Do you not consider this to be compelling a defendant to testify against themselves? (At least assuming the password only exists in their memory and not written down somewhere.) And more importantly, how do you deal with the case where a person legitimately lost or corrupted their key/password or has an automated system to destroy the key if some unrelated event occurs like power failure, an incorrect password attempt, a Bluetooth disconnect, or a wipe if the device is in an unfamiliar location. Is having a system like that a criminal offense itself?