Active shielding devices and active shielding methods

Abstract

An embodiment of an active shielding device and a method for active shielding is disclosed. In the embodiment, an active shielding device includes: a current source configured to generate a current; an analog line shielding unit connected to the current source; a current-to-voltage converter connected to the analog line shielding unit and configured to generate a voltage in response to the current generated by the current source; and a voltage comparator connected to the current-to-voltage converter and configured to compare the voltage generated by the current-to-voltage converter with a reference voltage.

Description

Technical Field

[0001] This invention relates to active shielding devices and active shielding methods. Background Technology

[0002] Intrusive attacks can be used to illegally access or alter information from circuits such as encrypted or secure circuits. Probing is an intrusive attack that attackers can use to read data from an integrated circuit (IC) chip or write data into the IC chip through a port (i.e., a probe head). For example, a focused ion beam (FIB) device can cut one or more traces in the metal layers of an IC chip and subsequently alter the IC chip's structure, for example, by depositing one or more new traces or isolation layers into the IC chip and / or by implanting ions to change the doping of a region of the IC chip's semiconductor substrate (e.g., silicon). To prevent intrusive attacks, active shielding techniques can be used to detect whether the circuit has been tampered with. For example, digital active shielding can form a physical barrier across the signal lines of an IC chip and disable the IC chip if it has been tampered with. However, while digital active shielding can provide protection against intrusive attacks, it is possible to compromise digital signals at the 0 / 1 level through long-term monitoring. Therefore, there is a need for active shielding techniques that can provide more sophisticated protection against intrusive attacks. Summary of the Invention

[0003] An embodiment of an active shielding device and a method for active shielding is disclosed. In the embodiment, an active shielding device includes: a current source configured to generate a current; an analog line shielding unit connected to the current source; a current-to-voltage converter connected to the analog line shielding unit and configured to generate a voltage in response to a current generated by the current source flowing through the analog line shielding unit; and a voltage comparator connected to the current-to-voltage converter and configured to compare the voltage generated by the current-to-voltage converter with a reference voltage.

[0004] In this embodiment, the current sources are connected in parallel with each other.

[0005] In one embodiment, the analog wire shielding unit includes an analog wire winding connected between the current source and the current-voltage converter.

[0006] In this embodiment, each of the simulated wire windings is connected to a different current source of the current source.

[0007] In one embodiment, the active shielding device further includes a switch connected between the current source and the analog line shielding unit.

[0008] In one embodiment, the active shielding device further includes a controller configured to generate control signals to control a switch or current-to-voltage converter.

[0009] In one embodiment, the controller includes a random number generator.

[0010] In an embodiment, the active shielding device further includes: a second set of current sources configured to generate a second set of currents; a second current-to-voltage converter connected to the analog line shielding unit and configured to generate a second voltage in response to the second set of currents generated by the second set of current sources; and a second voltage comparator connected to the second current-to-voltage converter and configured to compare the second voltage with a second set of reference voltages.

[0011] In one embodiment, the active shielding device further includes a third voltage comparator configured to compare results from the voltage comparator and from the second voltage comparator.

[0012] In one embodiment, the active shielding device further includes a first set of switches connected between the current source and the analog line shielding unit; and a second set of switches connected between the second set of current sources and the analog line shielding unit.

[0013] In one embodiment, the active shielding device further includes a controller configured to generate control signals to control the first and second sets of switches.

[0014] In one embodiment, the controller includes a random number generator.

[0015] In an embodiment, the active shielding device includes: first, second, third, and fourth sets of current sources; an analog line shielding unit connected to the second and fourth sets of current sources; a first current-to-voltage converter connected to both the first and fourth sets of current sources via the analog line shielding unit; a first voltage comparator connected to the first current-to-voltage converter; a second current-to-voltage converter connected to both the second and third sets of current sources via the analog line shielding unit; a second voltage comparator connected to the second current-to-voltage converter; and a third voltage comparator. Each of the first, second, third, and fourth sets of current sources is configured to generate a current. The first current-to-voltage converter is configured to generate a first voltage in response to a current flowing through the analog line shielding unit generated by the first and fourth sets of current sources. The first voltage comparator is configured to compare the first voltage with a first reference voltage. The second current-to-voltage converter is configured to generate a second voltage in response to a current flowing through the analog line shielding unit generated by the second and third sets of current sources. The second voltage comparator is configured to compare the second voltage with a second reference voltage. The third voltage comparator is configured to compare the results from the first voltage comparator and the second voltage comparator.

[0016] In the embodiment, each current source in one of the first, second, third and fourth groups of current sources is connected in parallel with each other.

[0017] In one embodiment, the analog wire shielding unit includes an analog wire winding connected between a fourth set of current sources and a first current-voltage converter, and also connected between a second set of current sources and a second current-voltage converter.

[0018] In an embodiment, the active shielding device further includes a first, second, third, and fourth set of switches, which are respectively connected to a first, second, third, and fourth set of current sources.

[0019] In this embodiment, a first set of switches is connected between a first set of current sources and a first current-to-voltage converter; a second set of switches is connected between a second set of current sources and an analog line shielding unit; a third set of switches is connected between a third set of current sources and a second current-to-voltage converter; and a fourth set of switches is connected between a fourth set of current sources and an analog line shielding unit.

[0020] In one embodiment, the active shielding device further includes a controller configured to generate control signals to control the first, second, third, and fourth sets of switches.

[0021] In one embodiment, the controller includes a random number generator.

[0022] In one embodiment, a method for active shielding involves: generating a current using an active shielding device; conducting the current through analog wire windings of the active shielding device; generating a voltage using a current-to-voltage converter of the active shielding device in response to the current conducted by a plurality of analog wire windings; and comparing the voltage with a reference voltage using a voltage comparator of the active shielding device.

[0023] Other aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings and illustrated by way of examples demonstrating the principles of the invention. Attached Figure Description

[0024] Figure 1 An active shielding device according to an embodiment of the present invention is described.

[0025] Figure 2 Depicting Figure 1 An embodiment of the analog line shielding unit of the active shielding device depicted herein.

[0026] Figure 3 Depicting Figure 1 An embodiment of the current-voltage converter of the active shielding device described herein.

[0027] Figure 4 Depicting Figure 1 An embodiment of the voltage comparator of the active shielding device described herein.

