Challenge-Response Authentication via DRM Video Nonce Embedding

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Solution Overview

Problem

Existing node locking technologies are not accessible to web applications and require modifications to the operating system or specific hardware features, making them unsuitable for use with existing device infrastructure, especially in Android-based devices which are prone to unauthorized content distribution.

Innovation Solution

A challenge-response method using DRM protected video content that embeds a nonce within the video, allowing only authorized devices to decrypt and respond with the correct nonce, thereby preventing execution on unauthorized platforms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If node locking technologies are implemented using SIM functionality or specific hardware features, then challenge-response authentication is achieved, but the operating system must be modified or specific hardware features are required, making it unsuitable for existing device infrastructure

Engineering Contradiction:
Improvechallenge-response authenticationVSAvoidoperating system modification
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a DRM module as an intermediary component that bridges the gap between existing device infrastructure and node locking functionality. The DRM module acts as a mediator that provides challenge-response authentication without requiring operating system modifications, by leveraging the existing DRM hardware and software stack already present in Android devices

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent makes the DRM module accessible to multiple types of applications (native applications, virtual machine applications, and web applications) through a unified interface. This multi-functionality allows the same DRM infrastructure to serve diverse authentication needs across different application types without requiring separate implementations or system modifications

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If node locking is made accessible to web applications through browser API, then web applications can authenticate devices, but existing browser APIs do not expose such functions

Engineering Contradiction:
Improveweb application accessVSAvoidbrowser API extension
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the node locking functionality into distinct modules: a DRM module for cryptographic operations, a virtual machine layer for isolation, and a browser API layer for web application access. This segmentation allows each layer to be developed and modified independently, enabling web application access without compromising the security or stability of the underlying DRM infrastructure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a virtual machine as an intermediary layer between web applications and the DRM module. This virtual machine provides a controlled environment that translates web application requests into DRM module operations, enabling web applications to access node locking functionality without direct exposure to the complex DRM infrastructure

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If DRM protected content is rendered on unauthorized devices, then content distribution is compromised, but preventing this requires robust node locking mechanisms

Engineering Contradiction:
Improveunauthorized content distributionVSAvoidnode locking mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent performs preliminary binding of the application to the device during the challenge-response authentication process before content distribution. The node locking function binds the application to the specific device hardware characteristics in advance, ensuring that subsequent content rendering can only occur on the authorized device, preventing unauthorized distribution proactively

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the DRM module continuously verifies device identity and authentication status during content rendering operations. This real-time feedback ensures that any attempt to render content on an unauthorized device is detected and blocked, providing ongoing protection against unauthorized distribution

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3198498B1A challenge-response method and associated computing device
Publication Date: 2021.04.14 IRDETO BV
  • EP3198498B1 patent drawingFigure 1~2
  • EP3198498B1 patent drawingFigure 3~4
  • EP3198498B1 patent drawingFigure 5~6

AI summary

There is described a challenge-response method for a computing device. The method comprises steps of: (a) receiving challenge data at a secured module of the computing device, the challenge data comprising image content encrypted using an encryption key, and the image content including a nonce; (b) the secured module recovering the image content through decryption using one or more keys associated with the encryption key; (c) the secured module of the computing device outputting the recovered image content; (d) capturing the image content as output by the secured module; (e) processing the captured image content so as to obtain the nonce; and (f) providing the nonce as a response. There is also described a computing device arranged to carry out the challenge-response method, a computer program for causing a processor to carry out the challenge-response method, and a computer readable medium storing such a computer program.