A defense method against cross-technology signal simulation attacks

Abstract

The present invention belongs to the field of information science and technology, and is specifically a defense method for dealing with cross-technology signal simulation attacks, comprising the following specific steps: when a ZigBee device sends a signal, an auxiliary WiFi transmitter is selected as an anchor point, and the anchor point initially sends a signal with a mean of 0 and a variance of σ 2 AWGN noise; the ZigBee signal monitored by a WiFi attacker contains noise, and the resulting signal is z′(n,s); to carry out the attack, the WiFi attacker simulates the monitored ZigBee signal. Because of the noise, the calculated FFT points will be distorted. The present invention only needs to use an anchor point to transmit the ZigBee signal and noise at the same time, causing the signal simulated by the WiFi attacker to be significantly distorted. Ultimately, the simulated signal cannot pass the DSSS demodulation process of the ZigBee device, thereby achieving the purpose of defending against simulated attacks. Based on this, the present invention requires less cost and effort, while still being able to effectively defend against attacks and improve the security of the Internet of Things.

Description

Technical Field

[0001] The present invention relates to the field of information science and technology, and in particular to a defense method for coping with cross-technology signal simulation attacks. Background Art

[0002] There is a new physical layer attack, namely the cross-technology signal simulation attack, in which WiFi devices dynamically eavesdrop on the data packets of ZigBee devices at a long distance and further manipulate the ZigBee devices by simulating ZigBee signals. This will bring serious security issues to heterogeneous IoT devices. Based on this, there is an existing defense strategy that wants to distinguish in real time whether the received signal is from the WiFi attacker or the ZigBee transmitter by learning the behavior of the WiFi attacker and the ZigBee transmitter. However, the implementation of this solution requires a large amount of data, and the recognition accuracy is not high. Therefore, a defense method for dealing with cross-technology signal simulation attacks is invented. By using anchor points, when the ZigBee device sends a signal, it sends a signal with a mean of 0 and a variance of σ at the same time. 2 The noise n z (AWGN noise). Gaussian noise in the eavesdropped signal from a WiFi attacker will propagate into the signal simulation process, changing the eavesdropped signal. The noise sent by the anchor point will induce the WiFi attacker to quantize the FFT points into different QAM points. The new QAM points are farther away from the FFT points of the ZigBee signal without noise added, resulting in greater distortion in the simulated signal. Ultimately, the simulated signal cannot pass the DSSS demodulation process of the ZigBee device, thereby achieving the purpose of defending against simulation attacks. Summary of the Invention

[0003] In view of the above problems and / or the problems existing in an existing defense method for coping with a cross-technology signal simulation attack, the present invention is proposed.

[0004] Therefore, the purpose of the present invention is to provide a defense method for dealing with cross-technology signal simulation attacks, which can solve the above-mentioned existing problems.

[0005] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0006] A defense method for countering cross-technology signal simulation attacks includes the following specific steps:

[0007] Step 1: When the ZigBee device is sending a signal, an auxiliary WiFi transmitter is selected as the anchor point. The anchor point will initially send a mean of 0 and a variance of σ 2 AWGN noise;

[0008] Step 2: The ZigBee signal monitored by the WiFi attacker is noisy, and the signal obtained is z′(n, s), where n represents the nth data in the sample and s represents the sth sample;

[0009] Step 3: To carry out the attack, the WiFi attacker simulates the monitored ZigBee signal. Because it contains noise, the calculated FFT points will be distorted, and the calculation result will become Z′(k,s), where k represents the kth subcarrier.

[0010] Step 4: The WiFi attacker quantizes the FFT points into QAM points to produce greater distortion. The QAM point associated with the FFT point Z′(k, s) is expressed as Q′(k, s). The square error e′(k, s) between the quantized QAM point and the FFT point of the original signal is calculated and compared to observe the defense effect.

[0011] Step 5: The ZigBee receiver decodes the received signal and sends an acknowledgment frame to the ZigBee transmitter. If the ZigBee transmitter fails to receive the acknowledgment frame after sending the ZigBee signal, it indicates that noise is interfering with the ZigBee signal reception, so the anchor point is required to reduce its noise power.

[0012] Step 6: When the ZigBee transmitter receives an acknowledgment frame with an incorrect sequence number, it knows that the ZigBee receiver is under attack and allows the anchor point to increase its noise power. The congested router then feeds back congestion information to the upstream router.

[0013] Step 7: The process of step 6 is continued until a feasible noise power is found, ultimately achieving the goal of defending against simulated attacks.