[0028] Figure 5 An active shielding device comprising a plurality of switches to control a plurality of current sources is described according to an embodiment of the present invention.

[0029] Figure 6 An active shielding device comprising multiple current sources, multiple current-to-voltage converters, and multiple voltage comparators according to an embodiment of the present invention is described.

[0030] Figure 7 An active shielding device comprising a plurality of switches to control a current source is described according to an embodiment of the present invention.

[0031] Figure 8 An active shielding device comprising a combination of digital shielding units and analog line shielding units according to an embodiment of the present invention is described.

[0032] Figure 9 This is a flowchart of a communication method according to an embodiment of the present invention.

[0033] Figure 10 This is a flowchart illustrating a communication method according to another embodiment of the present invention.

[0034] Throughout the description, similar reference numerals can be used to identify similar elements. Detailed Implementation

[0035] It will be readily understood that the components of the embodiments generally described herein and illustrated in the accompanying drawings can be arranged and designed in a wide variety of different configurations. Therefore, the more detailed description of the various embodiments below, as illustrated in the drawings, is not intended to limit the scope of this disclosure, but merely to illustrate various embodiments. While various aspects of the embodiments are presented in the drawings, they are not necessarily drawn to scale unless specifically indicated.

[0036] The invention may be implemented in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are to be considered illustrative rather than restrictive in all respects. Therefore, the scope of the invention is indicated by the appended claims rather than by this specific embodiment. All variations within the meaning and scope of the equivalents of the claims are covered therewith.

[0037] Throughout this specification, references to features, advantages, or similar language do not imply that all features and advantages achievable with this invention should be present in any embodiment of the invention or in any embodiment of the invention. Rather, references to features and advantages should be understood as meaning that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Therefore, throughout this specification, discussions of features and advantages, as well as similar language, may, but do not necessarily, refer to the same embodiments.

[0038] Furthermore, the features, advantages, and characteristics of the invention described herein can be combined in any suitable manner in one or more embodiments. Those skilled in the art will recognize that, in view of the description herein, the invention can be practiced without having one or more specific features or advantages of a particular embodiment. In other instances, additional features and advantages that may be identified in some embodiments may not be present in all embodiments of the invention.

[0039] Throughout this specification, references to "an embodiment," "embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may, but not necessarily all, refer to the same embodiment.

[0040] Figure 1 An active shielding device 100 according to an embodiment of the present invention is depicted. Figure 1In the embodiments depicted, the active shielding device includes: a plurality of current sources 102-1, 102-2, ..., 102-N, where N is an integer greater than one; an analog line shielding unit 104 connected to the current sources; a current-to-voltage converter 106 connected to the analog line shielding unit; and a voltage comparator 108 connected to the current-to-voltage converter. The active shielding device is used to protect a circuit 110, which may be an encryption circuit, a security circuit, or other circuit. The circuit 110 may be connected to wires or cables within the analog line shielding unit, between the current sources and the analog line shielding unit, or between the analog line shielding unit and the current-to-voltage converter. The active shielding device can be used in various applications, such as automotive, communication, industrial, medical, computer, and / or consumer or electrical appliance applications. While the active shielding device 100 shown herein is illustrated with reference to certain components and described with reference to certain functions, other embodiments of the active shielding device may include fewer or more components to achieve the same, fewer or more functions. For example, the active shielding device may include more than one analog line shielding unit. In another example, in some embodiments, the active shielding device may include more than one current-to-voltage converter and more than one voltage comparator. In yet another example, although in Figure 1 The current sources 102-1, 102-2, ..., 102-N are shown as part of the active shielding device, but in some embodiments, the current sources are external to the active shielding device and are not components of the active shielding device. In some embodiments, the active shielding device is an active shielding circuit. Components of the active shielding circuit may be implemented on a single substrate (e.g., integrated into the same IC chip) or distributed across multiple substrates (e.g., implemented across multiple IC chips). For example, at least one of the current source, analog line shielding unit, current-to-voltage converter, and voltage comparator may be implemented on a single substrate (e.g., integrated into one IC chip) or distributed across multiple substrates (e.g., implemented across multiple IC chips). In some embodiments, the active shielding device and the circuit to be protected are integrated into the same IC chip.

[0041] Compared to active shielding devices that rely solely on digital shielding, Figure 1 The active shielding device 100 described herein implements analog active shielding that can be used independently of or in conjunction with digital active shielding. Figure 1In the embodiments depicted, the active shielding device utilizes multiple current sources 102-1, 102-2, ..., 102-N and an analog wire shielding unit 104 for active shielding. Due to less injected noise, active shielding in the current domain performs better than active shielding in the voltage domain. The current values ​​from the analog current sources can be generated randomly, in a known pattern, or in a combination of random and known patterns. Furthermore, digital probes or applications of 0 / 1 to the analog wire shielding unit can be easily detected. For example, any invasive attack such as cutting one or more wires or cables within the analog wire shielding unit 104 or applying 0 / 1 to one or more wires or cables within the analog wire shielding unit will affect one or more currents generated by the current sources 102-1, 102-2, ..., 102-N and alter the voltage range.

[0042] exist Figure 1 In the embodiments depicted, current sources 102-1, 102-2, ..., 102-N are configured to generate multiple currents I1, I2, ..., I... N Various types of current sources known in the art can be used to implement the current source. In some embodiments, the current is generated by different current sources (i.e., each current source generates a unique current). In other embodiments, the currents I1, I2, ..., I... N At least two currents in the circuit are generated by the same current source as each other. Figure 1 In the embodiments depicted, the current sources are connected in parallel with each other, such that currents I1, I2, ..., I... N Each current flows in parallel through the analog line shielding unit 104. In some embodiments, the current sources are connected to positive voltages, which may be the same as or different from each other.

[0043] exist Figure 1 In the embodiments depicted, analog wire shielding unit 104 is connected between current sources 102-1, 102-2, ..., 102-N and current-to-voltage converter 106. The analog wire shielding unit may include one or more cables or wires made of a conductive material (e.g., metal). In some embodiments, the analog wire shielding unit includes multiple analog wire windings connected between the current sources and the current-to-voltage converter. In these embodiments, each current source is connected to a different analog wire winding of the analog wire windings.

