Audio-Video Stream Key Distribution for Secure Multi-Hop Transmission

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing media interface protection standards lack sufficient security as downstream devices can decrypt audio-video data from previous-hop devices, leading to vulnerabilities in data transmission.

Innovation Solution

Implement identity authentication and key negotiation between source and downstream devices, encapsulating key distribution packets within audio-video streams to ensure only authorized devices can decrypt the data, enhancing encryption and decryption processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If all data on a link is centrally encrypted with a single key, then decryption is simplified for downstream devices, but transmission security deteriorates because any downstream device can decrypt audio-video data from previous-hop devices

Engineering Contradiction:

Improvedecryption simplicityVSAvoidtransmission security

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent segments the encryption key into multiple hierarchical levels: a root key at the source device, intermediate keys at each transmission hop, and content keys for actual data encryption. Each device only holds the keys necessary for its specific function, preventing any single downstream device from decrypting data intended for previous hops.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by assigning different encryption keys to different transmission segments and devices. Each hop in the transmission chain uses its own dedicated key pair, ensuring that security properties are optimized locally for each segment while maintaining overall system security.

Inventive Principle:

Principle #3Local quality

2Reliability

If identity authentication and key negotiation are implemented between source and downstream devices, then transmission security is improved, but device complexity increases due to additional authentication and key management mechanisms

Engineering Contradiction:

Improvetransmission securityVSAvoidauthentication and key management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs identity authentication and key negotiation as preliminary actions during device pairing and connection establishment. Once completed, these credentials are cached and reused for subsequent transmissions, avoiding repeated authentication overhead while maintaining security.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary key management system that facilitates secure key distribution and authentication. This intermediary layer handles the complex key negotiation and distribution tasks, reducing the burden on individual devices while ensuring robust security.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12537985B2Data transmission method and apparatus

Publication Date: 2026.01.27 HUAWEI TECH CO LTD

AI summary

The present disclosure relates to data transmission methods and apparatuses. In one example method, a source device performs identity authentication on and negotiate a key with a transmission device that needs to output audio-video data or perform transformation processing on a transmission path to a sink device, and generates a key distribution packet used to encrypt or decrypt an audio-video stream only for the transmission device that needs to output audio-video data or perform transformation processing.