SRAM PUF Inter-Hamming Analysis for Uniqueness Verification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing physically unclonable functions (PUFs) based on SRAM memory arrays face challenges in ensuring uniqueness and unclonability due to variations in power-up states, which affect their reliability and security as unique identifiers in integrated circuits.

Innovation Solution

An Inter-Hamming Distance (Inter-HD) analyzer is used to measure and verify the uniqueness of SRAM-based PUFs by analyzing the differences in responses under varying operating conditions, ensuring that the Inter-HD is close to 50% to guarantee uniqueness and unclonability, while the Intra-HD assesses reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If SRAM memory arrays are used to build PUFs based on power-up states, then unique identification is achieved, but reliability and security are compromised due to variations in power-up states

Engineering Contradiction:

Improvereliability of PUFVSAvoiduniqueness verification accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces physical measurement methods with logical analysis methods. Instead of measuring physical power-up states directly, the system uses Inter-Hamming Distance analysis to evaluate the uniqueness and reliability of PUF responses through bit pattern comparison, substituting physical measurement with logical computation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the evaluation parameter from direct power-up state observation to Inter-Hamming Distance measurement. By analyzing the Hamming distance between PUF responses under different operating conditions, the system can assess reliability and uniqueness without being affected by raw power-up state variations.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If Inter-Hamming Distance analysis is performed to verify uniqueness, then security is enhanced, but device complexity increases

Engineering Contradiction:

Improvesecurity of PUFVSAvoidcomplexity of analyzer

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The analyzer is divided into functional modules: a controller to manage the analysis process, a storage device to hold reference data, and a comparator to perform Hamming distance calculations. This segmentation allows each component to perform a specific function, simplifying the overall design while maintaining security.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The Inter-Hamming Distance analyzer is designed to work with SRAM-based PUFs and can evaluate multiple operating conditions. The same analyzer structure can be applied to different PUF implementations, providing a universal solution for PUF verification that enhances security without requiring separate complex systems for each application.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11210165B2Inter-hamming difference analyzer for memory array and measuring and testing methods for inter-hamming differences of memory array

Publication Date: 2021.12.28 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An inter-hamming difference analyzer for a memory array having a plurality of sections is provided. The inter-hamming difference analyzer includes a controller, a storage device and a comparator. The controller is configured to obtain contents of the plurality of sections operating in a first operating condition and a second operating condition. The storage device is configured to store the contents of the plurality of sections corresponding to the first operating condition. The comparator is configured to obtain a plurality of inter-hamming differences of the plurality of sections according to the number of unlike bits between the content of a first section of the plurality of sections corresponding to the second operating condition and the contents of a plurality of sections other than the first section stored in the storage device.