[0044] Figure 2 A simulated line shielding unit 204 is depicted, the simulated line shielding unit 204 being... Figure 1 The embodiment of the analog line shielding unit 104 depicted herein. However, Figure 1 The analog line shielding unit 104 depicted is not limited to Figure 2The embodiment shown. In Figure 2 In the embodiment depicted, the analog wire shielding unit 204 includes a plurality of analog wire windings 228-1, 228-2, ..., 228-N, which are connected to current sources 102-1, 102-2, ..., 102-N and to a current-to-voltage converter 106. In the analog wire shielding unit, each analog wire winding is connected to a different current source. For example, current I1 is conducted to the current-to-voltage converter through analog wire winding 228-1, current I2 is conducted to the current-to-voltage converter through analog wire winding 228-2, and current I... N Conducted to a current-to-voltage converter via analog wire winding 228-N. In some embodiments, at least one of the analog wire windings 228-1, 228-2, ..., 228-N is implemented on one or more top layers of an IC chip in which the active shielding device 100 is packaged. Secure routing can be implemented on metal layers to achieve minimum spacing and arithmetic logic unit (Alu) width. In some embodiments, unused channels and / or spaces are filled to create a shielding layout that can prevent optical inspection and / or probing. In some embodiments, random routing is used in parallel and multilayer interconnects are combined with high metal density, making it more difficult for attackers to obtain information about the lower metal layers. In some embodiments, the lower metal layer is used for signal lines and supply lines that are not visible and cannot be accessed via pin connections. In some embodiments, the lower metal layer is used for analog blocks other than ground lines and supply lines. While the analog wire shielding unit shown herein is illustrated in conjunction with certain components and described in conjunction with certain functions, other embodiments of the analog wire shielding unit may include fewer or more components to achieve the same, fewer or more functions. For example, the analog wire shielding unit may include, as Figure 2 The number of simulated wire windings shown may be more or fewer. In another example, although... Figure 2 The simulated wire windings 228-1, 228-2, ..., 228-N shown have wire windings of certain forms or patterns, but in other embodiments, at least one of the simulated wire windings 228-1, 228-2, ..., 228-N may have a form or pattern different from... Figure 2 The wire winding in the form or pattern shown.

[0045] Back Figure 1 The current-voltage converter 106 of the active shielding device 100 is configured to respond to the currents I1, I2, ..., I3 generated by the current sources 102-1, 102-2, ..., 102-N. NThis generates at least one voltage. In some embodiments, the current-to-voltage converter is configured to generate a voltage corresponding to currents I1, I2, ..., I... N Or related to currents I1, I2, ..., I N The voltage is proportional to the sum of the voltages.

[0046] Figure 3 A current-to-voltage converter 306 is depicted, the current-to-voltage converter 306 is Figure 1 The embodiment of the current-to-voltage converter 106 depicted herein. However, Figure 1 The current-to-voltage converter 106 described herein is not limited to Figure 3 The example shown. In Figure 3 In the embodiments depicted, the current-to-voltage converter 306 includes a resistor 336 and an amplifier 338. In some embodiments, the amplifier is an operational amplifier (op-amp). Figure 3 In the embodiments depicted, the resistor has a fixed resistance value "R". However, in other embodiments, the resistor may have a variable resistance value. In the example of the operation of the current-to-voltage converter 306, the amplifier and the resistor receive power from the voltage converter. Figure 1 The active shielding device 100 depicted in the diagram generates currents I1, I2, ..., IN from current sources 102-1, 102-2, ..., 102-N. N And generate currents I1, I2, ..., I N The total output voltage "V" is proportional to the sum of the values. OUT In the embodiment, the output voltage V OUT This can be expressed as:

[0047] (1)

[0048] While this document illustrates and describes the illustrated current-to-voltage converter in conjunction with certain components and certain functions, other embodiments of the current-to-voltage converter may include fewer or more components to achieve the same, fewer or more functions. For example, the current-to-voltage converter may include more than one amplifier and / or resistor or use different schemes / designs.

[0049] Back Figure 1The voltage comparator 108 of the active shielding device 100 is configured to compare at least one voltage generated by the current-to-voltage converter 106 with at least one reference voltage. In some embodiments, the voltage comparator is configured to compare the voltage generated by the current-to-voltage converter 106 with a plurality of reference voltages. Based on the comparison result between the voltage generated by the current-to-voltage converter and at least one reference voltage, it can be determined whether the cable or wire within the analog line shielding unit 104 has been tampered with (e.g., involving intrusion into the cable or wire within the analog line shielding unit or voltage detection that alters at least one voltage or current in the cable or wire within the analog line shielding unit). In some embodiments, if the voltage generated by the current-to-voltage converter is the same as at least one reference voltage, or is within a threshold (e.g., ±1%) of at least one reference voltage, it is determined that the cable or wire within the analog line shielding unit has not been tampered with. In these embodiments, if the voltage generated by the current-to-voltage converter is different from at least one reference voltage, or is not within a threshold (e.g., ±1%) of at least one reference voltage, it is determined that the cable or wire within the analog line shielding unit has been tampered with. In some embodiments, the active shielding device includes a controller configured to determine whether the cable or wire within the analog line shielding unit has been tampered with. The controller may be implemented in hardware (e.g., one or more circuits), software, firmware, or a combination thereof. In embodiments, the controller is implemented using a processor such as a microcontroller, main processor, host, digital signal processor (DSP), or central processing unit (CPU). In some embodiments, the controller is configured to shut down or deactivate the protected circuit 110 in the event of tampering with the cables or wires within the analog line shielding unit.

[0050] Figure 4 A voltage comparator 408 is depicted, the voltage comparator 408 is Figure 1 The embodiment of voltage comparator 108 depicted herein. However, Figure 1 The voltage comparator 108 depicted is not limited to Figure 4 The example shown. In Figure 4 In the embodiment depicted, voltage comparator 408 includes two voltage comparison circuits 446-1 and 446-2. In an example of voltage comparator operation, voltage comparison circuit 446-1 compares the output voltage V from current-to-voltage converter 306. OUT With reference voltage Vref+ The voltage comparison circuit 446-2 compares the output voltage V from the current-to-voltage converter 306. OUT With reference voltage Vref- A comparison is performed. A result signal is generated based on the comparison result of voltage comparison circuits 446-1 and 446-2. Although the voltage comparator shown herein is illustrated with reference to certain components and described with reference to certain functions, other embodiments of the voltage comparator may include fewer or more components to achieve the same, fewer or more functions. For example, the voltage comparator may include a single voltage comparison circuit or more than two voltage comparison circuits for different levels of voltage comparison accuracy.

