Reliably Erasing Data From Flash-Based Solid State Drives

Sarad AV jtrjtrjtr2001 at yahoo.com
Fri Feb 18 01:31:58 PST 2011


This may be of interest

Abstract:
Reliably erasing data from storage media (sanitizing the media) is a critical
component of secure data management. While sanitizing entire disks and
individual files is well-understood for hard drives, flash-based solid state
disks have a very different internal architecture, so it is unclear whether
hard drive techniques will work for SSDs as well. We empirically evaluate the
effectiveness of hard drive-oriented techniques and of the SSDsb built-in
sanitization commands by extracting raw data from the SSDbs flash chips
after applying these techniques and commands.

Our results lead to three conclusions:
First, built-in commands are effective, but manufacturers sometimes implement
them incorrectly.
Second, overwriting the entire visible address space of an SSD twice is
usually, but not always, sufficient to sanitize the drive. Third, none of the
existing hard drive-oriented techniques for individual file sanitization are
effective on SSDs.
This third conclusion leads us to develop flash translation layer extensions
that exploit the details of flash memorybs behavior to efficiently support
file sanitization. Overall, we find that reliable SSD sanitization requires
built-in, verifiable sanitize operations.

http://www.usenix.org/events/fast11/tech/full_papers/Wei.pdf





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