Slashdot Mirror
Self-Encrypting Drives Hardly Any Better Than Software-Based Encryption (cio.com)
itwbennett writes: The main security benefit of Self-Encrypting Drives (SEDs) is that the encryption key is not stored in the OS memory, but on the disk itself, which makes it less exposed to theft. However, some attacks that work against software-based encryption products also affect SEDs, including evil maid attacks and those that bypass Windows authentication. Once a SED is unlocked, it remains in that state until the power to it is cycled or a deauthentication command is sent. When the laptop is put in sleep mode the drive state is locked, but when it resumes from sleep, the pre-boot management software, which is already loaded in memory, unlocks the drive. [A team of] researchers devised three attacks to take advantage of this situation.
Self encrypting hard drives require trusting the code in the drive to be correct. While there are places people are willing to trust proprietary code, this should not be one of them. Proprietary code creates a "break once, own anywhere" setup, in the one place where that is the most ludicrous thing.
Who has the keys? Does the manufacturer have the keys? That seems to be the case, and what your password becomes is a way to unlock the copy of the key that the device has. This means when you change the password, you aren't actually changing the encryption key (which in some of the vulnerable drives cases here, was actually available on the goddamned drive in plaintext, but in the best case is hashed, and in ALL cases is in theory known to the drive manufacturer).
If you have data worth encrypting, you should use software based encryption. It doesn't require special tools to uncover mistakes, and the mistakes that we've seen already (including *just leaving the fucking key plaintext*) are really amateur level shit.
Then we have another problem- even IF the key is properly maintained, and even IF the manufacturer doesn't have a cabinet full of keys, how did they generate those keys? How is their random number generator? Remember, it's going to be just ONE target for an attacker here, since the keys all have a common source, so any mistakes are much more likely to be discovered, and much more likely to function.
Open source software encryption or gtfo. Bonus: You can choose an algo, or stack algos. AES-128 / AES-256 not to your liking? Layer them with Twofish and Serpent, or drop it in favor of those. You may not need to take the performance hit, but shouldn't it be your choice?
Software encryption is actually encryption. Hardware encryption is someone's marketing stunt.