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Of Encrypted Hard Drives and "Evil Maids"
Schneier has a blog piece about Joanna Rutkowska's "evil maid" attack, demonstrated earlier this month against TrueCrypt. "The same kind of attack should work against any whole-disk encryption, including PGP Disk and BitLocker. ... [A] likely scenario is that you leave your encrypted computer in your hotel room when you go out to dinner, and the maid sneaks in and installs the hacked bootloader. ... [P]eople who encrypt their hard drives, or partitions on their hard drives, have to realize that the encryption gives them less protection than they probably believe. It protects against someone confiscating or stealing their computer and then trying to get at the data. It does not protect against an attacker who has access to your computer over a period of time during which you use it, too."
physical access > digital security
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Someday I want to invent an attack, but only because I want the privilege of naming it.
Just another good reason to take your bootloader with you on a thumb drive or other type of removeable media.
When you encrypt your system partition with Truecrypt it forces you to make a CD (you actually have to burn and mount it before it will let you continue). This CD contains a copy of the bootloader and encryption key. If you always boot off that CD it won't help to attacker to replace the bootloader on the HDD.
Of course they could target the CD but at least you can keep a mini CD in your wallet at all times.
const int one = 65536; (Silvermoon, Texture.cs)
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I didn't read the RTFA, but aren't MSFT's BitLocker supposes to validate the boot path (from BIOS code to bootloader up to the BitLocker decrypter) with the help of the TPM chip?
It does, and thus the attack doesn't work here:
"The key used for the disk encryption is sealed (encrypted) by the TPM chip and will only be released to the OS loader code if the early boot files appear to be unmodified."
Now we'd just need someone to reverse the decision that TPMs are all evil and should not be used.
Worse than that. It says the outfit is sold out. I am NOT going outside or answering the door this Halloween.
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Bullshit.
The bootloader is signed. Use this in combination with the TPM chip (embedded smartcard) on your laptop - AS SPECIFIED BY THE GUIDANCE - and use a PIN. There's no loading the disk or getting at the data without cracking AES. At least once.
So... Start your engines.
"Speaking the Truth in times of universal deceit is a revolutionary act." -- George Orwell
If you are the kind of person that are in the danger zone of this happening (not that you would leave a computer with such sensitive information in your hotel room.); You would probably feel a lot better if you were able to checksum the bootloader when returning, maybe from an external usb drive. This would offcourse run it's own OS, not being done from the bootloader(for obvious reasons).
Which is why you want a blackberry. One of the common complaints about blackberries is that they take a very long time to turn on after a power cycle. Five minutes or longer to boot isn't uncommon. Compared to most cellphones which boot in a few seconds, this is very irritating.
The reason is that the blackberry is verifying the boot ROM, boot loader, OS, and firmware for signs of tampering.
Windows 7 is different from Vista in the way businesses and enterprises use it. Vista had two editions that were activated via an internal KMS system (very important when you have thousands of PCs and do not want them touching the Internet for activation). Windows 7 has only one edition that has this functionality, the Enterprise edition. This is available via volume license key agreements. Other than the MAK/KMS model of activation, this edition is the exact same as Ultimate which has BitLocker, BranchCache, and the other items.
So, if a company is using a volume license of Windows 7, they will have access to BitLocker functionality. Server-wise, Windows Server 2008 and Windows Server 2008 R2 both have BitLocker functionality built in.
This way, if a corporation that is running Windows 7 orders a bunch of laptops, they would be fools not to order ones with TPM chips because their OS will easily support this functionality. If they have an Active Directory infrastructure and no existing encryption product (PGP, PointSec), getting BitLocker deployed enterprise wide wouldn't be too difficult with AD holding recovery keys to machines.
I'm glad Microsoft did this. No worry if a company has Business or Enterprise editions for features (like the issues with Vista). Now, if a company has a VLK and uses a key management server for internal activations [1], they have BitLocker available with W7.
[1]: I'm not a fan of activation at all. Personally, my wish is they would have gone back to how XP VLK editions handled this. Businesses are not going to be pirating Windows because the BSA will come for a visit. Pirates will crack any activation. So, there is no real antipiracy benefit to Microsoft in forcing businesses to have an activation infrastructure.
I worked for a quasi-governmental agency for a number of years. Although we adopted disk encryption, our primary defense was the one you describe: you don't go anywhere without your laptop. That's right--not left in the conference room over lunch, or even unattended in the airport bathrooms. I still can't believe how many brain donors set their laptop bags down near the entrance or the sink and then go do their business. It's either in the stall, over your shoulder, or on the floor against your legs. They were even told not to leave them in their cars if they stopped at the grocery store on the way home (we had one stolen that way during a "3 minute" stop). We even had some good training videos that showed how quickly someone could swap laptop bags (for so long, most of them looked alike), or pop open the bag and replace the laptop with a phone book in under 30 seconds while a speaker was busy talking to guests after a presentation.
In addition, there were reports that had to be filled out to inform management if a laptop was lost or stolen. There were disclosures to the entities that were supervised. The consequences of losing a laptop were so painful that no one wanted to lose one.
I use irony whenever I can, but my shirts are still wrinkled...
BIOS BOOT PASSWORD