Common Encryption Keys for Adaptive Bitrate Streaming

Solution Overview

Problem

Existing adaptive streaming systems face challenges in efficiently switching between alternative streams of protected content without requiring multiple sets of cryptographic information and reinitializing the decryption engine.

Innovation Solution

The system employs a common set of encryption keys for all alternative streams, which are stored in a DRM Header element within Matroska container files, allowing seamless switching between streams without the need for reinitializing the decryption engine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple sets of cryptographic information are used for different alternative streams, then each stream can be securely protected, but the playback device must reinitialize the decryption engine when switching streams, increasing complexity and time loss

Engineering Contradiction:

Improvecontent protectionVSAvoiddecryption engine management

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by using a single common set of cryptographic information (encryption keys) that can decrypt all alternative streams of protected content. This universal key set eliminates the need for multiple decryption engines or key management systems, allowing one decryption engine to handle all streams securely without reinitialization.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the cryptographic information for all alternative streams into a single common set of encryption keys. Instead of managing separate key sets for different streams, the system combines them into one shared key set stored in the DRM Header element, simplifying the decryption process and eliminating the need for reinitialization when switching streams.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If multiple sets of cryptographic information are used for different alternative streams, then each stream can be securely protected, but time is lost during reinitialization when switching streams

Engineering Contradiction:

Improvecontent protectionVSAvoidstream switching time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies universality by using a single common set of cryptographic information (encryption keys) that can decrypt all alternative streams of protected content. This universal key set eliminates the need for multiple decryption engines or key management systems, allowing one decryption engine to handle all streams securely without reinitialization.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements preliminary action by pre-storing the common set of cryptographic information in the DRM Header element of each container file before the playback device needs to switch streams. This preliminary placement of cryptographic data eliminates the need for reinitialization during stream switching, as the keys are already available for immediate use.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If separate encryption keys are used for each alternative stream, then stream-specific security is achieved, but computational overhead increases when switching between streams

Engineering Contradiction:

Improvestream securityVSAvoidcomputational overhead

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies universality by using a single common set of cryptographic information (encryption keys) that can decrypt all alternative streams of protected content. This universal key set eliminates the need for multiple decryption engines or key management systems, allowing one decryption engine to handle all streams securely without reinitialization.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the cryptographic information for all alternative streams into a single common set of encryption keys. Instead of managing separate key sets for different streams, the system combines them into one shared key set stored in the DRM Header element, simplifying the decryption process and eliminating the need for reinitialization when switching streams.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS20250168426A1Systems and Methods for Distributing Content Using a Common Set of Encryption Keys

Publication Date: 2025.05.22 DIVX LLC

AI summary

Systems and methods for performing adaptive bitrate streaming using alternative streams of protected content in accordance with embodiments of the invention are described. One embodiment of the invention includes a processor, and memory containing a client application. In addition, the client application configures the processor to: request a top level index file identifying a plurality of alternative streams of protected content, where each of the alternative streams of protected content are encrypted using common cryptographic information; obtain the common cryptographic information; request portions of content from at least the plurality of alternative streams of protected content; access the protected content using the common cryptographic information; and playback the content.