The key term is foregone conclusion, at least in the US. If the contents of the device are known, they can be ordered decrypted. If they are unknown, it is prot

The key term is foregone conclusion, at least in the US. If the contents of the device are known, they can be ordered decrypted. If they are unknown, it is protected by the 5th amendment. >Whether the government can compel decryption in this manner depends on a legal doctrine called “foregone conclusion” that was first articulated in a 1976 Supreme Court ruling relating to paper documents in a tax fraud case. >Under the “foregone conclusion” doctrine as applied to digital documents, handing over files is not considered testimony if the government already knows that the files exist and what machines they live on. And when there is no testimony, the protection of the Fifth Amendment’s self-incrimination clause is not available. Prosecutors with specific information about the existence and location of files on encrypted hard drives are more likely to convince a court to order a suspect to decrypt them. 1. http://www.slate.com/articles/technology/future_tense/2012/03/encrypted_files_child_pornography_and_the_fifth_amendment_.html http://www.slate.com/articles/technology/future_tense/2012/0...