[0014] As a preferred solution of the defense method for dealing with cross-technology signal simulation attacks described in the present invention, the calculation formula of the FFT point is as follows:

[0015]

[0016] As a preferred solution of the defense method against cross-technology signal simulation attacks described in the present invention, the calculation formula of the noisy ZigBee signal z′(n,s) eavesdropped by the WiFi attacker in step 2 is as follows:

[0017] z′(n,s)=z(n,s)+n z (n, s)

[0018] Where z(n,s) represents the nth data in the sth sample, n z (n,s) is the noise data sent by the anchor point.

[0019] As a preferred solution of the defense method against cross-technology signal simulation attacks described in the present invention, the FFT point calculation formula obtained by the WiFi attacker in step 3 by calculating the noisy ZigBee signal is as follows:

[0020] Z′(k,s)=Z(k,s)+N Z (k, s)

[0021] The calculation formula of Z(k, s) is as follows:

[0022]

[0023] The FFT point Z(k, s) represents the component on subcarrier k in the sth original sample in the frequency domain, K=64, N Z (k, s) is the FFT point of AWGN in the frequency domain.

[0024] As a preferred solution of the defense method against cross-technology signal simulation attacks described in the present invention, the calculation formula for the square error e′(k, s) between the QAM point and the FFT point of the original signal after the WiFi attacker is quantized in step 4 is as follows:

[0025] e′(k,s)=(Z Re (k, s)-αQ′ Re (m)) 2 +(Z Im (k,s)-αQ′ Im (m)) 2

[0026] If AWGN noise is not emitted, the square error e(k,s) of the FFT point Z(k,s) is calculated as follows:

[0027] e(k,s)=(Z Re (k,s)-αQ Re (m)) 2 +(Z Im (k,s)-αQ Im (m)) 2

[0028] Where α is a scalar introduced by the WiFi attacker to minimize the quantization error, and its calculation formula is as follows:

[0029]

[0030] where Z Re (k,s) and Z Im (k, s) represents the real and imaginary parts of the FFT point Z(k, s), and SS and SE represent the starting and ending positions of the selected FFT point, respectively.

[0031] Compared with existing technologies:

[0032] The present invention only needs to use an anchor point to send a signal and noise in ZigBee at the same time, so that the signal simulated by the WiFi attacker is greatly distorted. Ultimately, the simulated signal cannot pass the DSSS demodulation process of the ZigBee device, thereby achieving the purpose of defending against simulated attacks. Based on this, the present invention requires less cost and effort, and can still achieve the effect of defending against attacks, thereby improving the security of the Internet of Things. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0035] The present invention provides a defense method for dealing with cross-technology signal simulation attacks. Figure 1 , including the following specific steps: When the ZigBee device is sending a signal, an auxiliary WiFi transmitter is selected as the anchor point, and the anchor point initially sends a mean of 0 and a variance of σ 2 The attacker then simulates the ZigBee signal to implement the attack. The calculated FFT points are distorted, resulting in Z′(k,s). The attacker then quantizes the FFT points to QAM points, generating even greater distortion. The QAM points associated with the FFT point Z′(k,s) are denoted as Q′(k,s). The squared error e′(k,s) between the quantized QAM points and the FFT points of the original signal is calculated. The squared error e(k,s) between the QAM points and the FFT points of the original signal without noise is then calculated. The defense effectiveness is then compared. The ZigBee receiver then decodes the received signal and sends an acknowledgment frame to the ZigBee transmitter. If the ZigBee transmitter fails to receive the acknowledgment frame after sending the ZigBee signal, it indicates that noise is interfering with ZigBee signal reception. Therefore, the anchor point is required to reduce its noise power. If the ZigBee transmitter receives an acknowledgment frame with an incorrect sequence number, it knows that the ZigBee receiver is under attack and allows the anchor point to increase its noise power. The above process continues until a feasible noise power is found, ultimately achieving the goal of defending against simulated attacks.

[0036] in:

[0037] The calculation formula of FFT points is as follows:

[0038]

[0039] The formula for calculating the noisy ZigBee signal z′(n,s) that a WiFi attacker can eavesdrop on is as follows:

[0040] z′(n,s)=z(n,s)+n z (n,s)

[0041] Where z(n,s) represents the nth data in the sth sample, n z (n,s) is the noise data sent by the anchor point.

[0042] The FFT point calculation formula obtained by the WiFi attacker to calculate the noisy ZigBee signal is as follows:

[0043] Z′(k,s)=Z(k,s)+N Z (k,s)

[0044] The calculation formula of Z(k, s) is as follows:

[0045]

[0046] The FFT point Z(k,s) represents the component on subcarrier k in the sth original sample in the frequency domain, K = 64, N Z (k,s) is the FFT point of AWGN in the frequency domain.