[0051] In some embodiments, one or more switches are used to select one or more current sources 102-1, 102-2, ..., 102-N to be applied to the analog line shielding unit 104. Therefore, the voltage on the analog line shielding unit can vary depending on the number of current sources or the selected current sources, making it more difficult for an attacker to access information by probing the voltage of the analog line shielding unit. Figure 5 An active shielding device 500 according to an embodiment of the present invention is depicted, comprising a plurality of switches 550-1, 550-2, ..., 550-N to control a plurality of current sources 502-1, 502-2, ..., 502-N. Figure 5 In the embodiments depicted, the active shielding device includes: current sources 502-1, 502-2, ..., 502-N; an analog line shielding unit 504 connected to the current sources; a current-to-voltage converter 506 connected to the analog line shielding unit; a voltage comparator 508 connected to the current-to-voltage converter; switches 550-1, 550-2, ..., 550-N; and an optional controller 552. Figure 5 In the depicted embodiments, current sources 502-1, 502-2, ..., 502-N, analog line shielding unit 504, current-to-voltage converter 506, and voltage comparator 508 are respectively connected to... Figure 1The current sources 102-1, 102-2, ..., 102-N, analog line shielding unit 104, current-to-voltage converter 106, and voltage comparator 108 in the depicted embodiments are identical or similar. While the active shielding device 500 shown herein is illustrated with reference to certain components and described with reference to certain functions, other embodiments of the active shielding device may include fewer or more components to achieve the same, fewer, or more functions. For example, the active shielding device may include more than one analog line shielding unit. In another example, in some embodiments, the active shielding device may include more than one current-to-voltage converter and more than one voltage comparator. The active shielding device may operate in a first operating mode, wherein the active shielding device uses random data or a known sequence to drive values ​​on the cable or wire between the current source and the current-to-voltage converter, and subsequently checks the results from the voltage comparator. The active shielding device may also operate in a second operating mode, which allows specific values ​​to be written to the active shielding device and the results to be read back, making the active shielding device a confidential component, the confidentiality of which is lost in the event of damage to the active shielding device.

[0052] exist Figure 5 In the embodiments depicted, current sources 502-1, 502-2, ..., 502-N are configured to generate multiple currents I1, I2, ..., I... N Various types of current sources known in the art can be used to implement the current source. In some embodiments, the current is generated by different current sources (i.e., each current source generates a unique current). In other embodiments, the currents I1, I2, ..., I... N At least two currents in the circuit are generated by the same current source as each other. Figure 5 In the embodiments depicted, the current sources are connected in parallel with each other, such that currents I1, I2, ..., I... N Each current flows in parallel through the analog line shielding unit 504.

[0053] exist Figure 5 In the embodiments depicted, an analog wire shielding unit 504 is connected between current sources 502-1, 502-2, ..., 502-N and a current-to-voltage converter 506. The analog wire shielding unit may include one or more cables or wires made of a conductive material (e.g., metal). In some embodiments, the analog wire shielding unit includes multiple analog wire windings connected between the current sources and the current-to-voltage converter. In these embodiments, each current source is connected to a different analog wire winding of the analog wire windings.

[0054] exist Figure 5In the embodiments depicted, the current-to-voltage converter 506 is configured to respond to currents I1, I2, ..., I3 generated by current sources 502-1, 502-2, ..., 502-N. N This generates at least one voltage. In some embodiments, the current-to-voltage converter is configured to generate a voltage corresponding to currents I1, I2, ..., I... N Or related to currents I1, I2, ..., I N The voltage is proportional to the sum of the voltages.

[0055] exist Figure 5 In the embodiments depicted, voltage comparator 508 is configured to compare at least one voltage generated by current-to-voltage converter 506 with at least one reference voltage. In some embodiments, the voltage comparator is configured to compare the voltage generated by current-to-voltage converter 506 with a plurality of reference voltages. Based on the comparison result between the voltage generated by current-to-voltage converter and at least one reference voltage, it can be determined whether the cable or wire within the analog line shielding unit 504 has been tampered with (e.g., involving intrusion into the cable or wire within the analog line shielding unit or voltage detection that alters at least one voltage or current in the cable or wire within the analog line shielding unit). In some embodiments, if the voltage generated by current-to-voltage converter is the same as at least one reference voltage, or within a threshold (e.g., ±1%) of at least one reference voltage, it is determined that the cable or wire within the analog line shielding unit has not been tampered with. In these embodiments, if the voltage generated by current-to-voltage converter is different from at least one reference voltage, or is not within a threshold (e.g., ±1%) of at least one reference voltage, it is determined that the cable or wire within the analog line shielding unit has been tampered with.

[0056] exist Figure 5 In the embodiment depicted, switches 550-1, 550-2, ..., 550-N are connected between current sources 502-1, 502-2, ..., 502-N and analog line shielding unit 504, and are configured based on control signals D1, D2, ..., D N Select one or more current sources to apply to the analog line shielding unit. Figure 5 In the embodiment depicted, controller 552 is configured to generate control signals D1, D2, ..., D... NControl switches 550-1, 550-2, ..., 550-N and / or current-to-voltage converter 506 are used. By controlling the switches and / or the current-to-voltage converter, the voltage on the analog line shielding unit can be varied (e.g., depending on the number or selection of current sources), making it more difficult for an attacker to access information by probing the voltage of the analog line shielding unit. The controller can be implemented in hardware (e.g., one or more circuits), software, firmware, or a combination thereof. In embodiments, the controller is implemented using a processor such as a microcontroller, main processor, host, DSP, or CPU. Control signals D1, D2, ..., D N It may be a digital signal, which can be a random digital signal / sequence or a predefined digital signal / sequence. In some embodiments, the controller includes a random number generator configured to generate random digital sequences. Although in Figure 5 The controller is shown as a component of the active shielding device 500, but in other embodiments, the controller is external to the active shielding device. In some embodiments, the controller is configured to determine whether cables or wires within the analog line shielding unit have been tampered with. In some embodiments, the controller is configured to shut down or deactivate a protected circuit in the event of tampering with cables or wires within the analog line shielding unit, which may be connected to wires or cables within the analog line shielding unit, wires or cables between a current source and the analog line shielding unit, or wires or cables between the analog line shielding unit and a current-to-voltage converter. In some embodiments, digital active shielding may be combined with analog active shielding to provide more sophisticated protection against invasive attacks. In some embodiments, one or more digital logic circuits are connected in series with the cables or wires such that the digital logic circuits can alter the signals in the cables or wires. For example, the voltage on the cables or wires may vary depending on the location or section of the cable or wire being probed, making it more difficult for an attacker to access information by probing the voltage of the cables or wires.

