V2P Direct Link Key Switching for Secure V2X Release

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Solution Overview

Problem

Existing V2X communication systems lack effective methods for secure vehicle-to-pedestrian communication, particularly in managing key identifiers for direct links between wireless transmit/receive units.

Innovation Solution

Methods and apparatus for initiating wireless transmit/receive units to manage direct links with peer units using a first key identifier of a root key, involving the exchange of security information and determination of a second key identifier for secure communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct link release procedures are implemented in V2X communication systems, then communication security is improved, but system complexity increases due to key identifier management

Engineering Contradiction:
Improvecommunication securityVSAvoidkey identifier management
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the key management process by introducing distinct key identifiers (first key identifier and second key identifier) for different communication phases. The first key identifier is used during the direct link establishment phase, while the second key identifier is used after link release. This segmentation allows secure transition between communication states without requiring complete key reconfiguration, thereby improving security while managing complexity through structured key lifecycle management.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by pre-configuring the second key identifier before the direct link release occurs. The network entity provides the second key identifier to the wireless device in advance, stored securely in memory, so that when link release is triggered, the device can immediately switch to the second key identifier without computational delays. This preliminary preparation enhances security response time while simplifying the actual key transition process.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If key identifier switching is implemented for secure communication, then communication reliability is improved, but processing time increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidkey switching time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent stores the second key identifier in the wireless device's memory before the link release event occurs. The network entity provides this key in advance during a previous communication phase, allowing the device to have the alternative key readily available. When link release is triggered, the device performs a simple memory retrieval and switching operation rather than engaging in complex key generation or negotiation, significantly reducing the time loss while maintaining high reliability.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If direct link release with key management is implemented, then security against unauthorized access is improved, but device operation complexity increases

Engineering Contradiction:
Improvesecurity against unauthorized accessVSAvoiddevice operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements self-service by enabling the wireless device to autonomously manage the key identifier switching process. Upon receiving a link release indication (whether from the network or triggered internally), the device automatically retrieves the pre-stored second key identifier from its memory and switches to using it for subsequent communications. This self-service mechanism eliminates the need for manual key configuration or complex interaction with network entities during the key transition, thereby improving security while maintaining ease of operation.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4468659B1Methods, apparatus and systems using vehicle-to-everything (V2X) enhancements to support vehicle-to- pedestrian (V2P) communication
Publication Date: 2026.01.21 INTERDIGITAL PATENT HOLDINGS INC
  • EP4468659B1 patent drawingFigure 1A
  • EP4468659B1 patent drawingFigure 1B
  • EP4468659B1 patent drawingFigure 1C

AI summary

V2X Enhancements to support V2P communication are disclosed. In particular, Vehicle to Pedestrian Communications are provided. Methods and apparatus for operation by an initiating wireless transmit/receive unit (WTRU) for direct link with a peer WTRU using a first key identifier of a root key are provided. In one embodiment, a method includes sending, by the initiating WTRU to the peer WTRU, a release request message to release the direct link with the peer WTRU, the release request message including information indicating first security information associated with a second key identifier of the root key. The method further includes receiving, receiving, by the initiating WTRU from the peer WTRU, a response to the release request message including second security information associated with the second key identifier of the root key. The method also includes determining, by the initiating WTRU, the second key identifier of the root key using the first security information and the second security information; and sending, by the initiating WTRU to the peer WTRU, a message including information indicating the second key identifier of the root key.