Who is required to hand over the encryption keys to authorities?
Mandatory key disclosure laws require individuals to turn over encryption keys to law enforcement conducting a criminal investigation. How these laws are implemented (who may be legally compelled to assist) vary from nation to nation, but a warrant is generally required. Defenses against key disclosure laws include steganography and encrypting data in a way that provides plausible deniability.
Steganography involves hiding sensitive information (which may be encrypted) inside of ordinary data (for example, encrypting an image file and then hiding it in an audio file). With plausible deniability, data is encrypted in a way that prevents an adversary from being able to prove that the information they are after exists (for example, one password may decrypt benign data and another password, used on the same file, could decrypt sensitive data).
* (people who know how to access a system may be ordered to share their knowledge, however, this doesn’t apply to the suspect itself or family members.)