[0057] In some embodiments, multiple sets of current sources, current-to-voltage converters, and voltage comparators are used in conjunction with the analog line shielding unit. Therefore, the voltage on the analog line shielding unit can be repeatedly tested or verified, making it more difficult for an attacker to access information by probing the voltage of the analog line shielding unit. Figure 6 An active shielding device 600 according to an embodiment of the present invention is depicted, the active shielding device comprising: multiple sets of current sources 602-1, 602-2, ..., 602-N, 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N, 632-1, 632-2, ..., 632-N; current-to-voltage converters 606-1, 606-2; and voltage comparators 608-1, 608-2, 608-3. Figure 6In the embodiments depicted, the active shielding device includes: a first group of current sources 602-1, 602-2, ..., 602-N; a second group of current sources 612-1, 612-2, ..., 612-N; a third group of current sources 622-1, 622-2, ..., 622-N; and a fourth group of current sources 632-1, 632-2, ..., 632-N; an analog line shielding unit 604 connected to the current sources; first and second current-to-voltage converters 606-1 and 606-2 connected to the analog line shielding unit; first and second voltage comparators 608-1 and 608-2 connected to the current-to-voltage converters; and a third voltage comparator 608-3 connected to the first and second voltage comparators 608-1 and 608-2. Figure 6 The current sources 602-1, 602-2, ..., 602-N, 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N, 632-1, 632-2, ..., 632-N, the analog line shielding unit 604, the current-to-voltage converters 606-1, 606-2, and the voltage comparators 608-1, 608-2, 608-3 in the embodiments depicted herein are respectively connected to... Figure 1 The current sources 102-1, 102-2, ..., 102-N, analog line shielding unit 104, current-to-voltage converter 106, and voltage comparator 108 in the embodiments depicted herein are the same or similar. While the active shielding device 600 shown herein is illustrated with reference to certain components and described with reference to certain functions, other embodiments of the active shielding device may include fewer or more components to achieve the same, fewer, or more functions. For example, the active shielding device may include more than one analog line shielding unit.

[0058] exist Figure 6 In the embodiments depicted, each of the following current sources is configured to generate multiple currents I1, I2, ..., I... N Various types of current sources known in the art can be used to implement the current source. In some embodiments, the current is generated by different current sources (i.e., each current source generates a unique current). In other embodiments, the currents I1, I2, ..., I... NAt least two currents in the circuit are generated by the same current source as each other. Figure 6 In the embodiments depicted, each current source within one of the first, second, third, and fourth groups of current sources is connected in parallel with each other, such that currents I1, I2, ..., I... N Each current flows in parallel through the analog line shielding unit 604.

[0059] exist Figure 6 In the embodiments depicted, the analog wire shielding unit 604 is connected to a second set of current sources 612-1, 612-2, ..., 612-N, and to a fourth set of current sources 632-1, 632-2, ..., 632-N. The analog wire shielding unit may include one or more cables or wires made of a conductive material (e.g., metal). In some embodiments, the analog wire shielding unit includes a plurality of analog wire windings connected between the second set of current sources 612-1, 612-2, ..., 612-N or the fourth set of current sources 632-1, 632-2, ..., 632-N and the current-to-voltage converters 606-1, 606-2. In these embodiments, each current source in the second group of current sources 612-1, 612-2, ..., 612-N is connected to a different simulated wire winding of the simulated wire winding, and / or each current source in the fourth group of current sources 632-1, 632-2, ..., 632-N is connected to a different simulated wire winding of the simulated wire winding.

[0060] exist Figure 6 In the embodiment depicted, a first current-to-voltage converter 606-1 is connected via an analog line shielding unit 604 to a first group of current sources 602-1, 602-2, ..., 602-N and a fourth group of current sources 632-1, 632-2, ..., 632-N. A first current-to-voltage converter 604-1 is configured to respond to currents I1, I2, ..., I... generated by the first and fourth groups of current sources 602-1, 602-2, ..., 602-N, 632-1, 632-2, ..., 632-N. N And thus generate the first output voltage V out1 In some embodiments, the first output voltage V out1 With currents I1, I2, ..., I N Or related to currents I1, I2, ..., I N The sum is proportional.

[0061] exist Figure 6 In the embodiment depicted, the first voltage comparator 608-1 is connected to the first current-to-voltage converter 606-1 and is configured to convert the first output voltage V out1The voltage is compared with at least one reference voltage to generate a result signal CMP1, which may be an analog signal or a digital signal. In some embodiments, the first voltage comparator includes a plurality of voltage comparison circuits configured to compare the first output voltage V with at least one reference voltage to generate a result signal CMP1, which may be an analog signal or a digital signal. out1 Compare with multiple reference voltages.

[0062] exist Figure 6 In the embodiment depicted, the second current-to-voltage converter 606-2 is connected via an analog line shielding unit 604 to a second set of current sources 612-1, 612-2, ..., 612-N and to a third set of current sources 622-1, 622-2, ..., 622-N. The second current-to-voltage converter is configured to respond to currents I1, I2, ..., I... generated by the second and third sets of current sources 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N. N This generates a second output voltage V. out2 In some embodiments, the second output voltage V out2 With currents I1, I2, ..., I N Or related to currents I1, I2, ..., I N The sum is proportional.

[0063] exist Figure 6 In the embodiment depicted, the second voltage comparator 608-2 is connected to the second current-to-voltage converter 606-2 and is configured to convert the second output voltage V out2 The voltage is compared with at least one reference voltage to generate a result signal CMP2, which may be an analog signal or a digital signal. In some embodiments, the first voltage comparator includes a plurality of voltage comparison circuits configured to compare the second output voltage V with at least one reference voltage to generate a result signal CMP2, which may be an analog signal or a digital signal. out2 Compare with multiple reference voltages.

