Secure Content Protection System Incremental Revocation Verification

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Solution Overview

Problem

Existing content protection systems for premium AV sources are vulnerable to hacker attacks due to insecure revocation list verification processes, which can lead to unauthorized access and resource inefficiencies, particularly when large revocation lists need to be stored on chips.

Innovation Solution

Implementing an elliptic-curve-cryptography-based content protection system that performs dynamic signature verification and unique ID comparison incrementally, without storing the entire revocation list on the chip, by processing it in portions and using Secure Hash Algorithm (SHA-1) to reduce memory overhead and enhance security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the revocation list is stored on the chip for secure verification, then security is improved, but memory usage and system resources are increased

Engineering Contradiction:
ImprovesecurityVSAvoidmemory usage
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The revocation list verification process is segmented into incremental steps where the firmware sends portions of the revocation list to the device sequentially. The device verifies each portion incrementally without needing to store the entire list in memory, thus maintaining security while minimizing memory usage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The verification process transitions from a static memory-storage model to a dynamic stream-processing model. Instead of loading the entire revocation list into memory at once, the system processes it as a flowing data stream in incremental portions, changing the temporal dimension of data availability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Speed

If the entire revocation list is loaded into memory for verification, then verification speed is improved, but memory overhead increases

Engineering Contradiction:
Improveverification speedVSAvoidmemory overhead
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The revocation list is divided into manageable portions that are transmitted and verified incrementally. This segmentation allows the system to maintain a steady verification pace without requiring large memory allocations, balancing speed requirements with memory constraints.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system processes the revocation list in partial increments rather than attempting to load everything at once. This partial action approach provides sufficient verification speed for security purposes while avoiding the excessive memory overhead that would result from loading the complete list.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If the revocation list is transmitted in full to the device, then verification accuracy is improved, but data exchange overhead increases

Engineering Contradiction:
Improveverification accuracyVSAvoiddata exchange overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The complete revocation list is segmented into sequential portions transmitted from firmware to device. Each portion contributes to the overall verification accuracy when processed incrementally, achieving the same verification result as full transmission but with reduced per-transmission data overhead.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2371131B1Method, apparatus and system for employing a secure content protection system
Publication Date: 2018.08.15 LATTICE SEMICON CORP
  • EP2371131B1 patent drawingFigure 1
  • EP2371131B1 patent drawingFigure 2
  • EP2371131B1 patent drawingFigure 3

AI summary

A method, apparatus and system for employing a secure content protection system is disclosed. In one embodiment, a certificate having a unique device identification associated with a first device is received, and, at a second device, a revocation list having unauthorized device identifications is received. The unique device identification is incrementally compared with the unauthorized device identifications of the revocation list, and media content is transmitted from the second device to the first device, if the unique device identification is not matched with the unauthorized device identifications of the revocation list.