Comment by higherpurpose | Hacker News Reader

Comment by higherpurpose | Hacker News Reader

A feature I'd like to see on both our laptops and mobile devices to protect their privacy from random and abusive border searches: being able to hide the fact that you have an encrypted account.

Use case: Say you pass the UK border, and they can willy nilly decide to check your laptop or mobile phone. But you have an account that is password protected and encrypted, and they see that, and ask you for your password. You say no - and you get arrested for it. If they couldn't see you have that password protected account, and all they could see is a "normal" (clean of sensitive stuff) account, then they'd just check that and move on. Or you could even password protect that, too, and give them the password to it, and they'd be none the wiser.

All you'd need is to be able to hide that account from the main screen when you turn on the laptop or mobile device, and you should only be able to re-enable it from a menu prior to booting into the OS. It shouldn't be easily accessible either, otherwise it defeats the point.

I don't see Microsoft doing something like this - ever. Apple might if enough people asked for it, but I'd incline to say they wouldn't for now. Google probably won't do it either for Android or Chrome OS, since they probably see no benefit to it. But it would be nice if that feature at least came to Linux and some custom Android ROMs like Cyanogen.

It's called deniable encryption[1]. TrueCrypt supports it[2]. Bruce S is not a fan of their implementation, however[3].

[1] http://en.wikipedia.org/wiki/Deniable_encryption

[2] http://www.truecrypt.org/docs/plausible-deniability

[3] https://www.schneier.com/blog/archives/2008/07/truecrypts_de...

Huh. I hadn't thought about multiple-image attacks.

Could that be mitigated by having TC occasionally randomly write random data to unused blocks?

The table of unused blocks would violate your deniability. Indeed, any such mutating of ostensibly free space by TrueCrypt would give it up.

You have to consider the adversary. Are you a non-targeted individual who want to keep some things private from a spurious search by law enforcement or border agents, then simply the ability to boot up and not have sensitive stuff and not have an obvious encrypted partition lying around will do the trick.

If, on the other hand, you're targeted by someone with a strong reason to believe that you are hiding stuff on your computer, maybe even someone who will break into your apartment every day to image your computer, you're gonna have a bad time (and a keylogger on your computer, but that's a different kettle of fish). Basically, evidence of the existence of your hidden partition can leak out into the real world, not because of bad cryptography, but because you're human.

> Bruce S is not a fan of their implementation, however[3].

Its worth pointing out that his concerns seem to apply only to using Truecrypt to encrypt a portion of a drive, as opposed to whole-disk encryption.

For the purposes of border searches, the best approach is to use full-disk encryption and have a separate OS installed. You can then configure your bootloader to default to the plain OS and not to show itself unless a key is pressed. This will mean that the encryption is not obvious to the 'turn it on and look' inspection.

If you want to hide the presence from a disk image (for example), then it will be much more difficult. Truecrypt's hidden partitions can make it difficult to prove that the hidden partition exists, though if you're not extremely careful then circumstantial evidence can point strongly towards it.

Here's an idea that I've been toying with for several months now.

Many modern laptops have an mSATA port in addition to a regular 2.5" SATA hard drive. If you install a tiny SSD in the mSATA port and move your OS to the SSD, you can enjoy the speed of SSD without giving up the capacity of the hard drive.

But what if you installed a large (480GB or 960GB) SSD in the mSATA port and used it for all of your storage needs? Then the regular hard drive becomes completely redundant. But TSA agents are not known for their tech savvy, so most of them will not realize that you're not even using the regular hard drive.

So put a decoy OS on the regular hard drive, with no encryption whatsoever. All the encrypted stuff goes on the mSATA SSD instead. Prior to the trip, configure your BIOS to boot from the regular hard drive, and dislocate the mSATA SSD just a couple of millimeters in its slot so that it's not even recognized. When the agent boots the laptop, all he's going to see is a clean OS that takes up the entire hard drive, and even if he takes a disk image, there will be nothing suspicious on it.

Now you only need to make up some story along the lines of your computer crashed last week and you had Geeksquad reformat it but you didn't have time to copy all your family photos back from the external drive at home.

Well, now that I've spilled the beans on HN, they'll probably try to pull my mSATA SSD the next time I try to enter the US. Shit.

I used to do this on a pre-unibody Macbook Pro. The main drive still had OS X, I used that only when I was in coffee shops or airport lounges. But I also had a 40GB SSD expresscard that was bootable that was fully encrypted that I used for my personal use. It worked really good, you just slipped in the expresscard and held down the option key when you started up, and chose the other drive. I carried the card on my person when I traveled, if someone stole my machine I didn't lose anything, and I suppose if it was searched at a border, nobody would know it wasn't my main OS.

On Windows, you can hide accounts from the logon screen using the SpecialAccounts registry key. I use it to hide admin accounts on relatives' computers that I setup. You can still run programs as them using the "Run as different user" option.

> "you should only be able to re-enable it from a menu prior to booting into the OS."

How would you be able to hide this from police once such feature is built into every OS?

Assuming that feature by default asks for a password regardless of whether such protection has been enabled by the user or not (first time setting up the device/computer) -- so that no information is leaked on whether the user IS actually using the feature -- I supposed the police can still arrest you or keep you longer there to investigate whether you are lying or not.

It depends on the sophistication of the attacker. If you have TrueCrypt installed and a big chunk of random data on your disk then it's pretty obvious that you're hiding something. Even stenography is pretty easy to detect for non-trivial amounts of data.

Another issue is that you never know if the border patrol is going to add some unwanted monitoring software or hardware to your computer. It seems unlikely but with the NSA revelations we had I wouldn't be surprised anymore.

Put glitter nail polish along all the seams of the device. Then photograph the dried pattern. Once the device is through the border, compare the patterns to the known ones to check for tampering.

And re-flash all your EEPROMs that are scattered across devices.

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