Dynamic Shape Level Lines for Secure Document Authentication
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Solution Overview
Problem
Current anti-counterfeiting methods for security documents and valuable products are inadequate as they can be easily replicated using high-quality photocopiers and desktop publishing systems, and existing phase shift techniques are limited by their inability to destroy line gratings and ease of image recreation.
Innovation Solution
The method involves embedding a spatial elevation profile within one layer of a security item, which is revealed by superposing a base layer with a modified line grating, creating shape level lines that move dynamically between motif shape boundaries and centers, providing enhanced authentication through geometric transformations and special inks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phase shift techniques with line gratings are used for authentication, then authentication capability is provided, but the line gratings can be easily copied and the latent image can be recovered by counterfeiters
Solution Approach 1:
The invention changes the fundamental parameter from static phase-shifted line gratings to dynamic shape level lines that move between boundaries and centers. This dynamic behavior cannot be captured by standard photocopiers or desktop publishing systems, making counterfeiting extremely difficult while maintaining authentication capability
Solution Approach 2:
The invention introduces dynamic elements by creating shape level lines that move between motif shape boundaries and centers. This dynamic characteristic distinguishes the invention from static phase shift techniques and prevents easy reproduction by counterfeiters using standard equipment
2Ease of manufacture
If standard photocopiers and desktop publishing systems are used to reproduce security documents, then reproduction cost is reduced, but authentication security is compromised
Solution Approach 1:
By changing from static to dynamic visual elements (shape level lines that move between boundaries and centers), the invention creates an authentication feature that cannot be reproduced by standard photocopiers or desktop publishing systems, maintaining security while allowing legitimate production
3Reliability
If latent binary images are embedded in base layers with line gratings, then authentication features are added, but the images can be easily revealed and recreated
Solution Approach 1:
The invention transforms the authentication feature from a static latent binary image that can be easily revealed to dynamic shape level lines that move between motif shape boundaries and centers. This dynamic parameter change makes the authentication feature much harder to detect, capture, and recreate
Solution Approach 2:
By making the authentication feature dynamic (moving shape level lines), the invention increases the difficulty of detection and measurement compared to static latent images, as standard imaging equipment cannot capture the temporal variation
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 security by making it difficult for counterfeiters to replicate the dynamic shape level lines, even with advanced printing equipment, while maintaining production costs, and allows for individualized and time-varying security features.
Implementation Method 1
The method involves embedding a spatial elevation profile within one layer of a security item, which is revealed by superposing a base layer with a modified line grating, creating shape level lines that move dynamically between motif shape boundaries and centers
Data Source
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AI summary
The disclosed method and system may be used for creating advanced protection means for various categories of documents (e.g. bank notes, identity documents, certificates, checks, diploma, travel documents, tickets) and valuable products (e.g. optical disks, CDs, DVDs, CD-ROMs, prescription drugs, products with affixed labels, watches) hereinafter called "secure items". Secure items are authenticated by shape level lines. The shape level lines become apparent when superposing a base layer comprising sets of lines and a revealing layer comprising a line grating. One of the two layers is a modified layer which embeds a shape elevation profile generated from an initial, preferably bilevel, motif shape image (e.g. typographic characters, words of text, symbols, logo, ornament). In the case of an authentic document, the outline of the revealed shape level lines are visual offset lines of the boundaries of the initial bilevel motif shape image. In addition, the intensities, respectively colors of the revealed shape level lines are the same as the intensities, respectively colors of the lines forming the base layer sets of lines. By modifying the relative superposition phase of the revealing layer on top of the base layer or vice-versa (e.g. by a translation or a rotation), one may observe shape level lines moving dynamically between the initial bilevel motif shape boundaries and shape foreground centers, respectively background centers, thereby growing and shrinking. In the case that these characteristic features are present, the secure item is accepted as authentic. Otherwise the item is rejected as suspect. Pairs of base and revealing layers may be individualized by applying to both the base and the revealing layer a geometric transformation. Thanks to the availability of a large number of geometric transformations and transformation parameters, one may create documents having their own individualized document protection. The invention also proposes a computing and delivery system operable for delivering base and revealing layers according to security document or valuable product information content. The system may automatically generate upon request an individually protected secure item and its corresponding authentication means.