Centralized Key Management in eMBMS Split Architecture
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Solution Overview
Problem
In the management of key pairs for evolved Multimedia Broadcast Multicast Service (eMBMS), existing technologies face challenges in providing centralized key management in a split architecture, leading to mobility issues and security concerns, especially when scaling, as the transmission of individual keys results in high overhead and potential interception risks.
Innovation Solution
A method where each Broadcast Multicast Service Center (BMSC) generates Multimedia Broadcast Multicast Traffic Keys (MTKs) using a received MBMS Service Key (MSK) and an MTK seed value, employing a standardized key generation function, and a centralized key management server transmits only the MSK to BMSCs, allowing BMSCs to generate MTKs locally for encrypting content, thereby reducing overhead and enhancing security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If individual keys are transmitted to each BMSC, then key management is achieved, but overhead increases and security deteriorates
Solution Approach 1:
The patent extracts the key generation function from the centralized authority and places it at each BMSC. Instead of transmitting individual MTKs to each BMSC, only the MSK and key generation algorithm are distributed. Each BMSC independently generates its own MTKs using the received MSK, thereby eliminating the need for repeated key transmissions while maintaining security.
Solution Approach 2:
The MSK acts as an intermediary that enables secure key generation at distributed BMSCs without requiring direct transmission of individual MTKs. The centralized authority transmits the MSK once to each BMSC, and this intermediate key then enables local generation of multiple MTKs, reducing overall communication overhead while maintaining security.
2Quantity of substance
If multiple keys are transmitted together, then overhead is reduced, but security becomes more imperative and complex
Solution Approach 1:
The patent segments the key management process into two distinct parts: (1) distribution of the master MSK from the centralized authority to each BMSC, and (2) local generation of multiple MTKs using the MSK and key generation algorithm. This segmentation allows overhead reduction through single transmission of MSK while keeping security management simpler through standardized local key generation.
Solution Approach 2:
The MSK is preliminarily distributed to each BMSC before actual content distribution begins. This preliminary action enables all subsequent MTKs to be generated locally at each BMSC using the pre-distributed MSK and key generation algorithm, eliminating the need for repeated key transmissions and simplifying security management.
3Ease of operation
If centralized authority manages all keys, then key distribution is simplified, but load on centralized authority increases with scaling
Solution Approach 1:
Each BMSC is equipped with the key generation algorithm and receives the MSK, enabling it to autonomously generate its own MTKs without requiring continuous intervention from the centralized authority. This self-service capability significantly reduces the load on the centralized authority, especially when scaling to multiple BMSCs, while maintaining simplified key distribution through the initial MSK transmission.
Data Source
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AI summary
A split architecture eMBMS with distributed BMSCs providing the same eMBMS service allows for a centralized key service where each BMSC is able to derive a set of MTKs from the MSK using the MTK-IDs as the differentiating input. This avoids the need to send MTKs to the BMSCs.