This seems somewhat narrow, unfortunately. Suppose I have a laptop with an encrypted hard drive, and I'm known to use that laptop. It's going to be hard to convince someone that I don't own the laptop and drive, so it seems like the government could still compel me to decrypt it. Of course, this would protect me if I happen to have encrypted hard drives scattered randomly around, but that's not typically how one woul…
Obviously all these things would need to look like they were genuine rather than thought-up for legal purposes, so I imagine if I ever ended up in this situation this comment might act against me... but as a non-American, the fifth is unlikely to be relevant anyway. On top of the fact that I currently have no encrypted drives.
Even without circumstantial suggestions that there are multiple options, I wonder if you could simply make the argument that possession of a single encrypted drive does not indicate usage of said drive, and therefore there is no reason to believe you have access to the encrypted contents?