Rick Moen wrote:
Schneier has had a number of articles about creative ideas to deal with that scenario. There are some very creative people out there, and I cannot remember most of the nuances. One was a filesystem that, if you give it one key gives access to the real data but if given a different key gives access to innocuous decoy data.
Assange had a patch to ext ages ago (like, when ext2 was current) to give you multiple filesytems inside ext, with deniability. The game theory goes something like "unless ALL blocks are allocated to filesystems you know about, you CAN'T know that I've given you all the access keys, therefore you have no reason to ever stop hitting me with that rubber hose". I'm not sure how that works in practice. If you just mounted it as normal ext, it'd consider those secret filesystems' blocks as not reserved, so they might be trashed by writes.
Yes, it's an interesting problem. One possibility is to bring only a generically loaded machine with the intent of later wiping it upon reaching one's destination and downloading the intended substantive contents off an Internet repository established in advance for that purpose. The trick would be to keep the download size and transfer time reasonable.
And avoiding MITM if $bad_guy can lift the key material off your person / out of your head beforehand.