Linux – SandForce SSD encryption – security and support

linuxssdthinkpad

I'm currently thinking about buying a ThinkPad X201 and equip it with a SSD drive. Now, to protect my data I always used Linux with LUKS full disk encryption on my laptops. However, as stated in another SuperUser post, this would disable the support for TRIM – so that doesn't seem to be a good idea with a SSD drive.

I've read that SandForce-1200 based SSDs offer integrated AES encryption tied to the BIOS password. However I can't find proper documentation on this. Questions:

  • Any general drawbacks to this approach?
  • I suppose this would require BIOS support for the feature – how to find out if works on a X201?
  • Old BIOS versions only supported short (like 6 or 8 characters) passwords, has this situation improved to provide sufficient security for a disk encryption?

Update: This Source says you can't even set any password on these drives. Huh? That doesn't make sense, why would you even do the complicated AES operatins when you don't allow to use a key?

Thank you for any expert advice on the matter 🙂

Best Answer

Answering my own question, this is what I've found out after searching on the net for a couple of hours:

  • The SandForce devices have AES encryption turned on by default, but there are issues with this (see below)
  • If you zero out the drive using ATA Secure Delete, the key will be wiped and later regenerated and thus the old data will not be accessible anymore - making this an acceptable solution when you're about to sell or trash your SSD
  • It is, however, not possible to set a user password that would prevent someone who steals your laptop with an SandForce SSD from reading your data
  • The encryption key is not linked to the ATA security and/or BIOS
  • Setting a user password would be possible if there was a tool for this. OCZ promised a program called their "toolbox" that would allow this very often on their support forums, but when it was finally released in october 2010, it still didn't have the functionality (and still not today)
  • I guess even if you could set the password using the toolbox, it would not be possible to use the device as a boot device any more because you couldn't unlock it from the bios.
  • Using software full-disk-encryption on an SSD seriously impacts the performance of the drive - up to a point where it can be slower than a regular hard disk.

Source for some of this information.

Update: If you're interested, I wrote a little more about the issues in a dedicated blog post.

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