Physically Unclonable Function Structure via Controlled Phase Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing PUF structures face challenges in achieving a balance between security and reproducibility, as they need to be unclonable yet reproducible with predictable properties for reliable manufacturing.

Innovation Solution

A method involving local demixing of a precursor to create domains of different substances with a random distribution, utilizing self-organization and spontaneous structure formation, controlled by process parameters to ensure reproducibility and randomness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PUF structures are made as random as possible to achieve unclonability and security, then security is improved, but manufacturing reproducibility and reliability deteriorate

Engineering Contradiction:
ImprovesecurityVSAvoidreproducibility
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by controlling the phase separation process through temperature, time, and composition parameters. By adjusting these parameters, the invention achieves a balance between random domain distribution (for security) and reproducible manufacturing conditions. The phase separation is induced under controlled parameters that ensure both randomness and manufacturability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The core of the invention utilizes phase transitions - specifically phase separation in polymer blends. The precursor composition undergoes phase separation to form domains with different physical properties. This phase transition naturally creates random spatial distributions while being controllable through processing parameters, thus resolving the contradiction between security (randomness) and reproducibility.

Inventive Principle:
Principle #36Phase transitions

2Reliability

If PUF structures use spontaneous structure formation to achieve randomness, then unclonability is improved, but control over device properties deteriorates

Engineering Contradiction:
ImproveunclonabilityVSAvoidcontrol over device properties
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention employs self-service through spontaneous phase separation of the precursor composition. The system automatically forms domains with random spatial distributions without requiring external intervention or complex patterning processes. This self-organizing behavior provides unclonability while simplifying manufacturing.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

While utilizing spontaneous structure formation, the invention maintains control by adjusting processing parameters such as temperature, composition ratios, and processing time. These parameter changes allow control over domain size, distribution characteristics, and device dimensions, balancing unclonability with manufacturability.

Inventive Principle:
Principle #35Parameter changes

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

Enables the production of PUFs with high reliability and robustness, maintaining key properties for extended periods without external influence, facilitating secure and economical manufacturing.

Implementation Method 1

the precursor is provided in a first phase and the local demixing of the precursor involves a change in the state of the precursor to effect a phase transition

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 2

generating the characteristic structure by locally demixing a precursor to obtain a plurality of domains of a first substance and a plurality of domains of a second substance

Methodology Applied
Scientific EffectDemixing:

Implementation Method 3

arranging a measuring structure for measuring the physical property at a plurality of sub-areas in the measuring area in order to evaluate the physically unclonable function

Methodology Applied
Scientific EffectPhysical property measurement:

Data Source

PatentEP4661071A1Device for providing a physically unclonable function and method for manufacturing
Publication Date: 2025.12.10 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP4661071A1 patent drawingFigure 1
  • EP4661071A1 patent drawingFigure 2~3
  • EP4661071A1 patent drawingFigure 4~5

AI summary

Exemplary embodiments include a method for producing a device for providing a physically unclonable function based on a characteristic structure. The method has the following features: generating the characteristic structure by locally demixing a precursor to obtain a plurality of domains of a first substance and a plurality of domains of a second substance, in order to obtain a random spatial distribution of the domains of the first and second substances in a measuring range, wherein domains of the first substance and domains of the second substance differ in a physical property such that differences in the physical property at least partially provide the physically unclonable function. Furthermore, exemplary embodiments include devices for providing a physically unclonable function.