Wireless Signal Reciprocity Authentication Against Relay Attacks

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Solution Overview

Problem

Keyless entry systems for vehicles are vulnerable to relay attacks and other active attacks, compromising security and enabling unauthorized access.

Innovation Solution

An authentication method utilizing wireless signal feature information reciprocity to detect and prevent relay attacks, involving signal feature information sampling, encryption, and similarity threshold checks to ensure mutual authentication between devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If keyless entry systems use digital keys stored in personal devices with BLE technology for communication, then ease of usage is improved (physical key not needed, multiple users authorized), but security deteriorates (vulnerable to relay attacks and active attacks)

Engineering Contradiction:
Improveease of usageVSAvoidsecurity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary actions by measuring and recording RSSI traces during a calibration phase before actual authentication. These pre-collected RSSI profiles are stored and used later to verify the legitimacy of communication paths, preventing relay attacks by comparing current measurements against established baselines

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms by continuously monitoring RSSI values during authentication and comparing them against stored profiles. The authentication result is determined based on the correlation between measured and expected RSSI patterns, providing real-time verification that either confirms legitimate access or detects potential relay attacks

Inventive Principle:
Principle #23Feedback

2Reliability

If RSSI measurement is used to detect relay attacks by comparing signal traces, then security is improved (relay attack detection), but device complexity increases (requires sampling and comparison mechanisms)

Engineering Contradiction:
ImprovesecurityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses the existing BLE communication infrastructure and RSSI measurement capabilities that are already present in standard mobile devices and Bluetooth modules. By making these existing components multi-functional (using RSSI both for connection quality assessment and security verification), the patent avoids adding dedicated hardware while still achieving relay attack detection

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system creates copies of RSSI measurement patterns during a calibration phase and stores them as reference profiles. During authentication, it compares current RSSI measurements against these copied profiles to verify legitimacy. This copying approach allows verification without requiring additional sensors or complex hardware

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4245046B1Authentication method and device, and related products
Publication Date: 2025.11.12 YINWANG INTELLIGENT TECHNOLOGIES CO LTD
  • EP4245046B1 patent drawingFigure 1~2
  • EP4245046B1 patent drawingFigure 3
  • EP4245046B1 patent drawingFigure 4

AI summary

Provided are an authentication method and a device, and related products, the method includes: the first authentication device obtains first signal feature information by sampling a first wireless signal sent by a second authentication device, receives second signal feature information from the second authentication device, and determines whether the authentication is successful according to the first signal feature information and the second signal feature information, due to reciprocity property of the wireless channel, if the first signal feature information and the second signal feature information show high correlation, then the authentication is successful.