RRC Connection Re-establishment Security Algorithm Handling

Solution Overview

Problem

In LTE systems, the inability to update the access layer security algorithm during RRC connection re-establishment leads to UE access failures, as each eNB maintains unique security algorithms, causing compatibility issues during handovers.

Innovation Solution

The method involves the eNB determining whether the original access layer security algorithm is supported and, if not, selecting a new algorithm with the highest priority supported by the UE, updating the security algorithm configuration in the RRC connection re-establishment message, and implementing communication protection using the new algorithm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If each eNB maintains unique security algorithms independently, then security flexibility and adaptability are improved, but compatibility during handover deteriorates, causing UE access failures

Engineering Contradiction:

Improvesecurity algorithm flexibilityVSAvoidhandover compatibility

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The eNB performs preliminary action by selecting and configuring a new security algorithm before the RRC connection re-establishment is completed. The eNB determines whether the original algorithm is supported, and if not, proactively selects a new algorithm from the UE's security capability list and configures it in the re-establishment message, ensuring compatibility before the handover finalizes.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by dynamically modifying the security algorithm parameter during the RRC connection re-establishment process. The eNB changes the security algorithm from the original one to a new one that is mutually supported by both the UE and the target eNB, thereby resolving the compatibility issue while maintaining security flexibility.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If the eNB does not update the security algorithm during RRC connection re-establishment, then processing simplicity is maintained, but UE access success rate deteriorates due to algorithm incompatibility

Engineering Contradiction:

Improveprocessing simplicityVSAvoidUE access success rate

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The eNB performs preliminary action by selecting and configuring a new security algorithm before the RRC connection re-establishment is completed. The eNB determines whether the original algorithm is supported, and if not, proactively selects a new algorithm from the UE's security capability list and configures it in the re-establishment message, ensuring compatibility before the handover finalizes.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by having the eNB check the UE's security capability information (which was provided during initial context establishment) and use this feedback to determine whether algorithm update is necessary. The eNB then provides feedback to the UE through the RRC connection re-establishment message, notifying the UE of the new algorithm to be used.

Inventive Principle:

Principle #23Feedback

3Ease of operation

If the eNB selects security algorithm based only on UE capability without considering eNB support, then UE autonomy is improved, but communication security reliability deteriorates due to unsupported algorithms

Engineering Contradiction:

ImproveUE autonomy in security selectionVSAvoidcommunication security reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by making the security algorithm selection process localized to each eNB's capabilities. Each eNB independently determines whether it supports the original algorithm and makes the final decision based on its own local configuration and the UE's capabilities, ensuring that the selected algorithm is actually supported by the specific eNB instance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies parameter changes by dynamically modifying the security algorithm parameter during the RRC connection re-establishment process. The eNB changes the security algorithm from the original one to a new one that is mutually supported by both the UE and the target eNB, thereby resolving the compatibility issue while maintaining security flexibility.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP2528403B1Method and system for security processing during RRC connection re-establishment

Publication Date: 2014.11.12 ZTE CORP

Figure 1
Figure 2
Figure 3

AI summary

This disclosure claims a method for security processing during RRC connection re-establishment, comprising: a UE sends an RRC connection re-establishment request message to the eNB; after receiving the request message, the eNB determines whether an original access layer security algorithm used by the UE is supported by the eNB itself according to the current status and configuration; if supported, the communication protection with UE is implemented via the original access layer security algorithm; if not supported, according to the security capability of UE, the access layer security algorithm which has the highest priority and is supported by the UE is selected from the access layer security algorithms configured by the eNB itself to be the new access layer security algorithm, and the communication protection between the eNB and the UE is implemented by the new access layer security algorithm. This disclosure also claims a system for security processing during the RRC connection re-establishment.