Wireless Key Change Procedure for Radio Resource Optimization
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Solution Overview
Problem
Current key change procedures in LTE-based communications networks consume radio and network resources, particularly due to the need for wireless devices to perform a RACH procedure and flush buffers, which can impact performance and resource utilization, especially in future 5G systems with increased key change frequency and device numbers.
Innovation Solution
A method and system for efficiently changing keys by exchanging key use information between wireless devices and network nodes, allowing key changes without requiring a RACH procedure and avoiding buffer flushes, thereby preserving radio resources and improving resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a RACH procedure is performed to change AS keys, then key synchronization between wireless device and radio access network node is achieved, but radio resources and network resources are consumed
Solution Approach 1:
The patent extracts the essential function of key synchronization from the complete RACH procedure. By separating the key update mechanism from the random access procedure, the invention allows key changes to occur through direct signaling exchange between the wireless device and network node, eliminating the need to perform a full RACH procedure just for key synchronization purposes.
Solution Approach 2:
The patent implements preliminary action by having the wireless device and network node exchange key update information through signaling messages before actual key change is needed. The device receives key update indicators and PDCP sequence numbers in advance, allowing it to prepare for key changes without waiting for RACH procedures, thus proactively maintaining synchronization.
2Reliability
If buffers are flushed during key change, then security protection consistency is maintained, but transmission latency increases and resources are wasted
Solution Approach 1:
The patent applies preliminary action by having the network node provide PDCP sequence number information in advance through signaling. This allows the wireless device to identify exactly which packets in its buffers need to be retransmitted with the new key, rather than flushing all buffers. The device can prepare the minimal necessary packet list for retransmission before the key change occurs.
Solution Approach 2:
The patent implements local quality by applying the new key selectively only to specific packets that require retransmission, rather than uniformly applying it to all buffered data. The wireless device uses the provided PDCP sequence numbers to identify precisely which local buffer entries need security reprocessing, leaving other packets untouched and avoiding unnecessary retransmissions.
3Reliability
If key change frequency is increased to meet 5G security requirements, then security is improved, but resource consumption and system complexity increase
Solution Approach 1:
The patent applies universality by designing a key update mechanism that uses existing signaling frameworks and message structures. The key update information is conveyed through standard signaling channels already present in the system, allowing the same infrastructure to handle both regular communication signaling and key management functions, thus avoiding the need for separate dedicated key management protocols.
Solution Approach 2:
The patent implements parameter changes by introducing key update indicators and PDCP sequence number parameters into existing signaling messages. Rather than creating new complex key management protocols, the invention modifies existing message parameters to carry key update information, allowing frequent key changes through simple parameter adjustments in standard signaling exchanges.
Data Source
AI summary
There is provided mechanisms for configuring use of keys for security protecting packets communicated between a wireless device and a network node. A method is performed by the wireless device. The method comprises exchanging key use information with the network node in conjunction with performing a key change procedure with the network node during which a first key is replaced with a second key. The key use information indicates which of the packets are security protected using which of the first key and the second key.