Apparatus for detecting a distance fraud attack, system for detecting a distance fraud attack, and method of operating the same

Abstract

The present invention relates to a distance forgery attack detection device, a distance forgery attack detection system, and a method of operation thereof. A distance forgery attack detection device according to one embodiment of the present invention may include a synchronization processing unit that transmits and receives shared information regarding a master key or a session key to a transmitting device; a random variable generation unit that generates a random variable for each positioning session based on the shared information to determine a random delay value and a random STS length; a correlation verification unit that receives a signal from the transmitting device and calculates a correlation between the signal and a local template adjusted based on the random delay value to determine whether a time-of-arrival-based peak is formed; a first attack verification unit that detects a distance forgery attack by performing time verification on the time when the peak occurs; and a second attack verification unit that detects a distance forgery attack by monitoring energy in the interval immediately after the reception window of the signal is terminated.

Description

Technology Field

[0001] The present invention relates to a distance forgery attack detection device, a distance forgery attack detection system, and a method of operation thereof. It relates to a technology for detecting an attacker's distance forgery attack by generating a random variable based on security parameters shared between a transmitting device and a receiving device that measure distance, determining a random delay value and a random STS length according to the random variable, and performing time verification and residual energy detection on a transmitted and received signal based on the random delay value and the random STS length. Background Technology

[0002] Ultra-Wideband (UWB) technology calculates the distance between two terminals by measuring the Time of Arrival (ToA) between the transmitting and receiving terminals using very short pulse signals.

[0003] UWB technology uses one of the LRP (Low Rate Pulse) or HRP (High Rate Pulse) modes depending on the pulse period and intensity. LRP uses high intensity and a small number of pulses, whereas HRP uses a large number of pulses with low intensity.

[0004] UWB technology has been adopted as an IEEE standard and is recently defined by the 802.15.4z standard, which has improved accuracy and security.

[0005] In other words, UWB technology can provide high positioning accuracy in centimeters (cm) by utilizing the physical characteristic that the signal propagation speed is constant through a ToA-based distance measurement method.

[0006] As a result, UWB is being widely applied to services requiring high reliability, such as vehicle smart keys, access control systems, and security authentication tags.

[0007] However, the ToA-based distance measurement method contains security vulnerabilities in that it calculates distance based on the first path signal reached by the receiving terminal device.

[0008] An attacker can exploit these characteristics to distort distance measurement results by causing a forged signal to reach the receiving terminal earlier than the signal actually transmitted by the sending terminal.

[0009] This type of attack is called a distance reduction attack because it causes a shorter distance to be measured than the actual distance.

[0010] For example, if a vehicle smart key system measures the distance between the vehicle and the key using UWB, an attacker can position themselves between the vehicle and the key and perform an attack in the following manner.

[0011] The attacker receives UWB pulses transmitted from the key, analyzes the structure of part or all of the received pulses, and regenerates pulses of the same or similar form.

[0012] By transmitting the regenerated pulse to the vehicle's receiver faster than the original signal, the vehicle is misled into believing that the key is closer than its actual location.

[0013] Unlike relay attacks that simply amplify and relay signals, these attacks are difficult to detect with existing security mechanisms because they directly manipulate the arrival time of the signal.

[0014] In particular, since UWB signals have a deterministic structure in which the pulse position, period, and modulation method are predefined at the physical layer, it is possible for an attacker to predict the signal pattern or generate some pulses early.

[0015] As a result, an attacker can perform a distance reduction attack by selectively forging only the initial pulse that affects the distance calculation, even without restoring the entire frame.

[0016] Previous studies have proposed methods to detect forged signals, primarily targeting the Low Rate Pulse (LRP) mode, by identifying single pulses of high intensity or analyzing correlations between pulses.

[0017] However, in High Rate Pulse (HRP) mode, since multiple low-strength pulses are transmitted in a distributed manner, it is difficult to apply single-pulse-based detection methods.

[0018] In addition, since HRP mode is designed for high-speed data transmission and energy efficiency, inserting additional security verification procedures leads to problems such as system delays or increased power consumption.

[0019] Therefore, to effectively defend against distance reduction attacks in UWB-based distance measurement systems, a new security technology is required that can fundamentally block attacks exploiting the deterministic structure of the physical layer while also considering the signal characteristics of HRP mode. Prior art literature

[0020] Korean Registered Patent No. 10-2772962, "Electronic device performing ranging via UWB (ULTRA WIDE BAND) in a wireless communication system and method of operation of the electronic device" Korean Published Patent No. 10-2024-0048410, "Method and apparatus for estimating position using UWB signals"

[0021] Ju Gyeong-ho et al., "Protecting HRP UWB Ranging System Against Distance Reduction Attacks", 2023.11.21 The problem to be solved

[0022] The present invention aims to generate a random variable based on security parameters shared between a distance measuring transmitting device and a receiving device, determine a random delay value and a random STS length according to the random variable, and effectively respond to an attacker's distance forgery attack or distance reduction attack using the random delay value and the random STS length.

