Key Management Facility Multi-Device Key Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LMR key management architectures face difficulties in managing and distributing security keys across multiple interworking clients in LTE systems, requiring a more efficient method to maintain key management states and update keys seamlessly.
Innovation Solution
A Key Management Facility (KMF) that utilizes a single common identifier, such as the twenty most significant bits of the Source RSI, to manage keys for multiple mobile devices, enabling seamless key management and updates using the Over-The-Air Rekeying (OTAR) standard without modifying existing procedures, and supports up to sixteen unique interworking devices for a single user.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing LMR KMF key management architecture is used, then key management for single devices is maintained, but managing and distributing security keys across multiple interworking clients in LTE systems becomes extremely difficult
Solution Approach 1:
The patent segments the key management approach by introducing a specific field (e.g., twenty most significant bits of Source RSI) that can uniquely identify multiple devices while maintaining compatibility with existing single-device key management protocols. This segmentation allows the system to handle multiple devices through structured identification rather than requiring complete architectural redesign.
Solution Approach 2:
The patent makes the key management system universal by designing it to handle both single-device and multi-device scenarios using the same underlying protocol structure. The common identifier field serves multiple functions: it works for single device identification, multi device grouping, and maintains backward compatibility with existing LMR systems, thereby achieving multi-functionality without increasing complexity.
2Reliability
If multiple interworking clients are provisioned with the same set of keys, then encrypted communication is enabled, but maintaining the same key management state across each client becomes extremely difficult
Solution Approach 1:
The patent applies copying by provisioning the same key material to multiple clients while using a common identifier to link them. The key management state is copied across clients but associated with a shared identifier, allowing automatic state synchronization without complex manual management. This copying approach enables reliable encrypted communication while simplifying state maintenance through automated processes.
3Ease of manufacture
If the Over-The-Air Rekeying (OTAR) standard is used without modifications, then existing procedures are maintained, but managing keys for multiple devices represented by a single common identifier is not supported
Solution Approach 1:
The patent introduces dynamics by making the identifier field configurable and extensible within the existing OTAR framework. The system dynamically adapts to handle both single-device and multi-device scenarios by interpreting the common identifier field differently based on context, allowing the same standard procedures to serve multiple purposes without modification while gaining multi-device capability.
Data Source
AI summary
A method and Key Management Facility (KMF) for managing keys of a single user having a plurality of devices is provided. The KMF receives an Over-The-Air Rekeying (OTAR) message relating to a first device and including an interworking bit. If the interworking bit is set, the KMF retrieves a main source RSI and a Sub-RSI field from the OTAR message. If the main source RSI matches other main source RSIs from other devices, the KMF manages keys for all devices that have the same main source RSI in an identical manner.