Integrated Circuit Trustworthy Time Reception via Certificate Validation

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Solution Overview

Problem

Integrated electronic circuits, particularly those used in card verifiable certificates, face challenges in obtaining trustworthy time information for certificate validation without external access, leading to potential security vulnerabilities and inefficiencies.

Innovation Solution

A method where integrated electronic circuits receive and store trustworthy time information from certificates or signed messages, updating this information periodically to ensure the validity of subsequent certificates, using either internal clock updates or external time synchronization signals, thereby maintaining accurate time references for cryptographic checks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If integrated electronic circuits use external servers for time synchronization, then time accuracy is improved, but device complexity and external dependency increase

Engineering Contradiction:

Improvetime accuracyVSAvoidexternal dependency

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses certificates as intermediaries to transfer trustworthy time information from external sources to the integrated electronic circuit. The certificates, issued by trusted certification authorities, contain time stamps that serve as reliable time references without requiring continuous external server access. This resolves the contradiction by maintaining time accuracy through certificate-based time information while reducing external dependency.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary time synchronization by obtaining time information from certificates before cryptographic operations are executed. The integrated electronic circuit stores time information from validated certificates in advance, allowing it to perform time-based validation independently without real-time external server access. This preliminary action ensures time accuracy while eliminating continuous external dependency.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If integrated electronic circuits store time information from certificates, then security against replay attacks is improved, but time information may become outdated

Engineering Contradiction:

Improvesecurity against replay attacksVSAvoidtime information freshness

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements a feedback mechanism where the integrated electronic circuit continuously validates received certificates against stored time information. When a certificate with a newer time stamp is received and validated, the system updates its stored time information. This feedback loop ensures time information remains current while maintaining security, as each update comes from a validated certificate source.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically updates time information based on received certificates rather than using static time references. The integrated electronic circuit adapts its time information storage by comparing new certificate time stamps with stored values, automatically updating when more current information is available. This dynamic approach maintains both security and time freshness.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If integrated electronic circuits perform internal certificate validation without external access, then device independence is improved, but ability to verify current time is worsened

Engineering Contradiction:

Improvedevice independenceVSAvoidcurrent time verification

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

4Use of energy by moving object

If devices without continuous power supply use stored time information, then energy consumption is reduced, but time accuracy deteriorates

Engineering Contradiction:

Improveenergy consumptionVSAvoidtime accuracy

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent uses certificates as disposable time reference carriers that can be validated and stored without continuous power. Each certificate contains a self-contained time stamp that can be verified using the certificate's cryptographic signature. This allows devices without continuous power supply to maintain time accuracy by using these self-contained time references, consuming energy only when receiving and validating new certificates rather than maintaining continuous clock operation.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP2102720B1Method for receiving a confidential time information

Publication Date: 2017.09.13 BUNDESDRUCKEREI GMBH

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AI summary

The invention relates to a method for receiving a confidential time information, comprising the following steps: reception of a certificate (118), said certificate comprising an indication of the initial time (TA) of its validity period; verification of the validity of the certificate; storage of the initial time as a confidential time information in a memory (126) when the certificate is detected as being valid.