[0064] exist Figure 6In the embodiment depicted, the third voltage comparator 608-3 is configured to compare the result signal CMP1 from the first voltage comparator 608-1 with the result signal CMP2 from the second voltage comparator 608-2 to produce a comparison result. Based on the comparison result from the third voltage comparator, it can be determined whether the cable or wire within the analog line shielding unit 604 has been tampered with (e.g., involving intrusion into the cable or wire within the analog line shielding unit or voltage detection that alters at least one voltage or current in the cable or wire within the analog line shielding unit). In some embodiments, if the result signal CMP1 from the first voltage comparator 608-1 is the same as the result signal CMP2 from the second voltage comparator 608-2, or is within a threshold (e.g., ±1%) of the result signal CMP2 from the second voltage comparator 608-2, it is determined that the cable or wire within the analog line shielding unit has not been tampered with. In these embodiments, if the result signal CMP1 from the first voltage comparator 608-1 is different from the result signal CMP2 from the second voltage comparator 608-2, or is not within a threshold (e.g., ±1%) of the result signal CMP2 from the second voltage comparator 608-2, it is determined that the cable or wire within the analog line shielding unit has been tampered with. In some embodiments, the active shielding device includes a controller configured to determine the analog line shielding unit. Whether the cables or wires within the wire shielding unit have been tampered with. The controller may be implemented in hardware (e.g., one or more circuits), software, firmware, or a combination thereof. In embodiments, the controller is implemented using a processor such as a microcontroller, main processor, host, DSP, or CPU. In some embodiments, the controller is configured to shut down or disable the protected circuit in the event of tampering with the cables or wires within the analog wire shielding unit, which may be connected to wires or cables within the analog wire shielding unit, wires or cables between a current source and the analog wire shielding unit, or wires or cables between the analog wire shielding unit and a current-to-voltage converter. In some embodiments, digital active shielding may be combined with analog active shielding to provide more sophisticated protection against invasive attacks. In some embodiments, one or more digital logic circuits are connected in series with the cables or wires such that the digital logic circuits can alter the signals in the cables or wires. For example, the voltage on the cables or wires may vary depending on the location or segment of the cable or wire being probed, making it more difficult for an attacker to access information by probing the voltage of the cables or wires.

[0065] In some embodiments, one or more switches are used to select one or more current sources among 602-1, 602-2, ..., 602-N, 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N, 632-1, 632-2, ..., 632-N to be applied to the analog line shielding unit 604, the first current-to-voltage converter 606-1, or the second current-to-voltage converter 606-2. Therefore, the voltage on the analog line shielding unit can vary depending on the number of current sources or the selected current sources, making it more difficult for an attacker to access information by probing the voltage of the analog line shielding unit. Figure 7 An active shielding device 700 according to an embodiment of the present invention is depicted. The active shielding device includes a plurality of switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N to control current sources 602-1, 602-2, ..., 602-N, 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N, 632-1, 632-2, ..., 632-N. Figure 7 In the embodiments depicted, the active shielding device includes: current sources 602-1, 602-2, ..., 602-N, 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N, 632-1, 632-2, ..., 632-N; an analog line shielding unit 604 connected to the current sources; and first and second current-to-voltage converters 606-1 and 606-2 connected to the analog line shielding unit; and first and second... Voltage comparators 608-1 and 608-2, the first and second voltage comparators 608-1 and 608-2 being connected to a current-to-voltage converter; a third voltage comparator 608-3, the third voltage comparator 608-3 being connected to the first and second voltage comparators 608-1 and 608-2; switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N; and an optional controller 752. Figure 7In the embodiments depicted, switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N and controller 752 are respectively connected to... Figure 5 The switches 550-1, 550-2, ..., 550-N and controller 552 in the embodiments depicted herein are identical or similar. While the active shielding device 700 shown herein is illustrated with reference to certain components and described with reference to certain functions, other embodiments of the active shielding device may include fewer or more components to achieve the same, fewer, or more functions. For example, the active shielding device may include more than one analog line shielding unit.

[0066] exist Figure 7 In the embodiments depicted, switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N are configured based on control signals D1, D2, ..., D N Select one or more current sources from 602-1, 602-2, ..., 602-N, 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N, 632-1, 632-2, ..., 632-N to apply to the analog line shielding unit 604, the first current-to-voltage converter 606-1, or the second current-to-voltage converter 606-2. Figure 7 In the embodiments depicted, controller 752 is configured to generate control signals D1, D2, ..., D... N The controller controls switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N and / or at least one of the first and second current-to-voltage converters 606-1, 606-2. By controlling the switches and / or the current-to-voltage converters, the voltage on the analog wire shielding unit can be varied (e.g., depending on the number or selection of current sources), making it more difficult for an attacker to access information by probing the voltage of the analog wire shielding unit. The controller can be implemented in hardware (e.g., one or more circuits), software, firmware, or a combination thereof. In embodiments, the controller is implemented using a processor such as a microcontroller, main processor, host, DSP, or CPU. Control signals D1, D2, ..., D NIt may be a digital signal, which can be a random digital signal / sequence or a predefined digital signal / sequence. In some embodiments, the controller includes a random number generator configured to generate random digital sequences. Although in Figure 7 The controller is shown as a component of the active shielding device 700, but in other embodiments, the controller is external to the active shielding device. In some embodiments, the controller is configured to shut down or deactivate a protected circuit in the event of tampering with a cable or wire within the analog line shielding unit, which may be connected to a wire or cable within the analog line shielding unit, a wire or cable between a current source and the analog line shielding unit, or a wire or cable between the analog line shielding unit and current-voltage converters 606-1, 606-2.

[0067] Digital active shielding can be combined with analog active shielding to provide more sophisticated protection against invasive attacks. In some embodiments, one or more digital logic circuits are connected in series with a cable or wire, allowing the digital logic circuits to alter the signal in the cable or wire. For example, an even number (e.g., 2, 4, 6, 8, 14, 20) of inverters can be connected in series with the cable or wire such that when a digital signal flows through these inverters, the output signal of the even number of inverters is the same as the original signal. However, when an attacker probes the cable or wire, the probed voltage may not correspond to the original digital signal. For example, when an attacker probes the cable or wire after an odd number of inverters, the probed voltage corresponds to an inverted version of the original digital signal. However, when an attacker probes the cable or wire after an even number of inverters, the probed voltage corresponds to the original digital signal. Therefore, the voltage on the cable or wire can vary depending on the location or section of the cable or wire being probed, making it more difficult for an attacker to access information by probing the voltage of the cable or wire.

