequency unit detects that there is an encrypted smart card within the current detection distance, the radio frequency unit is set to a working mode of periodically sending a card reading signal, receiving a radio frequency signal returned by the encrypted smart card, parsing the radio frequency signal returned by the encrypted smart card after secret key authentication, and obtaining the electronic information in the encrypted smart card.

[0054] In this step, if the RF unit detects an encrypted smart card within the current detection distance, it enters card reading mode and emits a card reading signal. This card reading signal is an electromagnetic wave. After the electromagnetic wave is coupled by the encrypted smart card, the encrypted smart card can transmit the encrypted information stored internally. The structure and operating principle of the encrypted smart card and RF unit are prior art and will not be elaborated here.

[0055] In step S2, the card reading distance of the radio frequency unit is shortened to within the card detection distance. Therefore, no matter where the card is, as long as the smart card is within the card detection distance range of the radio frequency unit, the smart card can be read by the radio frequency unit. Therefore, steps S2~S3 provide sufficient time and distance for swiping the card, which can greatly reduce the failure of reading the encrypted smart card.

[0056] Actual tests were conducted using the solution of this embodiment and a prior art solution. The prior art solution maintained a constant card detection distance greater than the card reading distance, and immediately switched from detection mode to reading mode upon sensing a card. An operator swiped the card 10,000 times using any motion. The prior art solution failed 1,890 times, while the solution provided by this application failed 0 times. This demonstrates that the present invention significantly reduces the probability of card swiping failures.

[0057] Furthermore, the RF unit includes a card swiping coil, and the method for configuring the card detection distance and card reading distance of the RF unit specifically includes: adjusting the field strength emitted by the card swiping coil to adjust the card detection distance and / or card reading distance of the RF unit.

[0058] The card swipe coil is an existing technology. During transmission, it converts high-frequency current into electromagnetic waves in space. During reception, it converts these electromagnetic waves into high-frequency current and transmits them to the receiver. The output energy of the card swipe coil is positively correlated with the card detection and / or reading distance. Therefore, increasing the output energy of the card swipe coil can also increase the card detection and / or reading distance. The output energy of the card swipe coil is positively correlated with the card detection and / or reading distance of the radio frequency unit.

[0059] This embodiment controls / changes the field strength emitted by the card swiping coil, thereby controlling the card detection distance and / or card reading distance of the radio frequency unit.

[0060] Furthermore, the radio frequency unit includes a matching network, which is connected to the card swiping coil. The matching network is used to amplify energy and output it to the card swiping coil, so that the card swiping coil emits a signal of corresponding field strength. By adjusting the carrier energy input into the matching network, the field strength emitted by the card swiping coil is adjusted.

[0061] The matching network is conventional technology. Its function is to match the resistance of the transmitting circuit to a value close to the output resistance of the card swiping chip, thereby amplifying the energy of the carrier wave output by the card swiping chip. The carrier wave energy of the matching network is positively correlated with the card detection and / or reading distance of the radio frequency unit.

[0062] This embodiment changes the carrier energy input to the matching network, thereby matching the network's output energy, ultimately affecting the field strength emitted by the card swipe coil. Therefore, increasing or decreasing the carrier energy of the matching network can increase or decrease the card reading / detection distance of the card swipe coil.

[0063] Furthermore, the encrypted smart card stores a card reading count, which can be read and written by the radio frequency unit. The electronic information includes the card reading count and the card number. After obtaining the electronic information in the encrypted smart card, the following steps are included:

[0064] The card reading times are compared with the card swiping times corresponding to the card number. If the card reading times are less than the card swiping times, the encrypted smart card is determined to be a duplicate card and the corresponding authorization is stopped; if the card reading times are greater than or equal to the card swiping times, the encrypted smart card is determined to be a valid card and the corresponding authorization is granted.

