Mike McNally writes:
In light of a conversation (not a private conversation; it was at an EFF-Austin gathering) with Mike Godwin in which he stated that the court has ample precedent to cite you for contempt upon refusal to produce encryption keys, I think it's clear that no decypherable encryption scheme is really adequate to protect private materials during a legal investigation. Similarly, I suspect that a scheme to protect information by automatic destruction or obfuscation (as a friend described it, "digital flash paper") would be considered illegal obstruction of justice.
Therefore, were I to be in possession of information that for political or business reasons I strongly required absolute privacy, I would resort to physical security as the closest thing to a sure-fire solution. Back things up onto high-density tape, and keep the tapes (*and* the tape drive, lest its presence be taken as prima facie evidence of the existance of off-line "evidence") in some secure place.
Note that a court could cite you for contempt for not complying with a subpoena duces tecum (a subpoena requiring you to produce objects or documents) if you fail to turn over subpoenaed backups. To be honest, I don't think *any* security measure is adequate against a government that's determined to overreach its authority and its citizens' rights, but crypto comes close. --Mike