[0023] The present invention aims to improve security against distance forgery attacks on a system that operates based on the positioning of a transmitting device and a receiving device in a device and system utilizing Ultra-Wideband (UWB) based applications such as a digital key. means of solving the problem

[0024] A distance forgery attack detection device according to an embodiment of the present invention may include a synchronization processing unit that transmits and receives shared information regarding a master key or a session key to a transmitting device; a random variable generation unit that generates a random variable for each ranging session based on the shared information to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length; a correlation verification unit that receives a signal from the transmitting device and calculates a correlation between the signal and a local template adjusted based on the random delay value to determine whether a time-of-arrival-based peak is formed; a first attack verification unit that detects a distance forgery attack by performing time verification on the time when the peak occurs; and a second attack verification unit that detects a distance forgery attack by monitoring energy in the interval immediately after the reception window of the signal is terminated.

[0025] The above random variable generation unit has a minimum response time (T min ) and maximum response time (T maxA random value can be generated as a random variable between the above and determined as a random delay value, and a random length can be generated as a random variable within a preset STS length range to determine the random STS length.

[0026] The first attack verification unit can detect a distance forgery attack by performing a time verification that inversely calculates the random delay value at the time the peak occurs and verifies whether the time the peak occurs is located within a preset time range.

[0027] The second attack verification unit can detect a distance forgery attack by performing residual energy detection based on energy monitoring for the period immediately after the signal reception window is terminated, and checking whether the energy of the period immediately after termination is greater than or equal to a threshold.

[0028] In a distance forgery attack detection system comprising a transmitting device and a receiving device according to an embodiment of the present invention, the transmitting device and the receiving device transmit and receive shared information regarding a master key or a session key, and the transmitting device and the receiving device generate a random variable for each ranging session based on the shared information to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length, the transmitting device generates a variable-length STS frame according to the random STS length to the receiving device, delays the generated variable-length STS frame by the random delay value, and transmits a signal, and the receiving device receives the signal from the transmitting device and calculates a correlation between the signal and a local template adjusted based on the random delay value to check whether a peak is formed based on the arrival time, and the receiving device can detect a distance forgery attack by performing time verification on the time when the peak occurs or by monitoring energy in the interval immediately after the reception window of the signal ends.

[0029] The transmitting device and the receiving device have a minimum response time (T min ) and maximum response time (T max A random value can be generated as a random variable between the above and determined as a random delay value, and a random length can be generated as a random variable within a preset STS length range to determine the random STS length.

[0030] The receiving device can detect a distance forgery attack by performing a time verification that inversely calculates the random delay value at the time the peak occurs to verify whether the time the peak occurs is located within a preset time range, or by performing residual energy detection based on energy monitoring for the section immediately after the signal reception window ends to determine whether the energy of the section immediately after the end is greater than or equal to a threshold.

[0031] A method of operation of a distance forgery attack detection device according to an embodiment of the present invention may include: a step of transmitting and receiving shared information regarding a master key or session key with a transmitting device in a synchronization processing unit; a step of generating a random variable for each ranging session based on the shared information in a random variable generation unit to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length; a step of receiving a signal from the transmitting device in a correlation verification unit and calculating a correlation between the signal and a local template adjusted based on the random delay value to determine whether a peak based on arrival time is formed; a step of detecting a distance forgery attack by performing a time verification on the time when the peak occurs in a first attack verification unit; and a step of detecting a distance forgery attack by monitoring energy in a section immediately after the reception window of the signal is terminated in a second attack verification unit.

[0032] The step of generating a random variable for each positioning session based on the above shared information to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length is the minimum response time (T min ) and maximum response time (T maxIt may include the step of generating a random value as a random variable between ) to determine the random delay value, and generating a random length as a random variable within a preset STS length range to determine the random STS length.

[0033] The step of detecting a distance forgery attack by performing a time verification on the point in time when the peak occurs may include the step of detecting a distance forgery attack by performing the time verification to verify whether the point in time when the peak occurs is located within a preset time range by inversely calculating the random delay value at the point in time when the peak occurs.

[0034] The step of detecting a distance forgery attack by monitoring energy in the interval immediately after the reception window of the signal is terminated may include the step of detecting a distance forgery attack by performing residual energy detection based on energy monitoring for the interval immediately after the reception window of the signal is terminated, which determines whether the energy in the interval immediately after the termination is greater than or equal to a threshold.

