Anti-Stokes Security Pattern Verification for Tamper Detection

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Solution Overview

Problem

Existing security documents with anti-Stokes luminescent materials are vulnerable to manipulation and counterfeiting, particularly in cases where tampering with elements like postage stamps or labels is difficult to detect.

Innovation Solution

A security feature is designed with a pattern of anti-Stokes luminescent materials applied in a way that allows differentiation between removable and non-removable portions, enabling detection of tampering through luminescence intensity patterns and characteristic functions to verify authenticity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If anti-Stokes luminescent materials are used in security documents, then security features can be provided with characteristic luminescence patterns, but the security documents become vulnerable to manipulation and counterfeiting when tampering is difficult to detect

Engineering Contradiction:
Improvesecurity verification reliabilityVSAvoidmanipulation and counterfeiting vulnerability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The security feature is divided into multiple pattern areas with different luminescence characteristics. Each pattern area contains anti-Stokes luminescent material with specific properties that create a unique spatial and temporal luminescence pattern, making counterfeiting difficult

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different pattern areas have locally differentiated luminescence properties, including variations in luminescence intensity, decay times, and characteristic functions. This local differentiation creates a complex security pattern that is difficult to replicate

Inventive Principle:
Principle #3Local quality

2Productivity

If luminescence intensity patterns are used to detect tampering, then rapid verification is possible, but the complexity of evaluating multiple luminescence parameters increases

Engineering Contradiction:
Improveverification speedVSAvoidluminescence evaluation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The verification system uses feedback from detected luminescence parameters (intensity, decay time, characteristic function) to automatically determine authenticity. The system compares measured patterns against stored reference patterns, providing rapid binary verification without manual analysis

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent evaluates multiple luminescence parameters simultaneously, including intensity, decay times, and characteristic functions. By analyzing the temporal and spatial variations of these parameters, the system achieves rapid verification despite the complexity of multiple measurement dimensions

Inventive Principle:
Principle #35Parameter changes

3Reliability

If anti-Stokes luminescent materials are applied in removable and non-removable portions, then tampering detection capability is enhanced, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvetampering detection capabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The anti-Stokes luminescent material is applied to the security feature in predetermined pattern areas with specific binding properties before final assembly. This preliminary application ensures that removable versus non-removable portions are already differentiated, simplifying subsequent verification processes

Inventive Principle:
Principle #10Preliminary action

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 method allows for rapid and accurate verification of security elements, detecting manipulation and ensuring the presence of the correct luminescent substance, enhancing security and reliability.

Implementation Method 1

Anti-Stokes phosphors absorb electromagnetic radiation of a wavelength known as the excitation wavelength and emit at least some of the luminescence radiation at an anti-Stokes wavelength that is shorter than the excitation wavelength

Methodology Applied
Scientific EffectAnti-Stokes luminescence: Photoluminescence

Implementation Method 2

These anti-Stokes phosphors belong to the group of photoluminescent materials, which can be excited by electromagnetic radiation to emit electromagnetic luminescence

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP3999356B1Method for evaluating volatile non-resistant Anti-stokes luminescent substances on value documents, device for verifying such security elements and such security elements
Publication Date: 2025.12.03 BUNDESDRUCKEREI GMBH
  • EP3999356B1 patent drawingFigure 1
  • EP3999356B1 patent drawingFigure 2~3b
  • EP3999356B1 patent drawingFigure 4a~4c

AI summary

The invention relates to a security element (2) with a pattern (110) made of pattern regions (120) as a security feature (100). The pattern regions (120) comprise at least one first pattern region (121, 121-x) and a second pattern region (122, 122-x), and the first pattern region (121, 121-x) and the second pattern region (122, 122-x) have an anti-Stokes luminescent substance (200) in a non-manipulated state of the security element (2), said luminescent substance exhibiting a luminescence in an anti-Stokes wavelength range when excited with a light signal (407) with a wavelength in an excitation wavelength range. The first pattern region (121, 121-x) and the second pattern region (122, 122-x) differ in that the content of anti-Stokes luminescent material (200) which can be removed from the security element (2) by manipulation is greater in the second pattern region (122, 122-x) than in the first pattern region (121, 121-x). The invention additionally relates to a verification method and a device for verifying such a security element (2), wherein an evaluation of the anti-Stokes luminescence is carried out via a respective communication attachment.