This is why all of my disks are encrypted. Power turns off, data is gone. If someone shows up at your door threatening you to provide them with a disk image, you can happily comply. When they realize the data is useless without the Constitutionally-protected secret key that only exists in your mind, they will have to file charges, and get a judge to order you to testify against yourself. And right about then, the investigation stops, because you committed no crime, and the order to testify against yourself is illegal. (If anything, it means you have plenty of time to talk to your attorney. They are not getting the data any other way, so you have the power to say, "wait, let me get my lawyer first", even if they physically seize your hardware.)
I also have a few drives in my house that look like LUKS encrypted disks, but are actually a LUKS header with random data following it. There is no way I could ever decrypt these disks, as there is no data on them; just random bits.
Anyway, you can tell that this was never a real criminal investigation, because a real investigator would get Gmail records from Google, not from some random guy with a laptop. This was purely to scare the blogger into not publishing information about the TSA anymore. "Chilling effect."
Your fake encrypted disks are so that you can't be forced to decrypt every disk, even under thermorectal cryptanalysis? Did you do that after reading about pre-commitment in game theory, and do you have a plan to avoid the flaw in pre-commitment strategies under asymmetric information exposed in Dr. Strangelove?
My main enemy is some random person in the airport stealing my laptop bag. My theoretical enemy is the government.
Neither of these adversaries can afford a technical attack. The guy at the airport will say "oh well", format the disk, and eBay it. The government will try to convince me that I do know the key, will fail, and will have to support its (theoretical, of course) case against me with actual evidence instead.
There is one thing I just thought of, though; the SMART log shows how much activity the disk has experienced. It should be easy to check this log to see which disk I use the most. I will come up with some way to plug this leak :)
But anyway, I am not sure this would "prove beyond a reasonable doubt" that I know the key. If any case against me ever depended on me decrypting my disk, I would first refuse. Then, theoretically, a charge of obstruction of justice would be filed against me, and the government would have to prove that before they could even consider their original case. (And that's no cakewalk, as there is case law saying I don't have to give up the password, and I don't think SMART data has ever been used in court.)
So anyway, I think my system is good enough. I don't have any friends in the government feeding me classified information, anyway :( So, it's likely that I will never get to test my system. But I hope the "Real Criminals" read this and perhaps use this information to help themselves stay safe from their oppressive regime.
Be sure that you are aware of the laws on where you travel to. In the United Kingdom, the police can seek a warrant that requires you to either decrypt a specific piece of data or to surrender any encryption private key or password under Part III of the Regulation of Investigatory Powers Act 2000. Refusing to do so under this act is a criminal offence with a sentence of two years in prison (longer if they allege that the encrypted data is either related to terrorist activity or child pornography).
The crazy thing about the TSA: I flew back from SFO to London last month. I had three laptops in my carry-on bag. I also had a can of Red Bull. Apparently, the can of Red Bull is highly suspicious, but the three laptops are not. I had a perfect excuse though: one was running OS X, another was running Linux and the last was running XP.
The TSA is not supposed to care if you are doing something illegal, they are only supposed to prevent you from bringing certain things into the secure area of the airport. Liquids (or cans that contained them) are what they are supposed to watch for. Laptops are fine.
Customs is another story; they would probably ask about your laptops.
I also have a few drives in my house that look like LUKS encrypted disks, but are actually a LUKS header with random data following it. There is no way I could ever decrypt these disks, as there is no data on them; just random bits.
Anyway, you can tell that this was never a real criminal investigation, because a real investigator would get Gmail records from Google, not from some random guy with a laptop. This was purely to scare the blogger into not publishing information about the TSA anymore. "Chilling effect."