Hierarchical Key Management for Encrypted Content Streaming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing content streaming systems face challenges in efficiently managing and distributing cryptographic keys to multiple clients while controlling access to encrypted content, especially when dealing with hundreds or thousands of content streams and the need for real-time changes in encryption and content policies.
Innovation Solution
The method involves embedding an encrypted content key within each content stream as a leaf license, which includes intermediate decryption keys derived from a scalable root license, allowing clients to decrypt only the content they are subscribed to, and enabling real-time changes in encryption and policy by updating the intermediate keys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional key distribution methods are used for content streaming, then content access control is maintained, but key management complexity increases significantly when serving hundreds or thousands of content streams to multiple clients
Solution Approach 1:
The patent segments the key management system into a hierarchical structure with master keys at the top level and individual content keys at the leaf level. This segmentation allows the system to manage thousands of content streams by organizing keys in a tree structure, where each node represents a key level. The hierarchical organization reduces management complexity by breaking down the large-scale key distribution problem into smaller, manageable segments.
Solution Approach 2:
The patent implements a nested key structure where content keys are encrypted using intermediate keys, which are in turn encrypted using master keys. This nesting approach allows multiple levels of key encryption to be contained within each other, enabling efficient key distribution. The nested structure allows a single master key to protect numerous content keys through intermediate layers, reducing the overall key management burden.
2Reliability
If individual content keys are distributed to each client for each content stream, then content access control is precise, but the number of keys to manage and distribute increases exponentially
Solution Approach 1:
The master keys in the hierarchical structure serve multiple functions: they protect numerous intermediate keys, which in turn protect multiple content keys. This multi-functionality allows a single master key to effectively control access to hundreds or thousands of content streams. The universal nature of the master keys reduces the total number of individual keys that need to be distributed to clients, as they can derive multiple content keys from fewer intermediate keys.
Solution Approach 2:
The patent implements dynamic key derivation where clients can obtain different intermediate keys based on their subscription preferences. The system dynamically determines which intermediate keys to distribute to each client based on the content streams they wish to access. This dynamic approach allows the system to manage key distribution flexibly, providing clients with only the keys they need for their subscribed content, thereby reducing the overall quantity of keys distributed.
3Adaptability or versatility
If content encryption and policy changes are implemented in real-time, then content security and adaptability are improved, but key distribution and management become more challenging
Solution Approach 1:
The hierarchical key structure enables dynamic real-time changes in encryption policies by allowing the system to update intermediate keys without affecting the entire key tree. When policy changes occur, the system can generate new intermediate keys for affected content streams while maintaining the integrity of other branches. This dynamic capability allows real-time encryption policy changes while managing key distribution complexity through the organized hierarchical structure.
Solution Approach 2:
The intermediate keys act as mediators between the master keys and content keys, enabling flexible real-time policy changes. When encryption policies need to be updated, the system can introduce new intermediate keys that serve as intermediaries for the affected content streams. These intermediary keys allow the system to implement real-time changes without directly manipulating the entire key distribution system, thereby reducing the complexity of key distribution during policy updates.
4Productivity
If the same encrypted content stream is streamed to all clients, then content delivery efficiency is improved, but access control precision decreases
Solution Approach 1:
The patent segments the content delivery system by embedding individual content keys within each content stream through the hierarchical key structure. This segmentation allows the same encrypted content stream to be delivered efficiently to all clients while maintaining precise access control. Each client receives the same content stream but can only decrypt content for which they possess the corresponding intermediate keys, achieving both delivery efficiency and access control precision through the segmented key distribution approach.
Data Source
AI summary
Encrypted content streaming is provided by a method comprising holding an encrypted content stream that is cryptographically encrypted from a content stream with a content key, and holding an encrypted content key that is cryptographically encrypted from the content key with one or more intermediate encryption keys. The method further comprises serving the encrypted content stream to a plurality of content consumption devices, wherein the encrypted content stream is embedded with a leaf license comprising the encrypted content key, and wherein the encrypted content stream is cryptographically decryptable by a content consumption device having a scalable root license providing one or more intermediate root keys from which the content consumption device derives the one or more intermediate decryption keys paired to the one or more intermediate encryption keys.