[0035] A method of operation of a distance forgery attack detection system according to an embodiment of the present invention may include the steps of: transmitting and receiving shared information regarding a master key or a session key at each of a transmitting device and a receiving device; generating a random variable for each ranging session based on the shared information at each of the transmitting device and the receiving device to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length; at the transmitting device, generating a variable-length STS frame according to the random STS length and transmitting a signal by delaying the generated variable-length STS frame by the random delay value; at the receiving device, receiving the signal from the transmitting device and calculating a correlation between the signal and a local template adjusted based on the random delay value to determine whether a time-of-arrival-based peak is formed; and at the receiving device, detecting a distance forgery attack by performing a time verification on the time when the peak occurs or detecting a distance forgery attack by monitoring energy in the interval immediately after the reception window of the signal ends.

[0036] The step of detecting a distance forgery attack by performing time verification on the point in time when the above peak occurs or by monitoring energy in the interval immediately after the signal reception window ends may include the step of detecting a distance forgery attack by performing time verification to verify whether the point in time when the peak occurs is located within a preset time range by inversely calculating the random delay value at the point in time when the above peak occurs, and the step of detecting a distance forgery attack by performing residual energy detection to check whether the energy in the interval immediately after the end is greater than or equal to a threshold value based on energy monitoring for the interval immediately after the signal reception window ends. Effects of the invention

[0037] The present invention generates a random variable based on security parameters shared between a transmitting device and a receiving device that measure distance, determines a random delay value and a random STS length according to the random variable, and can effectively respond to an attacker's distance forgery attack or distance reduction attack by using the random delay value and the random STS length.

[0038] The present invention can enhance security against distance forgery attacks on a system that operates based on the positioning of a transmitting device and a receiving device in a device and system utilizing Ultra-Wideband (UWB) based applications such as a digital key. Brief explanation of the drawing

[0039] FIG. 1 is a drawing illustrating a distance forgery attack detection device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a distance forgery attack detection system according to an embodiment of the present invention. FIGS. 3a to 3c are drawings illustrating a distance forgery attack detected by a distance forgery attack detection device according to an embodiment of the present invention. FIG. 4 is a diagram illustrating the operation method of a distance forgery attack detection device according to an embodiment of the present invention. FIG. 5 is a diagram illustrating the operation method of a distance forgery attack detection system according to an embodiment of the present invention. Specific details for implementing the invention

[0040] Hereinafter, various embodiments of this document are described with reference to the attached drawings.

[0041] The embodiments and the terms used therein are not intended to limit the technology described in this document to specific embodiments and should be understood to include various modifications, equivalents, and / or substitutions of said embodiments.

[0042] In describing various embodiments below, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted.

[0043] Furthermore, the terms described below are defined considering their functions in various embodiments, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0044] In relation to the description of the drawings, similar reference numerals may be used for similar components.

[0045] A singular expression may include a plural expression unless the context clearly indicates otherwise.

[0046] In this document, expressions such as "A or B" or "at least one of A and / or B" may include all possible combinations of the items listed together.

[0047] Expressions such as "first," "second," "first," or "second" may modify the corresponding components regardless of order or importance, and are used merely to distinguish one component from another without limiting the components.

[0048] Where it is stated that a certain (e.g., first) component is "(functionally or telecommunicationally) connected" or "connected" to another (e.g., second) component, said certain component may be directly connected to said other component or connected through another component (e.g., third component).

[0049] In this specification, "configured to" may be used interchangeably with, depending on the context, for example, in hardware or software, "suitable for," "capable of," "modified to," "made to," "capable of," or "designed to."

[0050] In some situations, the expression "device configured to..." may mean that the device is "able to..." together with other devices or parts.

[0051] For example, the phrase “a processor configured (or set) to perform A, B, and C” may mean a dedicated processor for performing said operations (e.g., an embedded processor), or a general-purpose processor capable of performing said operations by executing one or more software programs stored in a memory device (e.g., a CPU or an application processor).

[0052] Also, the term 'or' means an inclusive disjunction rather than an exclusive disjunction.

[0053] That is, unless otherwise noted or is not clear from the context, the expression 'x uses a or b' means any one of the natural inclusive permutations.

[0054] Terms such as '..bu', '..gi' used below refer to a unit that processes at least one function or operation, and this may be implemented in hardware or software, or a combination of hardware and software.

[0056] FIG. 1 is a drawing illustrating a distance forgery attack detection device according to an embodiment of the present invention.

[0057] FIG. 1 illustrates the components and operation of a distance forgery attack detection device according to an embodiment of the present invention.

[0058] Referring to FIG. 1, a distance forgery attack detection device (100) according to one embodiment of the present invention includes a synchronization processing unit (110), a random variable generation unit (120), a correlation verification unit (130), a first attack verification unit (140), and a second attack verification unit (150).

[0059] The synchronization processing unit (110) can transmit and receive shared information regarding the master key or session key with the transmitting device.

