Dynamic Broadcast Code for Vehicle Wireless Security

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Solution Overview

Problem

Existing methods for establishing a wireless communication channel between a vehicle and a vehicle accessory, such as a trailer, are vulnerable to replay attacks, which can compromise security and lead to unauthorized connections.

Innovation Solution

The method involves configuring a plurality of global broadcast parameters using an out-of-band communication channel and using these parameters to form a unique broadcast identifier code for a network advertising broadcast. This code is dynamic and valid only for a specific broadcast event, making it resistant to replay attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a unique code is broadcast for wireless connection establishment, then connection convenience is improved, but security deteriorates due to vulnerability to replay attacks

Engineering Contradiction:
Improveconnection convenienceVSAvoidsecurity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making the broadcast code time-dependent and changing. Instead of using a static unique code that can be replayed, the system generates codes that are valid only for specific time windows or broadcast events. This dynamic approach ensures that even if a code is intercepted, it cannot be reused for replay attacks, thus maintaining security while preserving connection convenience.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of the broadcast code from static to dynamic by incorporating time-based or event-based variables. The code is generated using parameters such as current time, broadcast sequence number, or other changing system states. This parameter transformation ensures code uniqueness for each broadcast event, preventing replay attacks while maintaining ease of connection establishment.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If clock synchronization is implemented across the system, then replay attack prevention is improved, but system complexity increases

Engineering Contradiction:
Improvereplay attack preventionVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses an intermediary approach by introducing a trusted authority or pre-shared secret that both the broadcaster and receiver use to generate and verify codes independently. This eliminates the need for clock synchronization between devices, as each party can locally generate the expected code using the intermediary reference. This reduces system complexity while maintaining replay attack prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system enables self-service by allowing each device to independently generate and verify broadcast codes using pre-configured parameters and local computation. Devices do not need to synchronize clocks or exchange timing information; instead, they autonomously validate codes based on their own internal state and pre-shared secrets, simplifying the overall system architecture.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4283927B1Wireless communications for vehicles
Publication Date: 2025.02.12 VOLVO TRUCK CORP
  • EP4283927B1 patent drawingFigure 1~2
  • EP4283927B1 patent drawingFigure 3
  • EP4283927B1 patent drawingFigure 4

AI summary

The disclosed technology includes methods, systems and related aspects for establishing a wireless communication channel between a broadcaster, for example, a vehicle (100) or vehicle accessory (102), which transmits data advertising its network is available and an observer, for example, another vehicle (100) or vehicle accessory (102), which detects and seeks to form a connection with the broadcaster as a result. The method comprises configuring a plurality of global broadcast parameters using an out-of-band communication channel and using at least one of the plurality of global broadcast parameters to form a broadcast unique identifier code for a network advertising broadcast. The global broadcast parameters include at least one synchronization value and one or more global parameters based on the capabilities of both the broadcaster and the observer comprising: a minimum network advertising broadcast interval between sequential network advertising broadcasts, a minimum network advertising broadcast synchronization, MinNABS offset comprising a minimum interval between transmission of a synchronization value and the network advertising broadcast, and a maximum network advertising broadcast synchronization, MaxNABS, offset comprising a maximum validity time-period for a synchronization value. In this way, replay attacks which spoof the broadcaster may be prevented. In this way, vehicles (100) and vehicle accessories (102), such as trailers and body building equipment, may be more robust against spoof relay attacks.