Adaptive PUF Stabilizer Circuit Using Dark-Bit Masking

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Solution Overview

Problem

Existing PUF technologies face high hardware costs, poor security, and low reliability due to significant resource consumption and reliance on heavyweight error-correcting codes, limiting their application in cost-restricted environments like RFID systems.

Innovation Solution

An IC for adaptive PUF stabilization using a PUF stabilizer with a non-volatile memory, comprising PUF units, a statistic processor, majority voting generator, and dark-bit masker, which adaptively stabilizes PUF sources through multi-round evaluations and dark-bit masking to reduce error rates and maintain effective PUF bits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional PUF structures are used to achieve encryption functionality, then security requirements can be met, but hardware cost and resource consumption increase significantly

Engineering Contradiction:
ImprovesecurityVSAvoidhardware cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts only the essential stabilization function from complex error-correcting codes, implementing a lightweight dark-bit masking mechanism that identifies and corrects only the most critical unstable bits in PUF output, thereby maintaining security while dramatically reducing hardware overhead

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the operational parameters of PUF stabilization by using adaptive dark-bit masking with configurable masking ratios, allowing the system to adjust the level of stabilization based on observed PUF stability characteristics, thus achieving security with minimal hardware resources

Inventive Principle:
Principle #35Parameter changes

2Reliability

If heavyweight error-correcting codes are used to stabilize PUF output, then reliability improves, but computation overhead and manufacturing cost increase

Engineering Contradiction:
ImprovePUF output stabilityVSAvoidcomputation overhead
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts only the essential stabilization function from complex error-correcting codes, implementing a lightweight dark-bit masking mechanism that identifies and corrects only the most critical unstable bits in PUF output, thereby maintaining security while dramatically reducing hardware overhead

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of applying full error-correcting codes to all PUF bits, the patent applies partial correction by identifying and masking only the darkest (most unstable) bits, achieving sufficient stabilization with minimal computation and hardware resources

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If more PUF units are used to improve security, then encryption strength increases, but hardware resources and cost increase

Engineering Contradiction:
Improveencryption strengthVSAvoidhardware resources
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the operational parameters of PUF stabilization by using adaptive dark-bit masking with configurable masking ratios, allowing the system to adjust the level of stabilization based on observed PUF stability characteristics, thus achieving security with minimal hardware resources

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4379591B1Integrated circuit for adaptive PUF stabilization process
Publication Date: 2026.03.04 INTELLIGENT INFORMATION SECURITY TECHNOLOGY INC
  • EP4379591B1 patent drawingFigure 1
  • EP4379591B1 patent drawingFigure 2
  • EP4379591B1 patent drawingFigure 3

AI summary

An IC for adaptive PUF stabilization process includes a PUF stabilizer and a non-volatile memory. The PUF stabilizer has PUF units, a statistic processor, a majority voting generator, and a dark-bit masker. The statistic processor is connected to the PUF units, and performs measurements on the PUF units to output results. The majority voting generator is connected to the statistic processor to accumulate the results into a statistic result, which is output as a PUF bit. The dark-bit masker is connected to the PUF units, and marks unstable PUF units bit as dark-bit and create dark-bit masks. The non-volatile memory is connected to the PUF stabilizer to store the dark-bit masks, and the dark-bits are replaced by specific bit sequences provided by the PUF stabilizer. This decreases bit error rates of the PUF measurement results, and allows customization of the quantity of dark bits per dark-bit mask used.