Ring Oscillator PUF Using Memory Repair Data for Stable Responses

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Solution Overview

Problem

Existing PUF technologies suffer from response instability across temperature ranges and process corners, susceptibility to reverse engineering via machine learning algorithms, and vulnerability to side-channel attacks.

Innovation Solution

A PUF device utilizing ring oscillators, counters, comparators, and memory repair data to generate a robust and unique identifier through a two-stage process involving error correction and calibration, ensuring consistent responses and resistance to attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing PUF technologies are used, then a unique identifier is generated, but the response stability across temperature ranges and process corners deteriorates

Engineering Contradiction:

ImprovePUF response stabilityVSAvoidtemperature range variation

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent employs calibration circuits that measure the actual PUF response across different temperature conditions and use this feedback to adjust compensation values. These compensation values are stored and applied to correct the PUF response, ensuring stability across temperature ranges and process corners through continuous adaptation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent changes the operating parameters of the PUF by introducing temperature compensation mechanisms and calibration procedures. By adjusting compensation values based on measured responses at different temperatures and process corners, the system maintains consistent PUF response characteristics despite parameter variations.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If existing PUF technologies are used, then a unique identifier is generated, but susceptibility to reverse engineering via machine learning algorithms increases

Engineering Contradiction:

Improvesecurity robustnessVSAvoidmachine learning attack vulnerability

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent enhances the PUF response by combining multiple independent PUF instances with memory repair data, creating a multi-dimensional response space. This dimensional expansion makes it significantly more difficult for machine learning algorithms to model and reverse-engineer the PUF, as the attack complexity increases exponentially with each added dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent creates a composite PUF system by integrating multiple PUF instances, memory repair data, and calibration information into a unified response generation mechanism. This composite structure leverages the strengths of each component while mitigating their individual weaknesses, resulting in enhanced security robustness against machine learning attacks.

Inventive Principle:

Principle #40Composite materials

3Reliability

If existing PUF technologies are used, then a unique identifier is generated, but vulnerability to side-channel attacks increases

Engineering Contradiction:

Improvesecurity robustnessVSAvoidside-channel attack vulnerability

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces calibration circuits and compensation mechanisms as intermediary layers between the physical PUF and the output response. These intermediaries process and mask the raw PUF response, making it significantly more difficult for side-channel attacks to extract meaningful information about the underlying physical characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If calibration and error correction processes are implemented, then PUF response stability improves, but device complexity increases

Engineering Contradiction:

ImprovePUF response consistencyVSAvoidcalibration circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs calibration and error correction procedures during the manufacturing and initialization phase, storing the resulting compensation values in non-volatile memory. This preliminary action eliminates the need for complex real-time calibration circuits during operation, reducing device complexity while maintaining response consistency through pre-computed compensation.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12519663B2Synergistic physical unclonable function (PUF) using memory repair data and ring oscillators

Publication Date: 2026.01.06 INFINEON TECHNOLOGIES AMERICAS CORP

AI summary

A physical unclonable function (PUF) device is disclosed. The PUF device includes ring oscillators. Each ring oscillator generates an oscillating signal based on an input challenge. The PUF device further includes counters. Each counter counts a number of oscillations in an oscillating signal generated by a corresponding ring oscillator, and produce a counter value representing the counted number of oscillations. The PUF device further includes comparators. Each comparator compares a counter value with a median counter value, and produce a resulting value. The PUF device further includes a response generator that generates a first response based on the resulting values. The first response includes an address used to index into a memory device to read PUF data and memory repair data from the memory device. The PUF device further includes a PUF output generator that generates a second response based on the PUF data and the memory repair data.