[0060] The synchronization processing unit (110) mutually shares security parameters based on shared information regarding the transmission device and the master key or session key.

[0061] The synchronization processing unit (110) can perform synchronization for security parameters to share security parameters, such as random variables, challenge values, response values, password-derived parameters, timestamps, sequence numbers, message authentication codes, authentication tags, and physical layer-linked security parameters, with the transmitting device.

[0062] The random variable generation unit (120) can generate a random variable for each ranging session based on shared information to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length.

[0063] The random variable generation unit (120) has a minimum response time (T min ) and maximum response time (T max A random value can be determined as a random delay value by generating a random variable between ), and a random length can be determined as a random STS length by generating a random variable within a preset STS length range.

[0064] The random variable generation unit (210) can generate a random variable and determine a random delay value by adding the random variable to the delay value between the minimum response time and the maximum response time.

[0065] The correlation verification unit (130) receives a signal from the transmitting device and calculates the correlation between the signal and the local template adjusted based on the random delay value to determine whether a peak is formed based on the arrival time.

[0066] The first attack verification unit (140) can detect distance forgery attacks by performing time verification on the time when the peak occurred.

[0067] That is, the first attack verification unit (140) can detect a distance forgery attack by performing a time verification that calculates a random delay value inversely at the time the peak occurs and verifies whether the time the peak occurs is located within a preset time range.

[0068] For example, the first attack verification unit (140) performs a time verification to verify whether the value obtained by subtracting the delay time corresponding to a random delay value from the time of arrival (ToA) between the transmitting device and the receiving device corresponding to the time when the peak occurred is included in the valid range of the preset time of arrival.

[0069] The first attack verification unit (140) can verify the attack by determining that a normal distance measurement has occurred if it is included within the valid range, and determining that a distance forgery attack has occurred if it is out of the valid range.

[0070] The first attack verification unit (140) estimates the time when the maximum peak occurred in the correlation result confirmed by the correlation verification unit (130) as the time of arrival (ToA).

[0071] The estimated arrival time at this time includes not only the actual propagation delay of the signal, but also a random delay shared in advance between the transmitter and receiver and an internal system processing delay.

[0072] The first attack verification unit (140) estimates the pure propagation delay taken for the signal to propagate through space by removing a known random delay value from the arrival time.

[0073] Afterward, the first attack verification unit (140) calculates the distance between the transmitter and receiver based on the propagation delay and checks whether the distance falls within a predefined effective distance range.

[0074] For example, the first attack verification unit (140) determines that if the inverse distance satisfies the valid distance range, the corresponding correlation peak was generated by a normal signal.

[0075] Conversely, the first attack verification unit (140) determines that if the reversed distance exceeds the allowed range, it is an abnormal signal involving additional delay or manipulation, i.e., a signal with potential for attack.

[0076] The first attack verification unit (140) can verify not only whether a correlation peak exists, but also whether the peak occurred at a physically possible location, through a time verification procedure, thereby effectively detecting time-based attacks such as relay attacks or replay attacks.

[0077] The second attack verification unit (150) can detect a distance forgery attack by monitoring energy in the interval immediately after the signal reception window is closed.

[0078] For example, since the attacker cannot know the random STS length of the current session, they send pulses of the maximum length to increase the attack success rate.

[0079] In this case, the distance forgery attack may generate residual energy based on the energy for the maximum length.

[0080] The second attack verification unit (150) can detect this residual energy and detect a distance forgery attack.

[0081] The second attack verification unit (150) can detect a distance forgery attack by performing residual energy detection based on energy monitoring of the period immediately after the signal reception window is terminated, and checking whether the energy of the period immediately after termination is greater than or equal to a threshold.

[0082] For example, the threshold used for residual energy detection can be determined based on the amount of energy used for signal transmission.

[0083] The first attack verification unit (140) and the second attack verification unit (150) may be composed of a single attack verification unit. That is, the first attack verification unit (140) and the second attack verification unit (150) are included in the attack verification unit.

[0084] A distance forgery attack detection device (100) according to one embodiment of the present invention corresponds to a receiving device of a distance forgery attack detection system.

[0085] Accordingly, the present invention generates a random variable based on security parameters shared between a transmitting device and a receiving device that measure distance, determines a random delay value and a random STS length according to the random variable, and can effectively respond to an attacker's distance forgery attack or distance reduction attack by using the random delay value and the random STS length.

[0087] FIG. 2 is a diagram illustrating a distance forgery attack detection system according to an embodiment of the present invention.

[0088] FIG. 2 illustrates the configuration and operation of a distance forgery attack detection system according to an embodiment of the present invention.

[0089] Referring to FIG. 2, a distance forgery attack detection system (200) according to an embodiment of the present invention is composed of a receiving device (210) and a transmitting device (220), and an attacker (230) attacks a signal (231) transmitted and received between the receiving device (210) and the transmitting device (220) with an overshadowing attack signal. Here, the overshadowing attack signal may be referred to as a distance forgery attack signal.