[0047] After the WiFi attacker quantizes, the square error e′(k,s) between the QAM point and the FFT point of the original signal is calculated as follows:

[0048] e′(k,s)=(Z Re (k, s)-αQ′ Re (m)) 2 +(Z Im (k,s)-αQ′ Im (m)) 2

[0049] If AWGN noise is not emitted, the square error e(k,s) of the FFT point Z(k,s) is calculated as follows:

[0050] e(k,s)=(Z Re (k, s)-αQ Re (m)) 2 +(Z Im (k, s)-αQ Im (m)) 2

[0051] Where α is a scalar introduced by the WiFi attacker to minimize the quantization error, and its calculation formula is as follows:

[0052]

[0053] where Z Re (k,s) and Z Im (k, s) represents the real and imaginary parts of the FFT point Z(k, s), and SS and SE represent the starting and ending positions of the selected FFT point, respectively.

[0054] Although the present invention has been described above with reference to embodiments, various modifications may be made thereto and equivalent components may be substituted without departing from the scope of the present invention. In particular, as long as there are no structural conflicts, the various features of the embodiments disclosed herein may be combined with each other in any manner, and the omission of an exhaustive description of such combinations in this specification is solely for the sake of space and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A defense method for dealing with cross-technology signal simulation attacks, characterized in that: The specific steps are as follows: Step 1: When the ZigBee device is sending a signal, an auxiliary WiFi transmitter is selected as the anchor point. The anchor point will initially send a mean of 0 and a variance of σ 2 AWGN noise; Step 2: The ZigBee signal monitored by the WiFi attacker is noisy, and the signal obtained is z′(n, s); n represents the nth data in the sample, and s represents the sth sample; Step 3: To carry out the attack, the WiFi attacker simulates the monitored ZigBee signal. Because of the noise, the calculated FFT points will be distorted, and the calculation result will become Z′(k, s), where k represents the kth subcarrier. Step 4: The WiFi attacker quantizes the FFT points into QAM points to produce greater distortion. The QAM point associated with the FFT point Z′(k, s) is expressed as Q′(k, s). The square error e′(k, s) between the quantized QAM point and the FFT point of the original signal is calculated and compared to observe the defense effect. Step 5: The ZigBee receiver decodes the received signal and sends an acknowledgment frame to the ZigBee transmitter. If the ZigBee transmitter fails to receive the acknowledgment frame after sending the ZigBee signal, it indicates that noise is interfering with the ZigBee signal reception, so the anchor point is required to reduce its noise power. Step 6: When the ZigBee transmitter receives an acknowledgment frame with an incorrect sequence number, it knows that the ZigBee receiver is under attack and allows the anchor point to increase its noise power. The congested router then feeds back congestion information to the upstream router. Step 7: The process of step 6 is continued until a feasible noise power is found, ultimately achieving the goal of defending against simulated attacks.

2. A defense method for dealing with cross-technology signal simulation attacks according to claim 1, characterized in that: The calculation formula of the FFT point is as follows:

3. A defense method for dealing with cross-technology signal simulation attacks according to claim 1, characterized in that: The calculation formula for the noisy ZigBee signal z′(n, s) eavesdropped by the WiFi attacker in step 2 is as follows: z′(n,s)=z(n,s)+n z (n,s) Where z(n,s) represents the nth data in the sth sample, n z (n,s) is the noise data sent by the anchor point.

4. A defense method for dealing with cross-technology signal simulation attacks according to claim 1, characterized in that: In step 3, the WiFi attacker calculates the FFT point formula of the noisy ZigBee signal as follows: Z′(k,s)=Z(k,s)+N Z (k,s) The calculation formula of Z(k, s) is as follows: The FFT point Z(k, s) represents the component on subcarrier k in the sth original sample in the frequency domain, K=64, N Z (k, s) is the FFT point of AWGN in the frequency domain.

5. The method for defending against cross-technology signal simulation attacks according to claim 1, characterized in that: The calculation formula for the square error e′(k, s) between the QAM point quantized by the WiFi attacker and the FFT point of the original signal in step 4 is as follows: e′(k,s)=(Z Re (k,s)-αQ′ Re (m)) 2 +(Z Im (k,s)-αQ′ Im (m)) 2 If AWGN noise is not emitted, the square error e(k, s) of the FFT point Z(k, s) is calculated as follows: e(k,s)=(Z Re (k,s)-αQ Re (m)) 2 +(Z Im (k,s)-αQ Im (m)) 2 Where α is a scalar introduced by the WiFi attacker to minimize the quantization error, and its calculation formula is as follows: where Z Re (k, s) and Z Im (k, s) represent the real and imaginary parts of the FFT point Z(k, s), SS and SE represent the starting and ending positions of the selected FFT point, respectively.

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