Difference between revisions of "Full Disk Encryption (FDE)"

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(Disadvantages)
(Disadvantages)
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This can be seen as a security risk.
 
This can be seen as a security risk.
  
dm-crypt solutions are better in this respect as they will prompt for a password on the reboot.
+
Dm-crypt solutions are better in this respect as they will prompt for a password on any reboot.
  
 
Another disadvantage is that the disk can not be read if it is put in a USB enclosure.
 
Another disadvantage is that the disk can not be read if it is put in a USB enclosure.

Revision as of 09:18, 4 October 2010

Full Disk Encryption

Lenovo's 'Full Disk Encryption' (FDE) is a technology incorporated into some of Seagate's FDE-ready hard disks. It provides encryption of all of the contents of the hard disk.


Features

  • Multi platform (Linux, Windows).
  • Protects the whole disk (including FAT partition...)
  • No performance impact.
  • Compatible with TPM
  • AES (the chip which performs AES encryption has been certified by NIST )
  • Wiping the disk (for disposal...) takes just a second.


FDE Hard disk Photo, credits: seagate.com

Using Seagate FDE

Using FDE as as easy as setting up the hard disk password (from BIOS). You can choose to have just a user password, or both a user and a master password. You can export the key to an external storage, for password recovery (you need the password !!)

N.B.: The Lenovo FAQ on FDE specifically states that on the T60 & T61, there is no means of backing up or exporting the key, but that the drive may be used in another system (it is evidently not tied to a motherboard Trusted Platform Module).

Lost password

Three possibilities :

  • Use the master password to change the user key.
  • Recover the password using the previously exported key. (See note from Lenovo FAQ, above.)
  • Reset the encryption key (which causes the hard disk to be instantly "wiped", and resets the "hard disk password").

Wipe the disk

Wiping the disk is as easy as reseting the encryption key from the BIOS..

TPM

It should be possible to use TPM (with fingerprint readers...) not tested yet.

  • T61 with TPM & fingerprints, FDE password works with a configured fingerprint but you must use windows based software to program the imprint. By keeping a small windows partition, I am able to boot linux with a fingerprint, fingerprint passes the TPM power-on password AND the FDE disk 1 password, which is separate.

Disadvantages

FDE is only safe when the computer is off or hibernated. When the computer is stolen while it is on or suspended, a restart which boots from a USB stick will reveal your data. The problem is that these warm restarts will not ask for the HD password, nor the power-on-password for that matter. This can be seen as a security risk.

Dm-crypt solutions are better in this respect as they will prompt for a password on any reboot.

Another disadvantage is that the disk can not be read if it is put in a USB enclosure. Again, dm-crypt does allow to mount encrypted partitions from a USB disk (password protected, of course), which is useful when upgrading disks.

Software alternatives

It is possible to get similar security, at a very slight performance impact, by using appropriate software-based full disk encryption solutions. For example, under Linux, you can use dm-crypt to encrypt the whole disk (including swap and root partitions) except for a bootloader. Numerous tutorials are available on the Internet.

Links