Distributed User Plane Key Generation for eNodeB Load Reduction

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Solution Overview

Problem

The existing key generation method for user plane data transmission between user equipment and secondary eNodeB in 4G communications systems causes a heavy load on the master eNodeB and has low security, as all user plane keys for a user equipment and secondary eNodeB are the same, making them vulnerable to cracking.

Innovation Solution

User plane keys are generated separately by the user equipment and secondary eNodeB, using unique key parameters such as DRB IDs, random numbers, or counter values, reducing the load on the master eNodeB and enhancing security by creating distinct keys for different data radio bearers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If user plane keys are generated by the master eNodeB and sent to user equipment and secondary eNodeB, then key distribution is simplified, but the load on the master eNodeB becomes extremely heavy

Engineering Contradiction:
Improvekey distribution complexityVSAvoidmaster eNodeB processing capacity
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the key generation process by introducing intermediate key parameters (first key parameter, second key parameter) that are generated locally by user equipment and secondary eNodeB respectively. This divides the centralized key generation task into distributed local operations, reducing the master eNodeB's processing burden while maintaining security through hierarchical key derivation.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If only one user plane key is generated for same user equipment and secondary eNodeB, then key management is simplified, but security is low because all keys are the same and vulnerable to cracking

Engineering Contradiction:
Improvekey management complexityVSAvoiduser plane key security
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the single user plane key into multiple distinct keys (first user plane key, second user plane key, third user plane key) derived from different key parameters. Each key protects different data radio bearers, so compromising one key does not expose other communications. This maintains manageable complexity through systematic key derivation while dramatically improving security through key diversification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different key parameters are assigned to different data radio bearers based on their specific security requirements and traffic characteristics. Each bearer receives a key tailored to its local security needs, with more sensitive bearers potentially receiving stronger key protection, rather than applying a uniform key to all bearers.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3768039B1Key generation method, master enodeb, secondary enodeb and user equipment
Publication Date: 2024.02.28 HUAWEI TECH CO LTD
  • EP3768039B1 patent drawingFigure 1
  • EP3768039B1 patent drawingFigure 2
  • EP3768039B1 patent drawingFigure 3

AI summary

The present invention relates to a key generation method, a master eNodeB, a secondary eNodeB, and user equipment. The key generation method includes: determining a key parameter corresponding to a data radio bearer DRB; sending the key parameter to user equipment corresponding to the DRB, so that the user equipment generates a user plane key according to the key parameter and a basic key generated by the user equipment; receiving a basic key generated by a master eNodeB and sent by the master eNodeB; and generating the user plane key according to the key parameter and the basic key generated by the master eNodeB.