[0065] Since the original card is at risk of being copied, a verification of the number of card swipes is added during the card identification process to prevent copying. The main control chip and the encrypted smart card will automatically record the number of successful card swipes. When swiping the card, the secret key is authenticated first, then the card number is read, and then the valid number is compared. During the card swiping process, the card will report the number of card swipes to the main control chip, which will compare it with the number of times recorded by the card itself. If the number of card swipes is ≥ the number recorded by the main chip, the card is considered to be successfully swiped, the number of card swipes is increased by 1, and the number of card swipes recorded by the chip is increased by 1, realizing the anti-copying function.

[0066] Detailed process of successful card swiping: The card swipe count record stored in the card is transmitted to the main control chip via SPI signal. The main control chip will compare the card swipe count read with the card count stored internally. If the card swipe count read is greater than or equal to the card count stored in the main control chip, it is determined to be a valid card. The main control chip transmits the SPI signal to the card, the card count record is increased by 1, and the card count stored internally in the main chip is increased by 1.

[0067] An encrypted smart card swiping access control device based on the LPCD mode, used to implement the encrypted smart card swiping method based on the LPCD mode, comprising:

[0068] A card detection module is used to set the working mode of the radio frequency unit to periodically send a card detection signal, and configure the radio frequency unit to have a card detection distance greater than a card reading distance;

[0069] The secondary card detection module is configured to maintain the working mode of the radio frequency unit to periodically send a card detection signal if the radio frequency unit detects that there is an encrypted smart card within the current card detection distance, thereby reducing the card detection distance of the radio frequency unit and increasing the card reading distance of the radio frequency unit, so that the card detection distance of the radio frequency unit is less than or equal to the card reading distance;

[0070] The card reading module is used to set the working mode of the radio frequency unit to periodically send a card reading signal if the radio frequency unit detects the presence of an encrypted smart card within the current card detection distance, receive the radio frequency signal returned by the encrypted smart card, and analyze the radio frequency signal returned by the encrypted smart card after key authentication to obtain the electronic information in the encrypted smart card.

[0071] An encrypted smart card swiping circuit based on LPCD mode, used to implement the encrypted smart card swiping method based on LPCD mode, reference Figure 4 , the circuit comprises:

[0072] A card swiping chip, wherein the card swiping chip integrates a card detection signal sending module and a card reading signal sending module, and the card detection signal sending module and the card reading signal sending module can output carrier waves of different energies;

[0073] A main control chip, communicatively connected to the card swiping chip, the main control chip being used to control the card swiping chip to periodically send a card detection signal and / or a card reading signal, and to control the card swiping chip to output a carrier wave of corresponding energy in the card detection signal sending module and the card reading signal sending module;

[0074] a matching network connected to the card detection signal sending module and the card reading signal sending module, configured to receive carrier waves of corresponding energy output by the card detection signal sending module and the card reading signal sending module, and amplify the carrier waves of corresponding energy;

[0075] The card swiping coil is connected to the matching network and is used to receive the amplified carrier and send out a card detection signal or a card reading signal of corresponding field strength.

[0076] Furthermore, the card swiping chip includes TX1 and TX2 pins, and the card swiping chip is connected to the matching network through the TX1 and TX2 pins. The card swiping chip is integrated with a radio frequency energy configuration register. The card swiping chip outputs a carrier of corresponding energy at the TX1 and TX2 pins according to the value of the radio frequency energy configuration register. The matching network amplifies the carrier of corresponding energy and sends a signal of corresponding field strength through the card swiping coil, thereby reducing or increasing the field strength emitted by the card swiping coil, and further reducing or increasing the card detection distance and card reading distance.

[0077] Furthermore, the card swiping chip includes an SPI pin, and the card swiping chip communicates with the main control chip via the SPI pin. The main control chip configures the value of the radio frequency energy configuration register by sending an instruction to set the radio frequency energy configuration register to a corresponding value.

