I am less convinced. If the GMan nabs you, sees you are using a tool which heavily advertises a hidden partition, and coincidentally your drive has a large unused block of random data - they are unlikely to be fooled.

If your security concerns are about governmental intrusions, then you have a security need that no single tool can resolve anyway. You need to address overall behavior and habits, which are likely to include things like not keeping sensitive data on machines that can be easily accessed regardless of the use of encryption or obfuscation.

> otherwise it seems very suspicious to have a disk filled with random data ;-)

You could always argue that the drive was previously "securely erased" and filled w/ random data and/or that it was "securely encrypted" with a key that was then destroyed?

They could still try rubber-hose interrogation techniques until you remember the key...

There was an interesting talk at one edition of CCC that boiled down to saying those techniques work only if you have the right to remain silent. Which depends on the country you're in. And I heard that in the USA, even though you have the right to remain silent, they still have the right to put you in jail if you refuse to give out your key.

You're thinking the RIP Act in the UK where the police can get an order from a judge for you to turn over a key/passphrase and you need to either prove you don't know it or face up to two years in jail (five for cases of child abuse or national security).

I'm not American but I'm pretty sure no law like that in the US would be upheld at appeal, it's pretty directly conflicting with the 5th amendment.

I heard it specifically for the USA in at least two occasions. I don't remeber the first, but the latter was in the Brett Jonson's show: in an episode, he talked about another criminal that had some encrypted material and refused to give out the key. He was put in jail until he decided to give it, and at that point IIRC he got an even longer sentence due to the proof he gave them access to. But now that I think about it, it could be that the USA had him arrested by a third country, so maybe some other state's law was at stake. But I would still not bet my safety on it. Even if you successfully appeal it, you would still risk to spend quite some time in prison.

I'm not a lawyer, but from what I remember in the USA the 5th amendment defense works only with some kinds of keys: it works with a password, but wouldn't work with a "pattern" (i.e. Android's option of drawing a pattern by connecting dots) or biometric authentication.

I remember a case too. They were 100% certain a hard drive contained CP but could not get the password. I'm pretty sure he was jailed for contempt until it was given out. Definitely inside the USA.

I remember a case too. They were 100% certain a hard drive contained CSAM but could not get the password. I'm pretty sure he was jailed for contempt until it was given out. Definitely inside the USA.

This might be it, I might be misremember the finer details:

https://www.bbc.com/news/technology-36159146

"prove you don't know"

It might be my lack of coffee, but how would that work? You can prove you know something, but how would you prove you don't?

Does full disk encryption not look like random data?

Basically yes. But as I understand it this is the reason why some border guard might ask you to boot up your machine to show him your system as a used and "lived in" installation. You might want to avoid arousing suspicion by lugging around a piece of dead metal (a laptop with unusable bit noise on its discs) or by presenting a fresh and empty OS.