[0090] However, the distance forgery attack detection system (200) according to one embodiment of the present invention can detect a distance forgery attack by performing distance measurement using a random delay value and a random STS length based on information shared between a receiving device (210) and a transmitting device (220).

[0091] In a distance forgery attack detection system (200) according to an embodiment of the present invention, a transmitting device (220) and a receiving device (210) transmit and receive shared information regarding a master key or a session key.

[0092] The transmitting device (220) and the receiving device (210) generate a random variable for each positioning session based on shared information to determine a random delay value and a random STS length.

[0093] The transmitting device (220) and the receiving device (210) generate random variables by driving a pseudo-random number generator based on a pre-shared master key or session key to determine a random delay value and a random STS length.

[0094] The transmitting device (220) and the receiving device (210) synchronize a random delay value and a random STS length for each positioning session.

[0095] The random delay value is the minimum response time (T min ) and maximum response time (T max It is determined between ).

[0096] The random STS length is determined by selecting an arbitrary length from the predetermined lengths, such as the STS length defined in the standard.

[0097] STS length is determined by the number of symbols and chips and can refer to units of time length.

[0098] The transmitting device (220) generates a variable-length STS frame according to a random STS length to the receiving device (210), and transmits a signal by delaying the generated variable-length STS frame by a random delay value.

[0099] For variable-length STS frames, the random delay value can change randomly per session.

[0100] The receiving device (210) receives a signal from the transmitting device (220) and calculates the correlation between the signal and the local template adjusted based on the random delay value to determine whether a time-of-arrival-based peak is formed.

[0101] The receiving device (210) checks whether the received signal forms a normal correlation peak with the template of STS length and verifies whether it is within the valid distance range when the random delay value is inversely calculated at the time the peak occurs.

[0102] The receiving device (210) detects a distance forgery attack by performing a time verification on the time when the peak occurred.

[0103] Since the attacker (230) does not know the variable STS length, he / she transmits pulses of the maximum length to increase the success rate of the attack.

[0104] Additionally, the receiving device (210) can detect a distance forgery attack by monitoring energy in the interval immediately after the signal reception window is closed.

[0105] The receiving device (210) detects a distance forgery attack and destroys the session, considering it a distance forgery attack because it is evidence that an attacker attempted to overwrite a longer signal when residual energy is detected.

[0106] The STS setting parameters defined in the IEEE 802.15.4z standard for the receiving device (210) and the transmitting device (220) can be summarized as shown in Table 1 below.

[0107] [Table 1]

[0108]

[0109] The packet structure used in the present invention may be Packet Configuration 2 (SP2) defined in the IEEE 802.15.4z standard.

[0110] The packet structure used in the present invention may be a structure in which the STS is located after the data ([SHR] + [PHR] + [Data Payload] + [STS]).

[0111] The receiving device (210) uses a secure key to form a random variable in the PRNG, changes the local template, and controls the receiving window based on the random variable.

[0112] The receiving device (210) defines a window for the received signal and detects distance forgery attacks through correlation verification and residual energy check for arrival time estimation.

[0113] The transmitting device (220) generates a random delay value using a secure key, generates a variable variable for STS length by forming a random variable in a PRNG, and generates an STS frame of variable STS length based on the variable variable.

[0114] The attacker (230) transmits a long pulse to increase the success rate of the attack, but the attack is detected based on a random delay value and a random STS length that vary based on information previously shared between the transmitting device (220) and the receiving device (210).

[0115] The present invention can provide a distance forgery attack detection system that detects an attacker's distance forgery attack by generating a random variable based on security parameters shared between a transmitting device and a receiving device that measure distance, determining a random delay value and a random STS length according to the random variable, and performing time verification and residual energy detection on the transmitted and received signals based on the random delay value and the random STS length.

[0117] FIGS. 3a to 3c are drawings illustrating a distance forgery attack detected by a distance forgery attack detection device according to an embodiment of the present invention.

[0118] FIG. 3a illustrates a propagation delay situation in relation to a distance forgery attack detected by a distance forgery attack detection device according to an embodiment of the present invention.

[0119] Referring to FIG. 3a, the environment (300) in which a propagation delay occurs shows that in a NLoS (None-line-of-sight) situation, the signal of the direct path is reduced due to an obstacle and enters the receiving device, and the signal of the reflected path has a high correlation.

[0120] FIG. 3b illustrates a back-search algorithm in relation to a distance forgery attack detected by a distance forgery attack detection device according to an embodiment of the present invention.

[0121] Referring to FIG. 3b, graph (310) shows the generation of the signal-based maximum peak value of the reflection path described in FIG. 3a.

