一句话：提出Evanesco，通过锁定闪存页/块访问而非物理销毁，实现高效且可靠的数据净化。
随着数据隐私与安全需求增长，如何从存储系统中安全擦除数据变得与可靠存储同等重要。但在现代闪存存储中，不可恢复地净化文件往往带来较大性能或可靠性代价。本文提出Evanesco，一种面向高密度3D NAND闪存的数据净化技术。不同于物理销毁数据，它通过阻止对已删除数据的访问来实现净化：利用闪存芯片中的空闲单元，支持页级pLock与块级bLock两种锁命令，且只有数据被擦除后锁才能解除，从而在更强威胁模型下提供安全保证。作者实现SecureSSD仿真闪存系统并评估，结果显示其能以较小性能开销有效支持数据净化，且无可靠性退化。
As data privacy and security rapidly become key requirements, securely erasing data from a storage system becomes as important as reliably storing data in the system. Unfortunately, in modern flash-based storage systems, it is challenging to irrecoverably erase (i.e., sanitize) a file without large performance or reliability penalties. In this paper, we propose Evanesco, a new data sanitization technique specifically designed for high-density 3D NAND flash memory. Unlike existing techniques that physically destroy stored data, Evanesco provides data sanitization by blocking access to stored data. By exploiting existing spare flash cells in the flash memory chip, Evanesco efficiently supports two new flash lock commands (pLock and bLock) that disable access to deleted data at both page and block granularities. Since the locked page (or block) can be unlocked only after its data is erased, Evanesco provides a strong security guarantee even against an advanced threat model. To evaluate our technique, we build SecureSSD, an Evanesco-enabled emulated flash storage system. Our experimental results show that SecureSSD can effectively support data sanitization with a small performance overhead and no reliability degradation.
DOI 原文 ·
@inproceedings{paperbot5402,
title = {Evanesco},
author = {Myungsuk Kim and Jisung Park and Genhee Cho and Yoona Kim and Lois Orosa and Onur Mutlu and Jihong Kim},
booktitle = {ASPLOS},
year = {2020},
doi = {10.1145/3373376.3378490}
}