In the U.S. I believe at least one court circuit has ruled that you cannot be compelled to give up an encryption key if doing so would involve self-incrimination [1].

The 'catch' is that if the government already knows generically what incriminating data you have they can order you to produce it (as it's not any further incriminating). Or something like that? Recent decision though, so things can still change.

http://yro.slashdot.org/story/13/04/24/1458203/federal-magis...

You don't have to give up the key, just decrypt the data upon request...

Unless decrypting it would force you to incriminate yourself...

yes, but at least you get to make that choice for yourself, rather than having somebody else get to decide 'go to prison or hand over DanBC's key?'

I was wondering, what if you are trying the key and it doesnt work... you forgot it for example. You just really cannot open it yourself! Would that be contempt of court?? How do you convince the judge...