Vehicle Keyless Entry Relay Attack Prevention via Signal Strength History
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Keyless entry systems are vulnerable to relay attacks where a malicious third party uses a relay device to perform unauthorized wireless communication between a portable device and a vehicle-mounted device, allowing fraudulent operation of a vehicle.
Innovation Solution
The system employs multiple transmission antennas and a reception antenna to transmit request signals with varying strength levels, and the vehicle-mounted device determines the legitimacy of the signal based on reception strength fluctuations, correlating with the position of the portable device, using history information to authenticate and authorize operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless communication is performed between portable device and vehicle-mounted device for keyless entry, then ease of operation is improved, but vulnerability to relay attacks increases
Solution Approach 1:
The patent replaces traditional physical key authentication with wireless communication-based authentication. The vehicle-mounted device transmits request signals and the portable device responds with authentication information, eliminating the need for physical key insertion while maintaining security through signal-based verification.
Solution Approach 2:
The patent introduces determination signals as an intermediary mechanism to verify the legitimacy of wireless communication. These signals are transmitted at different strength levels corresponding to different zones, and the portable device's response to these determination signals helps authenticate whether the communication is direct or relayed, thus preventing relay attacks.
2Ease of operation
If relay device is used to extend communication range, then ease of operation is improved, but security against fraudulent operation deteriorates
Solution Approach 1:
The patent applies different signal strength levels (local quality variations) to different spatial zones around the vehicle. Determination signals transmitted at different strength levels correspond to different zones, allowing the system to identify whether a portable device is in a legitimate position or being relayed through a malicious third party's device, thus preventing fraudulent operation.
3Device complexity
If authentication based on ID alone is used, then device complexity is reduced, but measurement precision of device position deteriorates
Solution Approach 1:
The patent segments the authentication process into multiple stages: initial ID-based authentication followed by determination signal response verification. The portable device must respond to determination signals transmitted at different strength levels, providing additional verification of its actual position. This segmented approach maintains relatively simple device complexity while significantly improving position determination precision and security.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A vehicle (2) is prevented from being operated by a fraudulent action. A vehicle-mounted device (100) includes a control unit (110) that generates a request signal, a transmission unit (104) that sequentially transmits a request signal generated by the control unit (110) from a plurality of respective transmission antennas (102), (202), a reception unit (108) that receives a response signal to the request signal, and a storage unit (112) that stores a history of information included in a response signal received by the reception unit, and, in a case where the response signal is newly received by the reception unit (108), the control unit (110) determines whether or not a vehicle (2) is caused to perform a predetermined operation on the basis of the information included in the response signal and the history of the information included in the response signal stored in the storage unit (112).