[0078] refer to Figure 5 U1 is the card swiping chip. Pins 29, 30, 31, and 24 of U1 are SPI signals, connected to the main control chip. The main control chip can adjust the internal resistance value of the RF energy configuration register of the U1 chip through SPI signals, thereby changing the card reading energy and card detection energy output by TX1 (pin 11) and TX2 (pin 13), thereby changing the corresponding card reading and detection distances. The TX1 and TX2 pins of the card swiping chip are used to output carrier waves. The card swiping chip outputs carrier waves of corresponding energy according to the value of the RF energy configuration register.

[0079] The TX output passes through the card matching network of L6, C42, C16, C18, C44 (L5, C43, C17, C19, C45), amplifies the energy and acts on the coil.

[0080] Example 2

[0081] This embodiment is basically the same as the first embodiment, except that:

[0082] The radio frequency unit includes a card swiping circuit, which is connected to the card swiping coil through a matching network. The card swiping circuit is powered by the output end of the DC-DC circuit. By adjusting the output voltage of the DC-DC circuit, the field strength emitted by the card swiping coil is adjusted.

[0083] refer to Figure 6The DC-DC circuit is used to perform DC-DC conversion on a DC voltage source, and output a corresponding DC voltage after stepping up or down. The DC-DC circuit includes an enable terminal EN. The DC-DC circuit works only when a high level is input to the enable terminal EN. The main control chip sends a PWM wave to the enable terminal EN of the DC-DC circuit. The main control chip outputs PWM with different duty cycles, which can make the DC-DC circuit output a predetermined target voltage. The output end of the DC-DC circuit is connected to the power supply voltage TDD end of the transmitter of the card swiping circuit. The transmitter sends a carrier with corresponding energy to the matching network according to the voltage received at the TDD end. By sending PWM with different duty cycles by the main control chip, the field strength of the card swiping coil can be controlled, thereby achieving the card reading distance or card detection distance corresponding to steps S1 to S4.

[0084] The output voltage of the DC-DC circuit is positively correlated with the card detection distance and / or card reading distance of the radio frequency unit.

[0085] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0086] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0087] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0088] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0089] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

Claims

1. A method for swiping an encrypted smart card based on the LPCD mode, characterized by: The following steps are involved: S1, setting the working mode of the radio frequency unit to periodically send a card detection signal, and configuring the radio frequency unit so that the card detection distance is greater than the card reading distance; S2, if the radio frequency unit detects that there is an encrypted smart card within the current card detection distance, maintaining the working mode of the radio frequency unit to periodically send a card detection signal, and configuring the radio frequency unit so that the card detection distance is less than or equal to the card reading distance; S3. If the radio frequency unit detects that there is an encrypted smart card within the current detection distance, the radio frequency unit is set to a working mode of periodically sending a card reading signal, receiving a radio frequency signal returned by the encrypted smart card, parsing the radio frequency signal returned by the encrypted smart card after secret key authentication, and obtaining the electronic information in the encrypted smart card.

2. The method for swiping an encrypted smart card based on the LPCD mode according to claim 1, characterized in that: The radio frequency unit includes a card swiping coil, and the method for configuring the card detection distance and the card reading distance of the radio frequency unit specifically includes: adjusting the field strength emitted by the card swiping coil to adjust the card detection distance and / or card reading distance of the radio frequency unit.

3. The method for swiping an encrypted smart card based on the LPCD mode according to claim 2, characterized in that: The radio frequency unit includes a matching network, which is connected to the card swiping coil. The matching network is used to amplify energy and output it to the card swiping coil, so that the card swiping coil emits a signal with corresponding field strength. By adjusting the carrier energy input into the matching network, the field strength emitted by the card swiping coil is adjusted.

4. The method for swiping an encrypted smart card based on the LPCD mode according to claim 2, characterized in that: The radio frequency unit includes a card swiping circuit, which is connected to the card swiping coil through a matching network. The card swiping circuit is powered by the output end of the DC-DC circuit. By adjusting the output voltage of the DC-DC circuit, the field strength emitted by the card swiping coil is adjusted.

