NAND Flash Memory PUF Data Generation via Bit Line Potential Difference

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Solution Overview

Problem

Existing semiconductor devices face challenges in maintaining the randomness and reproducibility of inherent data while minimizing circuit element variations, which can lead to decreased non-predictability and reliability in PUF technologies.

Innovation Solution

A semiconductor device incorporating a NAND-type flash memory with a selection mechanism for specific memory areas, a reading mechanism for bit line pairs, and a generating mechanism that outputs inherent data based on detected potential differences, ensuring randomness and reproducibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If circuit elements and wiring are minimized for uniformity, then manufacturing precision and reliability are improved, but the randomness of PUF inherent data deteriorates

Engineering Contradiction:

Improveuniformity of circuit elementsVSAvoidrandomness of PUF data

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention divides the memory array into multiple blocks and selects specific blocks for PUF data generation. By segmenting the memory structure and using selection means to choose particular blocks, the system maintains manufacturing uniformity while preserving the randomness needed for PUF functionality through the natural variations that exist in selected blocks.

Inventive Principle:

Principle #1Segmentation

2Reliability

If inherent information is stored in non-volatile memory, then security is improved, but the risk of information leakage through analysis or improper access increases

Engineering Contradiction:

Improvesecurity of inherent informationVSAvoidrisk of information leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts PUF inherent data from the memory structure by detecting potential differences in selected memory blocks rather than storing traditional secret keys. This extracted physical characteristic data is inherently tied to the device's manufacturing variations, making it secure against conventional attacks while avoiding the storage of vulnerable cryptographic secrets.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses potential difference detection as an intermediary mechanism to access PUF data. Instead of directly reading stored information that could be leaked, the system uses the detection means to measure electrical potential differences in selected memory blocks, which indirectly reveals the inherent physical characteristics without exposing vulnerable stored secrets.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10971236B2Semiconductor device with a function of generating inherent information

Publication Date: 2021.04.06 WINBOND ELECTRONICS CORP

AI summary

The present invention utilizes a new method to provide a semiconductor device having a function of generating inherent data. The NAND-type flash memory of the present invention has a memory cell array, a page buffer/sense circuit, and a differential sense amplifier that detects the potential difference of a bit line pair of a dummy array when the dummy array of the memory cell array is read out, wherein the NAND-type flash memory outputs the inherent data of the semiconductor device according to the detection result of the differential sense amplifier.