[0068] Figure 8 An active shielding device 800 according to an embodiment of the present invention is depicted, the active shielding device 800 comprising a combination of a digital shielding unit 854 and an analog line shielding unit 604. Figure 8In the embodiments depicted, the active shielding device includes: current sources 602-1, 602-2, ..., 602-N, 612-1, 612-2, ..., 612-N, 622-1, 622-2, ..., 622-N, 632-1, 632-2, ..., 632-N; an analog line shielding unit 604 connected to the current sources; first and second current-to-voltage converters 606-1 and 606-2 connected to the analog line shielding unit; and first and second voltage comparators 608-1 and 608-2. Comparators 608-1 and 608-2 are connected to a current-to-voltage converter; a third voltage comparator 608-3 is connected to the first and second voltage comparators 608-1 and 608-2; switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N; an optional controller 852; a digital shielding unit 854 connected to a current source; two digital logic units 856-1 and 856-2; and a digital comparator 858. Figure 8 In the embodiments depicted, switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N and controller 852 are respectively connected to... Figure 5 The switches 550-1, 550-2, ..., 550-N and controller 552 in the embodiments depicted herein are identical or similar. While the illustrated active shielding device 800 is shown and described herein in conjunction with certain components and certain functions, other embodiments of the active shielding device may include fewer or more components to achieve the same, fewer or more functions. For example, the active shielding device may include more than one digital shielding unit and / or more than one analog line shielding unit.

[0069] exist Figure 8 In the embodiment depicted, the digital shielding unit 854 is connected between the second group of current sources 612-1, 612-2, ..., 612-N and the third group of current sources 622-1, 622-2, ..., 622-N. Figure 8In the embodiments depicted, the digital shielding unit includes: a first group of inverters 866-1, 866-2, ..., 866-K, where K is a positive even integer, connected between a second group of current sources 612-1, 612-2, ..., 612-N and a third group of current sources 622-1, 622-2, ..., 622-N; and a second group of inverters 876-1, 876-2, 876-K connected between digital logic 856-2 and digital comparator 858. The digital shielding unit may include one or more cables or wires made of a conductive material (e.g., metal). In some embodiments, the cables or wires within the digital shielding unit are located on the top metal layer of the digital shielding unit 854. When an attacker probes the cables or wires, the probed voltage may not correspond to the original digital signal. For example, when an attacker probes a cable or wire after an odd number of inverters, the probed voltage corresponds to the inverted version of the original digital signal. However, when an attacker probes a cable or wire after an even number of inverters, the probed voltage corresponds to the original digital signal. Therefore, the voltage on the cable or wire can vary depending on the location or section of the cable or wire being probed, making it more difficult for an attacker to access information by probing the voltage of the cable or wire. While the digital shielding unit 854 shown herein is illustrated in conjunction with certain components and described in conjunction with certain functions, other embodiments of the digital shielding unit may include fewer or more components to achieve the same, fewer, or more functions. For example, the digital shielding unit may include only a set of an even number of inverters.

[0070] exist Figure 8 In the embodiments depicted, controller 852 is configured to generate digital control signals D1, D2, ..., D... M Where M is a positive integer greater than one, and the digital control signals D1, D2, ..., D... M The controller can be a random digital signal / sequence or a predefined digital signal / sequence. The controller can be implemented in hardware (e.g., one or more circuits), software, firmware, or a combination thereof. In embodiments, a processor such as a microcontroller, main processor, host, DSP, or CPU is used to implement the controller. In some embodiments, the controller includes a random number generator configured to generate random digital sequences. Control signals D1, D2, ..., D... NControl switches 750-1, 750-2, ..., 750-N, 760-1, 760-2, ..., 760-N, 770-1, 770-2, ..., 770-N, 780-1, 780-2, ..., 780-N, where N is an integer less than M. By controlling these switches, the voltage on the analog wire shielding unit 604 can be varied (e.g., depending on the number or selection of current sources), making it more difficult for an attacker to access information by probing the voltage of the analog wire shielding unit. Although in Figure 8 The controller is shown as a component of the active shielding device 800, but in other embodiments, the controller is external to the active shielding device. In some embodiments, the controller is configured to shut down or deactivate a protected circuit in the event of tampering with a cable or wire within the analog line shielding unit, which may be connected to a wire or cable within the analog line shielding unit, a wire or cable between a current source and the analog line shielding unit, or a wire or cable between current-voltage converters 606-1, 606-2 and the analog line shielding unit.

[0071] exist Figure 8 In the embodiments depicted, digital logic 856-1 is configured based on digital signals D1, D2, ..., D... M The resulting signal OUTi is generated. The digital logic 856-2 is configured based on digital signals D1, D2, ..., D... MA result signal OUTo is generated. Digital logic 856-1 and 856-2 are identical digital circuits and / or configured to perform the same function. In some embodiments, the digital logic is, for example, a NAND gate, an OR gate, or an XOR gate, or more complex digital logic. Digital comparator 858 is configured to compare the result signal OUTi from digital logic 856-1 with the result signal OUTo from digital logic 856-2 to produce a digital comparison result. Based on the comparison result from the digital comparator, it can be determined whether the cables or wires within the digital shielding unit 854 have been tampered with (e.g., involving intrusion into the cables or wires within the digital shielding unit or voltage detection that alters at least one voltage or current in the cables or wires within the digital shielding unit). In some embodiments, if the result signal OUTi from digital logic 856-1 is the same as the result signal OUTo from digital logic 856-2, it is determined that the cables or wires within the digital shielding unit have not been tampered with. In these embodiments, if the result signal OUTi from digital logic 856-1 is different from the result signal OUTo from digital logic 856-2, it is determined that the cables or wires within the digital shielding unit have been tampered with. In some embodiments... In embodiments, the active shielding device includes a controller (e.g., controller 852) configured to determine whether cables or wires within the digital shielding unit have been tampered with. The controller may be implemented in hardware (e.g., one or more circuits), software, firmware, or a combination thereof. In embodiments, a processor such as a microcontroller, main processor, host, DSP, or CPU is used to implement the controller. In some embodiments, the controller is configured to shut down or deactivate a protected circuit in the event of tampering with cables or wires within the digital shielding unit, the protected circuit being connected to wires or cables within the digital shielding unit, wires or cables between a current source and the digital shielding unit, or wires or cables between the digital shielding unit and a digital comparator.

