Declan McCullagh at CNET writes about the most recent skirmish over whether a person can be forced to decrypt their encrypted files.

In this case, Jeffery Feldman is suspected of having almost 20 terabytes of encrypted child pornography. Evidence of use of eMule, a peer to peer file sharing tool, showed filenames suggestive of such content. Child porn makes for some of the worst case law because it is such an emotionally charged issue.

A judge had ordered Mr. Feldman to decrypt the hard drive, or furnish the pass phrase, by today. After an emergency motion, he has been given more time while the challenge to the order is processed.

The challenge is over whether being compelled to decrypt data is equivalent to forced testimony against one's self, which is forbidden by the Fifth Amendment. The prosecution position is that an encryption key is similar to a key to a safe, which may be compelled. Some prior cases have come down on the side of forcing the decryption, but not all.

If it was plausible that the suspect might not know how to decrypt the file, that would make things even more interesting. For now, the moral of the story is that you can't rely on the Fifth Amendment to protect you from contempt of court charges in the United States if you try to protect your encrypted data. Outside the US, your mileage may vary.