Multi-AP WLAN Key Sharing for Faster STA Movement

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Solution Overview

Problem

There is a need for a method and device to share a security key based on a multi-AP operation in a WLAN system, and to enhance the speed and efficiency of station (STA) movement between multiple access points in such systems.

Innovation Solution

A method involving the generation and encryption of a multi-access point group temporal key (MAGTK) by a first STA, which is then shared with other STAs, enabling encryption and sharing of a security key among them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a STA moves between multiple APs in a multi-AP system, then the STA can access different network areas, but the security key management becomes complex and time-consuming

Engineering Contradiction:

ImproveSTA movement capabilityVSAvoidSecurity key management time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent pre-distributes the master key (PMK) to all APs in the multi-AP set before the STA moves. When the STA roams between APs, the security key can be quickly derived using the pre-shared PMK and the target AP's identifier, eliminating the need for time-consuming re-authentication and key generation processes during movement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a master key (PMK) as an intermediary that is shared among all APs in the multi-AP set. This PMK serves as a common foundation that enables rapid derivation of session keys during STA movement, acting as a mediator that simplifies the key management process across multiple APs without requiring direct STA-AP authentication for each transition.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If traditional security key management is used in multi-AP systems, then each AP operates independently, but the overall system security efficiency decreases

Engineering Contradiction:

ImproveAP operation independenceVSAvoidSecurity key management efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent merges the security key management of multiple independent APs by introducing a common master key (PMK) that is shared across all APs in the multi-AP set. This allows the APs to maintain operational independence while collectively benefiting from a unified key management approach that derives session keys from the shared PMK combined with AP-specific identifiers, thereby improving overall system efficiency.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP4642067A1Method and device for sharing security key on basis of multi-access point operation in wireless LAN system

Publication Date: 2025.10.29 LG ELECTRONICS INC

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AI summary

A method and a device for sharing a security key on the basis of a multi-access point (AP) operation in a wireless LAN system are disclosed. The method performed by means of a first station (STA) in a wireless LAN system, according to one embodiment of the present disclosure, may comprise steps in which: the first STA generates a multi-access point group temporal key (MAGTK); and the MAGTK encrypted on the basis of a key shared between the first STA and one or more second STAs is transmitted to the one or more second STAs. The security key for a third STA is encrypted on the basis of the MAGTK, and can be shared with the first STA and the one or more second STAs.