Electronic Key Apparatus Relay Attack Prevention via Sensor Detection

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Solution Overview

Problem

Smart entry systems are vulnerable to relay attacks, where unauthorized third parties intercept and manipulate radio signals between an electronic key apparatus and a vehicle, allowing unauthorized access and engine starting even when the user is at a distance.

Innovation Solution

The electronic key apparatus incorporates a GNSS receiver and an acceleration sensor to detect user movement and location, triggering a transmission stop mode that halts the radio signal for unlocking or starting the vehicle, thereby preventing relay attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the electronic key apparatus continuously transmits radio signals for unlocking the vehicle, then the ease of operation is improved, but the vulnerability to relay attacks increases

Engineering Contradiction:

Improveease of vehicle unlockingVSAvoidrelay attack vulnerability

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The electronic key apparatus performs preliminary detection of the user's movement state using acceleration sensors and GNSS receivers before transmitting radio signals. By detecting whether the user is moving or stationary in advance, the system decides whether to enable transmission, thus preventing relay attacks before they can occur while maintaining convenient operation when legitimate use is detected

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the user's movement state through acceleration sensors and GNSS receivers, providing real-time feedback on whether the user is moving or stationary. This feedback loop allows the transmission control to dynamically adjust based on current conditions, stopping transmission when movement is detected (indicating potential relay attack) and resuming when stationary (indicating legitimate use)

Inventive Principle:

Principle #23Feedback

2Object-affected harmful factors

If the electronic key apparatus stops transmission in stationary state, then relay attack vulnerability is reduced, but the ease of operation deteriorates

Engineering Contradiction:

Improverelay attack suppressionVSAvoidvehicle unlocking convenience

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The transmission control system dynamically adjusts its state based on real-time detection of user movement. Rather than being statically enabled or disabled, the transmission function transitions between states based on acceleration sensor and GNSS data, enabling transmission when the user is stationary (convenient for legitimate use) and disabling it when movement is detected (security against relay attacks)

Inventive Principle:

Principle #15Dynamics

3Reliability

If sensor devices are added to detect user movement, then relay attack detection is improved, but the device complexity increases

Engineering Contradiction:

Improverelay attack detection accuracyVSAvoidsensor device integration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The acceleration sensor and GNSS receiver are integrated into the electronic key apparatus with multi-functional capabilities. These sensors not only detect relay attacks by monitoring user movement but also enable other functions such as step counting, location tracking, and motion-activated operations, thereby justifying their inclusion through multiple benefits beyond just security

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The electronic key apparatus uses its own built-in acceleration sensor and GNSS receiver to autonomously detect user movement and determine transmission control decisions. The system serves itself by using its own sensor data without requiring external detection devices, thereby improving reliability while minimizing additional complexity

Inventive Principle:

Principle #25Self-service

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

This solution effectively suppresses relay attacks by ensuring the radio signal for unlocking or starting the vehicle is only transmitted when the user is in close proximity, significantly enhancing security against unauthorized vehicle operation.

Implementation Method 1

a sensor device including at least one of a GNSS (Global Navigation Satellite System) receiver

Methodology Applied

Scientific EffectGNSS satellite signal reception:

Implementation Method 2

a sensor device including at least one of a GNSS (Global Navigation Satellite System) receiver and an acceleration sensor

Methodology Applied

Scientific EffectAcceleration sensing: Accelerometer

Data Source

PatentUS10857978B2Electronic key apparatus, control method, and program

Publication Date: 2020.12.08 KYOCERA CORP

AI summary

An electronic key apparatus 100 used by a user of a vehicle in a smart entry system comprises a transceiver 110 configured to perform a radio communication with the vehicle, a sensor device including at least one of a GNSS receiver 161 and an acceleration sensor 162, and a controller 130 configured to control whether to set a transmission stop mode based on an output of the sensor device 160, the transmission stop mode being for causing the transceiver 110 to stop transmission of a radio signal used for unlocking the vehicle or starting a power source of the vehicle.