[0072] Figure 9 This is a process flow diagram of a method for active shielding according to an embodiment of the present invention. According to the method, at block 902, an active shielding device generates current. At block 904, current is conducted through an analog wire winding of the active shielding device. At block 906, a current-to-voltage converter of the active shielding device generates voltage in response to the current. At block 908, a voltage comparator of the active shielding device compares the voltage with a reference voltage. The active shielding device can be used with… Figure 1 The active shielding device 100 described in the document Figure 5 The active shielding device 500 described in the document Figure 6 The active shielding device 600 and / or described herein Figure 7 The active shielding device 700 described herein is similar to, identical to, or a component of those active shielding devices.

[0073] Figure 10 This is a process flowchart of a method for active shielding according to another embodiment of the present invention. According to the method, at block 1002, an active shielding device generates current. At block 1004, current is conducted through the analog winding of the active shielding device in response to a digital control sequence. At block 1006, a current-to-voltage converter of the active shielding device generates voltage in response to the current. At block 1008, the voltage is compared with a reference voltage using a voltage comparator of the active shielding device. At block 1010, before the digital control sequence is conducted through the inverter of the active shielding unit of the active shielding device, and after the digital control sequence is conducted through the inverter using the digital logic of the active shielding device, the digital control sequence is processed to generate a first processing result signal and a second result signal, respectively. At block 1012, the first processing result signal is compared with the second result signal. The active shielding device can be used with… Figure 8 The active shielding device 800 described herein is similar to, identical to, or a component of the active shielding device 800.

[0074] Although the operations of the methods herein are shown and described in a specific order, the order of operations for each method may be changed so that certain operations can be performed in reverse order, or that certain operations can be performed at least partially concurrently with other operations. In another embodiment, instructions or sub-operations of different operations may be implemented intermittently and / or alternately.

[0075] It should also be noted that at least some of the operations of the methods described herein can be implemented using software instructions stored on a computer-usable storage medium for execution by a computer. As an example, embodiments of a computer program product include a computer-usable storage medium for storing a computer-readable program.

[0076] Computer-usable or computer-readable storage media can be electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems (or devices or apparatuses). Examples of persistent computer-usable and computer-readable storage media include semiconductor or solid-state memory, magnetic tape, removable computer disks, random access memory (RAM), read-only memory (ROM), rigid disks, and optical discs. Current examples of optical discs include optical discs with read-only memory (CD-ROM), optical discs with read / write capability (CD-R / W), and digital video discs (DVDs).

[0077] Alternatively, embodiments of the present invention may be implemented entirely in hardware or in implementations that include both hardware and software elements. In software-based embodiments, the software may include, but is not limited to, firmware, resident software, microcode, etc.

[0078] While specific embodiments of the invention have been described and illustrated, the invention is not limited to the particular form or arrangement of the portions thus described and illustrated. The scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An active shielding device, characterized in that, The active shielding device includes: Multiple current sources, the multiple current sources being configured to generate multiple currents; A simulated line shielding unit, the simulated line shielding unit being connected to the current source; A current-to-voltage converter, connected to the analog line shielding unit and configured to generate a voltage in response to a current flowing through the analog line shielding unit generated by a current source; and A voltage comparator connected to the current-to-voltage converter and configured to compare the voltage generated by the current-to-voltage converter with a reference voltage; The analog wire shielding unit includes multiple analog wire windings connected between the current source and the current-voltage converter.

2. The active shielding device according to claim 1, characterized in that, The current sources are connected in parallel with each other.

3. The active shielding device according to claim 1, characterized in that, Each of the simulated wire windings is connected to a different current source of the current source.

4. The active shielding device according to claim 1, characterized in that, In addition, including: Multiple switches are connected between the current source and the analog line shielding unit.

5. The active shielding device according to claim 4, characterized in that, In addition, including: A controller configured to generate multiple control signals to control the switch or the current-to-voltage converter.

6. The active shielding device according to claim 5, characterized in that, The controller includes a random number generator.

7. The active shielding device according to claim 1, characterized in that, In addition, including: A second plurality of current sources, configured to generate a second plurality of currents; A second current-to-voltage converter is connected to the analog line shielding unit and is configured to generate a second voltage in response to the second plurality of currents generated by the second plurality of current sources; as well as A second voltage comparator is connected to the second current-to-voltage converter and is configured to compare the second voltage with a second plurality of reference voltages.

8. An active shielding device, characterized in that, The active shielding device includes: The first, second, third and fourth groups of current sources, wherein each of the first, second, third and fourth groups of current sources is configured to generate multiple currents; A simulated line shielding unit, the simulated line shielding unit being connected to the second and fourth sets of current sources; A first current-to-voltage converter is connected to the first group of current sources and the fourth group of current sources via the analog line shielding unit, wherein the first current-to-voltage converter is configured to generate a first voltage in response to the current flowing through the analog line shielding unit generated by the first and fourth groups of current sources. A first voltage comparator is connected to the first current-to-voltage converter and configured to compare the first voltage with a first reference voltage. A second current-to-voltage converter is connected to the second set of current sources and the third set of current sources via the analog line shielding unit, wherein the second current-to-voltage converter is configured to generate a second voltage in response to the current flowing through the analog line shielding unit generated by the second and third sets of current sources. A second voltage comparator, connected to the second current-to-voltage converter and configured to compare the second voltage with a second reference voltage; and A third voltage comparator is configured to compare the results from the first voltage comparator and the results from the second voltage comparator; The simulated wire shielding unit includes a simulated wire winding, which is connected between the fourth set of current sources and the first current-voltage converter, and also connected between the second set of current sources and the second current-voltage converter.

9. A method for active shielding, characterized in that, The method includes: Multiple currents are generated using an active shielding device; The current is conducted through multiple simulated wire windings of the active shielding device; The current-to-voltage converter using the active shielding device generates a voltage in response to the current conducted through multiple analog wire windings; and The voltage is compared with a reference voltage using the voltage comparator of the active shielding device.

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