UE Security Key Acquisition via Network-Assisted Derivation

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Solution Overview

Problem

Some user equipment (UEs) cannot derive security keys directly, leading to insecure data transmission with network side devices, compromising the reliability of communication.

Innovation Solution

A method for obtaining a key is provided, where first UE assists second UE in deriving a security key by reporting or negotiating the key with the network side device, ensuring encryption and integrity protection without direct transmission over the air interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If security keys are not transmitted over the air interface, then security of data transmission is improved, but some UEs cannot obtain or derive security keys, resulting in low reliability of data transmission

Engineering Contradiction:

Improvedata transmission securityVSAvoidkey derivation capability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces a network side device as an intermediary that assists UEs in obtaining security keys. The network side device receives key information from a first UE and uses it to generate or derive security keys for the second UE, thereby mediating the key acquisition process for UEs that cannot derive keys independently.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary key preparation by having the network side device pre-generate or pre-derive security keys using information from the first UE before the second UE needs them. This preliminary action ensures that keys are ready when needed, solving the problem of UEs unable to derive keys at the moment of need.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If some UEs lack direct key derivation capabilities, then device complexity is reduced, but data transmission reliability deteriorates due to inability to establish security

Engineering Contradiction:

ImproveUE key derivation capabilityVSAvoiddata transmission security

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The network side device serves as a mediator that compensates for the limited key derivation capabilities of certain UEs. By receiving key information from capable UEs and generating keys for incapable UEs, the network side device enables security establishment without requiring all UEs to have complex key derivation functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The network side device performs multiple functions: it acts as both an authentication entity and a key generation/derivation assistant for UEs with limited capabilities. This multi-functionality allows the system to support both capable and incapable UEs through a unified architecture.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP4145878B1Method and apparatus for obtaining key, user equipment, and network side device

Publication Date: 2026.01.28 VIVO MOBILE COMM CO LTD

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AI summary

Disclosed in the present application are a method and an apparatus for obtaining a key, user equipment, and a network side device. The method includes: sending, by a first UE, first key information to a network side device, where the first key information is used for indicating a first key of a second UE, and the first key is used for performing encryption and/or integrity protection on data in communication between the second UE and the network side device.