Statistical Luminescence Analysis for Document Authentication

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Solution Overview

Problem

Current methods for authenticating and distinguishing documents of value using luminescent feature substances are vulnerable to forgery and lack sufficient security, as they rely on simple detection of luminescence patterns without advanced statistical analysis to differentiate between genuine and counterfeit documents.

Innovation Solution

The method employs advanced statistical analysis using descriptive and numerical classification methods to evaluate location-dependent luminescence data, incorporating specific grain size distributions of luminescent particles to create unique signal fluctuations, allowing for the differentiation of document classes based on statistical parameters and intensity patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If simple luminescence detection is used, then the checking process is simple and fast, but the security against forgery is insufficient

Engineering Contradiction:
Improvesecurity against forgeryVSAvoidchecking process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by analyzing statistical parameters (mean, standard deviation, skewness, kurtosis) of luminescence signal distributions instead of simple intensity detection. This transforms the checking process from detecting whether luminescence exists to analyzing the statistical characteristics of luminescence signal distributions, thereby enhancing security while maintaining feasibility through computational analysis of existing measurement data

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from one-dimensional luminescence intensity detection to multi-dimensional statistical analysis by evaluating multiple statistical parameters (mean, standard deviation, skewness, kurtosis) simultaneously. This dimensional expansion in the analysis space enables more sophisticated forgery detection without requiring additional physical measurement dimensions, resolving the contradiction between security enhancement and process complexity

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

2Reliability

If luminescent particles with uniform grain size are used, then the manufacturing process is simple, but the luminescence signal distribution lacks unique identification characteristics

Engineering Contradiction:
Improvedocument identification capabilityVSAvoidgrain size distribution control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent deliberately introduces grain size distribution as a controlling parameter to create unique luminescence signal characteristics. By allowing controlled variations in particle size (D10, D50, D90 parameters) and using multimodal distributions, the system generates distinctive statistical signatures in the luminescence signals that enhance document identification capability while maintaining manufacturability through standard mixing processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating non-uniform grain size distributions within the luminescent particle population. Different size fractions (small, medium, large particles) contribute differently to the luminescence signal, creating local variations in signal intensity and statistical properties that provide unique identification characteristics for authentic documents

Inventive Principle:
Principle #3Local quality

3Measurement precision

If multiple statistical parameters are analyzed, then the differentiation between genuine and counterfeit documents is improved, but the evaluation complexity increases

Engineering Contradiction:
Improvedocument differentiation accuracyVSAvoidevaluation process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs partial action by selectively analyzing a subset of statistical parameters (mean, standard deviation, skewness, kurtosis) that provide the most discriminatory power for authentication. Rather than analyzing all possible statistical characteristics, the method focuses on these four key parameters that capture the essential features of luminescence signal distributions, achieving high differentiation accuracy while controlling evaluation complexity

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent implements feedback by comparing the measured statistical parameters of the luminescence signal against reference values or acceptance criteria for authentic documents. This feedback mechanism enables automated decision-making in the authentication process, where the statistical analysis results directly determine whether a document is genuine or counterfeit, streamlining the evaluation process despite the multi-parameter analysis

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly enhances the security of documents by providing a robust method to distinguish between genuine and counterfeit documents through unique luminescence patterns, leveraging statistical analysis and tailored particle size distributions to create distinct signal fluctuations.

Implementation Method 1

a) excitation of the luminescent particles with light of a wavelength suitable for excitation of the luminescent particles; b) detection of the luminescence at a plurality of locations on the document of value

Methodology Applied
Scientific EffectLuminescence: Luminescence

Data Source

PatentEP2901427B1Method for checking a value document, value document, use thereof and value document system
Publication Date: 2020.02.05 GIESECKE & DEVRIENT CURRENCY TECHNOLOGY GMBH
  • EP2901427B1 patent drawingFigure 1~2
  • EP2901427B1 patent drawingFigure 3~4
  • EP2901427B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for checking a value document, especially the authenticity and/or the nominal value of a value document having characteristic luminescent substances, the method comprising the steps of: a1) carrying out a location-specific measurement of first luminescence intensities (L1) at a first emission wavelength in different locations of the value document having the location coordinates (O), to thereby obtain pairs of measured values (O/L1); b1) statistically analyzing the first luminescence intensities (L1) measured on the basis of the individual location coordinates (O), by determining at least one statistical parameter by way of a statistical method; and c1) comparing the statistical parameter determined in step b1) to one or more threshold values.