From: karn@qualcomm.com (Phil Karn)
On the other hand, several other lawyers I've asked have responded "of course!" when I ask them whether the 5th amendment would protect a defendant from being compelled to divulge an encryption key without immunity for the evidence it might decrypt.
My own opinion, given that I seem unable to get a complete consensus from the lawyers, (has this *ever* been possible?) is that the issue is as yet untested in court and could go either way depending on the actual case. But Mike seems much more pessimistic, and he *is* a lawyer. I'm not.
One might, of course, validly ask what the potential penalty would be for failing to divulge the key. Presumably, you would be held to be in contempt of court and sent off to jail until you divulged the key -- but at best you are likely to be locked up for a few months before the judge gives up. Given that, one can make a decision on whether the data you had encrypted is worth the loss of a few months of your life. (Remember, by the way, that merely having been in contempt is not nearly the same as having, say, a felony conviction on your record.) So even if they might have an argument for why they should be able to order you to give them a key, that doesn't mean that they have any real way to get it -- you can still fail to hand it over if you are willing to pay the price. Perry