HDMI Content Protection Through Pre-Transmission Authentication
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Solution Overview
Problem
Existing high-definition multimedia interface (HDMI) technologies face issues with audio/video stream leakage during HDCP authentication, as the stream is transmitted before authentication is completed, compromising security.
Innovation Solution
Implementing authentication key exchange and session key agreement processes separately from audio/video stream transmission, ensuring authentication is completed before stream transmission, using HMAC and session keys to encrypt the stream, and updating revocation lists to maintain security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HDCP authentication is performed while transmitting the audio/video stream, then authentication can be conducted, but the audio/video stream may leak during the authentication process
Solution Approach 1:
The patent divides the authentication and stream transmission processes into separate time periods. The authentication process (including authentication key exchange and session key agreement) is completed first during link establishment, and only after successful authentication does the transmit end send the encrypted audio/video stream. This temporal segmentation ensures that the stream is never transmitted during authentication, eliminating the leakage risk while maintaining authentication security.
2Reliability
If the authentication process and stream transmission are separated into different time periods, then stream leakage is prevented, but the transmission link establishment time increases
Solution Approach 1:
The patent implements preliminary authentication actions during the link establishment phase before stream transmission begins. The authentication key exchange and session key agreement are performed in advance, so that when the stream needs to be transmitted, authentication is already complete. This preliminary action approach prevents stream leakage while minimizing the impact on overall transmission timing, as the authentication overhead is incurred only once during connection setup.
3Reliability
If authentication key exchange and session key agreement are performed during link establishment, then stream leakage is avoided, but the authentication process complexity increases
Solution Approach 1:
The patent merges the authentication key exchange and session key agreement processes into a unified authentication flow that occurs during link establishment. Rather than treating these as separate complex procedures, they are integrated into a single authentication sequence where the transmit end sends authentication requests, the receive end responds with authentication data, and both parties derive session keys together. This merging reduces procedural complexity while maintaining strong security through the separation of authentication and transmission phases.
Data Source
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AI summary
A content transmission protection method and a related device thereof are disclosed, to avoid leakage of an audio/video stream when a transmit end and a receive end perform authentication. The method includes: In a process of establishing a transmission link between a transmit end and a receive end, the transmit end performs authentication key exchange with the receive end to obtain an authentication key. The transmit end performs session key agreement with the receive end based on the authentication key to obtain a session key. The transmit end performs authorization control on the receive end after establishment of the transmission link between the transmit end and the receive end is completed. The transmit end sends an encrypted audio/video stream to the receive end after the transmit end completes authorization control on the receive end. The encrypted audio/video stream is encrypted based on the session key.