SSDs prove difficult to securely erase
At this week's Usenix FAST 11 conference on File and Storage Technologies in San Jose, California researchers published a paper examining the effectiveness of different secure erasure methodologies on Solid State Disks (SSDs).
Context & Ripple Effects
The SSD industry had spent 2008 racing on throughput — SanDisk's promise of 100x faster SSD writes being the emblematic claim — while security teams were still arguing over whether magnetic-disk assumptions held at all; CNET's 'Can you trust it?' examination of disk encryption that same year showed how unsettled the question already was. The Usenix FAST 11 paper is the first rigorous answer for erasure specifically: methodologies built for spinning platters do not map cleanly onto flash.
First-order effects
- Organizations decommissioning or reselling SSDs can no longer treat an overwrite-based wipe as verified destruction — every drive retired before this finding is a potential exposure.
- Vendors selling SSDs into enterprise and government channels face immediate pressure to document what their drives actually do when erase commands are issued.
Second-order effects
- Full-disk encryption becomes the practical fallback, since destroying the encryption key sidesteps the unreliable erase path — shifting the burden onto key management and reinforcing the trust questions raised in earlier coverage.
- Drive makers are pushed to expose firmware-level sanitize operations and to publish their behavior, because buyers who cannot verify a wipe will price that risk in.
Third-order effects
- If the pattern holds, data-destruction standards and disposal certifications written for hard drives need revising for flash media, adding an attestation layer to the secondary-market chain for used storage.
- Security practice splits by medium: magnetic-disk playbooks persist where they work while flash requires cryptographic erasure by default, making the erase method a purchasing criterion rather than an afterthought.
The trend: Storage-security assurance is being forced to catch up with each change in underlying media, as erasure guarantees that worked for one technology silently fail on its successor.