Vehicle Wireless Authentication Security Against Relay Attacks

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Solution Overview

Problem

Existing wireless communication systems for vehicles are insufficient in preventing relay attacks, as they complicate signal processing and may deteriorate authentication accuracy, failing to reliably prevent unauthorized access.

Innovation Solution

A wireless communication system that includes an in-vehicle unit and a portable device capable of transmitting authentication codes, with a security mode that can be set to stop the transmission of access signals and authentication codes, using random number codes for verification, thereby enhancing security without complicating signal processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex signal processing methods are used to prevent relay attacks (e.g., multiple modulation schemes, frequency changes, strength variations), then security against relay attacks is improved, but device complexity and processing time increase

Engineering Contradiction:
Improvesecurity against relay attacksVSAvoidsignal processing configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter of authentication from complex signal processing to simple time-based verification. The in-vehicle unit measures the time until the authentication code is received after transmitting the access signal, and compares it with a predetermined threshold. This time parameter change simplifies the processing configuration while maintaining security against relay attacks.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary action by setting a predetermined time threshold in advance for authentication verification. The in-vehicle unit prepares the access signal with embedded timing information beforehand, and the authentication process simply compares the measured time against this pre-set threshold, avoiding complex real-time signal processing.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If complex signal processing methods are used to prevent relay attacks, then security against relay attacks is improved, but authentication processing time increases

Engineering Contradiction:
Improvesecurity against relay attacksVSAvoidauthentication processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the authentication parameter from complex signal analysis to simple time measurement. By measuring the time interval between transmitting the access signal and receiving the authentication code, the system achieves fast authentication without complex processing, thus reducing authentication processing time while maintaining security.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent skips complex signal processing steps and directly measures the time parameter for authentication. This rushing through the authentication process using a simple time comparison allows the system to quickly verify authenticity without getting bogged down in complex signal analysis, thereby reducing authentication processing time.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Reliability

If complex signal processing methods are used to prevent relay attacks, then security against relay attacks is improved, but authentication accuracy deteriorates

Engineering Contradiction:
Improvesecurity against relay attacksVSAvoidauthentication accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the authentication parameter to time measurement, which provides high precision and is difficult to manipulate. The time-based authentication accurately measures the interval between signal transmission and code reception, providing precise verification that is resistant to relay attack manipulation while maintaining high authentication accuracy.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3470275B1Wireless communication system
Publication Date: 2022.08.10 ASAHI DENSO KABUSHIKI KAISHA
  • EP3470275B1 patent drawingFigure 1
  • EP3470275B1 patent drawingFigure 2
  • EP3470275B1 patent drawingFigure 3

AI summary

A wireless communication system includes: an in-vehicle unit (1) mounted on a vehicle and capable of wirelessly transmitting an access signal when an operation unit (1a) is operated; a portable device (2) capable of wirelessly transmitting a vehicle-specific authentication code on a condition that the access signal is received; and a determination unit (4) capable of determining whether or not the authentication code is a regular authentication code on a condition that the authentication code is received. Start of a driving source of the vehicle (99) is permitted or running of the vehicle is enabled when the determination unit (4) determines that the authentication code is the regular authentication code, and a security mode in which a function of transmitting the access signal by the in-vehicle unit (1) or a function of transmitting the authentication code by the portable device (2) is stopped can be set by a predetermined setting operation.