[0122] To find the signal of the direct path, a certain criterion (P) in an earlier time window of 100ns to 300ns ms The process of finding the leading edge of the first signal that exceeds ) is called the back search algorithm.

[0123] In summary, the distance measurement method performs a back search algorithm, which is a process of finding a leading edge to find a signal along the path. In a distance spoofing attack, an attacker manipulates the STS field to generate a fake leading edge, causing the receiving device to measure a reduced Time of Arrival (ToA).

[0124] In other words, in distance measurement methods, a result occurs where incorrect distances are measured based on distance forgery attacks utilizing fake leading edges.

[0125] FIG. 3c illustrates a distance forgery attack detected by a distance forgery attack detection device according to an embodiment of the present invention and an attack by an attacker who overwrites a normal STS field with a strong pulse.

[0126] Referring to FIG. 3c, the timing diagram (320) illustrates an attack in which the attacker overwrites the victim's normal STS field with a new, more powerful pulse.

[0127] Here, the biggest reason an attack is possible is that the attacker can predict the timing of the target transmitter's frame transmission.

[0128] Accordingly, the present invention detects distance forgery attacks by performing a verification of the recognition of a legitimate STS field for a positioning system of a device using the HRP mode of UWB technology, and effectively responds to previously known ghost peak attacks based on random delay values ​​and random STS lengths.

[0129] To date, detection technologies for distance forgery attacks applicable to HRP UWB devices perform attack detection by modifying the receiver design or relying on high-level software implementations such as machine learning models.

[0130] However, the present invention can effectively counter distance forgery attacks by using at least one of a random time delay value and a random STS length in the receiver.

[0132] FIG. 4 is a diagram illustrating the operation method of a distance forgery attack detection device according to an embodiment of the present invention.

[0133] FIG. 4 illustrates a procedure for detecting a distance forgery attack using a method of operation of a distance forgery attack detection device according to an embodiment of the present invention.

[0134] Referring to FIG. 4, in step (S401), the method of operation of a distance forgery attack detection device according to an embodiment of the present invention performs security parameter synchronization.

[0135] That is, the operation method of a distance forgery attack detection device according to one embodiment of the present invention can perform security parameter synchronization by transmitting and receiving shared information regarding a master key or session key with a transmitting device.

[0136] In step (S402), the method of operation of the distance forgery attack detection device according to an embodiment of the present invention determines a random delay value and a random STS length.

[0137] That is, the operation method of the distance forgery attack detection device according to one embodiment of the present invention can determine a random delay value and a random STS length by generating a random variable for each positioning session based on shared information.

[0138] In step (S403), the method of operation of a distance forgery attack detection device according to an embodiment of the present invention checks the correlation between a received signal and a local template.

[0139] That is, the operation method of a distance forgery attack detection device according to one embodiment of the present invention can receive a signal from a transmitting device and calculate a correlation between the received signal and a local template adjusted based on a random delay value to determine whether a peak is formed based on the arrival time.

[0140] In step (S404), the method of operation of a distance forgery attack detection device according to an embodiment of the present invention detects a distance forgery attack by performing time verification.

[0141] That is, the operation method of the distance forgery attack detection device according to one embodiment of the present invention can detect a distance forgery attack by performing a time verification that inversely calculates a random delay value at the time a peak occurs and verifies whether the time at which the peak occurs is located within a preset time range.

[0142] In step (S405), the method of operation of a distance forgery attack detection device according to an embodiment of the present invention detects a distance forgery attack by monitoring residual energy.

[0143] That is, the method of operation of a distance forgery attack detection device according to one embodiment of the present invention can detect a distance forgery attack by performing residual energy detection based on energy monitoring for the period immediately after the signal reception window is terminated, and checking whether the energy of the period immediately after termination is greater than or equal to a threshold.

[0145] FIG. 5 is a diagram illustrating the operation method of a distance forgery attack detection system according to an embodiment of the present invention.

[0146] FIG. 5 illustrates a procedure for detecting a distance forgery attack using an operation method of a distance forgery attack detection system according to an embodiment of the present invention.

[0147] Referring to FIG. 5, in step (S501), the method of operation of a distance forgery attack detection system according to an embodiment of the present invention involves the transmitting device and the receiving device performing security parameter synchronization.

[0148] That is, the operation method of a distance forgery attack detection system according to one embodiment of the present invention performs security parameter synchronization by transmitting and receiving shared information regarding a master key or session key between a transmitting device and a receiving device.

[0149] In step (S502), the method of operation of a distance forgery attack detection system according to an embodiment of the present invention determines a random delay value and a random STS length.

[0150] That is, the operation method of a distance forgery attack detection system according to one embodiment of the present invention generates a random variable for each positioning session based on information shared between a transmitting device and a receiving device to determine a random delay value and a random STS length.

