Unless you are the one who is being compelled to decrypt the drive. Producing the key is an act of testimony. You could not state for the record, the passphra

Unless you are the one who is being compelled to decrypt the drive. Producing the key is an act of testimony. You could not state for the record, the passphrase for the key, if you did not know it. Breaking his crypto in some way, to access his files without cooperation, on the other hand... that is no fifth-amendment violation, to be sure. It also doesn't prove that he's been in control or owns the data.