Mike Godwin (formerly, I understand) of EFF and I had a lively discussion on precisely this topic back at the Hackers' Conference. Mike insists that there is no firm legal theory or case law on which to base an assertion that the 5th amendment would shield you from being compelled to divulge an encryption key that could then be used to decrypt information to be used as evidence against you. He says that the closest the Supreme Court came to this issue was an offhand remark in a 5th amendment case to the effect that "of course, we couldn't compel the defendant to, say, reveal the combination on a lock". I forget the precise legal term that Mike used to refer to this comment, but he said it didn't establish a binding legal precedent because it didn't relate directly to an issue in the case at hand. 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. Don't give up working on those steganographic schemes just yet. And wherever practical (e.g., for communications as opposed to storage), use a key management scheme that doesn't leave anything around that can be seized or subpeonaed after the fact (e.g., Diffie's "perfect forward secrecy" scheme.) Phil