Vehicle Control System Phase Difference Relay Attack Detection
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Solution Overview
Problem
Existing vehicle remote control systems, such as PEPS, are vulnerable to 'relay' attacks where attackers can unlock vehicles from a distance by intercepting and retransmitting authentication signals, bypassing the owner's proximity.
Innovation Solution
A control system that transposes received signals to predetermined frequencies, determines phase differences between these signals, and only activates vehicle functions if the phase difference is within a predetermined threshold, indicating the signal is not being relayed over a significant distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If relay attack devices are used to extend communication distance, then the vehicle can be unlocked from a greater distance, but the security of the authentication system is compromised
Solution Approach 1:
The system transmits authentication signals at two different frequencies and compares the phase difference between the received signals. By changing the frequency parameter and measuring its effect on phase, the system can detect relay attacks while maintaining legitimate remote authentication.
Solution Approach 2:
The system measures the phase difference of signals received at different frequencies and uses this feedback to determine whether to authorize vehicle access. The phase difference measurement provides critical feedback about signal transmission distance and potential relay attack conditions.
2Measurement precision
If phase measurement is performed using a dedicated circuit, then phase measurement accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent uses the existing digital signal processing circuit to perform multiple functions: it processes the authentication signal and simultaneously measures the phase by analyzing zero-crossing points. This eliminates the need for a dedicated phase measurement circuit while maintaining measurement capability.
Solution Approach 2:
The phase measurement function is merged with the existing digital signal processing operations. The same circuit that processes authentication data also determines phase information by detecting zero-crossing points, combining multiple functions into a single processing path.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents unauthorized access by ensuring that vehicle functions are only activated when the signal is received from a close proximity, thereby enhancing security against relay attacks.
Implementation Method 1
a receiver circuit designed to transpose a received signal (of variable frequency) to a predetermined frequency
Implementation Method 2
an analog-to-digital converter designed to convert the transposed signal into a digital signal
Implementation Method 3
a processing circuit designed to receive said digital signal and to determine, on the basis of said digital signal, a phase of the received signal
Data Source
Figure 1~3
AI summary
The invention relates to a system (12) for controlling a function of a vehicle, comprising: - a receiving circuit (20) designed for transposing a received signal to a predetermined frequency; - an analogue to digital converter (28) designed for converting the transposed signal into a digital signal; - a processing circuit (16) designed for receiving said digital signal and for determining, on the basis of said digital signal, a phase of the received signal; - a processor (14) designed for obtaining, as a first phase value (Φ1), the phase determined by the processing circuit (16) when the received signal has a first frequency and, as a second phase value (Φ2), the phase determined by the processing circuit (16) when the received signal has a second frequency different from the first frequency, and for controlling said function only if a value dependent on the difference between the first phase value (Φ1) and the second phase value (Φ2) is less than a predetermined threshold. Also disclosed are an assembly comprising an identifier and such a control system, as well as a control method.