[0151] For example, the transmitting device and the receiving device can randomly change the random delay value and the random STS length for each session.

[0152] In step (S503), the method of operation of a distance forgery attack detection system according to an embodiment of the present invention transmits a signal based on a random delay value and a random STS length.

[0153] That is, the operation method of a distance forgery attack detection system according to an embodiment of the present invention involves a transmitting device generating a variable-length STS frame according to a random STS length determined in step (S502), and transmitting a signal to a receiving device that delays the variable-length STS frame by a random delay value.

[0154] In step (S504), the method of operation of a distance forgery attack detection system according to an embodiment of the present invention checks the correlation between a received signal and a local template at a receiving device.

[0155] That is, the method of operation of a distance forgery attack detection system according to one embodiment of the present invention involves, in a receiving device, receiving a signal from a transmitting device and calculating a correlation between the received signal and a local template adjusted based on a random delay value to determine whether a peak is formed based on the arrival time.

[0156] In step (S505), the method of operation of a distance forgery attack detection system according to an embodiment of the present invention determines that a peak is formed between the received signal and the local template in step (S504), and checks whether the peak is valid within a preset range.

[0157] A method of operation of a distance forgery attack detection system according to an embodiment of the present invention performs a time verification by inversely calculating a random delay value at the time a peak occurs to verify whether the time at which the peak occurs is located within a preset time range, and determines whether the peak is valid within the preset range.

[0158] The operation method of a distance forgery attack detection system according to one embodiment of the present invention proceeds to step (S506) if valid within a preset range, and proceeds to step (S507) if invalid.

[0159] Meanwhile, the operation method of the distance forgery attack detection system according to one embodiment of the present invention can proceed to step (S508) by confirming that transmission and reception between a transmitting device and a receiving device are for normal distance measurement if valid within a preset range, and terminate the procedure after determining that it is a normal distance measurement.

[0160] That is, the method of operation of the distance forgery attack detection system according to one embodiment of the present invention can determine a normal distance measurement by confirming that no time delay caused by a delay time attack has occurred.

[0161] In step (S506), the method of operation of a distance forgery attack detection system according to an embodiment of the present invention checks for the presence of residual energy at the end of the window of the received signal.

[0162] That is, the method of operation of a distance forgery attack detection system according to one embodiment of the present invention detects a distance forgery attack by monitoring energy in the interval immediately after the signal reception window is terminated at a receiving device.

[0163] The method of operation of a distance forgery attack detection system according to one embodiment of the present invention proceeds to step (S507) to detect a distance forgery attack when residual energy is detected.

[0164] Meanwhile, the operation method of the distance forgery attack detection system proceeds to step (S508) and determines a normal distance measurement when no residual energy is detected.

[0165] Accordingly, the present invention can improve security against distance forgery attacks on a system operating based on the positioning of a transmitting device and a receiving device in a device and system utilizing an Ultra-Wideband (UWB) based application such as a digital key.

[0167] The device described above may be implemented as a hardware component, a software component, and / or a combination of a hardware component and a software component. For example, the device and components described in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and one or more software applications executed on said operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. In addition, other processing configurations, such as parallel processors, are also possible.

[0168] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or command the processing unit independently or collectively. Software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave so as to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

[0169] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0170] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below. Explanation of the symbols

[0171] 100: Distance Forgery Attack Detection Device 110: Synchronization processing unit 120: Random variable generation unit 130: Correlation Verification Section 140: 1st Attack Verification Unit 150: Second Attack Verification Unit

