(yep, it's the "hit him with a wrench" one)

- I don't find it reasonable for "them" to grill me too much. I don't need to hide my encrypted partitions or use hidden partitions. I'm not a target of any interest to any three-letter agencies or customs officials. But I don't want to start discussing unlocking my laptop with anyone, I want to make it a matter of "can't" instead of "won't".

- The friend scheme might not be necessary or a good choice. I could just say I have the decryption keys at home which is entirely true. I can still use the machine: I have just deselected a few partitions out of use permanently until I return home

I think you'd have better luck giving them something they expect instead of sabotaging your system.

For this to work, you need to actually use the dummy partition for non-sensitive matters -- and be absolutely religious about separating the sensitive tasks from non-sensitive, which is much more difficult than it first sounds.

There is nothing unusual about that.

This won't help you legally. You may honestly claim that you don't have the passphrase, but you cannot honestly claim that you cannot decrypt the contents. You just have to call and ask your friend while you're detained at customs.

Ask the inverse: they decide to detain you, indefinitely, until you produce the encryption key or admit that there's some base level of contraband on your computer that you're responsible for. What happens in that case?

Maybe as a Canadian I see this differently. At least as an American you will have certain rights that you can hope to depend on in your own country. But I forfeit all those rights when I cross the border. What's to stop these guys from detaining me as an international terrorist?

Although TrueCrypt hidden volumes may have some practical applications, we think they are unlikely to be useful in the border search context because they are most helpful when lying to someone about whether there is additional hidden data on a disk. Lying to border agents is not advisable, because it can be a serious crime. [PDF: https://www.eff.org/sites/default/files/filenode/EFF-border-...]

Might hidden volumes help you pass a cursory check? Sure. But if someone really wants your data it's not likely going to keep you out of a contempt of court charge.

Now all that you have to do is prove that you either don't know or have forgotten the key that decrypts your random bits into a plan they will accept. How hard do you think it will be to convince an aggressive prosecutor/judge that you are innocent when you have no evidence (can't prove a negative) and the government has reasonable suspicion?

A small key does not contain enough information to make the data decrypt to any arbitrary thing.

This advice is based on the EFF document. IANAL.

https://www.eff.org/document/defending-privacy-us-border-gui...

How many border protection agents look into your /etc/fstab and know fdisk, mount and cryptsetup?

How is this supposed to be implemented?

They don't need to. Microsoft and other companies have been providing software on bootable CDs and USB keys to do quick 'security' audits of PCs for years to various police forces. I'd be extremely surprised if detecting encrypted/hidden partitions wasn't a common feature.

Is there software that detect HDDs that are disabled via BIOS? Do the border agents reset the BIOS? Are they looking at individual files and encrypted archives?

http://en.wikipedia.org/wiki/In_re_Boucher

In that case the government could only compel the defendant to produce his keys because they already knew what was on the drive in question.

It's a federal crime to lie to a border agent or government agent, and the EFF specifically says not to do this - see comment above.

Hidden volumes are fine for other uses and perhaps in other jurisdictions but will land you in hot water in the US/US Border.

The EFF advice is as follows:

Although TrueCrypt hidden volumes may have some practical applications, we think they are unlikely to be useful in the border search context because they are most helpful when lying to someone about whether there is additional hidden data on a disk. Lying to border agents is not advisable, because it can be a serious crime.

Lying to border agents clearly is a serious offence, but as far as I can see that is the "only" major problem with hidden volumes. Given many of the suggestions so far involve lying to border agents along with weird schemes that are less technically secure than hidden volumes it would appear hidden volumes have two things going for them:

1) No worse than other options (assuming you have to carry data with you somehow)

2) Give you a higher possibility that you won't need to lie to border agents (failing to tell them about your additional layer of security will get you in trouble, but is more defensible in court than outright lying)

Show them a partition with normal files encrypted with the display key, while keeping your secret-key-activated files on the hidden partition.

Of course, this won't stop a determined search, but it will likely get you by the security guards.