Work

Page-Overwrite Data Sanitization in 3D NAND Flash: Challenges, Feasibility, and the PULSE Solution

Year: 2025

Type: article

Abstract: Instant data deletion (or sanitization) in NAND flash devices is essential for achieving data privacy, but it remains challenging due to the mismatch between erase and write granularities, which leads to high overhead and accelerated wear. While page-overwrite-based instant data sanitization has proven effective for 2D NAND, its applicability to 3D NAND is limited due to the unique sub-block architecture. In this study, we experimentally evaluate page-overwrite-based sanitization on commercial 3D NAND flash memory chips and uncover significant threshold voltage disturbances in erased cells on adjacent pages within the same layer but across different sub-blocks. Our key findings reveal that page-overwrite sanitization increases the median raw bit error rate (RBER) beyond correction limits (exceeding 0.93%) in Floating-Gate (FG) Single-Level Cell (SLC) technology, whereas Charge-Trap (CT) SLC 3D NAND flash memories exhibit higher robustness. In Triple-Level Cell (TLC) 3D NAND, page-overwrite sanitization proves impractical, with the median RBER of ∼13% for FG and ∼5% for CT devices. To overcome these challenges, we propose PULSE , a low-disturbance sanitization technique that balances sanitization efficiency ( \({{\eta }_{san}}\) ) and data integrity (RBER). Experimental results show that PULSE eliminates RBER increases in SLC devices and reduces the median RBER to below 0.57% for FG and 0.79% for CT in fresh TLC blocks, demonstrating its practical viability for 3D NAND flash sanitization.

Source: ACM Transactions on Embedded Computing Systems

DOI: 10.1145/3761798

Authors: Matchima Buddhanoy, Aleksandar Milenkovic, Sudeep Pasricha, Biswajit Ray

Institutions: Colorado State University, University of Alabama in Huntsville

Language: English

Topic: Advanced Data Storage Technologies

Subfield: Computer Networks and Communications

Field: Computer Science

Domain: Physical Sciences

Open Access status: bronze

Funder: National Science Foundation

Awards: CNS Core: Small: Ensuring Privacy by Runtime Analog Sanitization of Solid State Storage Devices, Collaborative Research: SaTC: CORE: Small: Exploring Security Risks Arising from SRAM Data Remanence and Evaluating Innovative Sanitization Techniques, EAGER: SaTC: Applying Adversarial Machine Learning Techniques to Recover Deleted Information from Flash Storage