Authentication System CRL Update via Peer Device Feedback

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Solution Overview

Problem

Conventional authentication systems for home electric appliances and controllers do not effectively prevent unauthorized connections and information leakage, as they rely on Wi-Fi Protected Setup and Public Key Infrastructure (PKI) which fail to ensure the validity of devices, especially when CRLs are outdated or not updated properly.

Innovation Solution

An authentication method where devices manage lists of revoked certificates and compare new and old identification information to update CRLs, ensuring that only authorized devices connect by transmitting and updating CRLs within the authentication system, even when a controller is unauthorized or not connected to an external network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PKI authentication with CRL verification is used to ensure device validity, then authentication reliability is improved, but the system cannot detect revoked certificates when the controller is unauthorized or not connected to an external network

Engineering Contradiction:
Improveauthentication reliabilityVSAvoidunauthorized connection
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system implements feedback by having devices share CRL information with each other. When a device connects to the network, it shares its CRL with other devices, allowing them to update their local CRLs. This creates a distributed feedback mechanism where authentication information flows back through the network, enabling devices to detect revoked certificates even when the controller is unauthorized or offline.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces other devices as intermediaries for CRL distribution. Instead of relying solely on the controller to provide CRL updates, devices can obtain CRL information from peer devices that have network connectivity. This intermediary mechanism bypasses the need for a trusted controller, allowing CRL verification to function even when the controller is compromised or disconnected.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If devices rely on the controller to provide CRL updates, then device complexity is reduced, but the system becomes vulnerable when the controller is unauthorized or disconnected

Engineering Contradiction:
ImproveCRL management complexityVSAvoidauthentication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system implements self-service by enabling devices to autonomously update their CRLs by obtaining information from peer devices. Each device maintains its own CRL and can independently refresh it by communicating with other devices on the network. This eliminates dependency on the controller for CRL updates, allowing devices to self-manage their authentication credentials even when the controller is unauthorized or disconnected.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent makes devices multi-functional by enabling them to serve dual roles: as authentication clients verifying certificates and as CRL distribution points for other devices. This universality allows any connected device to contribute to the authentication infrastructure, reducing reliance on the controller while maintaining simplified individual device operation.

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

3Ease of operation

If CRL verification is performed only through the controller, then ease of operation is improved, but unauthorized devices can connect if the controller is compromised

Engineering Contradiction:
Improveconnection simplicityVSAvoidinformation leakage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by having devices obtain and store CRL information in advance from peer devices before attempting authentication. Devices proactively update their local CRLs by communicating with other devices on the network, ensuring they have current revocation information before connecting to the controller. This preliminary CRL acquisition prevents reliance on potentially compromised controller-provided CRLs while maintaining simple authentication operations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3086505B1Authentication system, authentication method and authentication device
Publication Date: 2020.12.30 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA
  • EP3086505B1 patent drawingFigure 1
  • EP3086505B1 patent drawingFigure 2
  • EP3086505B1 patent drawingFigure 3~4

AI summary

A first device, upon detecting participation in an authentication system, transmits new and old identification information of a first certificate revocation list that the first device manages to a second device. In a case where the new and old identification information of a second certificate revocation list that the second device manages is older than the new and old identification information of the received first certificate revocation list, the second device transmits a transmission request for the first certificate revocation list to the first device. Upon receiving the transmission request for the first certificate revocation list from the second device, the first device transmits the first certificate revocation list to the second device. the second device updates the second certificate revocation list using the received first certificate revocation list.