Claims

Claim 1 A distance forgery attack detection device characterized by comprising: a synchronization processing unit that transmits and receives shared information regarding a master key or session key to a transmitting device; a random variable generation unit that generates a random variable for each ranging session based on the shared information to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length; a correlation verification unit that receives a signal from the transmitting device and calculates a correlation between the signal and a local template adjusted based on the random delay value to determine whether a time-of-arrival-based peak is formed; a first attack verification unit that detects a distance forgery attack by performing time verification on the time when the peak occurs; and a second attack verification unit that detects a distance forgery attack by monitoring energy in the interval immediately after the reception window of the signal is terminated. Claim 2 In claim 1, the random variable generation unit has a minimum response time (T min ) and maximum response time (T max A distance forgery attack detection device characterized by generating a random value between ) using the random variable to determine the random delay value, and generating a random length within a preset STS length range using the random variable to determine the random STS length. Claim 3 A distance forgery attack detection device according to claim 1, wherein the first attack verification unit detects a distance forgery attack by performing a time verification that inversely calculates the random delay value at the time when the peak occurs and verifies whether the time when the peak occurs is located within a preset time range. Claim 4 A distance forgery attack detection device according to claim 1, wherein the second attack verification unit detects a distance forgery attack by performing residual energy detection based on energy monitoring for the period immediately after the reception window of the signal is terminated, and confirming whether the energy of the period immediately after termination is greater than or equal to a threshold. Claim 5 A distance forgery attack detection system comprising a transmitting device and a receiving device, wherein the transmitting device and the receiving device transmit and receive shared information regarding a master key or a session key, and the transmitting device and the receiving device generate a random variable for each ranging session based on the shared information to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length, the transmitting device generates a variable-length STS frame according to the random STS length to the receiving device, delays the generated variable-length STS frame by the random delay value, and transmits a signal, and the receiving device receives the signal from the transmitting device and calculates a correlation between the signal and a local template adjusted based on the random delay value to check whether a peak is formed based on the arrival time, and the receiving device detects a distance forgery attack by performing time verification on the time when the peak occurs or by monitoring energy in the interval immediately after the reception window of the signal ends. Claim 6 In paragraph 5, the transmitting device and the receiving device have a minimum response time (T min ) and maximum response time (T max A distance forgery attack detection system characterized by generating a random value between ) using the random variable to determine the random delay value, and generating a random length within a preset STS length range using the random variable to determine the random STS length. Claim 7 A distance forgery attack detection system according to claim 5, wherein the receiving device detects a distance forgery attack by performing a time verification that verifies whether the time at which the peak occurs is located within a preset time range by inversely calculating the random delay value at the time at which the peak occurs, or by performing residual energy detection that verifies whether the energy of the section immediately after the signal reception window ends is greater than or equal to a threshold value based on energy monitoring of the section immediately after the end. Claim 8 A method of operation of a distance forgery attack detection device, characterized by comprising: a step of transmitting and receiving shared information regarding a master key or session key with a transmitting device in a synchronization processing unit; a step of generating a random variable for each ranging session based on the shared information in a random variable generation unit to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length; a step of receiving a signal from the transmitting device in a correlation verification unit and calculating a correlation between the signal and a local template adjusted based on the random delay value to check whether a time-of-arrival-based peak is formed; a step of detecting a distance forgery attack by performing a time verification on the time when the peak occurs in a first attack verification unit; and a step of detecting a distance forgery attack by monitoring energy in a section immediately after the reception window of the signal is terminated in a second attack verification unit. Claim 9 In claim 8, the step of generating a random variable for each positioning session based on the shared information to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length comprises a minimum response time (T min ) and maximum response time (T max A method of operation of a distance forgery attack detection device characterized by including the step of generating a random value between ) as a random variable to determine the random delay value, and generating a random length within a preset STS length range as a random variable to determine the random STS length. Claim 10 A method of operation of a distance forgery attack detection device according to claim 8, wherein the step of detecting a distance forgery attack by performing a time verification with respect to the time at which the peak occurs includes the step of detecting a distance forgery attack by performing a time verification that verifies whether the time at which the peak occurs is located within a preset time range by inversely calculating the random delay value at the time at which the peak occurs. Claim 11 A method of operation of a distance forgery attack detection device according to claim 8, wherein the step of detecting a distance forgery attack by monitoring energy in a section immediately after the reception window of the signal is terminated includes the step of detecting a distance forgery attack by performing residual energy detection based on energy monitoring for the section immediately after the reception window of the signal is terminated, thereby confirming whether the energy in the section immediately after the termination is greater than or equal to a threshold. Claim 12 A method of operation of a distance forgery attack detection system, characterized by comprising: a step of transmitting and receiving shared information regarding a master key or a session key at each of a transmitting device and a receiving device; a step of generating a random variable for each ranging session based on the shared information at each of the transmitting device and the receiving device to determine a random delay value and a random Scrambled Timestamp Sequence (STS) length; a step of transmitting a signal at the transmitting device by generating a variable-length STS frame according to the random STS length and delaying the generated variable-length STS frame by the random delay value; a step at the receiving device of receiving the signal from the transmitting device and calculating a correlation between the signal and a local template adjusted based on the random delay value to determine whether a time-of-arrival-based peak is formed; and a step at the receiving device of detecting a distance forgery attack by performing a time verification on the time when the peak occurs or detecting a distance forgery attack by monitoring energy in the interval immediately after the reception window of the signal ends. Claim 13 A method of operation of a distance forgery attack detection system according to claim 12, wherein the step of detecting a distance forgery attack by performing time verification on the point in time when the peak occurs or by monitoring energy in the interval immediately after the signal reception window ends comprises: a step of detecting a distance forgery attack by performing time verification to verify whether the point in time when the peak occurs is located within a preset time range by inversely calculating the random delay value at the point in time when the peak occurs; and a step of detecting a distance forgery attack by performing residual energy detection to confirm whether the energy in the interval immediately after the end is greater than or equal to a threshold value based on energy monitoring for the interval immediately after the signal reception window ends.

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