5. The method for swiping an encrypted smart card based on the LPCD mode according to claim 1, characterized in that: The encrypted smart card stores a card reading count, which can be read and written by the radio frequency unit. The electronic information includes the card reading count and the card number. After obtaining the electronic information in the encrypted smart card, the method includes: The card reading times are compared with the card swiping times corresponding to the card number. If the card reading times are less than the card swiping times, the encrypted smart card is determined to be a duplicate card and the corresponding authorization is stopped; if the card reading times are greater than or equal to the card swiping times, the encrypted smart card is determined to be a valid card and the corresponding authorization is granted.

6. The method for swiping an encrypted smart card based on the LPCD mode according to claim 1, characterized in that: After executing step S1, the card detection distance of the radio frequency unit is configured to be 1.5-2.5 cm, and the card reading distance is configured to be 1-2 cm; After executing step S2, the card detection distance of the radio frequency unit is configured to be 0.5-1.5 cm, and the card reading distance is configured to be 1.5-2.5 cm.

7. An encrypted smart card access control device based on LPCD mode, used to implement the encrypted smart card access control method based on LPCD mode according to any one of claims 1 to 6, characterized in that: include: A card detection module is used to set the working mode of the radio frequency unit to periodically send a card detection signal, and configure the radio frequency unit to have a card detection distance greater than a card reading distance; a secondary card detection module, configured to maintain the working mode of the radio frequency unit to periodically send a card detection signal if the radio frequency unit detects that there is an encrypted smart card within the current card detection distance, and to configure the radio frequency unit so that the card detection distance is less than or equal to the card reading distance; The card reading module is used to set the working mode of the radio frequency unit to periodically send a card reading signal if the radio frequency unit detects the presence of an encrypted smart card within the current card detection distance, receive the radio frequency signal returned by the encrypted smart card, and analyze the radio frequency signal returned by the encrypted smart card after key authentication to obtain the electronic information in the encrypted smart card.

8. An encrypted smart card swiping circuit based on LPCD mode, characterized by: For implementing the encrypted smart card swiping method based on the LPCD mode as described in any one of claims 1 to 6, the circuit comprises: A card swiping chip, wherein the card swiping chip integrates a card detection signal sending module and a card reading signal sending module, and the card detection signal sending module and the card reading signal sending module can output carrier waves of different energies; A main control chip, communicatively connected to the card swiping chip, the main control chip being used to control the card swiping chip to periodically send a card detection signal and / or a card reading signal, and to control the card swiping chip to output a carrier wave of corresponding energy in the card detection signal sending module and the card reading signal sending module; a matching network connected to the card detection signal sending module and the card reading signal sending module, configured to receive carrier waves of corresponding energy output by the card detection signal sending module and the card reading signal sending module, and amplify the carrier waves of corresponding energy; The card swiping coil is connected to the matching network and is used to receive the amplified carrier and send out a card detection signal or a card reading signal of corresponding field strength.

9. The LPCD mode-based encrypted smart card swiping circuit according to claim 8, characterized in that: The card swiping chip includes TX1 and TX2 pins, and the card swiping chip is connected to the matching network through the TX1 and TX2 pins. The card swiping chip is integrated with a radio frequency energy configuration register. The card swiping chip outputs a carrier wave of corresponding energy at the TX1 and TX2 pins according to the value of the radio frequency energy configuration register. The matching network amplifies the carrier wave of corresponding energy and sends a signal of corresponding field strength through the card swiping coil, thereby reducing or increasing the field strength emitted by the card swiping coil, and further reducing or increasing the card detection distance and card reading distance.

10. The LPCD mode-based encrypted smart card swiping circuit according to claim 9, characterized in that: The card swiping chip includes an SPI pin, and the card swiping chip communicates with the main control chip via the SPI pin. The main control chip configures the value of the radio frequency energy configuration register by sending an instruction to set the radio frequency energy configuration register to a corresponding value.

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