2 replies to this topic

[Rootman]

I want to get a Samsung 850 SSD for my new Dell Latitude 7000 laptop.  It's an SSD with encryption built into the controller.  To really use it you have to pair it with the BIOSs ATA (or hard drive) password.  It's my understanding that the Samsung 850 works with the password and encrypts the contents using it with the key that's stored on the disk.

What concerns me is that I see a lot of talk about how trivial it is to defeat the ATA password.  Looks like you just use some some easily obtainable software on a live CD or PE from USB and you can blank or change the ATA password in a few minutes.  So does defeating the password simply allow the disk to then be accessed? Or does it protect itself from this vulnerability somehow? If it's so easily deflatable  then the SED is practically useless. 

I currently use a standard HDD and have about 9/10ths of it as a TrueCrypt partition. I would like to switch to the SSD with SED, but NOT if it can be defeated so easily. I was pondering using the SSD with TrueCrypt the same way but see others advising against it due to "wear leveling".  So does anyone know the full scoop on that?  I would think the number of writes would be the same regardless if it's a TC partition or not.

Next question:  Can I still use my Windows PE USB boot stick and back up the data on the SSD W/SED and the ATA password?  Can I insert the USB key, start the laptop, enter the ATA password to unlock the drive, peck F12 to use the USB key to boot to PE from and then see the SSDs contents?  I religiously back up my OS with Symantec Ghost every week using PE from a USB stick and would like to continue doing so.

[Wonko the Sane]

Well, AFAIK it is not at all "easy" to defeat the ATA password. (the fact that some implementations of it on some hard disks was badly implemented and/or the password was in "clear text" and in known accessible areas is another thing).

Also consider that there are both "High Security" and "Maximum Security" levels (the latter type is tricky, as to reset it normally you need the "High Security" "Master" password AND to initiate a Secure Erase).

Cannot say anything about SED (nor specifically for that SSD), but if it is anything like the FDE Seagate drives:
http://forum.hddguru...pic.php?t=15948
the encryption is on a "different level" from ATA password.


Wonko

[v77]

I would think the number of writes would be the same regardless if it's a TC partition or not.

 

Theoretically, yes. However, as all the data of the SSD will be encrypted, and because TC is used as an intermediary, the TRIM command will not work, and so, the SSD will work as if it was constantly full, with no cell erased in advance. This can lead to an important performance drop.
That said, it can still be faster than a mechanical hard disk and so, if you want to use TC, you first have to ensure that your CPU is fast enough. TC is not really known for its performances...

About SED, personally, I would never trust a closed source system of encryption and, moreover, a system which gives us practically no information about the encryption itself : key derivation function, hash algorithm, mode of operation...