Physical Unclonable Function Based on 3D-NAND Flash Array Structure With Multi-Chip Implementation

Area of Science:

• Electrical Engineering
• Computer Engineering
• Materials Science

Background:

• Physical Unclonable Functions (PUFs) are hardware security primitives using device variations for unique fingerprints.
• Conventional CMOS-based PUFs suffer from large area and power consumption.
• Existing PUF methods can lead to degradation due to stress.

Purpose of the Study:

• To propose a novel PUF design utilizing 3D-NAND flash memory.
• To leverage intrinsic string current variations for secure device identification.
• To overcome limitations of conventional PUFs, including area, power, and degradation.

Main Methods:

• A PUF architecture based on 3D-NAND flash arrays was developed.
• Read operations were employed for Challenge-Response Pair (CRP) extraction, avoiding stress.
• String select lines and bitlines applied challenges, with wordlines acting as PUF chips.

Main Results:

• Fabricated planar NAND flash arrays confirmed current variability due to process variations.
• A 3D-NAND PUF achieved near-ideal metrics, passing statistical tests and ML attack simulations.
• The design demonstrated high CRP capacity due to 3D-NAND's cell density.

Conclusions:

• 3D-NAND flash offers a promising platform for scalable and reliable hardware security.
• The proposed PUF design is robust against degradation and attacks.
• This approach enables integration of multiple PUF chips within a single array for enhanced security.